tinau bridge maintenance

of NepalMinistry of Physical Planning and WorksDEPARTMENT OF ROADS

BRIDGE PROJECTBabarmahal, Kathmandu, Nepal

FIELD REPORTContract No.: BP/SID/2070/71-03

Special Inspection And Design of Maintenance/Repair works of Tinau Khola Bridge

Along Mahendra Rajmarga in Rupandehi District.

Submitted By: Kathmandu, May 2014Gaurav Integrated Development Associates Nepal Ltd.Jv with GOEC Nepal Ltd & GIDAN P.LtdNew Baneshwor, KatmanduNepal

Date: 10 May, 2014To: Bridge ProjectDepartment of RoadsBabarmahal, KathmanduNepal

Sub: Field Report on Special Inspection and Design of Maintenance/Repair works of Tinau Khola Bridge along Mahendra Rajmarga in Rupandehi District.

Dear Sir,

We are pleased to submit the two copies of Field Report of Tinau khola Bridge along Mahendra Rajmarga in Rupandehi District. (Package No: BP/SID/2070/71-03)

Yours sincerely,

___________Mangal Raj ShresthaManaging Director

Special Inspection and Design of Maintenance/Repair works of Tinau Khola Bridge along Mahendra Rajmarga. TABLE OF CONTENTS

Table of Contents

1.0 INTRODUCTION.......................................................................................................11.1 Background...................................................................................................11.2 Purpose of the Project.................................................................................11.3 Bridge Site Location.....................................................................................11.4 Description of the Existing Bridge..............................................................2

1.4.1 Span Layout and Structural Types.................................................................21.4.2 Deck system...................................................................................................21.4.3 Substructure and foundation..........................................................................31.4.4 Existing Utilities..............................................................................................3

2.0 METHODOLOGY......................................................................................................42.1 Generals........................................................................................................42.2 Field work......................................................................................................42.3 Personnel Involved in Field survey.............................................................4

3.0 BRIDGE CONDITION, EXTENT AND URGENCY...................................................53.1 Superstructure..............................................................................................53.2 Substructure.................................................................................................7

4.0 DEFICIENCIES AND PROBLEMS IN THE BRIDGE...............................................85.0 REPAIR AND MAINTENANCE PROGRAMME.......................................................96.0 CONCLUSION AND RECOMMENDATIONS...........................................................9

APPENDICESAPPENDIX A: Photographic Records …………………………………………………………iAPPENDIX B: Inspection Forms ………………………………………………………………ii

1.0 Introduction

1.1 BackgroundDepartment of Roads, the sole governmental organization is responsible for overall management of bridges along strategic Roads in Nepal. In this regard the Department of Roads, Bridge Project utilizes the services of engineering consulting firms in the Special bridge inspection and design of maintenance /repair works. As such the Consultant conducted a special inspection of the Tinau khola Bridge crossing over Tinau Khola in Rupandehi district.

Running along the Mahendra Rajmarga, the bridge has been continuously facilitating to pedestrians, local peoples and hundreds of vehicles running daily in Rupandehi. The bridge is in the full authorization of Butwal Division of Department of Roads, Ministry of Physical Planning and Works which takes the responsibility of its management and maintenance. Seemingly, the bridge is still under its design period and our extensive inspections of each part of its components claim that it is in fairly good condition except minor repairs like painting, decking

Detailed Engineering Survey, Soil Investigation & Detailed Design of

PRELIMINARILY DESIGN REPORT

drainage, repair of concrete wearing surface, addition of gabion mattresses and boxes for river training works.

1.2 Purpose of the ProjectThe inspection and assessment of the bridge was carried out to establish scope and costs associated with repair and maintenance of the bridge elements. In this regard the purpose of the report is to describe and report the overall condition of the Tinau Khola Bridge so that safe facility for the public could be provided. It also suggests on maintaining and improving the existing condition of the bridge by correcting structural and functional deficiencies associated with the bridge. The report will address the issues, problems identified and inspected in the field visit.

1.3 Bridge Site LocationThe Tinau Khola Bridge lies in Rupandehi district of Nepal. This bridge crosses the Tinau khola and lies along the major highway, Mahendra Rajmarga. Geographically; it is located at 27⁰42’13.9” N Latitude and 83⁰27’45.4” E Longitude.

