Bridge Preservation and Management

　 The Ministerial Ordinance of the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) requires road administrations to conduct statutory inspections of road bridges. It also provides technical guidance and standards for bridge inspection. The Bridge and Structures Division of the National Institute of Land and Infrastructure Management studies the condition of road bridges in Japan. It closely supports the MLIT headquarters in establishing and improving the standards of preservation, maintenance, and inspection practices.

　 The Bridge and Structures Division also conducts international cooperative studies on bridge design, construction, and management with various institutions. To share information on national road bridge inspection standards with such colleagues, the Bridge and Structures Division prepares preliminary English translations of road bridge inspection standards. Any translation, including the title of the documents, is not official and has not yet been proofread or corrected by a native English speaker or a legal translation expert; this translation may be revised in the future. Only the original Japanese texts of the documents have legal effect, and the translations are to be used only as reference materials to aid in the understanding of the national standards summary. The Bridge and Structures Division is not responsible for the accuracy and reliability of the translation. In addition, please note that each road administration sets its standards to meet legal requirements and to follow the national standards, which often add their original data recording rules, for example.

Periodic inspection guidelines for highway bridges
(Technical advice under the Local Autonomy Act)

March 2024
Road Bureau, Ministry of Land, Infrastructure, Transport and Tourism

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Commentary to the Technical Advice to Road Administrators and Practical Standards

March 2024
Road Bureau, Ministry of Land, Infrastructure, Transport and Tourism

Scope

These guidelines apply to periodic inspections of bridges 2.0 m or longer in length, elevated roads, etc. (hereinafter referred to as “bridges”) on roads stipulated in Article 2, Paragraph 1 of the Road Act (Act No. 180 of 1952).

[Commentary]

Considering the purpose of periodic inspections and the fact that the Road Statistics Annual Report accounts for bridges with a length of 2.0 m or more on roads as road bridges, a periodic inspection is recommended for bridges with a bridge length of 2.0 m or longer be applied to a periodic inspection in conformity to the technical advice on bridge periodic inspection issued by Road Bureau, MLIT, in March 2024.

Additionally, it is advisable that any structure that crosses over an obstruction or a depression and supports traffic live loads as the body of the road as a bridge defined in this guideline. Additionally, it should be noted that even bridges with a length of less than 2.0 meters can experience deterioration or damage that may pose concerns for road safety and third-party harm.



Frequency of periodic inspections

In principle, periodic inspections must be conducted at intervals of 60 months for each road bridge. If necessary, periodic inspections at intervals shorter than five years should be considered.

[Commentary]

A periodic inspection finally determines one of the integrity diagnosis classifications defined in the notice, considering the change in bridge condition and the surrounding circumstances until the next periodic inspection, with identifying deficiencies at each structural member, inferring the performance of the bridge at the time of the inspection, and evaluating the relevant maintenance and repair needs and policy from the engineering viewpoint.

Depending on the installation and surrounding condition, it may be difficult to conduct a periodic inspection at the precise five-year interval. Even in such a case, periodic inspection must be conducted f at intervals not far exceeding five years. Depending on the integrity conditions, the bridge state could worsen rapidly and become critical in less than five years.

Accordingly, it may also be necessary to consider conducting the periodic inspection at an interval shorter than five years when needed.

Note that road administrators must conduct daily and other inspections properly regardless of integrity diagnosis classifications of periodic inspection, such as post-event or emergency inspections after an accident or disaster, in addition to the mandatory periodic inspection by the related regulations, and endeavor to maintain the proper functioning of road bridges, as stipulated in the Road Act and related regulations.



System of the periodic inspection system

Periodic inspections shall be performed by a team of persons who possess the necessary knowledge and skills to determine the integrity diagnosis classification appropriately.

[Commentary]

Road bridges are subjected to various ground conditions, traffic, and other surrounding conditions, with different structural member arrangements and materials. Accordingly, the impact of distress and damage at structural members on bridge performance and third-party risk of harm varies bridge by bridge, even if distress of the same type and extent develops at the same structural element type. Furthermore, the necessity and purposes of remedial measures for each road bridge will vary depending on the socio-economic and disaster preparedness roles of the bridge and road network, factors related to its durability, and other factors.

Accordingly, in periodic inspections, each bridge shall be diagnosed into the “integrity diagnosis classifications” defined in the ministry notification by a comprehensive assessment that considers the anticipated situations and surrounding circumstances until the next periodic inspection, the current condition and distress observed, ant the evaluation of the expected performance.

Therefore, actions that influence the quality of statutory inspections—such as understanding the condition, inferring the performance and its change over time, determining the integrity diagnosis classification, and making records to be preserved for the future—must be carried out by persons who possess the necessary knowledge and skills to perform these tasks appropriately. For example, satisfaction with any of the following requirements is an essential aspect of evaluating whether the person has the necessary knowledge and skills:

• Relevant qualifications or considerable work experience in road bridges
• Considerable expertise in the design, construction, and management of road bridges
• Considerable skills and work experience in periodic inspections of road bridges

Note that the required minimum technical level of understanding and evaluating the present and foreseeable bridge conditions and performances as part of a statutory periodic inspection is interpreted as equivalent to the level at which a person with the sufficient knowledge and skills can infer them roughly based on the information obtained basically within their close visual inspection. It does not necessarily require a structural analysis, precise surveying, or rigorous understanding of the condition through advanced tests.

It should be also noted that ultimately, for each bridge, the demands for the technical extent o and methodologies for inspectors to obtain and evaluate necessary information as part of a statutory inspection, such as inspection methods and specifications, must be authorized by road administrators, because the information obtained in inspection is used for the road administrators to categorize the bridge condition into one of the integrity diagnosis classifications.



Understanding the condition of each bridge

The condition of each bridge shall be observed using sufficient methods for the bridge administrator to determine the integrity diagnosis classification properly. Close-visual inspection is the principal method of gathering information to evaluate load-carrying, durability, and supplemental performance to fulfill functional or safety requirements. Alternative methods can be used when obtaining equivalent reliability of the information compared to those obtained by a close visual inspection to evaluate those performances.

[Commentary]

Periodic inspections require the determination of the “integrity diagnosis classifications” for each road bridge as defined in the ministry notification, based on the technical diagnosis from a person with the necessary knowledge and skills who inspects the bridge through the essential inspection method of close visual observation and evaluate its current condition and various other information and given conditions.

The bridge condition is one of the most essential pieces of information for determining the “integrity diagnosis classification”, and the ministerial ordinance stipulates that a person with the necessary knowledge and skills for bridge inspection and diagnosis shall acquire the information on the bridge condition through close visual inspection. The ministerial ordinance presumes that close visual inspections involve approaching the subjects to be examined to evaluate the condition and structural member performances close enough to observe the details of their external distress and irregularity and, if necessary, to perform tactile examinations or sounding or hammering. However, the ministerial ordinance does not entirely prohibit alternative inspection methods. It acknowledges that there can be cases where alternative methods if used with care and expertise, can provide a technical diagnosis with equal reliability to determine the “integrity diagnosis classification” compared to that via a close visual inspection.

In addition, there may be cases where the information obtained visually alone is considered clearly insufficient to determine the integrity diagnosis classifications as defined in the ministry the bridge integrity diagnosis classification also depends on the long-term service plan of the subject bridge and the foreseeable changes in the structural condition, surrounding and location environment, traffic, and other situations that may lead to a change in the evaluation result of the load-carrying, durability, and supplemental performances, in addition to the present bridge condition evaluated via a close visual inspection.

