(water tightness BS 8007: 1987)
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Index Scope Definition Responsibilities Safety
Method / Procedures Equipment
Attachment Scope
To transport the Sea Water to the Sea Water Basin and Testing the basin Definitions
PSM Project Site Manager CM Construction Manager
CS Construction Superintendent
FM Foreman
Responsibilities
CM shall plan and resource the required materials and plants ensuring that these are implemented according to this procedure.
CM shall ensure that all the Safety requirements are implemented and explained to the relevant work force and control the day to day activities.
CS shall ensure the implementation of technicalities involved.
FM shall control the work force ensuring the full implementation of the procedure.
Safety
Prior to the commencement of any activites, the labour force shall receive a toolbox talk on the Project Site Safety requirements. Traffic directory signs for the ramp breakers on 3 nos road crossings shall be installed. On the exposed pipe route the safety tags shall be installed with cones. A protection arrangement shall be made for the plants at the intake. A full time attendant shall keep the watch and ward on the route.
Procedures involved
Laying a 100 mm dia hose from the sea to the sea water approximately1800 m. Refer to sketch point # 1 to # 8 i.e. intake at sea and discharge to the basin respectively.
Constructing a concrete anchor at the sea to fix the intake pipe spout horizontally and vertically as well as to fix 2 # heavy duty centrifugal pumps at point #1
There are 3 nos road crossings en-route at points 2, 5 and 6 on which temporary 150 mm dia pipe sleeves are to be inserted in the form of the ramped speed breakers.Ref to the sketch. Otherwise, sleeves shall be inserted by road cutting, filling and making good when the job is over
Install a ‘round the clock’ generator to supply electricity to the pumps with the Distribution Board at point # 1 or to have electric connection through an alternative source.
Install a timber clamping platform on the ditch at point # 4 Water Heads calculations indicative only
At intake suction 1 m At intake disposal 1 m Vertical head loss 25 m At point Nos. 8 loss 10 m Total vertical head loss 37 m
Length of Pipe for friction loss 1800 m 4 f l v v / 2 g d
= 4x.015x1800x1.5x1.5 / 2x 9.81x.1=123.9m
Total head loss = static loss + dynamic loss = 37 +123.9 = 160.90 m
Work done= 42000x160.9 kgm, bhp = 42000x160.9 / 270000= 25 units, ihp = 35 units The water flow velocity has been assumed to be 1.5 m / sec giving a discharge of 42 cum per hour. It shall take 20 days to reach 20000 cum of water to the basin keeping round the clock pumping.
SEA WATER BASIN PLANNED PUMPING
DAY # QTYPUMPED
IN
QTY CUMM
CUM CUM
1 1008 1008
2 1008 2016
3 1008 3024
4 1008 4032
Statements were written by Professional Eng Suraj Singh Project Manager as well as Senior Project Engineer. Most of these were approved by EPC Contractor & Company (no sketches
5 1008 5040
6 1008 6048
7 1008 7056
8 1008 8064
9 1008 9072
10 1008 10080
11 1008 11088
12 1008 12096
13 1008 13104
14 1008 14112
15 1008 15120
16 1008 16128
17 1008 17136
18 1008 18144
19 1008 19152
20 1008 20160
21 1008 21168
First phase Testing
The tank completed with Protective Coatings as specified and sealant applied shall be cleaned and filled to the normal maximum level to meet the requirement of clause 9.2 BS 8007 : 1987 Testing of structures i.e. upto 11.5 m which should take 14 days and then be retained for a stabilising period of 7 days for a maximum design crack width of 0.1 mm, allowing absorption and the autogenous healing.
Test period starts now for 7 days and the drop in level recording be made every 24 hours during this 7 days period. Total permissible drop in level allowing evaporation etc. should not be more than 1 / 500 of the average water depth of the full tank which limits to 10 mm or another specified or calculated amount.
Having the test been successful, the backfill shall be carried out Second phase Testing
Let the tank be further filled upto 13 m level i.e another 7 days
Stabilisation period Another 7 days (for absorption and autogeneous healing) Test period Another 7 days (level drop recording at an interval of 24 hours) Basin Filling and Testing Schedule
S #
Description of the operation Duration in
days Remark
1 Ist phase water pumping 14 Pumping from sea
2 Retained water stabilisation to
allow absorption and
autogeneous healing
7
3 Testing at 24 hour intervals and monitoring
7 Loss should not be more than 1 / 500 of average fullwater depth or 10 mm or other specified value
but excluding evaporation.
4 Backfilling after successful testing
14
5 II phase water pumping 7 Pumping from sea
6 Retained water stabilisation and autogeneus healing
7 7 Testing at 24 hours intervals 7
8 Water loss monitoring Loss should not be more
than 1 / 500 of average fullwater depth or 10 mm or other specified value but excluding evaporation
The code provides that notwithstanding the satisfactory completion of the test, any evidence of seepage of the liquid to the outside faces of the liquid retaining walls should be assessed against the requirement of the specification. Any necessary remedial treatment of the concrete, cracks or joints should, where practicable, be carried out from the liquid face. When a remedial lining is applied to inhibit leakage at a crack, it should have adequate flexibility and have no reaction with the stored liquid.
Should the structure not satisfy the 7 days test then after the completion of the remedial work, it should be refilled and if necessary, left for a further stabilising period followed by a further test of 7 days’ duration should then be undertaken in accordance with this clause.
Equipment.
Pumps IHP 35, 2 Nos.
Other General Arrangements
Attachment
Sketch showing the Hose Route
#29