tspl-p143-cal-107-01

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Date : 23.08.10

Consultant: M/s.M.N Dastur & Company Pvt. Lt d.

Package : LP Piping

Sl. No. MND COMMENTS TSPL REPLY

A. Doc. no.TSPL-P143-CAL-107, Rev. 0 Design

calculation of Thrust Block for CW & ACW Pipes

1 For the horizontal load, the same shall be checked for

(self weight of pipe + self weight of

footing) x tan > 1.40 times total load as per clause

20.2, page 33 of IS:456:2000, 0.9 times of Dead Load

shall be considered as per IS.

This clause is not applicable for Thrust Blocks.

2 The designed thrust blocks are applicable only for

horizontal bends.

The submitted calculation is done as per AWWA M-11, and is

applicable for all bends.

Note: Please note that as per AWWA M-11, thrust blocks are

not required to be provided in case of all-welded pipe lines laidunderground.

3 If there are vertical bends, calculation to be submitted

separately.

Same as point no. A.2 above

4 The bottom of footing shall be indicated from existing

Ground Level

Drawing revised accordingly.

5 The structural design of the footings have not been

furnished.

The structural design of Thrust load is not in our scope. Same

shall be designed by customer based on the load data

provided by us. However, we recommend to follow the method

of construction indicated below:

Concrete shall be used for thrust blocks, and they shall be

poured in place or pre-cast. Poured in place thrust blocks shall

be constructed by pouring concrete between the fitting and the

undisturbed wall of the trench. A dry mixture shall be used so

that the concrete may be easily shaped into the desired form.

Portland cement, water, fine and coarse aggregate, and an air-

entraining mixture. The water cement ratio shall be 0.55 : 1

(0.55 Kg. of water to 1 Kg. of cement)

All aggregates shall be able to pass through a screen with two

(2) inch square openings.

Concrete used for thrust blocks shall have a 28-day

compressive strength of 2,500 psi. When no preliminary

strength tests of the concrete to be used are made, the water-

cement ratio shall not exceed the following values.

ForThermosystems Pvt. Ltd.

Project : 2x135MW TPP, Nellore

THERMOSYSTEMS PVT. LTD.

Response Sheet

Ref. No. : P143/RS/101

Client : Madhucon Projects Ltd.

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23.8.10 1 RKS US YADAV KRS

07.07.10 0 RKS US YADAV KRS

Date Rev. Prepared Checked Approved

STATUS :

UNITS :

SCALE : NTS SHEET 01 OF 05 REV.

OWNER :SIMHAPURI ENERGY PRIVATE LIMITED

MADHUCON GREENLANDS, BEGUMPET, HYDERABAD - 500 016, AP- INDIA

OWNER

ENGINEER :DEVELOPMENT CONSULTANTS PRIVATE LIMITED, KOLKATA

SUBMISSION FOR APPROVAL

SUBMISSION

PROJECT :

2 X 135MW THERMAL POWER PLANT (PHASE -1)TAMMINAPATNAM & MUMMIDI VILLAGES, CHILLAKUR MANDAL

SPSR NELLORE DISTRICT - 524121, ANDHRA PRADESH - INDIA

1

Revised as per MND comments

VENDOR/

SUPPLIER :

THERMOSYSTEMS PVT. LTD.

HYDERABAD

TITLE : DESIGN CALCULATION OF THRUST BLOCK FOR CW &ACW PIPESFILE NO :

ORIGINATOR :

EPC ENGINEERM.N.DASTUR & COMPANY (P) LIMITED, KOLKATA

DRG NO: TSPL-P143-CAL-107

EPC

CONTRACTOR :

MADHUCON PROJECTS LIMITEDROAD NO.36, JUBILEE HILLS, HYDERABAD - 500 033, AP - INDIA

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DESIGN CALCULATION OF THRUST BLOCK

1.0 ) THRUST AT CW PUMP DISCHARGE sh. 2 of 5

Input data

1. Diameter of pipe = 1600NB

2. Pressure = 5.4 Kg / cm2 (shut off head of CW pump)

3. Fluid = Water

4. Flow = 11550 m3/hr5 Soil bearing cap. = 3000lb/ ft2 or 14650 kg / m2 (Assumed)

Thrust block calculation as per AWWA M 11

Thrust Pressure at 90 Elbow T = 2 Sin /2 PA

Where,

T = The thrust force in kg

P = Pressure in Kg/ cm

2

(5.4 kg/cm

2

)A = Cross sectional area of 1600NB pipe in cm2 ( 0.7854xd2 = 20739.46 cm2 )

T = 2 Sin /2 PA

= 2 x 0.707106 x 5.4 x 20739.46= 158381.66 Kg.

Now bearing area as per cl 13.5 of AWWA M 11

Bearing area of thurst block = Thrust forceSafe horizontal bearing capacity of soil

= 158381.66 Kg.

14650 kg / m2

= 10 .81 m2

10 % extra margin consider = 10.81 x1.1

= 11.89 m2

1. 2.) THRUST AT DISCHARGE HEADER

Input data


2. Pressure = 5.4 Kg / cm2 (shut off head of CW pump)

3. Fluid = Water4. Flow = 23100 m3/hr (two pump working)


Where,


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Sh 3of 5

P = Pressure in Kg/ cm2 (5.4 kg/cm2)

A = Cross sectional area of 2200NB pipe in cm2 ( 0.7854xd2 =39239.43 cm2 )

T = 2 Sin /2 PA

= 2 x 0.707106 x 5.4 x 39239.43

= 299661.51 Kg.


Bearing area of thurst block = Thrust force

Safe horizontal bearing capacity of soil

= 299661.51 Kg.14650 kg / m2

= 20.45 m210 % extra margin consider = 20.45 x1.1

= 22.5 m2

2.0.) THRUST AT ACW PUMP DISCHARGE

Input data

1. Diameter of pipe = 700NB2. Pressure = 5.25 Kg / cm2 (shut off head of ACW pump)3. Fluid = Water

4. Flow = 2100 m3/hr

5 Soil bearing cap. = 3000lb/ ft2 or 14650 kg / m2 (Assumed)Thrust block calculation as per AWWA M 11


Where,



A = Cross sectional area of 700NB pipe in cm2 ( 0.7854xd2 = 3970.36 cm2 )

T = 2 Sin /2 PA

= 2 x 0.707106 x 5.25 x 3970.36

= 29478.4 Kg.

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Sh 4 of 5




= 29478.4 Kg.

14650 kg / m2

= 2.012 m2

10 % extra margin consider = 2.012 x1.1

= 2.2 m2

2. 2.) THRUST AT DISCHARGE HEADER

Input data


2. Pressure = 525 Kg / cm2 (shut off head of ACW pump)

3. Fluid = Water4. Flow = 4200 m3/hr (two pump working)


Where,



A = Cross sectional area of 900NB pipe in cm2

( 0.7854xd2

=6566.94 cm2

)

T = 2 Sin /2 PA= 2 x 0.707106 x 5.25 x 6566.94= 48756.98 Kg.




= 48756.98 Kg.

14650 kg / m2

= 3.33 m210 % extra margin consider =3.33 x1.1

= 3.66 m2

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tspl-p143-cal-107-01

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