Accordingly, when evaluating the condition and performance levels of the entire bridge, how close the inspector approaches each structural part in the close-visual inspection and the need to use inspection methods other than close-visual inspection, such as touching, sounding, and hammering, depends on the types and characteristics of the entire structure or structural details, the condition of neighboring structural portions and members, the anticipated causes and types of deterioration, environmental conditions, and surrounding conditions. Accordingly, the criteria to validate the enough distance in close-visual inspection or the need for other inspection methods cannot be uniformly set out for all bridges and structural members. The inspector is responsible for considering and proposing them, and the road administrator will make the final judgment of their relevancy at their discretion.

In a periodic inspection of bridges, the physical condition of the structure is assessed in terms of whether the bridge can be used appropriately under normal traffic conditions or those anticipated by the road administrator, focusing mainly on the traffic function and structural safety, primarily focusing on the load carrying performance, against the situations anticipated before the condition is assessed again in the next periodic inspection. The assessment of safety, the evaluation of age-related deterioration from the viewpoint of the need for preventive maintenance and the realization of the longevity of road bridges, and the assessment of the possibility of damage to road users and third parties due to falling parts or members from the body of a bridge or its appendages, etc., are made as technical opinions at the time of the periodic inspection based on available information. In addition, these technical opinions will also be considered in deliberating the measures that are deemed desirable to be taken before the next periodic inspection. Then, based on these as the primary basis, the road administrator will judge and decide which of the “integrity diagnosis classifications” defined in the notice corresponds to the final decision made by the road administrator on measures for the subject at that time.

In other words, periodic inspections are required to obtain information on the condition of deterioration and anticipated factors of deterioration that are considered necessary to perform these studies and assessments properly. It can be interpreted that the information obtained by a person with sufficient knowledge and skills through close visual inspection is considered the standard for such information.



Integrity diagnosis classifications

(1) Statutory periodic inspections must determine a relevant integrity diagnosis classification from Table 5.1, following the “Notice on the Classifications of the Results of Integrity Diagnosis of Tunnels, etc.”.

Table5.1 Integrity diagnosis classification

Classification		Definition
Ⅰ	Sound	There are no disruptions to the functionality of the bridge.
Ⅱ	Preventive maintenance stage	There are no disruptions to the bridge functionality, but it is desirable to take measures from a preventive maintenance perspective.
Ⅲ	Remedial action stage	There is a possibility that the bridge functionality is being impaired and measures should be taken early.
Ⅳ	Emergency action stage	The bridge functionality is already significantly impaired, or is likely to be substantially impaired, and urgent measures must be taken.

(2) When determining the integrity diagnosis classification, infer the anticipated load -carrying function state of the facility under situations it may encounter and assess the impact of the anticipated bridge state on the likelihood and possible extent of service impairment or damage to people under the bridge. In addition, consider the chance of implementing effective maintenance and repair. Then, finally, sum them up and review the desirable remedial work policy of the bridge for the next periodic inspection.

(3) The desirable remedial work policy, which is reflected in the integrity diagnosis clarification, basically comprises measures covering periodic or continuous monitoring, maintenance, repair/reinforcement, demolition, traffic restriction, and road closures.

(4) Although the periodic inspection for each bridge requires determining the integrity diagnosis classification for each facility unit (i.e., as a whole bridge system), it is reasonable to simultaneously evaluate what conditions the superstructure, substructure, and connection between superstructure and substructure are likely to be individually for the same anticipated situation as those considered in evaluating the facility (the whole bridge). Note that the definitions of superstructure, substructure, and super-substructure connection are specified in the Specifications for Highway Bridges, 2017.

[Commentary]

(1) The basic relationship between the integrity diagnosis classifications and anticipated remedial / countermeasure actions is as follows.

• I: Routine and scheduled maintenance are implemented, but no further preventive measures or monitoring are required until the next periodic inspection.
• II: It is timely to implement preventive and preservation measures, mainly to ensure longevity and durability, and actions are desirable before the next periodic inspection.
• III: Measures need to be taken before the next periodic inspection to ensure the bridge's structural safety and prevent harm to third parties.
• IV: Measures must be taken urgently to ensure the bridge safety and prevent harm to bridge users and third parties.

It may be desirable to implement temporary measures during periodic inspections to remove the risk to road users and third parties due to falling, such as flaking, detachment, corrosion fragments, and paint flakes

Suppose any such temporary measures were taken at the time of inspection. In that case, evaluating the possible bridge performance under the anticipated situations until the next inspection and deciding the integrity diagnosis classification should be based on a technical assessment of the bridge condition after the temporary measures were implemented.

(2) The decree requires that inspections consider the structure of the road, traffic conditions, maintenance or repair conditions, the terrain, geology, weather conditions of the area where the road is located, and other relevant factors. It also requires considering the need for efficient maintenance and repair of the road. The decree also requires diagnosing the integrity of a structure to account for the possibility of significant road structure malfunction or interference with traffic.

In other words, in statutory inspections, considering the desirable measures to maintain the bridge condition until the next statutory periodic inspection and declaring a relevant "integrity diagnosis classification" as defined in the ministry notification must be based on the road administrator's perspective on the expected role of the road bridge as part of the road section.

Plus, reviewing desirable remedial measures involves a comprehensive understanding of the bridge condition, factoring in the following aspects

• where and what kind of distress exists, specifically,
• what the possible bridge load-carrying state of the road bridge would be in response to the situations it may encounter until the next periodic inspection
• the potential risk of disruptions to traffic functionality and harm to third parties if the bridge reached such a state under an anticipated situation, in comparison to the road administrator's perspective on the expected role of the bridge
• timely and efficient implementation of preventive maintenance.

(3) When considering the preservation and remedial work polity for bridges, periodic or continuous monitoring, maintenance, repair, or reinforcement measures are reviewed to maintain or recover the bridge load-carrying functionality, durability, and demolition. In addition, traffic restrictions or closures should be considered when urgent actions are needed but cannot be taken.

The technical evaluation result of expected bridge performance should be needed for road administrators to review the measures that deserve to be taken and determine integrity diagnosis classifications for individual bridges. However, it is also essential for road administrators to recall the fact that periodic inspection is based on close visual observations Taking this fact into consideration, road administrators need to scrutinize not only the necessity and policy of measures but also the need for further investigations to make the measures reasonable and appropriate.

In addition to the technical evaluation result of the bridge, the role of the bridge on the road network from the viewpoint of social and economic activities and its mid and long-term maintenance strategy should be comprehensively incorporated in the decision-making process for the measures to be taken. Finally, as a result of these considerations, the integrity diagnosis classification must be decided, referring to the definitions of each classification in the ministry notification of the integrity diagnosis classifications.

When the maintenance and remedial work policy for the bridge is reconsidered as a result of obtaining additional information from detailed investigations or changing the bridge condition due to events like earthquakes after the periodic inspection, prompt reassessing the integrity diagnosis classification until the next inspection and updating the bridge integrity classification record is recommended.

Structural monitoring can be counted as one of the optional measures to be taken while waiting to implement the desirable remedial works and countermeasures in response to the inspection result. It is implemented to track the change in the state of distress such that the result can be a trigger to the management actions. It is also highly advisable that measures to curb the worsening of the functionality and durability state of the bridge should be used together when implementing structural monitoring, such that the bridge can avoid suddenly falling into acritical condition.

Note that, at the design and implementing stage of remedial measures to the bridge, the road administrator will comprehensively reexamine the specific details and methods considered during the periodic inspection.

(4) In periodic inspections, a relevant integrity diagnosis classification shall be determined for each facility as required in the ministry notification.

