TAMIL NADU HIGHWAYS DEPARTMENT BRIDGE MAINTENANCE AE TRAINING MATERIAL/17-05 4 A… · TAMIL NADU HIGHWAYS DEPARTMENT BRIDGE MAINTENANCE ... Submersible bridge / Vented causeway ...

TAMIL NADU HIGHWAYS DEPARTMENT

BRIDGE MAINTENANCE PREFACE

Bridges and Culverts are basic and important components in any of the various transportation networks, especially road networks. But, in spite of this known importance, bridges continue to receive lesser attention as though they never require maintenance and repair and can serve for long years in this condition. This results in the speedy damages which leads to great future losses with the structure requiring replacement of some components and sometimes complete reconstruction in order to perform its function. Hence regular maintenance of Bridge and culverts are the essential duty of an Highway Engineer.

Before understanding the way to maintain the bridges, an effective supervision

and maintenance requires knowledge of the basic component and function of bridge. BRIDGE

Bridge is a structure having total length of above 6 metres between the inner faces of the dirt walls for carrying traffic or other moving loads over a depression or obstruction such as channel, road or railway. These bridges are classified as minor and major bridges as per classification given below.

(a) Minor Bridge : A minor bridge is a bridge having a total length of upto 60m

(b) Major Bridge : A major bridge is a bridge having a total length of above 60

CULVERT

Culvert is a cross – drainage structure having a total length of 6 metres or less

between the inner faces of the dirt walls or extreme ventway boundaries measured at

right angles thereto. CLASSIFICATION OF BRIDGES 1. Foot Bridge

A foot bridge is a bridge exclusively used for carrying pedestrians cycles and animal 2. High Level Bridge

A High level bridge is a bridge which carries the roadway above the highest flood

level of the channel.

3. Submersible bridge / Vented causeway

A submersible bridge / vented causeway is a bridge designed to be overtopped

during flood DEFINITION OF BRIDGE ASSOCIATED 1. Channel

A Channel means a natural or artificial water course. 2. Clearance

Clearance is the shortest distance between the boundaries at a specified position

of a bridge structure. 3. Freeboard

Freeboard at any point is the different between the highest flood level after allowing

for afflux, if any, and the formation level of road embankment on the approaches or top

level of guide bunds at that point. 4. Highest Flood Level (H.F.L)

Highest flood level is the level of the highest flood ever recorded or the

calculated level for the design discharge. 5. Low Water Level (L.W.L)

Low water level is the level of the water surface obtaining generally in the dry

season and shall be specified in case of each bridge. 6. Length of Bridge

The length of bridge structure will be taken as the overall length measured along

the centre line of the bridge between inner faces of dirt walls. 7. Linear Waterway

Linear waterway of a bridge is the width of the waterway between the extreme

edges of water surfaces at the highest flood level measured at right angles to the

abutment faces. EFFECTIVE LINEAR WATERWAYS

Effective linear waterway is the total width of the waterway of the bridge at HFL

minus the effective width of obstruction. SAFETY KERB

Safety kerb is a roadway kerb for occasional use of pedestrian traffic.

BRIDGE COMPONENTS Some common terms are used to define the components of each bridge.

1. Deck: Supports the roadway on which traffic flows, and also distributes traffic

(live) loads and dead loads. 2. Superstructure: Supports loads transmitted through the Deck.

3. Bearings: Support that transfer loads from the superstructure to the

substructure, while permitting limited rotation and longitudinal movement. 4. Substructure: Elements that transfer all loads from the

superstructure to the ground. 5. Expansion Joint: Assembly or material designed to safely absorb the

expansion and contraction of the superstructure and to protect the bearings from

water and debris.

BRIDGE CULVERT COMPONENT

Some common terms are used to define the components of each culvert.

1. Apron: area that is intended to eliminate the potential scour caused by water exiting the culvert.

2. Barrel or Vent: opening that will allow water to pass unobstructed under roadway.

3. Wing wall: A tapering wall that originates from the corner of the culvert and is intended to retain soil under the roadway.

4. Parapet: short wall across top of openings used to retain fill material.

5. Toe Wall: A full width wall that extends downward from the bottom of the

culvert at both ends.

WIDTH OF CARRIAGEWAY

The width of carriageway is the minimum clear width measured at right angles

to the longitudinal centre line of the bridge between the inside faces of roadway kerbs

or wheel guards.

