Analytical Study of Foundation Soil Pipe Interaction · PDF fileAnalytical Study of Foundation – Soil ... In modeling of pipe-soil interaction soil can be modeled by an elastic continuum

International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 19 (2017) pp. 9176-9194

© Research India Publications. http://www.ripublication.com

9176

Analytical Study of Foundation – Soil – Pipe Interaction

Rafi M. Qasim

Department of Environmental and Pollution Engineering,

Basra Engineering Technical Collage, Southern Technical University, Basra, Iraq.

Abstract

Pipes and pipelines are structural element have important

substantial. Pipes gives various services for example transmit

of fluid. The evaluation of structural behavior more necessary

and more effect .In this paper, a three dimensional finite

element model is achieved by using numerical method to study

the static interaction between soil and pipe when it is path under

statically loaded foundation. The paper studying the influence

of buried depth, embedment ratio, foundation thickness, soil

type, pipe diameter, pipe wall thickness and pipe rigidity on

vertical displacement. In addition, investigation of shear force

and bending moment developed into the pipe. The ANSYS

program is utilized in this study.

Keywords: Foundation, Soil-Pipe-Interaction, Static Loading,

Numerical Modeling.

INTRODUCTION

Pipes and pipelines used to transmit drinkable water or disposal

of wastewater and drainage water are used to transmit oil and

gas or any liquid they are used as means of service in transport

of electric and communication cable. In general, pipes play

very effective and significant role in modern life, especially in

controlling of disaster after flood and seismic hazard. The

behaviour of a buried pipeline will depend very highly on how

its stiffness is compared with the stiffness of the native soil in

which it is to be buried in (1). A pipe must have sufficient

strength and/or stiffness to fulfill its intended use and must be

permanent during the serviceability of life the behavior of

buried pipes is much affected by geotechnical soil properties,

which are shared in the performance of buried pipes.

Evaluation of the behavior and stability of buried pipes are

shown in terms of permissible deflection and buckling

resistance (2) In modeling of pipe-soil interaction soil can be

modeled by an elastic continuum or by winkler model (3).

Modeling of buried pipelines can be carried out as: continuum

finite element modeling for the pipe and using special beam-

type finite elements for the pipe (4).

PROBLEM DEFINITION AND OBJECTIVE

Pipes or Pipelines play a vital role in modern life due to its

ability to convey any liquid between any system. This paper

deals with a problem of pipes buried into soil and pass under

spread foundation especially when the pipe locates under the

center of foundation or footing at shallow depth when the

thickness of superficial soil layer above the pipes can be

considered always small. This search includes numerical

application to study the static interaction between foundation

and pipe due to load transfer by soil layer that covers the pipe.

it is required to investigate:

1. Effect of buried depth and embedment ratio on

vertical displacement.

2. Effect of foundation thickness on vertical

displacement.

3. Effect of static load magnitude on vertical

displacement.

4. Effect of pipe diameter, also wall thickness and pipe

rigidity on vertical displacement.

5. The shear force and bending moment developed into

the pipe.

6. Effect of soil type on vertical displacement.

NUMERICAL MODELING

Finite element continuum method is adopted to represent and

analysis the problem. The ANSYS program is performed to

solve this problem. The pipe are modeled as linear elastic two

nodes beam element with circular section and six degrees of

freedom at each node (three translations and three rotations).

The soil is modeled as an elastic material by using solid

element, which has 8 nodes with three translational degrees of

freedom at each node. The foundation is modeled as an elastic

material by using solid element, which has 8 nodes with three

translational degrees of freedom at each node. Table (1)

reviews the descriptions of circular steel pipe for all case study.

Also table (2) reviews engineering properties of circular steel

pipe. Table (3) reviews the geotechnical data for different clay

soil used in the analysis of the problem. Table (4) shows the

dimension of square spread foundation. Table (5) shows the

concrete properties of foundation. Two different buried depth

0.5m and 1m are used in all case study to infer the static

interaction. The soil domain used to model the problem is

extended to 5 foundation width measured from the center of

foundation to soil boundary on each side and below the

foundation. Fixed boundary conditions applied at the side ends

of the soil domain and the bottom except the top is free. The

connection between the foundation and soil and the connection

between the pipe and soil is considered as perfect bond. The



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static load applied on foundation with range between (200-

1000) KN with constant load incremental about 200KN.

