SUSTAINABLE CONSTRUCTION TECHNIQUES

1. SUSTAINABLE CONSTRUCTION TECHNIQUES – A Case
Study On Precast Segmental Construction Techniques
Adopted For Hyderabad Metro Rail Project
by 1. K. Bhavani
2. Sunil. K
3. L.chandravanan
L&T Construction - Chennai - India
TISI-2015

2. CONTENTS

3. WHY MRTS?
Benefits
• 1/5th energy per passenger km
• Eco Friendly
• Less road space(2.4m)
• 3-4 lakhs passenger per hour
• Reduce transport problem
• Large area
• Many railway
crossings
• Less frequency
MMTS
• Wide roads
• Less passenger
flow
BRTS
MRTSDis-advantage
• Congestion on roads at
the time of construction
• Cost factor
• Environmental impact
Cost - Factor
• By integrate metros with others systems
considering - volume, structure, availability
of space & resources for traffic and
transportation.
Traffic Congestion
• Construction Techniques.MRTS – Sustainable Transport
system during operation.
During Construction ----?

4. HYDERABAD METRO - BRIEF
Corridor -1
Corridor -2
Corridor -3
Interchange
• VIADUCT: 71.16 KM
• STATIONS: 66 NOS
• DEPOT: 3 NOS
ROB

5. SELECTION OF TYPE OF METRO RAIL- ELEVATED VIADUCT
UNDER-
GROUND
RAIL
High cost (2-3
times)
Maintenance
& HVAC
High carbon
footprint
Security
concern
Deccan
plateau –
Underground
rocks

6. COMPLEXITY IN CONSTRUCTION - ELEVATED METRO
Traffic / Junctions –Least
disturbance to traffic
Heritage / Important structures
Existing Utility
Existing Railway Crossing
(ROB)
Paucity of space
Existing bridges / Structures
Utilityidentificationthrough trenching
Miyapur S R Nagar
Bharat Nagar
Metro Station (~150m)
Erragadda
Metro station (~600m)

7. CONSTRAINS – CONSTRUCTION METHODOLOGY
Sustainable
Construction
Methodology
Minimum
Disturbance
to public
Dismantling
to existing
structure
Quality of
Construction
Reduced
execution time
Overall
Economy

8. Span Alignment with 128m Curvature
Corridor
R≥600m
% / No’s
R <600 &
≥ 300m
% / No’s
R<300&
≥ 120m
% / No’s
C-1
89.4% /
744 No’s
6.5% /
54 No’s
4.1% /
34No’s
C-2
86.8% /
353 No’s
5.5% /
22 No’s
7.7% /
31 No’s
C-3
91.13% /
697 No’s
4.3% /
33 No’s
4.57% /
35 No’s
MINIMUM DISTURBANCE TO PUBLIC AND EXISTING STRUCTURE
Foundation
• 90% Open Foundation
• Reduced machinery
Substructure
• Single Pier
• Portal Pier & L-Pier to
avoid encroachment in
road
Superstructure
• Box Girder
• Viaduct-2.1m Height
• Station-1.8m Height
• 37m to 45m Span-
2.85m Height
Proposed Alignment - MGBS to SalarJung Museum
Revised Alignment - MGBS to SalarJung Museum
Alignment -
Curvature
Pier Alignment for Curved Span

9.  Cast segments are a major advantage of
segmental construction
 Casting yard brings
 Factory controlled production techniques
 Effiency
 Quality control
 reducing overall construction time.
 Two methods of segment casting are
available:
 Long line casting
 Short line casting
QUALITY CONSTRUCTION- PRECASTING YARD
Casting Yard
Casting Yard
Name
Segment Cast
Scope No.
Segment Cast
Nos.
1 Uppal 14000 6236
2 Qutubullahpur 14000 3735
Total 28000 9971
Casting
Stacking Transportation

10. • 28,000 No’s of segments – 2 precast yards of 64.5 acres and 46.2 acres respectively
• Asia’s second largest precast yard (second to Dubai metro)
PRECAST YARD-FEATURES

11. Pier head Segment
Casting Casting of Running Segment Match Casting of Segment
Match Casting of Curved Segment Stacking of segment
QUALITY CONSTRUCTION- SEGMENT CASTING & STACKING

12. SEGMENTAL CONSTRUCTION
- planning of USLG for stations
(Cycle time :2days/span)
Box girder
segments can be cast
& stacked parallel to
foundation and pier
fast progress
minimum
disturbance
curved
alignment
suitable for
varying span
lengths
flexibility
Construction
cost
2
7
15
32
50
34
45
51
67
58
70
63
73
86
75
70 68
43 44
48
0
20
40
60
80
100
Dec'12
Jan'13
Feb'13
Mar'13
Apr'13
May'13
Jun'13
Jul'13
Aug'13
Sep'13
Oct'13
Nov'13
Dec'13
Jan'14
Feb'14
Mar'14
Apr'14
May'14
Jun'14
Jul'14
Month wise Span Erection Spans Erected