The width of Bridge shall be minimum 4.25 m For two lane bridge width shall be 7.5 m and increase with 3.5 m for every additional lane. The foot path shall not be less than 1.5 m However safety Kerb 0.75 m on the either side of bridge may be provided in rural area where pedestrian movement is virtually nil.

Economical range of span lengths for different types of superstructures:

1. Simply supported RCC slabs 3 to 10 m

2. Simply supported RCC T beam 10 to 24 m

3. Simply supported PSC girder bridges 25m to 45 m

4. PSC box sections; 45 m to75 m

5. Cable stayed bridges More than 75 m TYPE OF FOUNDATIONS: The subsoil character decides the type of foundation. Also selection of foundation type

depends on type of structure and span arrangement.

1. Shallow foundations:

Isolated open foundations are feasible where an SBC of about 15 t/m2 or more is available at shallow depths upto 3 to 4 m. In cases, where the SBC is still less and where smaller spans arc economical raft foundations or box structures with floor' protection and curtain walls can be provided.

2. Deep foundations :

Where suitable founding strata is available at a depth of 6 m or more with

substantial depth of standing water, deep foundation like well foundation or most

commonly adopted piles foundation may be provided.

a) Well foundations: This is the oldest method adopted in India for river bridges due its simplicity, adaptability to different subsoil conditions and difficult site conditions like deep standing water and large depths to good founding strata. Caissons are an adaptation of well foundations to sites with deep standing water However construction time required is more and difficulty in sinking which had made this type of foundation obsolete.

b) Pile foundations: This type of deep foundations are suitable when good

founding strata a v a i l a b l e below large depth of soft soil or when hard strata

is not available at all. Those is the most common type of foundation

adopted when the structure span is more and is to be constructed on deep

standing water.

3. Classification of piles :

(a) Precast driven piles

(b) Bored cast-in-situ piles BEARING / FRICTION PILES:

A pile driven or cast -in-situ for transmitting the weight of a structure to the founding strata by the resistance developed at the pile base and by friction along its surface. If it supports the load, mainly by the resistance developed at its base, it is referred to as an end-bearing pile, and if mainly by friction along its surface, as a friction pile. BORED CAST-IN-PLACE PILE:

A pile formed with or without a casing by boring a hole in the ground and

subsequently filling it with plain or reinforced concrete. DRIVEN CAST-IN-PLACE PILE:

A pile formed in the ground by driving a permanent or temporary casing, and

filling it with plain or reinforced concrete. SHEET PILE:

One or a row of piles driven or formed in the ground adjacent to one another in a continuous wall, each generally provided with a connecting joint or interlock, designed to resist mainly lateral forces and to reduce seepage, it may be vertical or at an inclination. SUBSTRUCTURE :

Substructure include those portions of a bridge which are above the foundation

which include piers, abutments, pier caps, dirt walls, returns, wing wall etc. but excludes bearings and superstructure. It can be built of brick/ stone masonry, plain/reinforce prestressed concrete, steel. Selection of a particular type of substructure depends upon the span and type of superstructure, the height of substructure, availability of construction material and construction equipment’s, period and time of construction and above all on overall economy. The shape of piers and abutments in general, should be such as to cause minimum obstruction to flow of water.

BEARINGS:

Bearings are vital components of a bridge which while allowing of longitudinal

and/or transverse rotations and/ or movements of the superstructure with respect to

the substructure (thus relieving stresses due to expansion and contraction), effectively

transfer loads and forces from superstructure to substructure. Adequate care shall be

exercised in selecting the right type of bearings based on the guidelines given below:

(a) For solid slab superstructure resting on unyielding supports, no bearings are generally provided if the span length is less than 10m. The top of piers/abutments caps are however rubbed smooth with carborandumstone. and Kraft paper provided on the top .

(b) For girder and slab spans more than 10m length and resting on unyielding

supports, neoprene bearings may be considered.

(c) For spans larger than 25m roller and rocker bearings or PTFE bearings

could be considered. SUPERSTRUCTURE :

It is the superstructure of a bridge that directly supports the traffic and facilitates its smooth uninterrupted passage over natural/man made barriers like rivers, creeks, railways, roads etc. by transmitting the loads and forces coming over it to the foundation through the bearings and substructure.

