DESIGN PROJECTCIVIL DEPRATMENT

SNEKHA.G

PRINCE SHRI VENKATESHWARA PADMAVATHY ENGINEERING

COLLEGE(affiliated to Anna University)

HARISH.R SATHYA NARAYANAN.R

DESIGN OF STAYED CABLE SUSPENSION

BRIDGE

AbstractThis project focuses on designing a

unique, safe,elegant and economical bridge in India

that helps tomake a mark in the field of Structural Art.

Thebridge will be designed in a way that only

onesupporting tower will exist to carry the

entire bridge,thus making it a “Single Pylon Cable

Stayed Bridge”.Shahpura Pond of Shahpura Jogger’s Park

in Bhopal,Madhya Predesh is chosen as the site

location for thisbridge.

Suspension bridge Suspension Bridges are a type of bridge

structure that work on the mechanism of suspending the bridge deck from piers rather than supporting it from underneath.

Cable Stayed bridge Cable stayed bridges is a sub category of

Suspension Bridges. It is efficient as it uses the steel cables to its

full tensile potential, in turn reducing number of cables.

Single Pylon Cable Stayed bridges As the name states, these type of bridges

cover a nominal span using only one pylon or one tower to support the whole deck.

The tower is positioned at exact point in the span so that cables on both sides extend to equal distances.

Cable Stayed bridges are used for short span bridges and have a huge space for innovative designs as the principle of cable stay provides stability.

Langkawi sky bridge is one of the most successful curved pedestrian cable-stayed bridge in the world. This 125m engineering marvel is built 700m above sea level to access the famous mountain peak Gunung Mat Chinchang. It has become a popular tourist attraction ever since its erection in 2005.

Langkawi Sky bridge, Malaysia

Our Plan…

The intention is to construct a simple Cable Stayed Pedestrian Bridge across Shahpura Pond located in Bhopal, Madhya Pradesh, India.

Objectives

The main objective of this project is to improve the existing jogging track in Shahpura Park.

To give the park an aesthetic look and to attract more people.

To create a breakthrough in Structural Art by constructing the first ever SINGLE PYLON type cable stayed bridge in the whole of India.

Methodology

Initial Analysis

Type of Structure Purpose Site

Location

Data collection

Pond dimensio

ns

Water Propertie

s

Soil Propertie

s

Planning Site Map Plan and Elevation

conceptual Design

Methodology

Design Stage 1 Loading Deck Slab Beam &

Girder

Design Stage 2 Pylon Foundation Cables

Report Review Result & Conclusion Final Draft

Economic considerations The city of Bhopal has always had a keen

eye on promoting its city. It has a lot of significant historical places in the city many of which are civil related.

To promote an aesthetic view to the city and the lake, Shahpura Joggers Park was constructed.

An integral part of this park is the artificially created Shahpura Pond, over which the Single Pylon Bridge is to be designed.

This will increase the tourism revenue of Bhopal.

Taking into account, That the main purpose of this bridge is

to bring about an aesthetic look to the park.

That the people using the bridge would be joggers who need a smooth path.

That the span of the bridge had to be restricted to 50 meters.

An elliptical shape for the bridge was considered most suitable

Our design…

By extending the bridge deck and adding weights to the ends, we achieve the basic counter weight design.

Plan

Side Elevation

Front Elevation

Details Type of pond : Artificial (Man made) Purpose : To increase the

aesthetic look of Shahpura Joggers park.

Latitude  : 23˚12 N Longitude : 77˚25 E Maximum length : 200m Minimum width : 75m Average depth : 1.5m

Earthquake zone Since Bhopal is in the lowest hazard zone of earthquake,the design does not require resistance against lateral earthquake loads and vibrations.

Literature review Configuration, general layout and loading

conditions was obtained from “Cable – Stayed bridges” by Man-Chung Tang, T.Y. Lin International.

The different types of failures in cable stayed bridges were studied from “Cable-loss analyses and collapse behavior of cable-stayed bridges”, M. Wolff & U. Starossek.

The design concepts and procedure were studied from “Design of Bridges” by N.Krishna Raju.

Seasonal Analysis of Soil Sediment of Shahpura Lake a part of the International Journal of Environmental Science and Development, was done by Anu et.al. In this the soil samples of Shahpura Lake were analyzed due to the increase in garbage dumping near the lake.

Literature review The concept of Cable stayed bridges and the analysis of

each component of the bridge were studied from “Design ofBridges, Cable Stayed Bridge” by Jani Juvani , Olli Lipponen.

Design of a Pedestrian bridge crossing over Coliseum Boulevard was done by Renan Constantino, et.al,. The Indian Standard codes do not have a provision for pedestrian loading and thus the values of forces developed in a pedestrian bridge were obtained from this report.

