Geohazard Calculation

8/21/2019 Geohazard Calculation

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Client

Project Name and Number

LoactionContent Type

Seismic Zone (as per AIITK, Indian Seismic Code)

Site Specific Horizontal acceleration

PGD Landslide Faulting

Wave

propagation

I : Pipelines which would cause major impact in case

of failure or damage1.50 2.60 2.30 1.50

II : Pipelines which are vital but service of those canbe interrupted for minor repairs

1.35 1.60 1.50 1.25

III : Low pressure oil and gas pipelines and Water

supply pipelines for ordinary use1.00 1.00 1.00 1.00

IV : Pipelines of very little importance and impact in

the event of failure

Value

1.5095

1.219

1.203

0.0157

ILF CONSULTING ENGINEERS Rapid Assessment

of Seismic Safety of Buried Continuous Pipelines

INPUTS

Basic Information

Measurements

Geometry

Importance factor I p

Seismic conditions need not be considered

Class of pipeline

Cross Section Modulus

0.017627126

Cross Section Area

0.059350372

H

D

Dmin

t

=

=


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Grade of Pipe

Ramberg-Osgood parameters for steel Pipes

Grade of pipe X42 X52 X60 X70

310 358 413 517

n 15 9 10 5.5

r 32 10 12 16.6Yield Stress of Pipe material

Modulus of Elasticity

Yield Strain of the Pipe Material

Failure Strain of the Pipe in Tension

Linear Coefficient of Thermal Expansion of pipe

Poisson Ratio (v)

Density of Steel Pipe

Unit Weight of Steel Pipe

Density of Content

Unit Weight of Content

Soil Types hard Clay soft Clay Silty Sand Sandy Soil

Velocity of Shear Wave Vs 300 300

Coefficient of Cohesion of Backfill soil ( c) 50 30 0

Density of the Soil 2000 1600 1400 1630

Effective Unit Weight of the soil 19.62 15.696 13.734 15.9903

Saturated Unit Weight of the Soil 18

Dry Unit Weight of the Soil 16

Water Buoyancy Factor

Internal Friction Angle of the Soil 30f

1

0.9

0.8

0.7

0.6

0.6

Inputs for Peak Strain Calculation

Soil Properties

Material Properties

a) For Operational Longitudinal Strain in the Pipeline

Maximum Internal Operating Pressure of the Pipe (P)

Coal Tar

FBE

Rough Steel

Smooth Steel

Polyethylene

Friction Factor for Various Types fo pipes

Pipe Coating

Concrete

Temperature in the Pipe at the time of Installation (T1)

Temperature in the Pipe at the time of Operation (T2)

b) For Permanent Ground Deformation (PGD)

Length of PGD Zone (L)

Width of PGD Zone (W)

(MPa)

(MPa)

()


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Seismic Zone II III IV IV

PGAr (relative) 0.1 0.16 0.24 0.36

Classification of Soil at Site (Site Specifice)

Soil Type Class

Hard Rock ARock B

Very Dense and Soft Rock C

Dense/Still Soil D

Loose/ Soft Soil E

Ko

0.5 - 0.6

0.3 - 0.5

0.5 - 0.6

0.8 - 1.1

Over Consolidated 1.0 - 1.3

Average Normal Fault Displacement (dfn)

Dip Angle (Psi)

Fault Angle (Beta)

Length of Anchorage (La)

E) For Seismic Wave Propagation

Focal Length (F)

Transverse Displacement (dt)

C) For Liquefaction

Length of Liquefaction Zone (Lb)

Height of Soil Liquefaction from pipe (hw)

Height from Top Soil to Pipe Center Line ( C )

D) For Fault Crossing

Longitudinal Displacement (dl)

Soil Properties

Vel of Shear Wave Vs

(m/s)

Uncorrected S

Penetration Resi

Vs gt 1500760 lt Vs lt 1500

Distance from Earthquake Source

Magnitude of Design Basis Earthquake Considered Mw

Expected PGA of the site at Base Rock Layer (PGA)

Note: When sufficient detail of soil is unavailable to define site, soil can be assumed to be

Soil Type

Loose Soil

360 lt Vs lt 760

180 lt Vs lt 360

Vs lt 180

N gt 5

15 lt Vs lt

Vs lt 1

Adhesion Factor

Dense Soil

Clay (Drained)

Clay (Undrained)

Coefficient of Soil Pressure at rest

Interface angle of friction between soil and pipe Soil Type

=

= . . .

