Overpass Design at Vellore

8/2/2019 Overpass Design at Vellore

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Improvement of AccessRoad to Vellore city

Over Pass construction

By

Aravindh Prasanth

Karthickeyan .S

Karumanchi Ashok

Prabakaran M


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Problem Identification

City road of 6m width connects NH-234 with vellorecity. The length of the road is 0.7 km.

The Road is congested due to traffic generated byCMC college and Hospital as well residential areas .

We have identified that during peak hours ie.4 pm to8 pm the road is becoming inaccessible .

Thousands of patients coming to the CMC hospitalfacing so many problems with traffic, and if it is anemergency case means no body can assure theirlife.


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OBJECTIVE

To review of previous studies and plans relatedto the project, analysis of most effective andefficient roads development of the project.

To carry out necessary engineering surveys. To complete a detailed design for execution of

the project.

To carry out construction planning and cost

estimate. To prepare a draft tender documents for

execution of the project


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Location

Vellore NH234 near CMC hospital


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Methodology1. Preliminary study

1.1. To review the feasibility study conducted by DGH andother related information

1.2. To conduct supplementary present condition survey

2. Natural Condition Surveys

2.1. Topographic survey2.2. Geotechnical survey

2.3. Hydrological survey

3. Traffic Survey

3.1. To examine existing traffic data and analyze thepresent and future traffic flow

3.2. To carry out an additional traffic survey


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Methodology

4. Conduct of the Basic Design of the projects

5. Conduct of the Detailed Design6. Conduct of the Construction Plan

7. Preparation of Draft Tender Documents

8. Preparation on Environmental Management Plan (UKL)

and Environmental Monitoring Plan (UPL) during theconstruction period

9. Preparation of the Right-of-Way Acquisition Plan

10.Overall Evaluation and Recommendation


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W.C

All Dimensions are in mm

Kerb

Cantilever slab Inner slab


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IRC STANDARD LIVE LOADS

Live loads are those caused by vehicles,which pass overthe bridge and are transient in nature. These loadscannot be estimated precisely,and the designer has verylittle control over them once the bridge is opened totraffic. However hypothetical loadings, which are

reasonably realistic need to be evolved and specified toserve as design criteria.

IRC CLASS AA LOADING : This loading consists ofeither a tracked vehicle of 700 KN or a wheeled vehicle

of 400 KN with dimension s as shown in fig.


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IRC CLASS AA Loading


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IRC Class 70R loading

In recent years, there is an increasing tendency tospecify this loading in place of Class AA loading.Thisloading consists of a tracked load of 1000KN. Thetracked vehicle is similar to the Class except that the

contact length of the track is 4.57 m, the nose tail thelength of the vehicle is 7.92 m and the specifiedminimum spacing between the successive vehicles is30m.


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IRC Class 70R loading


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IRC Class A and B loading

Class A loading consists of a wheel load traingcomposed of a driving vehicle and trailers of specifiedaxle apcing and laods,as shown in fig.


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IRC Class A and B loading


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Impact Effect

Live load train produce higher stresses than those whichwould be caused if the loading vehicles were stationary.

In order to take into account the increase in stresses dueto dynamic action and still proceed with simpler

statistical analysis, an impact allowance is made. For I.R.C Class A loading

I = A/(B+L)Where I = Impact factor fractionA = Constant value for 4.5 for R.C. Bridge and 9.0 for

Steel bridgesB = Constant value 6 Reinforced concrete bridgesL = Span in meters.


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Factors

Impact factor for Class A loading = 4.5/(6+2.76)=0.513

Max impact factor for class A loading is 0.5

Impcat factor for Class AA loading is 25%


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Specifications

Clear width of the carriage way = 7.5m

c/c between beams of longitudinal girders =20m

Class AA tracked loading (or) 70R tracked loading (or)

class A wheel load which ever produce severe condition. M25 grade concrete is used and Fe415 steel is used.


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Design of Cantilever slab

Component D.L per m(KN)

Distance ofC.G from

the edge ofthe girder

Moment(KN-M)

Parapet 0.5 1.19 0.525

Kerb 1.478 1.04 3.328

W.C 1.478 0.42 0.621

Slab (rect) 3.72 062 2.306

Slab(Triangle)

2.17 0.413 0.896

Total 7.746

Dead Loads


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57KN


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Reinforcement details

Cantilever slab

Provide 16mm dia bars @ 200mm c/c

Provide 8mm dia bars@ 170mm c/c as distribution bars

Inner slabs 16mm dia bars@ 220mm c/c both top and bottom along

the breadth.

12mm dia bars@ 220mm c/c in longitudinal direction

both at top and bottom.

R i f d il f i d


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Reinforcement details of outer girders

Provide 10 nos 34mm dia bar and 6 nos 25mm dia bars Provide in 4 layers


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1 From edge to 4.18m 10mm dia 2 leggedstirrups@160

mm c/c

2 From 4.18m to 5.225m 10mm dia 2 legged

stirrups@240

mm c/c

3 From 5.225 to 7.5m 12mm dia 2 legged

stirrups@180

mm c/c

4 From 7.5 to 8.108m 12mm dia 2 leggedstirrups@200

mm c/c

5 From 8.1 to 10m 12mm dia 2 legged

stirrups@300

mm c/c


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Referred books and code books

IRC:86-1983 Geometric design standards for urbanroads .

Traffic engineering and transport planning by

L.R .Kadiyali IRC loading class.