1. Reinforced cement concrete superstructure: These are the most popular type of superstructure in the present day which may take the form of solid slab, voided slab. T-beam and slab, box girder, rigid frame, arch, balanced cantilever or bow-string girder.

2. Prestressed concrete superstructure: This may also take any of the above

forms referred in the previous para.

3. Steel superstructure: With increasing availability of quality steel at international prices in recent years the use of steel for superstructure is becoming an attractive option. The forms, these may take are steel beam, plate girder, box girder, steel truss, arch, cantilever suspension bridges and cable stayed bridges.

4. Composite Superstructure any combination of above materials considering

their distinct advantages for particular elements may be adopted. Most common types of composite construction are cast in situ or precast girder in prestrcssed concrete with R.C.C. deck or steel beam/plate girders with RCC deck or cable stayed bridges with RCC or PSC deck.

EXPANSION JOINTS:

Expansion joints are provided at the end of deck and cater for movement of deck due to temperature, shrinkage, creep etc. Expansion joints make the deck joint leak proof, protect the edges of slab/girder and also allow smooth passage of loads from one span to other by bridging the gap. Depending upon the gap width to be bridged, there are various types of expansion joints in use at present as detailed below.

1. Buried joints: Where the gap is 20mm or less, bituminous/asphalted surfacing is laid over a 12mm thick 200mm wide steel plate resting freely over the top surface of deck concrete. To keep the plate in position 8mm dia100 mm long nails spaced at 300mm c/c along the centre line of the plate are welded to the bottom surface of the plate and protrude into the gap.

2. Filler joint: This type of joint is suitable for fixed ends of simply supported

spans with insignificant movements or simply supported spans not exceeding 10

meters. It can cater for horizontal movement upto 20mm.

3. Elastomeric slab seal joint: It comprises of reinforced elastomeric seal fixed

on either side to deck concrete of adjacent spans through bolts. It can cater to a

maximum.

4. Strip seal expansion joint: It comprises of an extruded section of chloroprene held in position by edge beams made of either expanded or hot rolled steel section or cold rolled cellular steel sections with suitable profile to mechanically lock the scaling element. The edge beams are anchored to deck by reinforcing bars, headed studs or bolts or anchor plates. The working movement range of the sealing element shall be 70mm.

5. Modular Strip Seal/Box Seal Joint: A modular expansion joint consists of two

or more modules so as to cater to a horizontal movement in excess of 70mm. It allows movement in all the three directions and rotation about all the three axes as per design requirement. During all movement cycles of the joint, opening or closing of all modules are equal.

BRIDGE MANAGEMENT SYSTEM :

1. Maintenance: This is defined as the work needed to preserve the intended load carrying capacity of the bridge and ensure the continued safety of road users. It excludes any work leading to improvements of the structure, whether by strengthening to carry heavier loads, by widening or by vertical realignment of the road surface.

2. Repairs and Rehabilitation: These activities also meet the above definition of maintenance, but are larger in scope

and cost than maintenance. Rehabilitation operations aim at restoring the bridge to the

service level it once had and has now lost.

3. Improvements: Strengthening, widening, raising etc.., aim at upgrading the level of service of a

structure. The basic parameters taken into account in such improvements are:

i) Load carrying capacity and ii) Geometric parameters.

4. Replacement or Reconstruction:

Replacement or Reconstruction are the works carried out when the whole structure or

at least its major components such as whole superstructure are removed and replaced. BRIDGE MANAGEMENT PRESENT SCENARIO: Bridge Management deals with activities related to bridge “from their entry into service

until their reconstruction”, excluding bridge planning, design and construction. Bridge Inspection Introduction: Bridge inspection has many requirements and important aspects that must be satisfied for ensuring better outcomes of the inspection, given that the inspection results are used for determining the defects types and severity levels and consequently successful maintenance is based on accurate and careful inspection. Inspection methods: There are two inspection methods, namely inspection of concrete bridges and

inspection of steel bridges.