Table 1: circular steel pipe description

Diameter (m) Thickness (mm)

0.25 3 5 10

0.5 3 5 10

Table 2: engineering properties of circular steel pipe

Modulus of

Elasticity (MPa)

Poisson´s Ratio Density (Kg/m3)

200000 0.3 7850

Table 3: geotechnical data of soil

Modulus of

Elasticity (MPa)


30 0.45 1800

40 0.45 1800

50 0.4 1800

Table 4: foundation dimension

Dimension (m) Thickness (m)

1x1 0.3 0.5

Table 5: concrete properties of foundation

Modulus of

Elasticity (Pa)


25743 x 106 0.25 2400

RESULTS AND DISCUSSION

Effect of buried depth and embedment ratio on vertical

displacement.

The effect of buried depth and embedment ratio are inferred by

using numerical finite element method. Figures from (1) to (8)

review the response of pipe to vertical static load transmitted

through soil when the path of pipe located at different depth it

is obvious in figures from (1) to (4) as buried depth increase

the vertical displacement decrease .also figures from (5) to (8)

shows as embedment ratio increase the vertical displacement

decrease .

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(mm

)

Buried Depth (m)

Figure (1) relationship between displacement and buried depthfor pipe pass under foundation (1x1x0.3)m

D=250mm H=875mmD=250mm H=375mm

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(mm

)

Buried Depth (m)

Figure (2) relationship between displacement and buried depth for pipe pass under foundation (1x1x0.3)m

D=500mm H=250mmD=500mm H=750mm



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(mm

)

Buried Depth (m)


D=250mm H=375mm

D=250mm H=875mm

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0

2

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(mm

)

Buried Depth (m)


D=500mm H=250mm

D=500mm H=750mm

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(mm

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H/D

Figure (5) relationship between displacement and embedment ratio for pipe pass under foundation (1x1x0.3)m

D=250mm H/D=3.5D=250mm H/D=1.5

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(mm

)

H/D


D=500mm H/D=0.5

D=500mm H/D=1.5



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This is because the load transmitted by foundation and soil to

pipe dissipation with depth. If the structural capacity of pipe is

greater than the applied load which is combine of four

component (static load , foundation weight , soil weight and

pipe weight ) the pipe displacement will converse it is direction

.also this will appear in first loading condition as shown in

figures from (1) to (8).

Effect of foundation thickness on vertical displacement

The effect of foundation thickness is investigated using

numerical finite element method. Figures from (9) to (12)

shows there is no significant effect on pipe displacement due to

change foundation thickness. The obtained result has no

comparable values because the change in thickness can be

consider small in this paper so this change will not reflect on

pipe behavior.

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(mm

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H/D


D=250mm H/D=1.5

D=250mm H/D=3.5

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2

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(mm

)

H/D


D=500mm H/D=0.5

D=500mm H/D=1.5

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(mm

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Thickness (m)

Figure (9) relationship between displacement of pipe and foundation thickness

D=250mm T=0.3m

D=250mm T=0.5m



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Effect of static load magnitude on vertical displacement

The effect of static load and gradually increase in load

magnitude are investigated. Figures from (13) to (16) shows

that the displacement increase linearly with increasing in load

magnitude regardless of soil type, foundation and pipe

configuration respectively. Note that figure (13) represent the

path of pipe under foundation (1x1x0.3) m with H/D=1.5 and

H/D=3.5. Figure (14) represent the path of pipe under

foundation (1x1x0.5) m with H/D=1.5 and H/D=3.5. Also

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1

2

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(mm

)

Thickness(m)


D=250mm T=0.3m

D=250mm T=0.5m

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0

2

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(mm

)

Thickness (m)


D=500mm T=0.3m

D=500mm T=0.5m

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-2

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0

1

2

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(mm

)

Thickness (m)


D=500mm T=0.3m

D=500mm T=0.5m



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figure (15) represent the path of pipe under foundation

(1x1x0.3) m with H/D=0.5 and H/D=1.5.and figure (16)

represent the path of pipe under foundation (1x1x0.5) m with

H/D=0.5 and H/D=1.5.

