Service corridor at CP,Delhi Unique technological construction Construction management

1. PMS PRESENTATION
AG14082
AG14090
AG14143
AG14144
SERVICECORRIDORAT connaught place,
NEW DELHI

2. AERIAL VIEW

3. AC
FIRE
WATER
IRRIGATION
HT
L
T
FUTURE
EXPANSION
FUTURE
EXPANSION HT
FUTURE
EXPANSION LT
TELECOM
SIZE OF TRAY
 L.H.S : 1500 MM
 R.H.S : 2500
MM

4. SERVICE CORRIDOR
• Easy identification of services in corridor .
• Continuous monitoring.
• Quick fault detection.
• Ease and cost effectiveness of maintenance.
• Accessibility ensures any time serviceability
• Reduction in breakdown time.
• Future expansion of systems easier.
• Minimum inconvenience to public in case of maintenance.

5. Contractor and client
 Client : New Delhi Municipal Council (NDMC)
PMC: Engineers India Limited (EIL)

6. PROJECT INFORMATION
Estimated Cost Rs. 671 Crores
Service Corridor Cost Rs. 70 Crores
EIL Scope Of Work Project Management Consultancy
Project Zero Date 21.05.2008(TURNKEY
CONSULTANCY AGREEMENT
SIGNED BETWEEN NDMC & EIL)
Project Duration 30 Months
Funding Scope Partly By Govt. Of India(under
JNNURM SCHEME) And Partly By
NDMC
Type of contract Amended Turnkey Consultancy Contract
signed on 21.05.2008

7. Specifications
ITEMS NOS. FUTURE
EXPANSION
HT LINE 4 trays 1
LT CABLES 3 TRAYS 1
Telecom lines 1 tray -
Water supply 2(300mm dia) -
Gas lines - -
Fire water pipes 2(253-300mm dia) -
Air cooling system 1 duct -

12. SUBWAY & ROAD WORKS
• From B.K.S. Marg To
Panchkuian Road (Upto
DMRC Tunnel): 231m.
• From Panchkuian Road
(After DMRC Tunnel) To
Barakhamba Road:
716m. (Upto DMRC
Tunnel).
• From Barakhamba Road
To Janpath Lane: 223m
(After DMRC Tunnel).
Layout showing Proposed & Existing Subways
EXISTING
PROPOSED

14. TechnologyUsed
• Open cut method
• Top down method

15. TOP DOWN METHOD OF CONSTRUCTION
 Service Corridor, being made in Middle Circle of
Connaught Place is a tunnel of rectangular box
section of size (6.3 x 7 mtrs)
 Top Down Method of excavation adopted for the
project as deep excavation was to be carried out very
near to existing buildings

16. STEPS OF TOP DOWN METHOD
 Identification of Existing Utilities
 Shifting of Utilities & Making of Guide Wall
 Boring for Diaphragm Wall up to the required depth
 Lowering of R/F cage in the Bored Area
 Concreting of the Diaphragm Wall Panel
 Excavation & Chipping of Concrete up to the cut-off level
 RCC Top Slab for the Service Tunnel
 Excavation up to the Bottom Slab

17. Identificationof ExistingUtilities
 Making of Pre-trench across
the road at regular intervals
to identify the utilities
running along the Proposed
Service Tunnel
 After the utilities were
identified, methodology for
shifting of these utilities were
finalized
Pre – Trench showing the existing utilities

18. Shifting of Utilities & Making of Guide Wall
 The identified utilities were
diverted temporarily so as to
keep the utilities running & also
to make a guide wall for the
boring
 A Guide Wall was constructed
for a depth of 1.6 m along the
alignment of Service Corridor –
to assist in boring for
Diaphragm Wall & to shift any
unforeseen utilities which are
layed across the road & have
not been identified in the pre-
trench

19. Boring for Diaphragm Wall
 Boring done up to a depth of
14 m
 Boring done with the help of
bentonite slurry to help
stabilize the walls of the
boring till concreting is done
 The grab is tied to the body
of the crane as a safety
aspect to prevent it from
hitting any existing building

20. Lowering of R/FCage
• R/F Cage for Diaphragm
Wall Panels of Size (5.0
M) made ready before
boring is commenced
• Each R/F cage weighs
approximately 10.5 MT

21. Concreting for Diaphragm Wall
 Tremie Concreting done for
Diaphragm Wall
 Each Diaphragm Wall Panel is
56 cum

22. Excavationup to Bottom of Top Slab
 After the Diaphragm Wall is
casted, Excavation for bottom
of top slab is taken up, so
that the inconvenience to the
public is minimum.

23. TopSlab
 A top slab of 600 mm is casted,
leaving openings at regular
intervals, so that excavation inside
the tunnel can be carried out

24. Excavationfor Base Slab
 After the top slab is casted,
excavation inside the tunnel is
started for base slab works

26. Hindrances
• Existing utilities are a major
hindrance as work has to be
carried out without disturbing
these utilities
• No Drawings for the existing
utilities are available, which
makes the condition even
worse, as it slows down the
pace of the work

27. Hindrances
• Encroachment in Courtyards
make it difficult to work
• Encroachments exist, which
should be removed before any
work can be done

28. Hindrances
• Structurally weak columns
have caused the works to
proceed slowly
• Damaged roofs of buildings,
most of them being within
private property

29. Safety Measures
• Sumps And Pumps Are Proposed To Take Care Of
Instances Of Flooding. Further, No Service Line Has Been
Laid In The First 750mm From The Floor.
• As Far As Cables Are Concerned, Sufficient Fall Back
Space Has Been Provided As Per Relevant Codes Of
Practice.
• Gas Based Fire Fighting Measures Has Also Been
Provided In The Tunnel. Details Of The Fire Detection And
Fire Fighting Shall Be Dealt With Separately.
• Closed Circuit TV Shall Be Installed In The Tunnel For
Surveillance And Security.

30. Areas of Concern
• Excavation / Digging For Replacement Of Cables /
Other Services Results Can Be Avoided .
• Minimize Inconvenience To Public In Case Of
Maintenance.
• Avoid Traffic Diversions In Case Of Maintenance.
• Reduction In Breakdown Time Of Systems.
• Ease And Cost Effectiveness Of Maintenance.
• Identification Of Services In Tunnel Is Ensured Being
Centralized Systems.
• Future Expansion Of Systems Easier.
• Accordingly After Considering The Time Schedule
Involved In TBM Technology , It Is Proposed To
Construct The Tunnel By Open Cut And Cast In Situ
Method .

31. Conclusion