Construction Challenges For Bridges In Hilly Areas

Construction challenges for bridges in hilly areas 2014-15
1
A
PROJECT REPORT
ON
CONSTRUCTION CHALLENGES FOR BRIDGES
IN HILLY AREAS
BY
PATIL SHANTANU SANJAY
DEPARTMENT OF CIVIL ENGINEERING
S.S.V.P.S.’S B.S. DEORE COLLEGE OF ENGINEERING,
DHULE-424 005
2014-2015
Index
______________________________________________________________________________

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Sr No Description Page no
1. Abstract 1
2. Introduction 2
3. Construction challenges of bridges 4
4. Case study 5
5. Scour in boulder river bed 18
6. Design of bridges on landslides areas 21
7. Incremental launching method 24
8. Conclusion 30
9. References 31

3
ABSTARCT
Hilly region pose unique problem for bridge construction. In a restricted
hilly area itself climatic condition, Geographical features and hydrological
parameters affect considerably. Keeping in view the bridge site and various
constraints, type of bridges and method of construction are to be selected
carefully for safe, economical and successful completion of bridges construction.

4
INTRODUCTION
• A Bridge is a structurebuild to span a valley, road, river, body of water, or
any other physicalobstacle.
• Designs of Bridges will vary depending upon the function of the bridgeand
nature of the area where the bridge is to be constructed.
• The first bridges weremade by nature itself—as simple as a log fallen
across a stream or stones in the river.
• The first bridges made by humans were probably spans of cut wooden logs
or planks and eventually stones, using a simple support
and crossbeam arrangement.
• Some early Americans used trees or bamboo poles to cross smallcaverns or
wells to get fromone place to another.
• A common form of lashing sticks, logs, and deciduous branches together
involved the use of long reeds or other harvested fibers woven together to
forma connective rope capable of binding and holding together the
materials used in early bridges.
• Hilly region poseunique problem for bridge construction. In a restricted
hilly area itself climatic conditions, geological features and hydrological
parameters vary considerably.
• Keeping in view the bridgesite and various constraints, typeof bridge and
method of construction are to be selected carefully for
safe, economical and successful completion of bridge construction.

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Himalaya since Vedic times has been considered a vast repository of
valuable medicinal herbs, minerals, forest resources etc. Vedic literature
followed by the writings of Charaks, Susruta, Dhanwantri, Nagarjuna,
Parashar, Balmiki and various other saints, bear testimony to it. "Alexander,
The Great", who was much influenced because of its scenic beauty, bracing
climate and agro climatic conditions, made a great publicity of the
Himalayan Herb Science in Yunan and Rome during middle ages
(Anonymous, 1977; Chauhan, 1988). This potential, however, remained
unexploited especially in higher reaches due to inadequate means of
communication. After independence, Govt. of India gave a special emphasis
on road and bridge construction in order to bring socio-economic upliftment
of tribal inhabitants. But due to lack of proper planning it resulted in serious
ecological imbalances.
Society has now become aware of the environmental consequences
resulting from road and bridge construction in hill areas. Right from the days
of Vedas.
So, having the road and bridge network in hilly area of Himalayas in a
country like India is of greater importance, as it is bounded with the overall
progress of the country.so, it is a work of a civil engineer to find out the
problems as well as solutions associated with construction of the civil
engineering structures. Special efforts have been taken in this project to look
at bridges to be built in hilly areas.