.

; = . . .


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30

Factor a1 b1 c1

Nch 0 6.752 0.065 -11.063

Nqh 20 2.399 0.439 -0.03

Nqh 25 3.332 0.839 -0.09

Nqh 30 4.565 1.234 -0.089

Nqh 35 6.816 2.019 -0.146

Nqh 40 10.959 1.783 0.045

Nqh 45 17.658 3.309 0.048

Nqh value used 30 4.565 1.234 -0.089

30

Maximum Axial Soil Force Per Unit Length

Loose Soil

Dense Soil

Clay (Drained)

Clay (Undrained)

Over Consolidated

Maximum Lateral Resistance of Soil per unit length

Horizontal Bearing Capacity Factor for clay, (0

for c = 0)

Horizontal Bearing Capacity Factor for Sandy Soil, (0

for Phi = 0)

Vertical Uplift Soil Springs

Bearing Capacity Factor

Vertical Bearing Capacity Factor for clay, (0

for c = 0)

Vertical Bearing Capacity Factor for Sandy Soil, (0

for Phi = 0)


Vertical Bearing Soil Springs


=

= +

=

+

+ ;

= ;

= ;

=

;

= ;

=

; applicable for

=

;

= +

;

= . .

.

= ... ;


5/13

Units

m

m

m

m

m3

m2


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used val Units

517 MPa

5.5

16.6483 MPa

207000 MPa

0.00233

0.000012 /degC

0.3

7850 kg/m3

76.93 kN/m3

used val Units

300 m/s

0 kPa

1630 kg/m3

15.9903 kN/m3

18 kN/m3

16 kN/m3

30 deg

used Val Units

9.93 MPa

-10 degC

49 degC

used Val Units

100 m

m

0.6


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1.5 m

1.5 m

used Val Units

m

m

m

used Val Units

m

deg

deg

m

used Val Units

km

km

Class Used

used val

used val

used val

tandard

istance (N)

g

class D

Site

Specific

50

-0.361


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used val

d1 e1

7.119

0.001059 -0.0000175

0.005606 -0.0001319

0.004275 -0.0000916

0.007651 -0.0001683

-0.00543 -0.0001153

-0.00644 -0.0001299

0.004275 -0.0000916

val used Unit

val used Unit

val used Unit

0 kN/m

val used Unit

val used Unit

val used Unit

24.8422784 kN/m

val used Unit

val used Unit

val used Unit

0 kN/m

deg18

-3090.9419

5.25915181

5.59644955

74.2986054

0.84430233

x=

x=


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Val used

115.6497Val used

146.556

Val used

0.000559

Val used

0.000708

Val used

0.001267

Val used

1.5

Val used

1.5

A)Longitudinal PGD Val used

Peak Pipe Strain (Tensile/Compressive)

Longitudinal Stress due to Internal Pressure (Sp)

Longitudinal Stress due toTemperature (St)

ILF CONSULTING ENGINEERS Rapid Assess

Seismic Safety of Buried Continuous Pipelines

Operational Longitudinal Strain in the Pipeline

PEAK STRAIN CALCULATION

Longitudinal Strain Due to Internal Pressure (ep)

Longitudinal Strain due to Temperature Change

Total Operational Longitudinal Strain in Pipe

Effective Length Lc of the pipeline over which the force

Tu acts#NUM!

Effect of Permanent Ground Deformation

Design Longitudinal PGD

Design Longitudinal PGD

=

2

=

=

1

1

=

1

1

= +

=

=

=

1

+

+


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Unit

MPaUnit

MPa

Unit

Unit

Unit

Unit

m

Unit

m

Unit

ent of

Geohazard Calculation

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