It links Butwal bazar of Butwal municipality at left bank and Khaseuli of Butwal municipality at right bank through Mahendra Rajmarga. A bird’s eye view of the bridge site is shown as below:

Photo1: Location Map of Tinau khola Bridge and vicinity map (source: Google Earth)

1.4 Description of the Existing Bridge

1.4.1 Span Layout and Structural TypesThe Tinau khola Bridge is a through type concrete Bridge with concrete T-beams. The Bridge superstructure consist of three lateral concrete T-Beams, resting on east and west abutments which has been founded on pile foundation. The bridge has 6 no. of spans of overall length 231.15m and its orientation is east to west.

1.4.2 Deck systemThe bridge is a grid of three longitudinal beams with diaphragms supporting running slab. There is bituminous wearing surface over RCC structural slab for traffic movement. Cantilever slab projected to provide pedestrian path.

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Tinau Khola Bridge

To Butwal Bazar

To khaseuli

Tinau Khola

Direction of flow



Photo 2: Structural components of the Bridge

Photo 3: Components of decking at superstructure

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Longitudinal beam

Deck Slab

Lamp post

Bituminous running surface

Concrete Railing

Steel Pipe railing

Cross Beam

Kerb

Water Spout



1.4.3 Substructure and foundationAbutments of the bridge are close end, high stem seat type abutment, since the abutment has been constructed at the end of the waterway of the river. The bridge has pile foundation and 5 numbers piers are provided.

1.4.4 Existing UtilitiesOptical fiber lines runs along the northern side of the bridge. There is electrical lines at the southern part of the bridge.

Table: Summary of the Bridge informationDescription

1. Type of Bridge : Concrete bridge2. No. of Span : 6 nos.3. Total Length : 38.3+37.8+38.2+40.45+40.30+36.1=231.154. Carriageway : 7.1m5. Footpath width : 1.526. Overall width : 10.54m7. Posted load restriction : -8. Height restriction : -9. Foundation Type : Well Foundation10. Deck : : Concrete wearing course upon longitudinal RCC T-beams11. Railings : RCC and steel pipes12. Bearings : Steel Bearing13. Utility services : Optical fiber pipes runs parallel to the length of bridge

2.0 Methodology

2.1 GeneralsFollowing sequence of works had been followed for collection of field data;

Preparation of Inspection Report Forms as per DOR’s Bridge Inspection Manual for recording;

Desk study; Arrange team for carrying out different inspection works; Mobilization of the team to site.

2.2 Field workThe Field Works for Special Inspection works of the Tinau Khola Bridge generally comprising of the following works that had been carried out at site,

1. Inspect each part of the bridge thoroughly and its condition

2. Record its condition using the appropriate inspection report forms

3. Sketches to illustrate the location of any defects and problems

4. Collect samples of items such as broken concrete, corrosion products or paint flakes

5. Examine the condition of any previous maintenance or repair works

6. Photographs for the record of the inspector’s observations

The bulk of the inspection work was carried out in the 8th may 2014. The inspection consisted of a comprehensive detailed visual inspection from deck, underneath of bridge. All structural and non-structural components of the bridge were inspected. These components included floor beams, girders, abutments, piers, bearings, structural members, bituminous decking. Conditions of other

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non-structural components such as hand-railings, road barriers, embankment and sidewalks were also assessed. Field and photographic records of the inspection are provided in Appendix A.

Condition Rating SchemeStandard inspections forms and condition rating, (Guidelines for inspection and maintenance of bridges Vol.1 (DoR)), were used. Each components of the bridge, was evaluated using the standard condition rating scheme. Inspection forms summarizing this work are provided in Appendix B.Johnson Street Bridge Condition Assessment Report

2.3 Personnel Involved in Field surveyDuring the inspection works of the bridge following personnel were involved to carry out the field works. S.No

.Name Designation

III

Nabin PandeyRajesh Ghimire

InspectorInspector

3.0 Bridge Condition, Extent and Urgency According the bridge inspection results the condition of the bridge is rated as extremely poor condition and its extent and urgency rated as major and urgent respectively. The Inspection form adhering in the appendix II describes the detail inspection report of the bridge condition, extent of damage or deterioration and urgency to its remedy.

The condition of the each parts of the bridge has been briefly described below:

3.1 SuperstructureDeck Slab and concrete wearing coatThe inspection survey showed that bituminous wearing course was worn out with excessive pot holes and deterioration of materials. Riding quality was uneven with some bumps. Existing thickness of the wearing coat seemed insufficient due to excessive wearing to the surface material. As such the condition is rated as poor.

The concrete deck slab was examined from underneath for cracking, spalling and other signs of deterioration but no such serious problems was found except some minor superficial deteriorations.