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CONSTRUCTION CHALLENGES OF BRIDGES IN HILLY
AREA
Hilly region pose unique problem for bridge construction. In a restricted
hilly area itself climatic conditions, geological features and hydrological
parameters vary considerably. Keeping in view the bridge site and various
constraints, type of bridge and method of construction are to be selected carefully
for safe, economical and successful completion of bridge construction.
Various challenges that come across while constructing bridges in hilly area are -
1. Construction of bridge across deep gorges
2. Construction of bridge on rivers with boulder beds
3. Construction of bridges in extreme temperature zones
4. Construction of bridges on sharp turn on highway
5. Landslide or Debris flows
6. Problems in Seismic prone areas.
7. Geological Conditions at site.
Deep gorges, rivers with boundary beds, extremely low temperature condition,
high winds, landslide etc. in hilly regions require special attention to complete the
activities of bridge planning and construction in a systematic way and are
discussed here in-

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Case study
In this project, a case study of “JAMMU-UDHAMPURSRINAGAR-
BARAMULLA RAIL LINK PROJECT”has been undertaken to study the
problems faced during construction and the solutions for those problems.

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Construction of Jammu-Udhampur-Katra-Quazigund – Srinagar-Baramulla
new rail link is the biggest project undertaken by the Indian Railways in the
mountainous terrain since independence.
Challenges in the construction of a Railway line through the hilly terrain start
right from the conception stag itself. There are various constraints such as
allowable maximum speed, high gradients, sharp curves, stations to be kept for
optimum utilization, safety and minimum maintenance need in future in addition to
the basic need for providing the link with the rest of the network. Projects in
mountainous regions are associated with special features such as deep cuttings,
high embankments, tall piers and long span bridges across deep gorges and fast
flowing flash flood rivers with big boulders and unusually long tunnels etc. These
challenges are enhanced in view of the terrain in young Himalayas, where geology
is poorand changes occur frequently.
Surveys undertaken in the region have been a fascinating experience. The
territory from Salalto-Quazigund with virtually no habitation, no approachroads or
even rudimentary pathways through dense jungles without any light or water
connections, is a survey storey in itself. In this part of the project, the engineers are
expected to tackle tunnels for over 50 % of the length with the longest being about
10 km across PirPanjal range. The tallest bridge is about 360 m above bed level
and of a 505 m in length (Single Span) is also to be tackled in this
reach over river Chenab. The project is a challenge to the Engineers of India in
general and to the Railway Engineers in particular.

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BRIDGE
In the hilly terrain, the construction of the bridges has been a difficult task and
posed-numerous challenges. Apart from the complexity of design, the construction
of these bridges requires great amount of planning and special techniques. The
topography of the area resulted into long girders, combined with large pier heights.
This part of paper presents various Design features and technical solutions adopted
in construction of these bridges, some of which are being adopted for the first time
on Indian Railways.

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PLANNING FOR BRIDGES
A careful selection of alignment is being done to ensure shortest possible
height and length of bridges, keeping in view the ruling gradient of 1 in 100
(compensated). The choice of alignment is most important for planning of bridges
in hills. Detailed geological investigations were carried out. Geological features
consisting of variable strata of sand rock, soft and hard shale, boulder-studded soil,
etc. have also influenced the bridge lengths and span arrangements. The long spans
were necessitated as a result of fixing pier locations in the middle of the
gorges/streams so as to avoid constructing piers on sloping banks. This aspect itself
called for cantilever method of bridge construction in some bridges. This method
has the added advantage of elimination of costly centering and false work and
reduced requirement of shuttering and fast paceof construction. The design of the
bridges in question has been fairly complex and it was an elaborate task. Detailed
Design criteria were developed which were bridge specific. The long spans and tall
piers associated with highly seismic characteristics of the area have made the
designs cumbersome and tricky. The bridges have been designed for Modified
Broad Gauge (MBG) loading - 1987 as per Indian Railways Bridge Rules.
The design complexities were further compounded bythe stringent requirement of
maintaining 5% residual compressionin superstructure at all stages of
construction, which was finally relaxed to ‘no tension’ condition.