Effect of pipe diameter, also wall thickness and pipe rigidity

on vertical displacement

Figures from (17) to (20) shows the response of pipe due to

change in diameter it is clear as diameter increase the vertical

displacement will decrease because the increase in the moment

of inertia of the section and this will reflect on displacement

regardless of buried depth , embedment ratio , soil type ,

foundation configuration and value of applied load . If the

structural capacity of pipe is greater than the applied load the

pipe displacement will converse, it is direction and the pipe

diameter and vertical displacement are consider as

independent. also figures from (21) to (28) review the

relationship between vertical displacement and (t/D) it is clear

as the ratio (t/D) increase the displacement will decrease . also

figures from (29) to (35) shows the effect of pipe wall thickness

as the thickness increase the displacement will decrease due to

increase in the moment of inertia of the pipe and figures from

(36) to (41) shows that as the pipe flexural rigidity increase the

vertical displacement will decrease .

The shear force and bending moment developed into the pipe

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200 400 600 800 1000

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Load (KN)

Figure (13)relationship between pipe displacement and applied load

s1-3mm

s2-3mm

s3-3mm

s1-3mm

s2-3mm

s3-3mm

s1-5mm

s2-5mm

s3-5mm

s1-5mm

s2-5mm

s3-5mm

s1-10mm

s2-10mm

s3-10mm

s1-10mm

s2-10mm

s3-10mm

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200 400 600 800 1000

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(mm

)

Load (KN)

Figure (14) relationship between pipe displacement and applied load

s1-3mm

s2-3mm

s3-3mm

s1-3mm

s2-3mm

s3-3mm

s1-5mm

s2-5mm

s3-5mm

s1-5mm

s2-5mm

s3-5mm

s1-10mm

s2-10mm

s3-10mm

s1-10mm

s2-10mm

s3-10mm



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3

200 400 600 800 1000

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(mm

)

Load (KN)

Figure (15) relationship between pipe displacement and applied load

s1-3mm

s2-3mm

s3-3mm

s1-3mm

s2-3mm

s3-3mm

s1-5mm

s2-5mm

s3-5mm

s1-5mm

s2-5mm

s3-5mm

s1-10mm

s2-10mm

s3-10mm

s1-10mm

s2-10mm

s3-10mm-7

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0

1

2

3

200 400 600 800 1000

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(mm

)

Load (KN)

Figure(16) relationship between pipe displacement and applied load

s1-3mm

s2-3mm

s3-3mm

s1-3mm

s2-3mm

s3-3mm

s1-5mm

s2-5mm

s3-5mm

s1-5mm

s2-5mm

s3-5mm

s1-10mm

s2-10mm

s3-10mm

s1-10mm

s2-10mm

s3-10mm

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(mm

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Diameter (mm)

Figure (17) relationship between pipe diameter and displacement

H=0.5m D=250mm

H=0.5m D=500m

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(mm

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Diameter (mm)


H=1m D=250mm

H=1m D=500m



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men

t (m

m)

Diameter (mm)


H=0.5m D=250mm

H=0.5m D=500m

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(mm

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Diameter (mm)


H=1m D=250mm

H=1m D=500m

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t/D

Figure (21) relationship between displacement and t/D for pipe(250mm) with H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

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0.012 0.02 0.04

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(mm

)

t/D

Figure (22) relationship between displacement and t/D for pipe (250mm) with H/D=3.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN



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0.012 0.02 0.04

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(mm

)

t/D


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -6

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0.012 0.02 0.04

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(mm

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t/D

Figure (24) relatioship between displacement and t/D for pipe (250mm) with H/D=3.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