Every bridge comprises three primary structural parts from the viewpoint of the load paths and different primary roles in the load-carrying mechanism, “superstructure,” “substructure,” and “connection between superstructure and substructure,” where their functional roles and definitions are given in the Specifications for Road bridges, 2017. Accordingly, when considering the condition of the entire bridge under anticipated situations, it is reasonable first to assess if each structural component can retain the load-carrying function to fulfill its role under those conditions, such that the probable load-carrying function state of all components can be incorporated into the evaluation for the condition as the entire bridge. Furthermore, in recording and storing the bridge inspection result, it is desirable to record not only the evaluation result of the whole bridge but also the load-carrying function and function fulfillment assessment of those primary structural components, because the assessment result of the load- carrying performance of a road bridge serves as one of the primary bases for determining the integrity diagnosis classification and also will be referred in future maintenance and management.

• Superstructure is the structural components that play a role of part of the road thereof and directly support traffic loads of vehicles and pedestrians.
• Substructure is the structural component that plays a role in holding the super-substructure connection in an appropriate position.
• Super-substructure connection is the structural component that plays the role of the support points for the superstructure and transmits its load effects to the substructure.

The distinction between the superstructure, substructure, and the superstructure-substructure connection is based on the concept that a bridge must consist of role-wise structural components, regardless of bridge types, structural forms, or design concepts. Sometimes, one structural member serves multiple roles, making it difficult to identify which one of the primary structural components the structural member exactly contributes role-wise in inspection, depending on the type of the bridge and the structural member. However, when making a general assessment of the load-bearing performance of the bridge to obtain the overall integrity diagnosis classification, it is usually unnecessary to strictly identify or clarify the roles of the structural member.

Note that the statutory periodic inspection does not necessarily require structural analyses or calculations. It also does not basically require detailed surveys or measurements or the use of advanced investigation technologies. It requires fundamental observations commonly accepted in inspection practice, and such observations are enough to provide information to conduct the present and future performance evaluations for one of the primary bases in determining the integrity diagnosis classification. Accordingly, the classification of structural members and parts into one of the structural components of role, i.e., superstructure, substructure, and superstructure-substructure connection, and the technical level and reliability in the performance evaluation of the probable state of the identified components under anticipated situations until next inspection are regarded sufficient to be based on the subjective judgment by a person with enough knowledge and skill to fulfill these processes of the statutory periodic inspections and the person's close visual observations. However, the final judgment of these technical aspects and the requirement of the inspector's skill and knowledge rests with the road administrator.

When evaluating the structural role sufficiency of the primary structural components under anticipated situations until the next inspection, it is advisable to involve anticipated situations with load combinations that are unlikely under normal use but not impossible. These include excessive live load situations, such as simultaneous multiple heavy vehicles loading, earthquakes as large enough as the road administrator should conduct post-event patrols or emergency inspections, and rare flooding that could pose a risk to the bridge, which is best to anticipate based on its location. It is also advisable to consider other situations as needed, given the road bridge’s state and structural conditions. For example, typhoons or other strong winds would be considered, depending on the bridge type and structural characteristics.

The inspector’s evaluation of the probable state under those anticipated situations until the next inspection should account for structural safety, driving safety, and the risk of damage to third parties from the perspective of road functionality. Accordingly, the inspector should infer the bridge state to classify it into the following scale of A to C, which will be referred to by the bridge administrator in determining the integrity diagnosis classification:

• A: The likelihood of damage or irregularity to the dysfunction of the bridge is low.
• B: Although the likelihood of a critical state is low, there is a possibility of resulting in some damage or irregularity to disfunction the bridge.
• C: There is a possibility that the bridge falls into a critical state.

Note that these inferences and evaluations are allowed to be based on the information obtained.

A critical state herein refers to a condition where safe passage cannot be ensured without road closures or significant load restrictions. For example, this could include the state where, although it does not result in a complete bridge collapse, there is severe damage deterioration at the support points or main girders, rendering the bridge impassable. It could also include situations where the substructure is damaged or destabilized, making it unable to support the superstructure safely. Besides the condition from the perspective of the bridge's structural safety, it also includes conditions from the drivability standpoint, such as significant bumps or road surface subsidence that make passage difficult. The specific condition that is anticipated and the extent to which the bridge or roadway functions are at risk of being compromised at that time depends on the conditions of the bridge thereof and the surrounding ground to be evaluated together with the bridge. Accordingly, it should be determined for each bridge individually.

The classification in A to C represents a rough evaluation of the probable state in response to the anticipated situations. It is the subject of the condition of the bridge thereof. Assuming the state where there is a risk that corrosion fragments, concrete pieces, or any attachments fall down from the bridge, posing a risk of harming the third party on/under the bridge, prompt measures are usually implemented as soon as such distress is observed during the inspection, and it is not necessary to consider the classification in A to C as part of the result of the inspection. Inversely, in cases with a potential for severe third-party damage to occur due to such causes but no measures are taken to address them during the inspection, incorporate it into the classification in A to C if necessary.

In addition, when the road administrator determines the integrity diagnosis classification, it may be reasonable to consider the need to take some measures from a mid to long-term maintenance plan perspective. This includes the anticipated changes in condition and performance until the next periodic inspection and considerations on whether the implementation of preventive maintenance measures should be timely. Therefore, it is vital to pay special attention to factors such as fatigue, chloride ingress and salt damage, alkali-silica reaction, deterioration of anticorrosive function, and scouring, as well as earlier maintenance histories in the statutory periodic inspection, which are valuable to consider the need of preventive maintenance, such that the road administrator can conduct the integrity diagnosis classification relevantly following their mid to long-term bridge preservation policy. Additionally, it is advisable to keep records of these factors and the relationship between them and the road administrator’s integrity diagnosis classification because they often significantly impact the road administrator’s decision and are valuable.

Records

(1) The results of periodic inspections should be recorded in a form that can cover the information considered necessary to utilize in appropriate maintenance and management, including responses in the event of in-service damage as follows:

• Bridge name
• Route name
• Location
• Installation location (latitude and longitude)
• Facility ID
• Administrator
• Subgrade conditions
• Availability of alternate routes
• Type of road (whether it is a motorway or a general road)
• Emergency transportation road
• Occupied properties
• Bridge specifications (year built, length of bridge, width, bridge type)
• Integrity diagnosis classification as per the Ministry notice
• Date of periodic inspection (the final day on which the condition assessment was conducted)
• Periodic inspectors (persons with the knowledge and skills to perform periodic inspections)

(2) It is desirable to record the measures considered in Section 5 and their technical backgrounds that involve the views on the inferred functional states of the superstructure, substructure, and super-substructure connection under the anticipated situations, the necessity of preventive maintenance, and the potential for third-party damage under the anticipated situations.

[Commentary]

The results of periodic inspections are fundamental information used as a reference for planning maintenance and repair, etc., and should be recorded and accumulated appropriately.

There are no legal requirements regarding the form, content, or items of records related to periodic inspections. Recording information that the road administrator deems necessary for proper maintenance and management in an appropriate manner is sufficient.

Given the law, it is advisable to include observations on the state of the road bridge regarding its structural safety under anticipated situations, the necessity for preventive maintenance, and the potential for third-party damage. These observations are considered essential information for appropriately planning maintenance and repairs. Additionally, it is beneficial to include observations on the overall need for measures until the next periodic road bridge inspection. (See Form 1, Form 2 and Form 3)

At this time, as recommended in "5. Determination of integrity diagnosis classification (4)," it is desirable to retain the estimated results of the expected condition of each part of the bridge, including the superstructure, substructure, and connection between superstructure and substructure, which bear the load carrying performance of the bridge. This should clarify the relationship between the technical evaluation of the bridge's condition and the main reasons influencing the determination of the integrity diagnosis classification. Additionally, evaluating the fail-safes and expansion joints is often considered to influence the judgment of the necessity of measures, and recording these evaluations is also regarded as adequate for appropriate maintenance. For example, fail-safes are evaluated from the technical viewpoint of performing expected functions when they would be functional, and expansion joints are evaluated from the technical viewpoint of providing safe traffic, given various vehicles passing over.