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Seismic Designconsiderations
The bridge sites lie in the Seismic Zone IV & V as per the current Seismic
Zoning Map of India contained in IS:1893-1984. The data show that seismic events
having Richter’s magnitude greater than five occurat frequent intervals in this
area. The design of bridges with pier height up to 30 m has been done by using
seismic coefficient method as given in IS 1893-1984. The values given by this
method have stood the test of recent earthquake (year 2005) of 7.6 on Richter scale
having epicenter near Muzzafarabad. Forthe tall piers, site-specific spectrum has
been adopted. The work has been entrusted to earthquake engineering department
of IIT Roorkee.
The following additional seismic related measures have been adopted to reduce the
impact of earthquake: -
a) Bridges have been mainly provided with POT-PTFEbearings and elastomeric
pads attached to the vertical surface of the concrete projections on top of the pier
caps for seismic restraint devices.
b) Rigid structures absorb more seismic energy requiring a design for larger
seismic forces than a comparatively flexible structure. Some innovative shapes of
abutments have been adopted to make them substantially flexible in order to
achieve desired results. Abutments were conceptualized as consisting of a RCC
tank with 3 walls and a base and separate pier .The presence of a large tank with
soil along with a baseshear key gives effective resistance to longitudinal sliding.
Size of the pier has been kept to a minimum by providing large amount of
reinforcement in order to keep them more flexible. Additionally the piers have
been tapered in order to further reduce the stiffness, thereby reducing the seismic
forces experienced by the bridge.
c) The structures have been blended with the incorporation of Ductile Detailing.
Special confining reinforcement in the form of closely spaced stirrups/ties is
expected to impart reserve strength to the joints and connections where formation
of plastic hinges are anticipated.
d) STAAD III software has been used for dynamic analysis for the idealized
structure consisting of springs and member end release after a few simplifications.

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The longitudinal and transverse behaviour has been analyzed separately so as to
reduce the amount of computations and margins of errors.
GeologicalInvestigations
Trial bore holes using NX size heavy-duty diamond rotary core drills were
carried out at each foundation location up to a depth of about 1.5 times the width of
foundation below the founding level. The soil samples collected were tested for
bulk density, specific gravity, uni-axial compressive strength of rock and chemical
analysis. The standard penetration test were carried out at every 30 cm depth. The
founding strata consisted mostly of alternate bands of shale, sandstones, & boulder
studded soil matrices. Hence, in most of the cases, open raft foundations were
adopted.
The terrain at site is hilly. The slopes of both the approaches are gentle to steep.
The material constituting the steep bank slope comprises unconsolidated
sediments. Bed rock is nowhere exposed and lies buried under thick cover of
alluvial deposits comprising pebbles, cobbles and boulders set in sandy matrix with
occasionalthin pockets of silty matrix. The nallah bed is covered with boulders,

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gravels and sand.
Design of Foundations
Open foundations have been designed in the usual manner. Some of them have
become abnormally large due to the added problem of uplift of foundations owing
to the large seismic moments. Minimum 75% contact area at the base has been
ensured as per the provisions of IRS Codes for rocky strata.
The well foundations have been designed by and large as per the provisions of
IRC:78. The thickness of steining has been restricted to 1.25 (D/8 + H/100) subject
to a minimum of 1.2m, wherein D = external dia of well and H = height from bed
level to founding level. Stability analysis for the well has also been done.

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Constructionof Piers
To avoid construction joints piers are being cast using slip form construction.
Slip form construction essentially consist of hanging shutters supported byyoke
legs which in turn are supported on the radial beams. This whole assembly
continuously move upwards with the help of the jacks taking reaction from the
jackrods en sleeved in pier wall and resting on the bottomof pier. Fortapering the
radius is reduced by turn buckles and sliding shutters.
After completion of the piers the pier caps inM-40 grade of concretewere cast.

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Designof Hollow RCC Piers
The hollow RCC piers with continuously decreasing diameter and taper at
uniform rate have been constructed. These are additionally checked for a
temperature gradient of 200 C between the inside and outside faces of the pier
shafts. Ventilation holes covered with GI wire mesh are being provided at regular
intervals to reduce the temperature gradients.

