A Case of Utilizing Results

Reference documents concerning periodic inspectionsof road bridges (2013 edition) —Bridge Damage
Case Photo Collection—
TAMAKOSHI Takashi, HeadOOSHIRO Nodoka, Senior Researcher
KUBOTA Kosaku, Senior Researcher
KITAMURA Takanobu, Former researcher
YOKOI Yoshiteru, Researcher
Bridge and Structures Division, Road Department(Key words) Road bridge, maintenance, periodic inspections, damage case

1. Introduction
The percentage of Japan’s huge stock of road bridge
assets that has deteriorated is rapidly rising. We haveto economically and rationally maintain these assets aswe ensure safe and smooth traffic into the future.
Therefore, it is important to appropriately clarify andevaluate the present state of bridges and implement
systematic maintenance based on the results.
The Bridge Periodic Inspection Rules (Proposed)(March 2004) (below, “2004 Inspection Rules) havebeen enacted to cover road bridges operated by thenational government, stipulating that periodic
inspections formerly done at 10 year intervals becarried out every 5 years in the future, and that, inprinciple, all members be closely examined visually.
At this time, in order to be able to evaluate andanalyze characteristics of deterioration, in addition tothe diagnosis of the soundness of members (deciding
countermeasure categories), objective facts about thestate of damage (evaluations of the degree of damage)are recorded. At the same time, the NILIM has
published a technical report on the state of damage etc.
which has been accumulated by past surveys(TECHNICAL NOTE of NILIM, No. 196, December2004) to support technologists who perform
inspections and diagnoses.
Since then, the NILIM has continued by analyzing
the results of the 2004 Inspection Rules usednationwide, categorizing forms of damage,
hypothesizing causes, and conducting survey researchof design standards. And it has conducted studies
concerning forms of damage and bridge erection
environmental conditions by performing statisticalanalysis.
This fiscal year, based on knowledge obtained fromsurvey research on deterioration conducted since 2004,
technical consultations about defect cases, andtechnical support, a new collection of damage cases
for management personnel to use as reference material
has been prepared.

2. Configuration and outline of the Bridge
Damage Case Photo Collection
This document organizes damage cases under items(I) to (V) shown in Table 2 for each inspection item in
the Inspection Rules (26 types of damage shown inTable 1).
Damage to steel members[1] Corrosion[2] Cracking[3] Looseness, andfalling[4] Breakage[5] Deterioration ofcorrosion protection
function

Damage to concretemembers[6] Cracks[7] Exfoliation andexpose of rebars[8] Leakage or freelime[9] Falling[10] Damage toconcrete reinforcing
materials[11] Slab cracking[12] Flaking

Other damage

Common damage[13] Abnormalopening[14] Irregularities onroad surface[15] Defective paving[16] Obstruction offunctions of bearings[17] Others[18] Abnormal anchors[19] Discoloration anddeterioration[20] Leakage andwater retention[21] Abnormal noise orvibration[22] Abnormal
deflection[23] Deformation orchipping[24] Soil plugging[25] Settlement,
movement, leaning[26] Scouring

Table 1. Inspection Items (Types of Damage)(I) General properties and characteristics of damage
It shows photos of cases revealing general properties of damage and its
characteristics(II) Relationship with other damage
It shows points which are closely correlated with other damage, and whose data
must be carefully recorded.
(III) Evaluation of degree of damage
It shows examples (Photo 1) of cases where degree of damage of the damage casewas evaluated based on damage evaluation standards.
(IV) Deciding countermeasure category
It shows characteristic damage cases and related information, so that it can be used
as reference material to decide countermeasure categories(V) Other reference information
It shows information for use as references concerning past specific cases,
precautionary items, causes of damage, and change of materials used.

Table 2. Characteristics of the damage cases classified

A Case of Utilizing Results※Degree of damage is defined at 5 levels: a (no damage) and b, c, d, e(rising degree of damage)(a) Evaluation of degree ofdamage [b](b) Evaluation of degree ofdamage [e]Photo 1. Evaluation of Degrees of Damage (Exampleof Corrosion)
3. Summary
We are counting on the document being usedeffectively in the field and to contributing toappropriate diagnosis through inspections and todecision making concerning measures that managers
take. In the future, we will continually accumulate andanalyze inspection data, and develop comprehensive
road bridge service-lifetime extension technologies
including establishing, designing, and executing
rational maintenance methods based on predictions ofdeterioration of road bridges.
[Source]
Web page of the Bridge and Structures Division(Entered in TECHNICAL NOTE of NILIM No. 748)
http://www.nilim.go.jp/lab/gcg/index.htm