Moreover, insights into how the results of the various evaluations conducted to determine the “integrity diagnosis classification,” as mentioned above, ultimately led to the final decision are necessary for implementing appropriate measures. Therefore, it is considered essential to record these insights as observations.

Other than these, it is not precluded to enhance records as necessary, in addition to following the provisions indicated in these guidelines for proper maintenance. It is advisable to consider the selection of record items and methods by expressly assuming the purpose of use.

Furthermore, as stipulated in the regulations related to maintenance (Article 4-5-6 of the Order for Enforcement of the Road Act), the details of any measures taken must be recorded. The results of periodic inspections are fundamental information used as a reference for planning maintenance and repair, etc., and should be recorded and accumulated appropriately. There are no prescribed formats, contents, or items for recording measures. The road administrator should appropriately determine these.

It is advisable to refer to the explanation in Section 5 regarding the content that should be recorded.

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Appendix: Forms

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Guideline for recording basic data (Road Bridges) 2024 version

March　2024
National Highway and Engineering Division, Road Bureau, Ministry of Land,
Infrastructure, Transport and Tourism

1. Purpose

This guideline provides standard recording protocols to be used when objective recording is conducted for the statistical analysis of inspection data.  This guideline is designed to make such recording as minimum as possible, on the basis of knowledge on the deterioration tendency of road bridges acquired from earlier periodic inspections.  Note that it is bridge owners' discretion for the recording protocols and items depending on their needs.

 

2. Major members to be covered

Major members shall be selected as appropriate from structural types.  Members to be selected are as follows:

(1) For steel bridges

1) Steel slab girder bridge

* "Road surface" will be selected for all structural types, even if not specified.

2) Steel box girder bridge

3) Steel truss bridge

4) Through arch bridge

5) Deck arch bridge

6) Rigid-frame bridge

7) Cable-stayed bridge

8) Suspension bridge

(2) For concrete bridges

1) PC slab bridge

* "Road surface" will be selected for all structural types, even if not specified.

2) PC T-girder bridge

3) PC box girder bridge

 

3. Procedures for assessing the extent of damage

Table-3.1 lists the types and extent of damage.  For the purpose of classification, categories a-e are provided for each type of damage dealt with in this guideline.  The extent of damage appearance is objective, not subjective.  The extent of damage is defined with numerical and quantitative indicators wherever possible. Some damage types are covered by only ‘a’ and ‘e’, only ‘a’, ‘c’ and ‘e’, or ‘a’, ‘c’, ‘d’ and ‘e’.  Some damage types are classified using a combination of two parameters.  For example, corrosion is evaluated in terms of the decrease in plate thickness and the extent of the corroded area, and concrete cracking is measured by a combination of crack width and crack density.  Photographic examples are also given to avoid confusion in classifying the extent of damage.  Data-recording personnel are not allowed to incorporate their views on the maintenance and repair urgency into the classifications of the extent of damage; they must strictly match the damage appearance with the definitions and photographic examples.

Table 3.1 Types of damage and classifications of damage extents

Types of damage		Classifications of the extent of damage
Steel	Corrosion	a—e
	Cracking	a, e
	Bolt loss	a, e
	Rupture	a, e
	Deterioration of corrosion protection	a—e
Concrete	Cracking, water seepage, efflorescence	a—e
	Exposed rebar	a, e
	Deck slab punching failure	a, e
	Deck slab crack	a—e
	Distress in the tendon anchorage zone	a, e
Common / Others	Road surface crack, rutting, roughness etc.	a, e
	Bearing malfunctioning	a, e
	Damage to repair and reinforcement materials	a, e
	Subsidence, dislocation, tilting	a, e
	Scouring	a, e

(1) Corrosion

1) Classifications of the extent of damage

Guideline			Extent of damage
Existence of damage	Corrosion depth	Corrosion area
No	－	－	a
Yes	Decrease in plate thickness is negligible or rust has developed only on the plate surface	Rust areas are not widespread but exist only locally	b
		Rust or several ruts areas have spread over the data recording segment	c
	Decrease in plate sickness is notable or the swelling of rust is visible	Rust areas are not widespread but exist only locally	d
		Rust or several ruts areas have spread over the data recording segment	e

[Examples]

The extent of damage b	The extent of damage c
Some parts of the main girder have superficial rust	The lower flange has superficial rust all over it
The extent of damage d	The extent of damage e
The end part of the main girder has rust which is local but with the reduction of plate thickness	There is significant rusting throughout the main girder with the reduction of plate thickness

(2) Fissure

1) Classifications of the extent of amage

 

Guideline	Extent of damage
None Paint crack exists but is not related to the crack in the plate or at the welding connection. (Short paint coating crack without rust)	a
Clear cracking Identified paint crack is likely to be associated with the existence in the crack in the plate or at the welding connection (linear cracks, some rust)	e

[Examples]

The extent of damage a	The extent of damage a
Minute or very short crack	Paint coating crack that is assumed not to be associated with plate cracking
The extent of damage e	The extent of damage e
Cracking is linear and obvious	Paint coating crack that is likely to be caused by the crack in the plate or at the welding connection
The extent of damage e	The extent of damage e
Crack in the Gerber hinge connection	Crack in the bridge girder section with reduced depth at the bridge support

(3) Bolt fallout

1) Classifications of damage extents

Guideline	Extent of damage
No damage	a
Some bolts are lost (regardless of the number of the fallen bolts)	e

 

[Examples]

Damage extent e	Damage extent e
A bolt has fallen off	Bolts have broken and fallen off

(4) Rupture

1) Classifications of damage extents

Guideline	Extent of damage
No damage	a
Ruptured (If the member is not split apart, the distress may be identified as cracking, not rupture.)	e

[Examples]

Damage extent e	Damage extent e
A gusset plate in the sway bracing is	A gusset plate in the lateral bracing is ruptured

(5) Deterioration of the anticorrosive function

1) Classifications of damage extents

Classification 1: Paint coating

Guideline	Extent of damage
No damage	a
Discoloration or localized bubbling develops in top layer	c
The coat layers are partially peeling off, and the primer is exposed	d
The paint coating system deteriorates over a wide area with are some rust spots	e

[Examples]

Damage extent c	Damage extent c
The finish coat is discolored	Localized swelling is developed
Damage extent d	Damage extent d
The top and intermediate coats are partially peeling off and the primer is exposed	The top and intermediate coats are partially peeling off and the primer is exposed
Damage extent e	Damage extent e
Rust spots over a wide area	Rust spots spreads over a wide area

Classification 2: Galvanization protection or, metal spraying

Guideline	Extent of damage
No damage	a
The coating deteriorates locally with some rust spots.	c
The coating deteriorates over a wide area, with rust spots	e

 

[Examples]

Damage extent c	Damage extent c
The coating film deteriorates locally, and rust develops on the base material	The coating film deteriorates locally, and rust develops on the base material
Damage extent e	Damage extent e
The coating deteriorates over a wide area, with some rust spots	The coating deteriorates over a wide area, with many rust spots throughout the entire area

Classification 3: Weathering steel

Guideline	Extent of damage
No damage (Uniformly distributed, dark brown fine rust grains can be considered as fully developed protective rust) (Yellow, red , orange, or light brown rust can be considered in the early development stage to the protective rust)	a
No damage.  However, protective rust has not started being formed yet	b
Coarse grained or granular texture rust with 1 to 5 mm in diameter/size	c
Flakes with 5-25 mm in size	d
Delamination	e

Examples.