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Design and Detailing of Abutments
A unique design of abutment has been adopted. These innovative abutments are
provided with a small size pier to take the vertical load and a reinforced cement
concrete walltank filled with earth for counter acting the horizontal forces, both
supported by a common raft foundation with a provision of shear key at the base.
This tank filled with earth adds to the weight and helps in overcoming the problem
of sliding and the slender pier which is quite flexible reduces the seismic forces.
Both the abutments rest on well foundation and the pitching level of cutting edge is
at a depth of 12 to 25m from original ground level. Through soil investigation it
has been observed that strata at the locations of both the abutments is gravel
boulder matrix (sand, silt and clay).
At Udhampur approachof bridge there is tunnel, however at Katra end
approach
there is deep cutting, the depth of cutting being of the order of 18-20 meters.
LOCATION OF ABUTMENT A1 AT
UDHAMPUR END

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LOCATION OF ABUTMENT A2 AT
KATRA END & ASSEMBLY AREA
Total depth of abutments including well foundation is 14-25m. Strata is
conglomerateunto 100m from the ground level. Well foundation has been provided
to reduce the area of cutting and to transfer the load at greater depth so that
pressure line starting from bottom of foundation should remain at much below the
slope which is very steep. Well foundation of abutment have been designed for end
bearing only without considering any wall friction. The bottomplug of this well
foundation has been designed as RCC raft. The well is double-D type rectangular
in shape with over all dimensions 8.5mx10.5m and 16m deep.

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Cantilever constructionof Dudhar ,Tawi, Ringhal and Sardanbridges
As per the cantilever construction sequence, first of all pier head units about
10.5m long are cast over the pier cap and after attaining of sufficient strength the
pier head segment is pr-estressed longitudinally. Then the cantilever construction
equipment is erected over pier head unit and construction of cantilever segments
starts. After casting of cantilever segments is complete, end span on either side is
castonstaging and after concreteattains sufficient strength the end spanprestressed
continuity cables are stressed.Thenthe vertical holding down pre stresscables are
cut off and packing platesremoved so as to transfer the loads to thepermanent
bearings. Thereafter centralsegment for closure pour in the centreiscast on
shuttering supported from the twocantilever tips and after concrete gainsstrength
the central span prestressedcontinuity cables are stressed.
DUDHAR BRIDGE

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FEATURES OF BRIDGE NO.20 IN UDHAMPUR- KATRA
(Largestsingle simply supported span & tallestpier on Indian Railways)
Br. No. 20 is situated across JhajjarKhad at 20 Km from Udhampur on
Udhampur-Katra section. This bridge consists of 2 spans of triangulated truss
girders of span 153.4 m each. It consists of one Central pier and two abutments at
ends. Central pier is 90 m high and is resting on open raft foundation. Both the
abutments are resting on well foundations. This bridge is crapprox125 m deep
gorge.ossing a local khad named JhajjarKhad, which isapprox 125 m deep gorge.
Bridge No. 20 (General Elevation)