1. Concrete bridges inspection methods:

There are three methods for inspecting reinforced concrete bridges and pre-

stressed concrete bridges:

i) Visual inspection: There are two methods of visual inspection to be used by the person who performs the inspection. The first method is called routine inspection which is a review of the previous inspection report and then visual examination of the bridge parts from below. The second kind of visual inspection is called in-depth inspection. Here one or more elements are inspected above or under the water for detecting the defects which were not detected by routine visual inspection. There may be a need for more precise visual inspection for evaluating the concrete surfaces from a close distance and in this inspection non-destructive tests can be used.

ii) Physical Inspection: Physical tests are performed on the parts identified in the visual inspection using the inspection hammer for verifying the size and severity of the defect or using the metal wheel designed for this purpose instead of the hammer in large concrete surfaces and by means of the sound of the concrete we determine to what parts the defect extends.

iii) Advanced inspection techniques: In case the size of the defect cannot be

determined by visual or physical inspection, advanced inspection techniques

are used. These techniques include:

1. Acoustic wave sonic / ultrasonic velocity measurement.

2. Delamination detection machinery.

3. Rebound penetration methods.

4. Ultrasonic testing.

There is another set of testing’s, including:

Core sampling

Carbonation

Concrete permeability

Concrete strength

Moisture content BRIDGE INSPECTION RECORD:

Bridge inspection record consists of data gathered and recorded while

checking the condition of various spans and following up the deterioration process from

one inspection to another. Numbering of culverts/ Bridges :

All culverts and bridges on a highway should be assigned separate numbers. This is a means to their easy identification by the maintenance and inspecting personnel. A uniform system of numbering the cross-drainage structures being desirable Cross-drainage works on a road shall be numbered in serial order, in eachkilometre separately.

The number shall be in the form of a fraction, the numerator denoting thenumber of kilometre in which the structure is situated and the denominator thekilometre-wise serial number of the structure. For instance, the 5th cross-drainage structure in 4th kilometre (i.e. between kilometre stones 3 and 4) shallbe designated as 4/5. If any new culvert or bridge subsequently built say between 3rd and 4 th structure in 45th km then it shall be designated as 45 , 45

3/2 3/1

The following Information regarding CD shall be inscribed on the parapet

wall of the CD work

i) Number of Spans ii) Clear span length in m and iii) The type of decking or culverts indicated as

1 x 2 x S means, 1 Span of 2m with RCC Solid Slab.

S – RCC Solid slab

A- Arch B- Box culvert

P- Pipe Culvert

BRIDGE REGISTER

For maintenance of records of bridges, a bridge register as indicated at Appendix

shall be used. (i) Original Bridge Report

(ii) Inspection Report

Appendix

S.l No Name of bridge Location Page No.

/Br. No.

The following features of Bridge shall be recorded

(i) Soil Particulars:- Under this item it indicates the type of soil at the founding

strata, its safe bearing capacity, whether the soil is scour - able or not (based on past records), etc

(ii) Foundations:- Under this it indicates the type of foundations like well, piles, open, etc.,

(iii) Sub- Structure:- Under this item it indicates the type of substructure, e.g., masonry, plain cement concrete, reinforced cement concrete, prestressed cement concrete, etc.

(iv) Bearings:- Under this item it indicates the type of bearings, give brief details

like the design load, broad dimensions of the bearings, location of lifting

points, procedure for lifting, replacement of the bearings if done and the date, last date of greasing for metallic bearings, etc.

(v) Superstructure:- Under this item indicate the type of superstructure like reinforced cement concrete, prestressed cement concrete, steel, masanry arch, etc. Give brief of the various components (explain by sketch), method of prestressing, cross prestressing used or not, any other special features, etc.

(vi) Protective Works: Under this item it indicates the type of protective works

and briefly give the board dimensions of the layout, height, slope and

thickness, etc., ESSENTIAL MAINTENANCE Once a structure has reached the end of its useful life, only essential maintenance will

be performed. Essential maintenance consists of:

Keeping debris off the bridge deck and away from the

substructure Maintaining the deck drains

Emergency maintenance BRIDGE PRESERVATION

Bridge preservation is defined as actions or strategies that prevent, delay or reduce deterioration of bridges or bridge elements, restore the function of existing bridges, keep bridges in good condition and extend their life. Preservation actions may be preventive or condition-driven.

PREVENTIVE MAINTENANCE

Preventive Maintenance (PM) is a planned strategy of cost-effective treatments to an existing roadway system and its appurtenances that preserves the system, retards future deterioration, and maintains or improves the functional condition of the system (without substantially increasing structural capacity).