Damage extent b	Damage extent b
No protective rust has developed	No protective rust has developed
Damage extent c	Damage extent c
Rust is about 3 mm in size and coarse-grained	Rust is about 3 mm in size and coarse-grained
Damage extent d	Damage extent d
Flakes with 5 to 15 mm in size	Flakes with approximately 6 mm in size
Damage extent e	Damage extent e
Delamination	Delamination

(6) Cracking, water seepage, and efflorescence

1) Classifications of damage extents

Guideline			Extent of damage
Existence of cracks	Crack width	Water leakage and free lime
No	None or hair cracks	No water seepage or efflorescence	a
Yes	Less than 0.2 mm	No water seepage or efflorescence	b
	0.2 mm or larger	No water seepage or efflorescence	c
	Any width	Water seepage through a crack; no rust stain or efflorescence visible	d
		Efflorescence; no rust stain visible	d
		Water seepage involving notable mud-like stain or rust stain	e

2) Crack patterns

Crack patterns shall be categorized according to the tables below, and corresponding pattern numbers shall be recorded.

 

a) Superstructure (Common definitions for both PC and RC members)

Location	Crack pattern
Span center	(1) Transverse cracks on the bottom surface or vertical crack on the side surface/web of the main girder
	(2) Longitudinal cracks on the bottom surface of the main girder
1/4 point of span	(3) Transverse cracks on the bottom surface or vertical crack on the side surface/web of the main girder
Support section	(4) Diagonal cracks in the web at support
	(5) Transverse cracks on the bottom surface or vertical crack on the side surface/web of the girder at support
	(6) Diagonal cracks on the side of the girder at support
	(7) Cracks in in-span or Gerber hinge section or dapped-end beam
	(8) Vertical cracks in the upper part of continuous spans at intermediate support
Others	(9) Map cracking
	(10) Cracks occurring vertically at regular intervals in the web of the girder
	(11) Horizontal cracks near the junction between the web and the upper flange
	(12) Cracks in 45-extent diagonal direction occurring all over the girder
1/4 point of span, or the support section	(21) Longitudinal cracks on the bottom or side surface of the girder (excluding those that fall under (19))
	(22) Cracks on the upper flange
Entire span	(23) Horizontal cracks developed throughout the web
Cross beams	(24) Cracks on the cross beam

(1) Span center, transverse cracks on the bottom surface or vertical crack on the side surface/web of the main girder

(2) Span center, longitudinal cracks on the bottom surface of the main girder

 

(3) 1/4 point of span, vertical or diagonal cracks on the bottom or side surface of the main girder in the direction perpendicular to that of the girder

(4) Support section, diagonal cracks in the web at support

(5) Support section, transverse cracks on the bottom surface or vertical crack on the side surface/web of the girder at support

(6) Support section, diagonal cracks on the side of the girder at support

(7) Cracks in in-span or Gerber hinge section or dapped-end beam

(8) Support section, vertical cracks in the upper part of continuous spans at intermediate support

(9) Map cracking

(10) Cracks occurring vertically at regular intervals in the web of the girder

(11) Horizontal cracks near the junction between the web and the upper flange

(12) Cracks in 45-extent diagonal direction occurring all over the girder

(21) 1/4 point of span, or the support section, longitudinal cracks on the bottom or side surface of the girder (excluding those that fall under (19))

(22) 1/4 point of span, or the support section, cracks on the upper flange

(23) Entire span, horizontal cracks developed throughout the web

(24) Cracks on the cross beam

b) Superstructure (Additional definitions especially for PC members in addition to a))

Location	Crack pattern
Span center	(13) Cracks along tendons in the lower flange of the girder with variable cross section
	(18) Cracks in the vicinity of the upper flange of the main girder
1/4 point of span	(14) Cracks along tendons around the inflection point close to a intermediate support of the PC continuous girder
	(15) Cracks perpendicular to tendons around the inflection point close to the intermediate support of the PC continuous girder
Support section	(19) Horizontal cracks on the web of the main girder
	(25) Cracks in the connected cross beam section (RC structure section)
Others	(16) Cracks around the anchorage zone or the deflection point of tendons
	(17) Cracks in an area where tendons are concentrated
	(20) Cracks along the sheath
	(26) Gaps or separation at the segment connection
	(27) Cracks in an area with an abrupt change in cross section

 

(13) Span center, cracks along tendons in the lower flange of the girder with variable cross section

(14) 1/4 point of span, cracks along tendons around the inflection point close to a intermediate support of the PC continuous girder

(15) 1/4 point of span, cracks perpendicular to tendons around the inflection point close to the intermediate support of the PC continuous girder

(16) Cracks around the anchorage zone or the deflection point of tendons

(a) The vicinity of the anchorage protrusion

(b) Back-filled concrete area

　　　　　　　　

(17) Cracks in an area where tendons are concentrated

(18) Span center, cracks in the vicinity of the upper flange of the main girder

(19) Support section, horizontal cracks on the web of the main girder

(20) Cracks along the sheath

(25) Cracks in the connected cross beam section (RC structure section)

(26) Gaps or separation at the segment connection

(27) Cracks in an area with an abrupt change in cross section

c) Substructure

Location	Crack pattern
Abutment	(1) Vertical or diagonal cracking with a constant spacing
	(2) Cracks perpendicular or diagonal to the construction joint
	(3) Cracks at the rebar cut-off section
	(4) Map cracking
Bearing seat	(5) Diagonal cracking in the seat edge, initiating from the front of the bearing
Cantilever piers	(2) Cracks orthogonal or diagonal to the construction joint
	(3) Cracks in the vicinity of an area where main reinforcement is reduced
	(4) Map cracking
	(6) Cracks in the upper part of a pier-cap cantilever end
	(7) Vertical cracks on the pier-center line in the pier cap
	(8) Cracks at the corner of a pier cap-column connection
	(13) Vertical cracks on the side surface
Rigid-frame piers	(4) Map cracking
	(9) Cracks all around the top or base of a column or a corner of a hunch
	(10) Cracks all around a pillar
	(11) Cracks all around the pier cap or a hunch
	(12) Cracks on the bottom of the center span of the pier cap

 

[Ex. Superstructure]

Damage extent b
Cracks with the width smaller than 0.2 mm
Damage extent c	Damage extent d
Cracks in 0.2 mm wide or wider	Cracks with water leakage are identified
Damage extent d	Damage extent d
Cracks with water leakage and efflorescence	Cracks with water leakage and efflorescence
Damage extent e
Cracks with rust rust staining

[Ex. Substructure]

Damage extent b
Cracks with the width smaller than 0.2 mm
Damage extent c	Damage extent d
Cracks in 0.2 mm wide or wider	Cracks with water leakage are identified
Damage extent d	Damage extent d
Cracks with water leakage and efflorescence	Cracks with efflorescence
Damage extent e
Cracks with rust staining

 

(7) Exposed rebars

1) Classifications of damage extents

Guideline			Extent of damage
Existence of exposed rebars	Spread of exposure and corrosion	Extent of corrosion
No	－	－	a
Yes	Limited	Unmeasurable section loss
		Measurable section loss, or significant corrosion volume expansion of reinforcement
	Wide area	Unmeasurable section loss
		Measurable section loss, or significant corrosion volume expansion of reinforcement	e

[Examples]

Damage extent a	Damage extent a
Partial rebar exposure	Superficial rebar exposure over a wide area
Damage extent e	Damage extent e
Reinforcement corrosion over a wide area	Reinforcement corrosion over a wide area

(8) Fallout

1) Classifications of damage extents

Guideline	Extent of damage
Not applicable	a
Full-depth hole in the deck slab after concrete block has fell down out of the concrete deck slab	e

[Examples]