Design of column and pile foundation is obtained from “Design of Reinforced Concrete Elements” by N.Krishna Raju.

Present cable stayed bridges for the losses developed in them is analysed from Cable-loss analysis and collapse behavior of cable-stayed done by M.Wolff and U. Starossek.

Loading Dead Load :

Loads that are permanently applied to the structure. For the pedestrian bridge that is being designed, there are three sources for the dead load: the weight of the concrete deck, the weight of any railing on the side of the walkway, and the self weight of the structure.

In this case, all components are in concrete. So,

Unit Weight of Concrete = 25 kN/m3

FOS = 1.5

Loading Live Load :

Variable loads applied to the bridge that are in addition to the dead loads on the structure. In this case, the pedestrian load and minimum wind load. Specifications for pedestrian loads are not given in Indian Code books.

Pedestrian load = 100psf = 5 kN/m Wind load = Negligible

FOS = 1.5

Bridge deck and girder The shape of the bridge deck is 3/4th of

an ellipse. The width of the deck is 2 + 1.2 meters, to accommodate ample space for jogging.

Railings are provided on both sides for safety.

The girder is a standard T beam girder. The deck is extended outward at places

where the steel cables need to be connected.

A concrete T Beam girder with a concrete deck slab was considered most suitable

Cross Section of girders

Bridge deck and girder Deck is designed using Guyon – Massonet

method as it is most effective as it takes into account the torsion produced.

M25 concrete grade and Fe415 steel grade.

Main girder is two T beam provided at 0.6m intervals.

Moment developed in main girder = 516.138 kNm

Providing 16 numbers of 16 mm diameter bars at spacing of110mm centre to centre.

Bridge deck and girder The cross girder is a T beam provided at

4m intervals. M25 grade concrete and Fe415 grade

Steel. Distribution coefficients had to be

calculated for design. Moment developed in cross girder =

61.375 kNm Providing 4 numbers of 12 mm diameter

bars at spacing 120 mm centre to centre.

Bridge deck and girder

Slab The slab needed in this design was a typical

one way slab that was supported completely through its length.

The main function of the slab is to effectively transfer the loads on to the girders.

Span of slab = 20 m Width of slab = 3.12 m Moment produced in the slab = 29.63 x 106

Providing 10 mm diameter bars at spacing 110mm

Addition reinforcement of 10 numbers of 10 mm diameter bars of Fe250 are provided to resist local vibration and small impact forces.

Slab reinforcement

Pylon and Beam Bhopal comes under the lower ranges of

wind intensities, which means that minimum lateral wind loads can be adopted.

The counter – weight design reduces the external moment on the pylon by a large amount.

A single beam is provided from the column to the deck to resist the lateral loads and to prevent possible swaying of the bridge.

A circular concrete column with a rectangular concrete beam was considered most suitable.

Pylon and Beam Height = 10m Type : Circular column Diameter = 350mm Fe500 steel grade and M50 Concrete grade. Total factored axial load = 5220 kN Area of steel Asc = 9.673 x 103 mm2 Providing 12 numbers of 32mm diameter

rods as reinforcement. The horizontal beam is a pre- fabricated pre

stressed cantilever section of span 7.15 metres and respective depth.

Pylon

Foundation The moisture content of the surface soil at

the pond is high. The soil is under constant saturation as the

pond is perennial and will always have water.

The pond is artificially built, which implies very less variations in properties of soil.

Since it is a pond, no water currents or waves are present.

Pile foundation is considered to be most suitable for the bridge.

Foundation Length of pile above ground level = 0.6 m Total Length of pile = 6 + 0.6 = 6.6 m It is a slender member. Factored load on each pile = 9800/6 = 1633 kN Depth of foundation = 5 m Assume size of pile = 500 x 500 mm Spacing of pile = 1 m Grade of Concrete = 50 N/mm2

Grade of Steel = 500 N/mm2

Provide 4 numbers of 28mm diameter bars as reinforcement and 8mm diameter bars as lateral reinforcement.

Pile reinforcement

Extended slabs The spans of slabs extending from the

two ends to produce the counter acting mechanism were to be designed separately.

These slabs are filled with concrete with minimal reinforcement of steel.

Converting the total load of the deck in terms of weight, the dimensions of these two slabs were determined.

The reinforcements of the main girder are extended into these two slabs.

Extended slabs

Cables According to the plan, a total of 5 cables are

provided. The type of cable used is Freyssinet cable

for values from BS 5896 : 1980. The ultimate tensile force for one strand is

265 kN Dividing the total load by 5 and then by the

ultimate force we get, Diameter of one strand = 15.70 mm Type of anchorage : Saddle type

Cable Size : 5H15

Cables

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