Examples of PM activities may include but are not limited to the following:

1. Bridge Washing or Cleaning

2. Sealing Deck Joints

3. Facilitating Drainage

4. Sealing Concrete Deck

5. Epoxy Injection of Concrete Cracks

6. Painting Steel

7. Removing Channel Debris

8. Lubricating Bearings Examples of condition based preventive maintenance activities include but are not

limited to:

1. Sealing or replacement of leaking joints

2. Installation of deck overlays

3. Complete, spot, or zone painting/coating of steel structural elements

4. Installation of scour counter measures Cyclical Preventive Maintenance Activites can include the following activities.

1. Pressure wash. Periodically a bridge should be evaluated to see if it

needs to be pressured washed on all or some of the bridge surfaces.

2. Deck and joints – cleaning and washing Snow / Ice events – for those structures that experience a snow /

ice event that required de-icing, the structure should be cleaned at the end of the snow / ice season. Area Maintenance should clean joints once a year.

Bridge decks should be cleaned once every year.

3. Deck drains – Deck drains should be cleaned once a year.

4. Concrete Members --With the exception of the deck, pressure washing

and painting all concrete surfaces of the bridge is to be done. 5. Metal expansion joints (any expansion joint that is anchored into the deck,

edge beam, or back wall) – evaluate on the following cycles:

Less than 8 Percent of Trucks –on a 10 year cycle Equal to or greater than 8 Percent of Trucks –on a 5 year cycle

6. Expansion joints

Less than 8 Percent of Trucks – evaluate for replacement of joint on a 10 year cycle

Equal to or greater than 8 Percent of Trucks – evaluate for

replacement of joint on a 5 year cycle

7. Paint structural steel – The following schedule should be used to evaluate

the need to paint steel members:

Above the Fall Line and in places adjacent to the coast

Bridge with a continuous steel unit, 2 year cycle

Bridge with all simple spans, 4 year cycle

Below the Fall Line and in places away from the coast Bridge with a continuous steel unit, 5 year cycle

Bridge with all simple spans, 10 year cycle

CLEAN DECK DRAIN AND DRAINAGE SPOUT

Procedure: Flush drainage spout and drainage system, but prevent sediment and debris from

discharging into streams or waterways. Remove spout gratings and downspout clean-

out plugs to flush trapped debris, as necessary.

CLEAN EXPANSION JOINT

Procedure:Use brooms and shovels to remove excess debris near the joint. Remove

debris build up in the expansion joint, exercising care as not to damage the expansion

joint material.

SEALING DECK Procedure: Prior to work, patch deck spalls w i t h e p o x y c o n c r e t e .

CLEAN ABUTMENT / CAPS/BED BLOCK

Procedure: Collect and remove trash, dirt, and other debris from deck and gutters by sweeping, shovelling, vacuuming, or other suitable methods. Loosen dirt and debris with scrapers and stiff brushes, as necessary. Pressure wash the structure using clean, fresh water.

REDRESS RIP RAP Procedure:Clear the area of debris and vegetation. Provide filter media 250 mm and

overlay with a layer of rip rap 300 mm thick.

BUSH / TREE REMOVAL Procedure:Cut and remove vegetation from around substructures and approaches (

edge of bridge opening), to increase life of structure and minimising erosion, and

sedimentation.

DEBRIS ANE WOOD LOG REMOVAL Procedure: Coordinate work with PWD and District Authorities for River Training work.

Cut and remove debris from the river channel and overbank area. OTHER DECK MAINTENANCE : The following items should be considered on bridge decks in addition to the items

previously listed:

1. Sealant – evaluate 1 year after bridge deck is poured

2. Wearing Coat

Less than 8 Percent of Trucks – evaluate after 25 years after Overlay Equal to or greater than 8 Percent of Trucks – evaluate after 15 years after

overlay 3. Clean and reseal deck joints – Once the deck joints reach periodically.

4. Install Deck Overlays – Evaluate installing a deck overlay under the following

conditions: Once greater than 50% of the appropriate deck element is in bad condition

5. Repair expansion joint

6. Patch spalls - If the bridge deck develop any distress or pot holes it should be

evaluated for patching.

7. Paint Structural Steel

8. Scour Countermeasures—Any structure that is identified as scour critical or

having an unknown foundation should be evaluated for potential scour

countermeasure.

BRIDGE DECK SEATING Procedure :Clean existing bridge expansion joints of all dirt, refuse, and existing

sealant and seal joints using low density polyethylene sealant.