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“SCOUR IN BOULDERY BED”-
This is another problem, that is faced in construction of bridges ,which pass on
rivers, attempt has been made here to discuss solution of this problem.
Very little informationis available on scourobserved at bridge sites in India,
particularly for scourin bouldery rivers. This will be very useful in this regard
especially for them who are striving for developing appropriate mathematical
model for estimation of scour. It is observed that Lacey’s equation used in India (
IRC:5, IRC:78) for computation of scouris not applicable in bouldery rivers. In
fact, Lacey’s equation (1930) was derived forfinding approximate dimensions in
stable channels under regime conditions for incoherent fine alluvialchannels only.
Use of Lacey/Inglis type equation for finding scourdepth ( dsm= 1.34( Db2 /f )1/3
) should not be used for estimating localised scoure.g. constriction scourand local
scouraround piers and abutments.General scour in a river, however, can be
approximated by Lacey’s regime channel approachsubject to the
condition that the bed and bank of the channel is made of fine incoherent alluvial
soil which can be as easilyeroded as deposited. Where the banks are strong or
made of cohesive materials or rock or the stream flowing in gorges with hills on
either side.
Total scourin bridge piers and abutments should be estimated separately as
general scour, constriction scourand local scourand summed up. Morphological
behavior of river near the bridge governs the general scour.Estimation of general
scourhas been explained very nicely by Melville and Coleman (2000) in their
book“ Bridge Scour”. Apart from regime theory like that of Lacey(1930) and
Blench (1969), they have introducedcritical shear, critical mean velocity
approaches etc.to find maximum scoured flow depth. Scourin bends, scour
after stream confluence, scourdue to general degradation etc. have been quantified
for estimating the totalmaximum scourdepth (at the proposed bridge site) which
will occureven without the presence of bridge.

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Local Scour
Construction scourat a bridge site occurs due to restriction of normal
waterway. Laursen equation (1956) givenbelow is popularly used for finding
constriction scour.
Y 2/Y1 =(Q2/ Q1m)6/7 (W1/W2) k1
where Y1 and Y2 are the average depths of flow in the approachand contracted
sections respectively, W1 andW2 are the bottomwidths of the approachand
contracted sections respectively, Q1m is the discharge in the mainapproach
channel transporting sediments and Q2 is the total discharge passing through the
bridge, k1 is aconstant varying from 0.59(with predominantly bed load) to 0.69
(with predominantly suspended load)depending on nature of sediment transport.
The local scouroccurs due to vortex formation becauseof obstructioncaused by
piers and abutments and aregoverned by a number of geometric, flow and sediment
parameters stated under item 1 above. Melville andColeman expressed the local
scouras
D s =KybK1KdKsKθ KG Kt
Where Ds is the local scour below bed due to depth-size effect (Kyb), flow
intensity effect(K1), sediment sizeeffect (Kd), pier/abutment shape effect (Ks),
flow obliquity effect ( Kθ), channel geometry effect (KG) and timeto equilibrium
scoureffect (Kt ). Values of the various K- factors have been given by Melville
through graphs,tables and equations for different conditions. Similar to Melville

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approach, Richardson and Davis( 1995),Breussers and Raudkivi ( 1991), Kothyari,
Garde,andRaju (1992) have developed mathematical models for
local scourestimation in bridge piers and abutments.

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DESIGN OF BRIDGES ON LANDSLIDE AREAS
The number of bridges designed and built on landslide regions is quite small
since routes are normallydesigned to eliminate destructive effects of landslides.
Therefore, in literature, solutions anddesign guidelines for bridges on landslide
areas are scarce.
In Croatia (Nossan et. al,2009), a viaduct on landslide area is designed and
constructed utilizinga foundation system consisting of diaphragm walls under a
pile cap. The diaphragm walls arepositively connected to the pile cap, forming a
typical pile foundation system. The diaphragm
walls are socketed into the firm ground below movable soil. Soil layers that are
prone to landslideconsist of medium to highly plastic clay. The main idea of
designing such a laterally rigidfoundation system is to resist full thrust resulting
from a possible landslide. The diaphragm walls
are designed to sustain the lateral thrust of the sliding soil mass approximately
equal to threetimes the theoretical passive earth force. The view of this system is
presented in Figure
An Application for Design of a Bridge Foundation In a Landslide Area- (P1,
P2,P3, DIK5,DIK6, IK4 indicates inclinometer positions)
Inclinometer readings taken at various positions near the bridge indicates
stabilization of themobilized soil after completion of the diaphragm wall
construction. The initial yearly movement
of 15-20 mm reduced to 1-7 mm after construction of the diaphragm walls.