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0

1

2

0.012 0.02 0.04

Ver

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(mm

)

t/D


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -4

-3

-2

-1

0

1

2

0.012 0.02 0.04

Ver

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(mm

)

t/D


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN



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1

2

0.012 0.02 0.04

Ver

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(mm

)

t/D


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN-4

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1

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0.012 0.02 0.04

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(mm

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t/D

Figure (28) relationship between displacement and t/D for pipe of (500mm) with H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

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thickness (mm)

Figure (29) relationship between displacement and thickness for pipe(250mm) with H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN-6

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thickness (mm)

Figure (30) relationship between displacement and thickness for pipe (250mm) with H/D=3.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN



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3 5 10

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(mm

)

thickness (mm)


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -6

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thickness (mm)

Figure (32) relatioship between displacement and thickness for pipe (250mm) with H/D=3.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

-7

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0

1

2

3 5 10

Ver

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(mm

)

thickness (mm)


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -4

-3

-2

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0

1

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3 5 10

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(mm

)

thickness (mm)


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN



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-7

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3 5 10

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(mm

)

thickness (mm)


S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN-4

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1

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3 5 10

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(mm

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thickness (mm)

Figure (36) relationship between displacement and thickness for pipe of (500mm) with

H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

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EI

Figure (37) relationship between displacement and flexural rigidity for pipe(250mm) with

H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -6

-5

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI

Figure (38) relationship between displacement and flexural rigidity for pipe (250mm) with

H/D=3.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN



9188

-12

-10

-8

-6

-4

-2

0

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI


H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -6

-5

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI

Figure (40) relatioship between displacement and flexural rigidity for pipe (250mm) with

H/D=3.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

-7

-6

-5

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI


H/D=0.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI


H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN



9189

-7

-6

-5

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI


H/D=0.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN -4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

EI

Figure (44) relationship between displacement and flexural rigidity for pipe of (500mm) with

H/D=1.5

S1,F=200KN

S2,F=200KN

S3,F=200KN

S1,F=400KN

S2,F=400KN

S3,F=400KN

S1,F=600KN

S2,F=600KN

S3,F=600KN

S1,F=800KN

S2,F=800KN

S3,F=800KN

S1,F=1000KN

S2,F=1000KN

S3,F=1000KN

0

20000

40000

60000

80000

100000

120000

140000

160000

She

ar F

orc

e (

N)

Buried Depth (m)

Figure (45) relationship between shear force and buried depth

H=0.5m D=250mm

H=0.5m D=500m

0

20000

40000

60000

80000

100000

Shea

r Fo

rce

(N)

Buried Depth (m)


H=1m D=250mm

H=1m D=500m



9190

0

20000

40000

60000

80000

100000

120000

140000

160000Sh

ear

Forc

e (N

)

Buried Depth (m)


H=0.5m D=250mm

H=0.5m D=500m

0

20000

40000

60000

80000

100000

120000

140000

Shea

r Fo

rce

(N)

Buried Depth (m)


H=1m D=250mm

H=1m D=500m

0

10000

20000

30000

40000

50000

60000

70000

80000

Be

nd

ing

Mo

me

nt

(N.m

)

Buried Depth (m)

Figure (49) relationship between bending moment and buried depth

H=0.5m D=250mm

H=0.5m D=500m

0

10000

20000

30000

40000

50000

60000

Ben

din

g M

om

ent

(N.m

)

Buried Depth (m)


H=1m D=250mm

H=1m D=500m



9191

The variation of the shear force and bending moment with

buried depth are shown in figures from 45 to 52 respectively.

All figures show that the variation in shear forces and bending

moments due to different load applied and change in pipe

diameter take in consideration wall thickness and pipe rigidity

Figures 45,47,49 and 51represent the path of pipe (250mm)

under foundation (1x1x0.3)m also figures 46,48,50 and 52

represent the path of pipe (500mm) under foundation

(1x1x0.5)m. these figures shows the maximum value of shear

force and bending moment respectively.