Damage extent a	Damage extent a
Shall be assessed as "cracked deck slabs", since significant cracks have developed	Shall be assessed as "exposed rebars", since rebars are significantly exposed
Damage extent e	Damage extent e
A part of the deck concrete has fell down with a full-depth	Concrete block has fell down out of the longitudinal connection

(9) Cracked deck slabs

1) Classifications of damage extents

[Examples]

Damage extent b
One-directional cracks prevail (The cracks are marked with chalk)
Damage extent c	Damage extent c
One-directional cracks prevail (The cracks are marked with chalk)	Lattice cracks have developed (The cracks are marked with chalk)
Damage extent d	Damage extent d
One-directional cracks with efflorescence	Two-directional cracks with efflorescence (The cracks are marked with chalk)
Damage extent e	Damage extent e
Significant one-directional cracks and efflorescence	Dense lattice cracks with abrasions and efflorescence

(10) Abnormality in the PC anchorage zone

1) Classifications of damage extents

Guideline	Extent of damage
No damage	a
Damage to the tendon anchorage zone (in any extent) Damaged tendon	e

[Examples]

Damage extent e	Damage extent e
Rust staining in the anchorage zone	Rust staining in the anchorage zone
Damage extent e	Damage extent e
Spalling concrete and the corrosion of the exposed wedges and strand at the anchorage	Spalling of the concrete and sticking out of the transverse tendons at the anchor

(11) Uneven road surfaces

1) Classifications of damage extents

Guideline	Extent of damage
No damage There are uneven expansion joint of less than 20 mm (not so large as to impair traffic safety for vehicles)	a
Visible uneven joint about 20 mm or larger (large enough to impair traffic safety for vehicles)	e

[Examples]

Damage extent a	Damage extent e
Uneven joint between the bridge deck slab and the approach with a difference in level less than 20 mm	A difference in level about 20 mm or larger over the expansion joint

(12) Impaired bearing function

1) Classifications of damage extents

Guideline	Extent of damage
Damage that may affect the bearing function is none	a
The function of the bearing is impaired The function of the bearing is severely obstructed	e

[Examples]

Damage extent a	Damage extent a
A loose anchor bolt is present but the bearing is functioning	The bearing seat concrete is damaged but the bearing function is maintained
Damage extent a	Damage extent e
Pack rust is present, but cannot cause a significant bearing dysfunction.	Sediment accumulation causes the restriction of the bearing movement
Damage extent e	Damage extent e
The bearing is uplifted	The bearing is broken

(13) Damaged repair and reinforcement materials

1) Typeof repair and reinforcement materials

Repair and reinforcement materials shall be classified as follows.

A) Repair and reinforcement materials for concrete members

Classification	Repair and reinforcement materials
1	Steel plate
2	Fibers
3	Cementituous materials
4	Paint

(B) Repair and reinforcement for steel members

Classification	Repair and reinforcement materials
5	Added cover plates and stiffeners

2) Classifications of damage extents

Classification 1: Steel plate

[Examples]

Damage extent e	Damage extent e
The entire steel plate is corroded	A significant amount of rust staining is visible around the steel plate

Classification 2: Fibers

Guideline	Extent of damage
No damage	a
The reinforcement material is severely damaged or ruptured In addition, a large amount of water leakage or free lime is generated from reinforced concrete members	e

 

[Examples]

Damage extent e	Damage extent e
The fiber sheet is noticeably cracked, and water leakage with rust staining is identified	The fiber sheet is ruptured

Classification 3: Concrete series

Guideline	Extent of damage
No damage	a
A large amount of water leakage or free lime are generated from reinforced concrete members Or the reinforcement material is severely damaged	e

[Examples]

Damage extent e	Damage extent e
Significant cracks, water leakage and free lime are identified in the concrete jacketing	The concrete jacket is severely damaged

Classification 4: Paint

Guideline	Extent of damage
No damage	a
The paint peeling, and rust staining is identified. Or, a large amount of water leakage and free lime are identified	e

[Examples]

Damage extent e	Damage extent e
Protective coating peeling is present, and rust fluid is identified	Protective coating has noticeable cracks with rust staining

Classification 5: Steel plate (cover, etc.)

Guideline	Extent of damage
No damage	a
Significant damage (corrosion, crack, missing bolts, etc.) is identified in the steel plate (such as a cover)	e

[Example]

Damage extent e	Damage extent e

3) Note 

• Damage to reinforcement materials can take various forms depending on their material and structural details.  In addition, water leakage, free lime and other defects in reinforcement materials sometimes arise from the damage in the concrete members strengthened.  Such defects shall be treated as deterioration of the function of reinforcement materials and included in this category "damage to repair and reinforcement materials", separately from damage to the existing structural member.
• In Classification 3 when cracks or exposure of rebars is present in concrete jackets such damage also shall be assessed as cracks or exposure of rebar thereof
• As for Classification 4 the coating damage shall not be treated as "Deterioration of corrosion protection."
• As for Classification 5, damage to cover plates installed on steel members shall be dealt with only in this category, not in categories such as "Deterioration of corrosion protection" or "corrosion".  On the other hand, if the existing structural member is damaged as well due to the cover plate (damage), the damaged existing structural member shall be separately assessed as well
  

(14) Subsidence, dislocation, tilting

1) Classifications of damage extents

Guideline	Extent of damage
There is no sinking, dislocation or tilting	a
Either sinking, dislocation or tilting is identified	e

[Examples]

Damage extent e	Damage extent e
The substructure is sinking and tilted	The substructure is dislocated and tilted

(15) Scouring

1) Classifications of damage extents

Guideline	Extent of damage
Not identified Minor scouring is identified	a
Significantly scoured	e

[Examples]

Damage extent a	Damage extent e
Minor scouring is identified	Significantly scoured

 

4. Recording of data collection results

(1) Form 1:

This form exemplifies the specifications to be recorded in the bridge inspection database regarding the inspected bridge. The following are points should be kept in mind when recording.

 

1) Bridge name

Enter the name of the road bridge. If multiple highway bridges have the same name, sequential numbers should be assigned to distinguish them.

2) Route name

3) Facility ID

Facility ID is assigned, referring to the facility's longitude and latitude, following the corresponding manual

4) Location

The names of the prefecture and municipality at the starting points of the facility, following on the basis of the National Local Government Code.

5) Distance markings

For routes with distance markers (kilometer-posts), record the numbers of the distance markers at the starting and ending points of the facility.

[Example] 12.3kp + 45m -> 12.345

6) Administrator

Record the facility's administrator name.

7) Year of completion

Enter the year of completion in four digits.

If the year of completion is unknown, enter "Unknown". Do not leave the entry field blank.

[Example] 1980

8) Live load and grade

Enter the live load and grade by referring to the tables below.

9) Design specifications used
10) Bridge length

Record the distance (in meters) between front surfaces of parapet walls of abutments.  If the distance is known to a decimal point, enter the distance to the first decimal place, rounding off the second decimal place.  In the case of culverts, the external dimension shall be used as bridge length.