13. CHALLENGES – SEGMENTAL CONSTRUCTION
Various
Junctions/
Crossing
Existing
flyovers
Rail crossing
67% of viaduct
in curves
10% of viaduct
with 128m R
Pier height
varying form
8m to 25m
Construction
duration
Transportation
of precast
segment
Challenges in segment erection

14. SUPERSTRUCTURE TYPE COMPARISON FOR VARIOUS
METRO PROJECT – STATION SPANS
More than 50% cast insitu-
eliminated.
Concourse level & plat form level
Precast element.
Cycle time was reduced.Formwork for Slab/Beams
Completed view
Formwork for columns/piers Erection of Viaduct
platform level & Concourse - Erection
Completed view
Typical Cast In-situ Construction of Station Spans

15. Construction Elevated stations
Erragada Station - ErectionJNTU Station – Platform Erection
Concourse Level Platform Erection
Uppal Station

16. Viaduct Erection
Span by span
Over slung LG
(up to 128mR -31m span)
Hinged LG
Movable
Winch LG
Under slung LG
Balanced Cantilever /
Cantilever
Under slung LG
ROB erection
(39m+65m+39m)
Bridge Builder
Continuous span
Over slung LG
Pocket track
Loop line
Flexibility to feed
segment form
erected span
Segment Feeding
using crane
Station Viaduct
(13-17m span)
Special spans
(37m-45m span)
CONSTRUCTION METHODOLOGY - SEGMENTAL BOX
ROB erection
128m R spans
(39.5m+65m+32.5m)

17. SUPERSTRUCTURE TYPE COMPARISON FOR VARIOUS
METRO PROJECT
Description DMRC BMRC CMRL HMRL
Concrete in Cum 165 160 151 145
Steel in MT 32 25.6 22 20
Pre-stressing steel in MT 5.8 5.6 5.0 4.65
Project Delhi Metro
CC-17
Package
Delhi Metro
CC-28
Package
Hyderabad
MetroDescription
Viaduct length 5.45 km 5.72 km 72 km
Stations 3 No's 5 No's 66 No's
Total spans 199 No's 223 No's 2700 No's
Segmental spans 187 No's 198 No's 2680 No's
I-Girder spans 27 No's 25 No's -
Cast insitu spans - 8 No's 20 No's
Minimum Radius
of Curvature
250m 250m 128m
Maximum
segmental span
length
37m 37m 45m
I-girder
Deck slab
Typical Cross Section of Pocket track
Box girder
Insitu joint
Typical Cross Section of Pocket track used in HMRP
More than 95% spans are
segmental spans.
Special spans – Pocket track,
loop line & service line are with
box girder

18. THANK YOU … !

20. Capability of Hinged Launching Girder
 Erection of 34m span with a curvature of 250m.
 Erection of span ranging from 19m to 31m with a curvature of
128m
• Less disturbance to traffic
• Within Barrication width

21. 31m straight span
External ground support
31m span in 152m horizontal radius - CMRL
Advantage Of Introduction Of Hinge

22. Features
 34m span erection in 250 m Radius of Curvature
 31m span erection in 128m Radius of curvature
 No counter weight
 Segment can be picked from ground/completed deck
LAUNCHING GIRDER WITH MOVABLE WINCH
Typical Span Erection of Movable Winch LG over Flyover
• Less disturbance to traffic
• Feeding from erected deck

23. Capability of Underslung Launching Girder
 Erection of Special Spans (37m-45m).
 supported on the Trestles
Cycle time – 15 days /span
Typical Elevation of Under slung LG for 45m Span.
Cycle time – Cast insitu span
45 days/span

24. Capability of Underslung Launching Girder
 Erection of station span (13.4m & 17m).
 supported on the Pier bracket stressed along with the
station pier during erection and launching.
Cycle time – 2 days /span
• Reduce station completion
time

25. Construction Elevated stations
Erragada Station - ErectionJNTU Station – Platform Erection
Concourse Level Platform Erection
Uppal Station

26. BALANCED CANTILEVER/CANTILEVER– USLG

27. BALANCED CANTILEVER/CANTILEVER– USLG

28. BALANCED CANTILEVER/CANTILEVER– BRIDGE BUILDER
New Market
Metro station (~1000m)
Malakpet
Metro Station (~100m)
Miyapur L B Nagar

29. BALANCED CANTILEVER/CANTILEVER– BRIDGE BUILDER

30. CONTINOUS SPAN – POCKET TRACK
Pocket Track with Box Girder
Erection Sequence of Pocket Track Girders

31. CONTINOUS SPAN – LOOP LINE
Completed View of Loop
line (Nagole Depot)
Erection of Loop line (Nagole Depot)
View of Loop line
(Miyapur Depot)