Field Report Lothar Khola

Government of NepalMinistry of Physical Planning and Works

DEPARTMENT OF ROADSBRIDGE PROJECT

Babarmahal, Kathmandu, Nepal

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

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

Along Mahendra Highway in Makwanpur District.

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

Date: 20 May, 2014To: Bridge ProjectDepartment of RoadsBabarmahal, KathmanduNepal

Sub: Field Report on Special Inspection and Design of Maintenance/Repair works of Lothar Khola Bridge along Mahendra Highway in Makwanpur District.

Dear Sir,

We are pleased to submit the two copies of Field Report of Lothar Khola Bridge along Mahendra Highway in Makwanpur District.(Package No: BP/SID/2070/71-03)

Yours sincerely,

___________Mangal Raj ShresthaManaging Director

Special Inspection and Design of Maintenance/Repair works of Lothar Khola Bridge along Mahendra Highway. 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...................................................................................................31.4.3 Substructure and foundation..........................................................................41.4.4 Existing Utilities..............................................................................................4

2.0 METHODOLOGY......................................................................................................42.1 Generals........................................................................................................42.2 Field work......................................................................................................42.3 Personnel Involved in Field survey.............................................................52.4 Personnel Involved in Design Works..........................................................5

3.0 BRIDGE CONDITION...............................................................................................53.1 Superstructure..............................................................................................53.2 Substructure.................................................................................................9

4.0 DEFICIENCIES AND PROBLEMS IN THE BRIDGE.............................................105.0 REPAIR AND MAINTENANCE PROGRAMME.....................................................116.0 ESTIMATES AND COSTS.....................................................................................15

6.1 General........................................................................................................156.2 Quantity Estimates.....................................................................................166.3 Base Rate....................................................................................................166.4 Norms of Rate Analysis.............................................................................166.5 Construction Overhead..............................................................................166.6 Transportation Charges.............................................................................166.7 Physical Contingency................................................................................16

7.0 MAINTENANCE AND REPAIR WORKS PLAN.....................................................167.1 Construction Schedule..............................................................................167.2 Quality Control and Construction Supervision.......................................167.3 Method Statement for Maintenance and Repair Works..........................17

8.0 CONCLUSION AND RECOMMENDATIONS.........................................................19

APPENDICESAPPENDIX A: Photographic RecordsAPPENDIX B: Inspection Forms

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Special Inspection and Design of Maintenance/Repair works of Lothar KholaBridge along Mahendra Highway.

FIELD REPORT

1.0 Introduction1.1 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 Lothar Khola Bridge crossing over Lothar Khola in Makwanpur district.

Running along the Mahendra Highway, the bridge has been continuously facilitating to pedestrians, local people and hundreds of vehicles running daily through Makwanpur. The bridge is in the full authorization of Makwanpur 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 fair condition of goodness except minor repairs like, decking drainage, repair of concrete wearing surface, addition of gabion mattresses and boxes for river training work, maintenance of handrails.

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 Lothar 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 Lothar Khola Bridge is about 437.55 KM from East of Mahendra Highway and lies in boarder of Makwanpur-Chitwan district of Nepal. This bridge crosses the Lothar Khola and lies along the major highway, Mahendra Highway. Geographically; it is located at 27⁰35’133” N Latitude and 84⁰43’942” E Longitude.

It links ward no.01 of Manahari VDC at left bank and ward no 01 of Manahari VDC of Chitwan district and at right bank through Makwanpur District of Mahendra Highway. A bird’s eye view of the bridge site is shown as below:

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Special Inspection and Design of Maintenance/Repair works of Lothar Khola Bridge along Mahendra Highway.

FIELD REPORT

Photo1: Location Map of Lothar Khola Bridge and vicinity map (source: Google Earth)

1.4 Description of the Existing Bridge

1.4.1 Span Layout and Structural Types

7.6257.6257.6257.625 7.625 7.625 7.625 7.625

61.00

8.2

The general arrangement of the Lothar Khola Bridge is shown in figure below.

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Manahari VDC Ward No. 1

Flow Direction

Lothar Manahari VDC Ward No. 1


FIELD REPORT

The Lothar Khola Bridge is a through type concrete Bridge with concrete slab decking.The Bridge superstructure consist of two main concrete Girder ,as shown below, resting on east and west abutments which has been founded on normal rock. The super structure of bridge is designed under pre-stress method. Both pier and abutment are of RCC type with movement let free on one end and fixed on other end with use of elastomeric bearing. Railing has been made up of RCC and Metal Pipe. The bridge is a five span of overall length 150m and its orientation is east to west.

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Vertical Member

Cross Girder

Stiffening Member Stiffening Member

Wooden Joist

Bituminous wearing course

Timber Planks

1820 1820

4920

Stringer

5524

Stee

l Tru

ss-2

sou

ther

n Steel Truss-1 Northern

Figure 1.1: Typical cross section of the bridge superstructure


FIELD REPORT

1.4.2 Deck systemThe Bridge decking has concretewearing surface over RCC structural slab for traffic movement surface. Four steel stringers runs parallel to the bridge axis and simply supported at the cross beams.Cross beams are the main beams which support steel stringers and its each ends are connected at the nodes of the two parallel steel truss.

Photo 2: Structural components of the Bridge

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Kerb

Deck SlabPedestrian

path

Guard Railing an


FIELD REPORT

Photo 3: Configuration of structural elements at decking

1.4.3 Substructure and foundationBoth abutments of the bridge are founded on openly grounded geography. The bridge has submerged foundation of piers and open foundation at abutments having 4 piers.1.4.4 Existing UtilitiesLeakage of water through longitudinally situated water supply pipe at the mid span is a problem along with removal of debris from bridge axis. Optical fiber pipes are working well.