11) Total span count

[Example of entry of the bridge length and the total span count]

Bridge length	Bridge length (m)	Total span count
Bridge (simple girder bridge)	43.2	1
Bridge (continuous girder bridge)	123.5	3
Ditch bridge (culvert)	12.3	1

12) Superstructure type

(1) Steel bridge (bolt or welding joint)   (2) Steel bridge (rivet joint)

Structural type code	Structural type		Structural type code	Structural type
121	I-girder (nonsynthetic)		221	I-girder (nonsynthetic)
122	I-girder (synthetic)		22	I-girder (synthetic)
123	I-girder (steel plate)		2232	I-girder (steel plate)
124	I-girder (unknown)		224	I-girder (unknown)
125	H-beam (nonsynthetic)		225	H-beam (nonsynthetic)
126	H-beam (synthetic)		226	H-beam (synthetic)
128	H-beam (unknown)		228	H-beam (unknown)
130	Steel girder bridge (other)		230	Steel girder bridge (other)
131	Box girder (nonsynthetic)		231	Box girder (nonsynthetic)
132	Box girder (synthetic)		232	Box girder (synthetic)
133	Box girder (steel plate)		233	Box girder (steel plate)
134	Box girder (unknown)		234	Box girder (unknown)
140	Truss bridge		240	Truss bridge
150	Arch bridge (other)		250	Arch bridge (other)
151	Tied-arch (arch bridge)		251	Tied-arch (arch bridge)
152	Langer (arch bridge)		252	Langer (arch bridge)
153	Lohse (arch bridge)		253	Lohse (arch bridge)
155	Nielsen (arch bridge)		255	Nielsen (arch bridge)
156	Arch bridge		256	Arch bridge
160	Rigid-frame bridge		260	Rigid-frame bridge
172	Box girder (cable-stayed bridge)		-	-
199	Other (steel welded bridge)		299	Other (steel (iron) rivet bridge)

 

(3) RC bridge     (4) Prestressed concrete bridge

Structural type code	Structural type		Structural type code	Structural type
310	RC reinforced concrete slab		410	PC void slab
311	RC reinforced concrete slab		411	Pretensioned slab
312	RC void slab		412	Pretensioned void slab
-			413	Post-tensioned void slab
321	RC T-girder		421	Pretensioned T-girder
-			421	Pretensioned T-girder
-			422	Pretensioned T-girder (synthetic)
-			423	Post-tensioned T-girder
-			424	Post-tensioned T-girder (synthetic)
330	RC girder bridge (others)		430	PC girder bridge (others)
331	RC box girder		431	Pretensioned box girder
-			432	Pretensioned box girder (synthetic)
-			433	Pretensioned box girder
-			434	Pretensioned box girder (synthetic)
335	RC ditch bridge (box culvert)  * Ditch bridges other than the below		435	PC ditch bridge (box culvert)  * Ditch bridges other than the below
336	RC ditch bridge (box culvert)  * Small-scale rigid box structure with low impact from live loads and no risk of third-party damage		436	PC ditch bridge (box culvert)  * Small-scale rigid box structure with low impact from live loads and no risk of third-party damage
350	Arch bridge (others)		450	Arch bridge (others)
356	Arch bridge		456	Arch bridge
360	Rigid-frame bridge		460	Rigid-frame bridge
-			471	I-girder (cable-stayed bridge)
-			472	Box girder (cable-stayed bridge)
-			481	Corrugated steel plate web bridge
-			482	Steel pipe truss web bridge
-			-
399	Other (RC bridge)		499	Other (Prestressed concrete bridge)

 

(5) SRC bridge      (6) Stone bridge

Structural type code	Structural type		Structural type code	Structural type
556	Arch bridge		650	Arch bridge (others)
599	Other (SRC bridge)		656	Arch bridge
			699	Other (stone bridge)
(8) H-beam steel bridge (without joint)
Structural type code	Structural type		(9) Others
825	H-beam (nonsynthetic)		Structural type code	Structural type
826	H-beam (synthetic)		960	Rigid-frame bridge
828	H-beam (unknown)		972	Box girder (cable-stayed bridge)
830	Steel girder bridge (others)		999	Others

 

13) Substructure type

Abutment and pier structural type code	Abutment and pier structural type	Abutment and pier structural type and others
11	Gravity abutment
12	Semi-gravity abutment
13	Inverted T-type abutment
14	Anchored abutment
15	Rigid-frame abutment
16	Penetrating abutment
17	Spill-through abutment
18	Small abutment
19	Other (abutment)
19	Other (abutment)	L-type abutment
19	Other (abutment)	T-type abutment
19	Other (abutment)	U-type abutment
19	Other (abutment)	Arch abutment
19	Other (abutment)	Integral abutment
19	Other (abutment)	Pile bent type abutment
19	Other (abutment)	Bracket mounted
19	Other (abutment)	Bracket overhang
19	Other (abutment)	Box culvert
19	Other (abutment)	Box culvert side wall
19	Other (abutment)	Leaning type retaining wall
19	Other (abutment)	Deep foundation pile abutment
19	Other (abutment)	Stone masonry abutment
19	Other (abutment)	Pillared abutment (Pier abutment)
19	Other (abutment)	Box abutment
19	Other (abutment)	Overhang from main bridge
19	Other (abutment)	Overhang from the abutment of main bridge
19	Other (abutment)	Integrated with main line
19	Other (abutment)	Unknown
21	Jointless structure at abutment

 

Abutment and pier structural type code	Abutment and pier structural type	Abutment and pier structural type and others
21	Wall-type pier (RC)
222	Wall-type pier (SRC)
23	Wall-type pier (steel)
31	Pillar pier (RC)
32	Pillar pier (SRC)
33	Pillar pier (steel)
34	Pillar abutment with one round pier (RC)
35	Pillar abutment with one round pier (SRC)
36	Pillar abutment with one round pier (steel)
37	Pillar abutment with one elliptical pier (RC)
38	Pillar abutment with one square pier (SRC)
39	Pillar abutment with one elliptical pier (steel)
41	Rigid-frame bridge pier (RC)
42	Rigid-frame bridge pier (SRC)
43	Rigid-frame bridge piers (steel)
44	Pillar abutment with one square pier (RC)
45	Pillar abutment with one square pier (SRC)
46	Pillar abutment with one round pier (steel)
47	T-type pillar abutment with one square pier (RC)
48	T-type pillar abutment with one square pier (SRC)
49	T-type pillar abutment with one square pier (steel)
51	Two-layer rigid-frame bridge pier (RC)
53	Two-layer rigid-frame bridge pier (steel)
61	T-type pier (RC)
62	T-type pier (SRC)
63	T-type pier (steel)
64	T-type pillar abutment with one round pier (RC)
65	T-type pillar abutment with one round pier (SRC)
66	T-type pillar abutment with one square pier (steel)
67	T-type pillar abutment with one elliptical pier (RC)
68	T-type pillar abutment with one elliptical pier (SRC)
69	T-type pillar abutment with one elliptical pier (steel)
71	I-type pier (RC)
73	I-type pier (steel)
81	Pile bent type pier (RC)
82	Pile bent type pier (SRC)
83	Pile bent type pier (steel)
84	Pillar abutment with two square piers (RC)
85	(SRC)
86	Pillar abutment with two square piers (steel)
87	Pillar abutment with two round piers  (RC)
88	Pillar abutment with two round piers  (SRC)
89	Pillar abutment with two round piers  (steel)
91	Pillar abutment with two elliptical piers (RC)
92	Pillar abutment with two elliptical piers (SRC)
98	Arch fold
99	Other (abutment)
99	Other (abutment)	H-beam
99	Other (abutment)	Hinge section of gel bar
99	Other (abutment)	Hinge
99	Other (abutment)	Bracket type abutment
99	Other (abutment)	Bracket mounted
99	Other (abutment)	Bracket overhang
99	Other (abutment)	Box culvert partition
99	Other (abutment)	Rigid-frame bridge pier (PC)
99	Other (abutment)	Locking pier (steel)
99	Other (abutment)	Crossing piers
99	Other (abutment)	Piers attached to the main line section by structural steel
99	Other (abutment)	Steel pipe well pier
99	Other (abutment)	Steel
99	Other (abutment)	Hollow pier
99	Other (abutment)	Rigid-frame angle brace
99	Other (abutment)	Overhang from main bridge
99	Other (abutment)	Integrated with main line
99	Other (abutment)	Included in main bridge
99	Other (abutment)	Overhang from the abutment of main bridge
99	Other (abutment)	Girder overhang from the main bridge
99	Other (abutment)	Bolstering abutment
99	Other (abutment)	Folded pier
99	Other (abutment)	Unknown

14) Foundation type

Foundation type code	Foundation type	Foundation type and others
0	Direct foundation
1	Open caisson
1	Steel pipe soil cement pile
1	Pre-bored pile
2	Pneumatic caisson
3	Steel pipe sheet pile
4	Driven pile
4	Deep foundation (Columnar deep foundation, deep pile foundation)
5	Ready-made steel pile
6	Ready-made RC pile
7	Ready-made PC pile
8	Wooden pile
9	Other
9	Other	Prestressing concrete well
9	Other	PHC
9	Other	SC pile + PHC pile
9	Other	Lightweight steel sheet pile
9	Other	Pile head: SC pile
9	Other	Underground continuous wall
9	Other	Unknown

15) Traffic conditions

16) Bridge width

The definition of each dimension with respect to width is shown in the figure below.  If the width is known to a decimal point, record the width to the first decimal place, rounding off the second decimal place.