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ADOPTED SOLUTION
For Idemli bridge, following solutions were adopted.
There are two alternatives for foundation design of bridges located on landslides.
First solution asadopted byNossanet. al is to design a laterally rigid system
capable of resisting full lateralthrust applied by moving soil. According to authors,
this solution requires well documentation ofsite and geotechnical features.
Moreover, soil movement rates should be known for a long periodof time.
Second solution implies minimal interference of the foundations with movable soil.
This solutionnecessitates long span bridges with piles that are founded at a level
below the possible landslidedepth, and strong enough to resist the force arising
during a landslide. Instead of diaphragmwalls, piles with circular cross-sectionare
preferable in this solution since circular cross-sectionsexhibit Omni-directional
properties, being independent of the direction of the landslide, at least in
a cross-sectional basis without considering pile group effect. In case of diaphragm
walls, the directionof the landslide should be known exactly in order to place short
dimension of the wall perpendicularto landslide so as to reduce total lateral thrust
applied by the moving soil and to increaselateral rigidity of the foundation system.
In Idemli bridges, second alternative is adopteddueto uncertainties in character
and extent of the landslide expected at the bridge. The foundationsof the bridges
are located on relatively shallow landslide prone regions, as presented in Figure.
The piles are embedded into firm ground although not presented in Figure .
Embedmentlengths are in the range of 7-10 meters. The symmetrical arrangement
of the span lengths necessitatedsome foundations to be located on relatively deeper
movable soils as compared to others.
Figure - Foundations of the Idemli-2 Viaduct are Located on Relatively Shallow
Landslide Prone Regions

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View of Idemli Viaduct
Design of bridges located on movable soils is a special task due to uncertainties
associated withrate of movement and lateral thrust applied by mobilized soil.At the
site of Idemli Viaducts, depth of landslide can reach up to 20 meters and character
ofmovable soil ranges from loose soil to rockparticles. In design of these viaducts,
maximum spanlength of 75 meters was adopted which minimizes the risk of soil
accumulation due to very highgirder depths and also minimizes number of piers in
movable soils. In the foundation system, concrete filled steel tubes (CFT)are
utilized so as to minimize dimension of the system prone to lateralsoil movement,
while maximizing resistance of the cross-section. Sixteen steel CFT piles
areutilized at each pier foundation.

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INCREMENTAL LAUNCHING METHOD
Apart from conventional methods of bridge making, the new method of
construction of bridges called as “Incremental Launching Method” [ILM] is
gaining popularity and is used for many of the recent bridge construction projects.
ILM has been discussed in short in the following section :-

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Intro of this method
Bridges have been constructed using the incremental launching method (ILM)
for many years. In this method of construction, the bridge superstructure is
assembled on one side of the obstacle to be crossed and then pushed longitudinally
(or “launched”) into its final position. The launching is typically performed in a
series of increments so that additional sections can be added to the rear of the
superstructure unit prior to subsequent launches. The launching method has also
been applied to tied-arch or truss spans, although these are fully assembled prior to
launching.
The incremental launching method will never become the most economical
procedurefor constructing all bridges. The ILM requires a considerable amount of
analysis and design expertise and specialized construction equipment. However,
the ILM may often be the most reasonable way to constructa bridge over an
inaccessible or environmentally protected obstacle.
When used for the appropriate project, the ILM offers a number of significant
advantages to both the owner and the contractor, including the following:
• Minimal disturbance to surroundings including environmentally sensitive areas
• Smaller, but more concentrated area required for superstructure assembly
• Increased worker safety since all erection work is performed at a lower elevation
The ILM can be used to constructa bridge over a wide range of challenging sites
which feature limited or restricted access, including those with the following
characteristics:
• Deep valleys
• Deep water crossings
• Steep slopes or poorsoil conditions making equipment access difficult
• Environmentally protected species or cultural resources beneath the bridge
It is estimated that over 1,000 bridges worldwide have been constructed
using the incremental launching method. Swanson (1979) states that the first
incrementally launched highway bridge in the United States was constructed near
Covington, Indiana in 1977. One of the earliest published reports in North
America, however, describes the construction of a railroad truss span for the