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Photo 4: Cracks and potholes due to wear out of concrete Photo 4: Boulders seen due to wear out of concrete

Longitudinal Girders and Cross GirdersThe stems, webs of the girders and diaphragms were thoroughly inspected for cracking, spalling and disintegration but not such serious problems were observed except some deterioration of concrete at joints and over bearings. Hence, the conditions of the girders are rated as fair. Drainage spoutsThe drainage spouts provided on the deck slab lacks sufficient projection, due to which slopping of rain water over the soffit decking causing spot of fungal dirts that might deteriorate the concrete surfaces.

Expansion jointsDeck endings at piers and abutments lacks proper functioning joints. Joint gap are completely filled with bituminious material and no clearance exists for movements of bridge. No sealing material was observed.

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Photo 5: Cross beams



Photo 6: Expansion joint filled with bituminous material

Railings: The condition of railing is very poor. There are two types of railings, one is concrete and the other is steel pipe railing. Maximum parts of hand railings were damaged and some parts are missing. Figure below shows the condition of railings.

FoothpathsFootpaths were in fairly good condition.

Photo 8: damaged concrete railings Photo 9: missing parts in railing

Photo 10: Damaged concrete railing Photo 11: Damaged steel pipe railing

Approach slabConcrete approach slab at each sides of the bridge has no significant damages and deterioration.

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3.2 SubstructureBearings

There is dirt and debris accumulation on the bearing seats. Heavy corrosion of bearing plates and lack of lubricants in the bearings was found during inspection. No cracks were found in the abutment cap, pier cap.

Photo 12: Deterioration of bearing and bearing plates

Photo 13: Rusted bearings

Abutment/piersBoth right and left abutment of the bridge is founded on deep foundation and the inspection shows that its’ condition is in reasonable and good.

There was not any significant spalling or disintegration of concrete in piers except some locations at abutment joints.

Photo 14: Right Abutment Photo 15: Right Abutment

Retaining walls

All four retaining walls are in good condition. Vegetation are grown up in the retaining walls which is need to be cleared. Wing wall have some cracks and exposure of reinforcement is there.

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Photo 16: Right bank Retaining wall Photo 17: Cracks in the Right wing wall

4.0 Deficiencies and Problems in the BridgeThough the bridge has not any major structural deficiency, it lacks some components and facilities as listed below:

Insufficient wearing coat thickness; poor riding surface Expansion joints spacing, Well managed drainage facilities at deck.

Some parts of the bridge’s railing is missed, bearings are corroded which would rust further if not maintained timely that might lose its effective area, hence its structural strength, running surface have extreme condition which needs a quick attention.

5.0 Repair and Maintenance ProgrammeBased on the comprehensive inspection of the structural elements of the Tinau Khola Bridge an attention required within a couple of months for the protection of Bridge components.

The repair and maintenance program recommended in this regard consists of the following scope:

a) Complete scarifying the existing wearing coat and lying of new asphalt concreteb) Provision of GI pipes water spouts for proper drainagec) Repair and maintenance of RCC railings and steel hand railsd) Provision of rubber joint seal in deck end jointse) Reintegration by rich mortar or epoxy mortar at some spall areasf) Repair of stone pitching around the abutmentg) Painting traffic signs, divide lines, kerb etc.h) Bearings:

Under the repair and maintenance of bearings following works are provided; Cleaning the accumulated dirt, debris and removing corrosion by sand blasting; Painting the bearings with one coat of primer, one coat of epoxy and 1 coats of acrylic

polyurethane; Applying a coat of ordinary grease on bearings for its sufficient lubrication; Providing missing anchor bolts, if any.

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6.0 Conclusion and recommendationsComprehensive inspection of every features of the bridge suggests that the bridge is in poor condition. The bridge seemed unrepaired since many years.So the above recommended repair and maintenance program is developed to lengthen the life of the bridge to its intended design life.

It is recommended that the repair and maintenance works should be implemented within a few months to minimize the risks associated to the vulnerability of the bridge.

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Appendix- A: Photographic Records

Photo 18: Downstream of the Tinau khola bridge Photo 19: upstream of the Tinau khola bridge

Photo 18: Side view of Tinau khola bridge Photo 19: condition of concrete parapet

Photo 20: Condition of river protection work Photo 21: Gabion boxes at the bank of river

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Photo 22: River training works Photo 23: View of bridge from downwards

APPENDIX B: Inspection Forms

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tinau bridge maintenance

Documents