Note: Viewed from the starting point.

17) Distance from the coast

Enter the distance (in kilometers) from the coastline to the first decimal place, rounding off the second decimal place.

(Example): 25.46km -> 25.5

18) Designation of emergency transportation routes

Select the status of designation of the relevant highway bridge as an emergency transportation route from among "primary", "secondary", "tertiary", "municipal designation", and "not designated".

19) Availability of alternative

Record whether there is any alternative route in vicinity to serve as a vital route to prevent the isolation of towns and villages in the event of a disaster.  The criteria for judgment shall be as follows: If isolated settlements occur when the facility is closed to traffic due to a disaster, there is no alternative route.

20) Subsurface conditions

Select the type of land use under the bridge from the items below:

river, lake or pond, shore, road, railroad, other (specified in detail)

 

21) Overall view and span views

Attach the drawings listed below.

Overall view: Schematic view of the entire bridge

Typical view: Top view, side view, section view

(2) Form 2:Extent of damage

This form is for recording assessment results of the extent of damage and shall be prepared for each span in principle.

 

1) Span number

Span numbers are assigned starting from the starting point of the bridge.

2) Major member category and their member number

A) Major member category

Select and enter major member category by referring to "2. Major members to be covered".  In the case of a multi-span bridge, members shared by the precedent and subsequent spans such as piers, bearings of the intermediate supports of a continuous girder, and end-diaphragms and end-beams shall be regarded as a member belonging to the span nearer to the starting point.

B) Member number

Assign a member number to each of the major members as follows:

(1) Main girders and stringers

In principle, number individual main girders and stringers, separately.

i) Steel slab girders, T-girders, etc.

ii) Steel box girders, etc.

In the case of a slab bridge that cannot be separated by main girders, "main girder 01" shall be assigned to the entire bridge.

(2) Cross beams and lateral bracings

The numbering shall be divided into end parts and an intermediate part.  In the case of a bridge having both cross beams and lateral bracings, 01 and 03 shall be assigned to the end parts and 02 to the intermediate part (See the figure on the right below).

(3) Sway bracings

The numbering shall be separated by lines, which are separated by main girders.  If there are upper sway bracings and lower sway bracings such as in a truss bridge or an arch bridge, the numbering shall be separated as well.  Vertical separation shall be represented by adding "1" (for upper sway bracings) or "2" (for lower sway bracings) before the numbering separated by lines (As a result, the member numbers will be three digits).

i) Steel plate girders, etc.

ii) Steel truss bridges, steel arch bridges, etc.

(4) Deck slabs

The numbering shall be separated by lines, which are separated by main girders.

i) Steel plate girders, concrete T-girders, etc.

In principle, for prestressed concrete T-girders, only the longitudinal joints shall be treated as slabs, and for concrete T-girders, parts other than hunches shall be treated as slabs.  Upper flanges and hunches shall be included in main girders.

ii) Steel box girders, etc.

In slab bridges, overhanging slabs and spacing slabs shall be treated as deck slabs, and other slabs shall be included in main girders.

(5) Substructures (abutments and piers), towers and bearings

Numbers shall be assigned individually.

(6) Road surface

The overall road surface over the bridge shall be counted as one.

(7) Main structural trusses

Top and bottom chord members, diagonals and vertical materials shall be integrated to form a main structural truss.  The trusses are arranged on the left and right when viewed in cross section. 01 shall be assigned to the left truss viewed from the starting point, and 02 shall be assigned to the right one.

(8) Portal bracing

Numbers shall be assigned to each Portal bracing.

(9) Lateral struts

Numbers shall be assigned to each lateral strut.

i) Steel truss bridges, steel through arch bridges, etc.

Since member numbers are assigned to both end parts at the Portal bracing, care shall be taken to avoid duplicate numbering.

ii) Deck arch bridges, etc.

Since lateral struts are arranged up to the end parts, it should be noted that member numbers are assigned in a manner different from that of steel truss bridges, through arch bridges, etc.

(10) Arch ribs

Arch ribs are arranged on the left and right when viewed in cross section. 01 shall be assigned to the left rib viewed from the starting point, and 02 shall be assigned to the right one.

(11) Stiffening girders

Numbers shall be assigned to each stiffening girder.

(12) Suspension and columns

Numbers shall be assigned to each hanger or column.  Since these members are arranged on the left and right when viewed in cross section, the numbering shall be separated by left and right.  The left and right separation shall be represented by adding "1" (for the left side) or "2" (for the right side) before the number assigned to each member (As a result, the member numbers will be three digits).

(13) Rigid-frame main structure (girder and pier)

Girders and piers shall be separately dealt with.

i) Rigid frame

Since main structure girders are arranged on the left and right when viewed in cross section, 01 shall be assigned to the left girder viewed from the starting point, and 02 shall be assigned to the right one.

ii) Pier

Numbers shall be assigned to each main structure pier.  Since main structure piers are arranged on the left and right when viewed in cross section, the numbering shall be separated by left and right. The left and right separation shall be represented by adding "1" (for the left side) or "2" (for the right side) before the number assigned to each pier (As a result, the member numbers will be three digits).

(14) Stay cables

Numbers shall be assigned to each stay cable. It should be noted that the number is reassigned from 01 starting from the tower pillar, since spans are divided by the tower pillar position.  When cables are arranged on the left and right when viewed in cross section, so the numbering shall be separated by left and right. The left and right separation shall be represented by adding "1" (for the left side) or "2" (for the right side) before the number assigned to each cable (As a result, the member numbers will be three digits).  The attachment points on the girder and tower pillar sides shall be also evaluated.

i) Arranged as a single plane

ii) Arranged as two planes

Example of numbering (Stay cables on the left side)

Example of numbering (plan view)

(15) Main cables

Numbers shall be assigned to each cable.  Since main cables are arranged on the left and right when viewed in cross section, three-digit numbers "left101", "right201" shall be used to indicate whether a cable is on the left or right.  The attachment points of tower pillars and anchorages shall be also evaluated.

Example of numbering (main cable on the left side)

(16) Hangers

Numbers shall be assigned to each hanger.  Since hangers are arranged on the left and right when viewed in cross section, the numbering shall be separated by left and right.  The left and right separation shall be represented by adding "1" (for the left side) or "2" (for the right side) before the number assigned to each hanger (As a result, the member numbers will be three digits).  The attachment points on the girder and main cable sides shall be also evaluated.

Example of numbering (hangers on the left side)

(17) Anchorages

Numbers shall be assigned per bridge.  Since anchorages are arranged to the left and right of the starting and ending points, they shall be represented by three-digit numbers as shown in the figure below.

iii) Assessment of the extent of damage

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