DECK SPALL REPAIR

Procedure :Thoroughly clean existing reinforcement of concrete scale and rust by sand blasting before bonding into new construction.

Apply epoxy resin adhesive to all hardened concrete surfaces just prior to pouring

the concrete. Adopt same concrete strength as deck slab.

FULL DECK DEPTH REPAIR

Procedure :Place and tie all reinforcing steel in accordance with the Specifications.

Do not weld reinforcing steel. Apply epoxy resin adhesive to all

hardened concrete surfaces just prior to pouring the concrete.Bend existing reinforcement to be utilized in new construction in a manner to provide the maximum lap possible or as shown on the plans. Thoroughly clean existing reinforcement of concrete scale and rust by sandblasting before bonding into new construction.

BRUSH CURB POST REPAIR

Procedure Place and tie all reinforcing steel in accordance with the Specifications. Do not weld reinforcing steel. Apply epoxy resin adhesive to all hardened concrete surfaces just prior to pouring the concrete. Bend existing reinforcement to be utilized in new construction in a manner to provide the maximum lap possible or as shown on the plans. Thoroughly clean existing reinforcement of concrete scale and rust before bonding into new construction.

PSC PILE SECTION LOSS REPAIR EPOXY INJECTION ( CAP AND COLUMN ) CAP COLUMN SPALL REPAIR - SURFACE

CAP EXTENSION WIDENING

RIP RAP PLACEMENT

MAINTENANCE OF CULVERT INTRODUCTION: This section, which deals with the maintenance of culverts, complements the

inspection of culverts. This section contains the evaluation of problems, and

methods of repair, rehabilitation and replacement.

Identify the functionally deteriorated and old culverts and replacE. Adopt effective maintenance to prolong the serviceability and

expectancy. GENERAL PROBLEMS OF CULVERTS: There is a wide variety of types of culvert problems. These can be categorized

according to the strength capabilities. The following are the general problems of

culverts 1. Serviceability problems:

Scour and erosion of the stream bed and embankments

Inadequate flow capacity

Corrosion and abrasion of the steel parts of the culvert

Corrosion and abrasion of concrete and masonry components of the

culvert

Detachment and/or collapse of parts of the culvert

Inadequacy of the length of the culvert 2. Strength‐related problems:   

Cracking of the rigid culverts

Undermining and loss of structural support

Loss of the invert of culverts due to corrosion and abrasion

Over deflection and shape distortion of the flexible culverts PROBLEM IDENTIFICATION AND ASSESSMENT: 1. Scope: This section discusses how culvert problems are determined and culvert

appurtenances. 2. Determining Culvert Problems: The process of determining culvert’s problems can be identified visually in the field whether the culvert as a whole or one of its components does not function properly, or shows signs of distress that may lead to prevent the culvert from performing its intended functions. 3 Regular (Routine) Maintenance: The culvert and appurtenances must be inspected during the periodic maintenance works to determine the defects and repair the minor faults. Records must be maintained to rep[ort the faults, treatments, and recommendations regarding conducting further inspection and repair works. Inspection works inthe periodic maintenance allow the opportunity to determine and repairsimple faults before they become more serious. The protective maintenance isa major prevention against early deterioration of culverts and the resulting

hindrance to their functions. The following simple routine procedures help to

increase the life of structure and will function effectively.

1.REMOVAL OF VEGETATION IN THE VENTS

CULVERT IS PARTLY COMPLETELY BLOCKED BY SILT CULVERT IS ALMOST COMPLETELY BLOCKED BY VEGETATION

VENT CLEARED NO OBSTRUCTION TO WATER FLOW 2.CONSTRUCTION HEAD WALL TO PREVENT FAILURE OF STRUCTURE

CULVERT WITH NO HEAD WALL AND WITHOUT APRON

CULVERT WITH HEAD WALL AND APRON 3. REHABILITATING STRUCTURES

PIER REINFORCEMENT EXPOSED DUE TO SCOUR

REHABILITATING WITH REPLACEMENT OF REINFORCEMENT GROUTING RESPONSIBILITY Legally and morally, it is the site Engineer’s responsibility to maintain the culverts and

Bridges in their respective jurisdiction. The fundamental goal of bridge inspection is to enhance public safety by rehabilitating

the CD and Bridge work by means Safety of road users can be achieved.