In Difficult work condition we did the work without any delay with proper planning & minimum resource

1. TSPS/ISPSWORK – S1A1 BWSSB.
Prepared By- Ravikiran Chendake Page 1
TSPS /ISPS WORK IN RAJA CANAL
Project details-
In Bangalore water supply sewerage board project, the combined TSPS/ISPS construction work is in
progress near Raja Canal STP. Its include 40 mld terminal sewage pumping station for Raja canal & 20 mld
Intermediate sewage pumping station for Hormavu Sewage treatment plant.
Hurdles while starting the work-
 Sufficient space was not available for construction of TSPS/ISPS structure. After co-ordination with
the client, Raja Canal drain diverted parallel to the rail track by this way; we got the sufficient space
for construction as per the GFC drawing.
Photo showing the diversion ofexistingSWD drain.
 Location of proposed site is near to the existing Raja canal STP (40 mld ), the admin building & the
laboratory building are just 5 to 10 m away from the proposed TSPS & ISPS structure. Also depth of
excavation is 18 to 20 meter from natural ground level as per the GFC drawings, hence it is very
necessary to do proper planning & take proper precautionary measures before starting the
excavation of the proposed TSPS/ISPS structure.

2. TSPS/ISPSWORK – S1A1 BWSSB.
Prepared By- Ravikiran Chendake Page 2
Photo showing existing Structures arejust side ofexcavation line.
Hence we change the orientation of the structure as per the site condition to avoid any disturbance to
existing structure after proper approval from design team & client.
 Excavation for TSPS/ISPS –
The depth of excavation is 18 to 20 meter from natural ground level. The adjacent SWD drain and
existing STP admin buildings are very near to the line of excavation, hence we recommended to the
contractor to excavate sloping as well as stepping at an interval of every 2 to 4 m vertically, till the
hard strata found. After hard strata found we did the vertical excavation as shown in the
photograph below.
Photo showing-TSPS excavation work.
Every 2-4 m vertical interval 1-1.5 m horizontal step is provided, as shown in figure. It helped us in
the safety point of view. If any sudden collapse will happen the loose soil will slide gradually and
major quantity of soil will stands on the horizontal step provided, also very less quantity of soil will
reach up to the excavation bottom. Sufficient margin (2m to 2.5 m) has provided in between PCC
outer edge & excavation line (Bottom).
After completion of 50 % excavation suddenly collapse happen from the SWD drain side due to
excessive seepage & refilled soil. Hence we suggested to the contractor to do the sheet piling to
retain the loose soil (towards drain side).

3. TSPS/ISPSWORK – S1A1 BWSSB.
Prepared By- Ravikiran Chendake Page 3
Also sand bags are placed on the bank of drain for strengthening of drain as well as to minimize the
seepage, as shown in the above photograph.
After the sand bags lining on the bank of the drain we got better relief from the collapse as well as
seepage water.
 PCC & Reinforcement of raft-
After completing of PCC work the next challenging work was reinforcement of raft (ISPS/TSPS). As
sufficient space was not available to install the Crain, there is no any alternate to do the
transportation of steel manually at 18 m. depth below the natural ground level. It was done within
8 working days (Day & night), about 150 MT steel shifted for reinforcement of raft by 100 fitters &
helpers during the raining condition. It was the unbelieving experience for all of us, that we did this
work within such a short period.
The photo showing the reinforcement work is in progress.
After raft reinforcement completed

4. TSPS/ISPSWORK – S1A1 BWSSB.
Prepared By- Ravikiran Chendake Page 4
Casting of the Raft-
After completion of raft reinforcement the next most challenging work for us was, pouring the
concrete. (Quantity- 750 cum.)
While planning the concreting, it was very difficult to us as site RMC plant capacity is only 25
cum/hr. Also there are lots of obstruction to continuous supply of concrete due to traffic
department no entry for period of 8 am to 12 pm & 4 pm to 8 pm (Every day) , as site location is
inside the city, hence there is no any other alternate to complete the concrete work within 8 pm to
next day morning 8 am (within 12 hrs.).
Hence we planned to take the concrete from three different RMC plant vendors (Approved). As
depth of pouring is 18 m from ground level hence we brought 2 static concrete pumps & 2 boom
concrete placer ( truck mounted.) having boom length 36 & 42 m.
Photos showing the pump arrangement made for concreting.
By proper planning & efforts taken by all of us, we completed the raft concreting work within
12 hrs. at a rate of 62.5 cum / hr. It was amazing experience for all of us that such huge quantity
of concrete we did within the short time.

5. TSPS/ISPSWORK – S1A1 BWSSB.
Prepared By- Ravikiran Chendake Page 5
After completion of raft concrete.