Approach slab- Transition between a roadway pavement and bridge.Road level-level of road to which the level of bridge is adjoined by the approach slabBack wall-vertical wall at the end of the bridge supporting the expansion joints & extend up from abutment seat.Wing wall-adjacent to the abutments and act as retaining walls, provided at the both end to retain soil of earth filling for approach slab.Deck slab-a slab of concrete used to make the base for the roadway, railway, pedestrian walkaway, etc. on the bridge.Kerb-stone edging to a pavement or a pathGirder-a large iron or steel structure used for the framework of large structuresAbutment-a structure that is built to support the lateral pressure of the arch or span at the ends of the bridgePier-a support for the ends of the spanFoundation-lowest load bearing part of a building. H.F.L(highest flood level)-sufficient level of flood to cause inundation. Bearing-component that provide controlled movement & resting surface between bridge deck and piers.Parapet-low protective wall along the edge of bridge or roof or balcony. Expansion joint- joint for the allowance of thermal expansion.
Will present more of designing criteria in my next presentation.
Purpose Of BridgePurpose Of Bridge
A bridge is a structure providing passageA bridge is a structure providing passage
over an obstacle without closing the wayover an obstacle without closing the way
The required passage may be for a road, aThe required passage may be for a road, a
railway, pedestrians, a canal or a pipeline.railway, pedestrians, a canal or a pipeline.
The obstacle to be crossed may be a river, aThe obstacle to be crossed may be a river, a
road, railway or a valley.road, railway or a valley.
Components ofComponents of
Bridge StructureBridge Structure
DATA COLLECTIONDATA COLLECTION
Location of bridge site.Location of bridge site.
Transportation of bridge site.Transportation of bridge site.
Nature of crossing and affordability.Nature of crossing and affordability.
Availability of local material.Availability of local material.
Traffic volume.Traffic volume.
Availability of local bridge builders.Availability of local bridge builders.
Temporary crossing.Temporary crossing.
Local participation.Local participation.
SHORTEST DISTANCESHORTEST DISTANCE
FOR THE BRIDGEFOR THE BRIDGE
To construct a bridge the first part ofTo construct a bridge the first part of
analysis is to decide the shortest routeanalysis is to decide the shortest route
for the bridge from starting point to thefor the bridge from starting point to the
end point. & whether it is necessary &end point. & whether it is necessary &
economical to construct a bridge. In thiseconomical to construct a bridge. In this
part of analysis, curves ends of river arepart of analysis, curves ends of river are
excluded so as the distance will decreaseexcluded so as the distance will decrease
between the ends of bridge unless therebetween the ends of bridge unless there
is no other plan is possible for the bridge.is no other plan is possible for the bridge.
ECONOMICAL SPANECONOMICAL SPAN
Economic SpanEconomic Span
Depend UponDepend Upon
The Cost Of:The Cost Of:
SCOUR DEPTHSCOUR DEPTH
Depth of scour belowDepth of scour below
the High Flood Levelthe High Flood Level
Scour depth hasScour depth has
importance inimportance in
determination of depth ofdetermination of depth of
If mean score depth isIf mean score depth is
‘d’, then max scour depth‘d’, then max scour depth
for piers is ‘2d’for piers is ‘2d’
The depth which is produced due to the scouring action ofThe depth which is produced due to the scouring action of
Minimum verticalMinimum vertical
clearance of 5m should beclearance of 5m should be
ensure over the full width ofensure over the full width of
The vertical clearanceThe vertical clearance
should be measured withshould be measured with
regard to the highest pointregard to the highest point
of carriageway.of carriageway.
Allowance for any futureAllowance for any future
raising of pavement is alsoraising of pavement is also
be made.be made.
Analysis of traffic is alsoAnalysis of traffic is also
necessary for the bridgenecessary for the bridge
designing. Traffic projectiondesigning. Traffic projection
defines the amount of trafficdefines the amount of traffic
passing through the bridge. Thispassing through the bridge. This
helps in estimating the type ofhelps in estimating the type of
loading. Sometimes in case ofloading. Sometimes in case of
emergency the amount of trafficemergency the amount of traffic
increases so that a sufficient spaceincreases so that a sufficient space
is provided for the vehicles to gois provided for the vehicles to go
through the bridge without facingthrough the bridge without facing
any problems.any problems.
SELECTION OFSELECTION OF
BRIDGE TYPEBRIDGE TYPE
•Geometric condition of the site(road alignment, design flood andGeometric condition of the site(road alignment, design flood and
highest water mark)highest water mark)
•Traffic capacity.Traffic capacity.
•Structural stability.Structural stability.
•Foundation conditions and strength of a abutment.Foundation conditions and strength of a abutment.
•Available material.Available material.
•Knowledge and equipment of the contractor.Knowledge and equipment of the contractor.
•Clearance requirement above and below the road way.Clearance requirement above and below the road way.
•General requirements with respect to location ,financing andGeneral requirements with respect to location ,financing and
community values.community values.
What is deck slabWhat is deck slab
•A bridge with an upper horizontal beams that carriesA bridge with an upper horizontal beams that carries
Roadway or Railway is known as ‘Deck’ of theRoadway or Railway is known as ‘Deck’ of the
•In Deck Slab Bridges, the deck itself is the structuralIn Deck Slab Bridges, the deck itself is the structural
frame or the entire deck is thin beam acting entirelyframe or the entire deck is thin beam acting entirely
as one primary member. These types are used whereas one primary member. These types are used where
the depth of structure is critical factor.the depth of structure is critical factor.
•A slab deck is one where the deck is analyzed as aA slab deck is one where the deck is analyzed as a
plate. If the slab has the different stiffness in twoplate. If the slab has the different stiffness in two
directions right angle to each other, the bridge isdirections right angle to each other, the bridge is
analyzed as the orthotropic deck and the bridge isanalyzed as the orthotropic deck and the bridge is
known to be the Deck Slab Bridge.known to be the Deck Slab Bridge.