Table: Summary of the Bridge informationDescription

1. Type of Bridge : RCC 2. No. of Span : 53. Total Length : 5X30m4. Carriageway : 7.5m5. Footpath width : 1m each side6. Overall width : 9.70m7. Posted load restriction : Speed Limit8. Height restriction : .No9. Foundation Type : RCC submerged Foundation10. Deck : Longitudinal and Cross Girder of RCC with pavement

wearing course upon rubber joists11. Railings : RCC + Metal Pipe12. Bearings : Elastomeric Bearing13. Utility services : Telephone line, Optical fiber runs parallel to the length of

bridge

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Cross Beam

Deck Slab

Longitudinal Girder

Pier


FIELD REPORT

2.0 Methodology2.1 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 Lothar 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 over a two (2) day period from 27-28 th of Baishakh 2071 BS. 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 steel members, RCC components, bracing members, bituminous decking. Conditions of other non-structural components such as hand-railings, road barriers, embankment and sidewalks were also assessed. Field and photographic records of the inspection areprovided 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 pandeyNabin Koirala

Team Leader/Bridge EngineerInspector

3.0 Bridge Condition, Extent and Urgency According the bridge inspection results the condition of the bridge is rated as fairly good condition and its extent and urgency rated as minor and not 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:

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FIELD REPORT

3.1 SuperstructureDeck Slab and Bituminous wearing courseThe inspection survey shows that deck slab and wearing course are in good condition. No any cracks and pot holes were inspected. Through visual inspection of the structural deck sab suggests no major structural problem.

Photo 4: Bituminous wearing course Photo 5:Deck slab in condition

Cross Girder and Longitudinal GirderRCC girder of the bridge composed of four longitudinal girders and 4 cross girder in each spans. Longitudinal Girders running parallel to the bridge axis are in good condition, same is the condition of the cross girder. Spalling effects are not seen in girders and deck. No major deterioration and rusting were seen during its inspection.

Photo 8: Longitudinal Girders with optical fiber on side

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FIELD REPORT

Photo 9:Cross Girder

Deck Expansion JointsExpansions joints are provided and damaged partially. The photo shows the joint of bridge deck where boulders are filled to patch the hole of the joint. The Rubber band strip of the expansion joint was to be serviced and replaced.

Photo 11: Expansion joint material damaged Photo 12: joint Filling of boulders at joint

Railings and KerbGuard rails are to be repainted and serviced. Hand rails are in good condition except at few sections.. Kerb are also in satisfactory condition where repainting has to be done.

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FIELD REPORT

Photo 13-14: Railing bar with Hand rails and guard stands

Photo 15: Kerb in condition to be repainted

Approach slabConcrete approach slab at each sides of the bridge has no significant damages and deterioration, where as expansion joints have to be serviced and can be replaced.

Photo 16-17: Approach Slab to the Bridge

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Kerbs to be painted


FIELD REPORT

3.2 Substructure

AbutmentBoth right and left abutment of the bridge is founded on open foundation and the inspection shows that its’ condition is in reasonable and good. But the flow of debris and flood dirt has filled the abutment up to the maximum height, in the left abutment and middle piers. The debris filled above concrete base of the bridge has to be removed so as too keep bridge safe from high flood.

Photo 18: Left Abutment Photo 19: Right Abutment

Photo 20: Piers, filled with debris and flood aggregates upto the maximum height.

Photo: U/s of the left side bridge abutment filled up with weirs

Retaining walls and gabion BoxesAll four retaining walls are in good condition. Gabion boxes in some places in both banks have to be constructed and repaired.

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FIELD REPORT

Photo 20: Cracks in the Left wing wall Photo 21: Left bank of the river with distorted gabion wall.

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

Rubber seal inexpansion joints, Safety railings, Well managed water supply pipe at deck. Debris content in the piers and abutment. Gabion boxes Hand rail

Some parts of the main accessories like handrail and railing post has to be repaired

5.0 Repair and Maintenance ProgrammeBased on the comprehensive inspection of the structural elements of the Lothar Khola Bridge an attention required within a couple of years for the protection of steel members.

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

a) Provision of GI pipes water spouts for proper drainageb) Provision of rubber joint seal in deck end joints and expansion joints.c) Repair and replacement of RCC raining post and steel hand railingsd) Complete repainting of the bridge members,e) Painting traffic signs, divide lines, kerb etcf) Removal of fresh debris (accumulated in past 5-7 years) along the bridge axis.g) Replacement of existing damaged gabion boxesh) Water supply pipe repair and replacement necessity.i) Bearings:

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

polyurethane; Maintenance of elastomeric bearing and repositioning. Reposting the traffic signs and bridge info.

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FIELD REPORT

6.0 Conclusion and RecommendationsThe Lothar Khola Bridge is about 30 years of old and seems un-repaired and un-maintained well over the period due to which it would be problematic in operation and un-functional before its design life if not maintained as soon.

Comprehensive inspection of every features of the bridge suggests that the bridge superstructure is in fairly good condition while its foundation and abutments are at reasonably fairly poor condition. The deterioration and corrosion of expansion joint is giving significant vibration along the length. A strategic maintenance program is needed to be 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

Approaching part of the bridge Side View of the bridge

Right Abutment of the bridge Gabion Mattresses to protect river banks

Extensive deterioration of the expansion joint Handrail and railing post condition


FIELD REPORT

Superstructure parts in need of painting. Corrosion of the bottom node connection

Necessity of debris accumulation removal Loss of paints causing partial corrosion and superstructure and mismanaged traffic sign

appearance

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FIELD REPORT

Necessity of gabion box repair and reconstruction on left side of bridge

Debris filled up in the abutment on left side

APPENDIX B: Inspection Forms

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Field Report Lothar Khola

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