Effect of soil type on vertical displacement

Three types of soils are differed in properties are considered in

case study it is clear in figures from 53 to 59 as the soil modulus

of elasticity increase the response of buried pipe decrease for

the same loading condition regardless of foundation

configuration .except in the case when the structural capacity

of pipe greater than the applied load the soil modulus of

elasticity has no significant effect .

0

10000

20000

30000

40000

50000

60000

70000

80000B

end

ing

Mo

men

t (N

.m)

Buried Depth (m)


H=0.5m D=250mm

H=0.5m D=500m

0

10000

20000

30000

40000

50000

60000

Ben

din

g M

om

ent

(N.m

)

Buried Depth (m)


H=1m D=250mm

H=1m D=500m

-12

-10

-8

-6

-4

-2

0

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

Pipe Diameter (mm) with Soil modulus of elasticity (MPa)

Figure (53) relationship between pipe displacement and soil modulus of elasticity

D=250mm E=30MPa

D=250mm E=40MPa

D=250mm E=50MPa



9192

-6

-5

-4

-3

-2

-1

0

1

2V

erti

cal D

isp

lace

men

t (m

m)



D=250mm E=30MPa

D=250mm E=40MPa

D=250mm E=50MPa

-7

-6

-5

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)



D=500mm E=30MPa

D=500mm E=40MPa

D=500mm E=50MPa

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)


Figure (55)relationship between pipe displacement and soil modulus of elasticity

D=500mm E=30MPa

D=500mm E=40MPa

D=500mm E=50MPa

-12

-10

-8

-6

-4

-2

0

2

Ver

tica

l Dis

pla

cem

ent

(mm

)

Pipe Diameter (mm) with soil modulus of elasticity (MPa)

Figure (56) relationship between pipe displacement and Soil modulus of elasticity

D=250mm E=30MPa

D=250mm E=40MPa

D=250mm E=50MPa



9193

CONCLUSIONS

The main conclusions from this paper shows , The buried depth

and embedment ratio play important role on the response of

buried pipe , Foundation thickness has no significant effect on

the response of buried pipe , The vertical displacement of pipe

increase linearly with increasing in load magnitude , As the

pipe diameter , pipe wall thickness , ratio (t/D) , and pipe

rigidity increase the pipe displacement will decrease , The

variation of shear force and bending moment will reflect the

behavior of buried pipe , As the soil modulus of elasticity

increase the pipe vertical displacement decrease , The structural

capacity of pipe will reflect it is behavior under loading

condition .

REFERENCE

[1] J.L.Olliff , S.J.Rolfe , D.C Wijeyesekera and

J.T.Reginold , Soil-Structure-Pipe Interaction with

Particular Reference to Ground Movement Induced

Failures , Proceedings of Plastics Pipes XI , 2000.

-6

-5

-4

-3

-2

-1

0

1

2V

erti

cal D

isp

lace

men

t (m

m)


Figure (57) relationship between pipe displacement and Soil modulus of elasticity

D=250mm E=30MPa

D=250mm E=40MPa

D=250mm E=50MPa

-7

-6

-5

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)



D=500mm E=30MPa

D=500mm E=40MPa

D=500mm E=50MPa

-4

-3

-2

-1

0

1

2

Ver

tica

l Dis

pla

cem

ent

(mm

)



D=500mm E=30MPa

D=500mm E=40MPa

D=500mm E=50MPa



9194

[2] A . P . Moser, Buried Pipe Design: McGraw - Hill,

1990 .

[3] Jian Yu, Chenrong Zhang, Maosong Huang, Soil-Pipe

interaction due to tunneling: Assessment of Winkler

modulus for underground pipelines, Computers and

Geotechnices 50(2013),17-28.

[4] Bernardo Horowitz, Evandro Parente Jr , Assesment

of Simplified Pipe-Soil Interaction Models, 17th

International Congress of Mechanical Engineering,

November 10-14 , 2003.

Documents

Analytical Study of Foundation Soil Pipe Interaction · PDF fileAnalytical Study of Foundation – Soil ... In modeling of pipe-soil interaction soil can be modeled by an elastic continuum