28
Canadian Pacific Railway in 1907. Despite the advantages listed, the incremental
launching method of construction has seen very limited application in the United
States. The reason for this disparity is unclear and it is one of the goals of the
proposedwork to ascertain the reasons for and attempt to eliminate this potential
“knowledge gap” for bridge owners, designers and contractors. Specifically, the
project objective is to provide bridge owners, designers, and contractors with
information and understanding about the ILM, including applications and benefits

29
PROCEDURE
During the launching operation, the bridge superstructure is supported by a
series of rollers or sliding bearings. These rollers are removed following the
launching and the bridge is lowered to rest on permanent bearings identical to
those used for a conventionally constructed bridge. The thrust required to launch
the bridge forward can be provided by a variety of jacking systems, including
hydraulic pistons or hollow-core strand jacks more commonly used for post-
tensioning.
In order to reduce the cantilever moments and the amount of deflection that
occurs during launching operations, one of two systems (and sometimes both) may
typically be employed. The contractorcan constructa tapered launching nose on
the leading end of the girders. The
launching nose reduces the dead load of the cantilever span and utilizes its tapered
profile to assist in “lifting” the mass of the girders as they are launched forward
onto the landing pier. In other cases, the contractormay elect to use a kingpost
system utilizing temporary stays to reduce
the deflection of the leading end of the girders during launching.

30
SUMMERY
Bridge construction over deep valleys, water crossings with steep slopes, or
environmentally protected regions can offer many challenges. The incremental
launching method (ILM) for bridge construction may offer advantages over
conventional construction, including creating minimal disturbance to surroundings,
providing a more concentrated work area for superstructure assembly, and possibly
increased worker safety given the improved erection environment. The ILM
involves assembly of the bridge superstructure on one side of an obstacle to be
crossed, and then movement (or launching) of the superstructure longitudinally
into its final position. Despite potential advantages for certain situations, the use of
the ILM for bridge construction has been very limited in the United States. The
objective of the work summarized in this report was to provide bridge owners,
designers, and contractors with information about the ILM, including applications,
limitations and benefits.
To clarify the ILM procedureand the current state of practice, a
comprehensive literature search and survey were conducted. Recommendations
pertaining to bestpractices for planning, design,
and construction activities, as well as applications and limitations for the ILM are
also provided. Case studies are presented, which provide specific ILM bridge
project information. The use of the ILM for bridge construction will never be the
most efficient way to constructevery single bridge. However, it is thought that a
wider understanding of the applicability and potential benefits would allow
potential owners, designers, and contractors to make well-informed decisions as to
its use for their upcoming projects.

31

32
CONCLUSION
Construction management basically is a tool to complete the project
effectively within fixed amount but in less time. Manager should have knowledge
sequence of all the activities. Decision making for both sides the contractor and
the client needs to be fast and time bound otherwise the project will get delayed
which will have cost over run. Control in form of reviewing monitoring has a
catalyst effect to boost the progress.
• All bridges held generally the same amount of weight. The arch bridges
held a little more than the other bridges. They werein the 1400-1500 gram
range. The other bridges were in the 1000-1200 gram range.
• The bridges would not stand up on their own, so a support at each end had
to be constructed. Balancing the weights on the bridges required patience.
Clamps were used to hold the bridges during gluing.
• The bridges supported different amounts of weights because each type has
different construction. The arch bridges supported the most weight
because of the great natural strength of the arch. The pier bridges
supported the least weight because the supporting piers broke during
construction.

33
REFERENCES
 S.CRangwala Bridge Engineering
 Baidar Bakht, Leslie G Jaegev Bridge Analysis simulated
 www.construction-challanges –for bridge-in.html
 slidesshare.com

Construction Challenges For Bridges In Hilly Areas

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