STUDY OF SURFACE STRUCTURES DUE TO

VIBRATION OF UNDERGROUND TUNNEL AT

SHALLOW DEPTH

� The current population of the world is around

7 billion

� Demand for effective transportation system � Demand for effective transportation system

and better infrastructure is increasing

� Available area on the surface is decreasing

� The solution is underground structures and

transit

� Structures like tunnels, caverns etc.

� Structures subjected to loads; static and

dynamicdynamic

� Dynamic loads can be from the

*traffic

*seismic forces

*excavation methods

*explosions etc.

� Dynamic interaction can cause disturbance to the

environment and the users

� Risk management and safety measures can be � Risk management and safety measures can be

decided

� Economic construction

� To find the soil particle behavior on the surface due

to the vibration underground

� In terms of the velocity, acceleration and � In terms of the velocity, acceleration and

displacement

� Ground vibration prediction model

� Soil-structure interaction

� Loads can vary in time and space

� High frequency content of the loading is difficult to High frequency content of the loading is difficult to

measure and analyze

� Blast induced vibrations

� Train induced vibrations

� Blast loads to excavate the soil

� Tunnel is builtTunnel is built

� Train loads are applied

� Vibrations on the surface is studied

� Analytical solutions are accurate but tiresome for

complicated problems

� The tunnel soil interaction is not easy to study with � The tunnel soil interaction is not easy to study with

analytical methods

� Numerical solution comes for help

� FEM based PLAXIS 8x version

� Found in 1987 at the Technical University of Delft

For the analysis of deformation and stability in � For the analysis of deformation and stability in

geotechnical engineering projects

� To be used by geotechnical engineers who are

not necessarily numerical specialists

� 2D version

� The model was plane strain model

� State of strain in which the strain normal to

the x-y plane, εz and the shear strain γxz and

γyz are assumed to be zero

� dimension of the structure in one direction is

very large in comparison with the dimensions

of the structure in the other two directions

� the geometry of the body is essentially that

of a prismatic cylinder with one dimension

much larger than the others

� Rectangular model of length 66m and height 40m

� Absorbent boundaries on three sides

� Method of construction NATM

� Staged construction� Staged construction

� Tunnel diameter was chosen as 6m and depth

6m

� Loads were dynamic point loads

� Blast induced vibration

*amplitude 1000kPa*amplitude 1000kPa

*frequency 200 Hz

� Train induced vibration

*amplitude 200kPa

*frequency 80 Hz

� Consists of four phases

� First phase

� Tunnel was built

� Static forces act

� Plastic analysis

� Second stage▪ The blast point loads were applied

▪ Time interval 1 sec

▪ Dynamic analysis▪ Dynamic analysis

� Third stage▪ Excavation of soil and tunnel lining installation

▪ Plastic analysis

� Fourth phase

▪ The traffic loads were applied

Time interval 20 sec▪ Time interval 20 sec

▪ Dynamic analysis

� Point A▪ Directly above the centre of the tunnel

▪ Co-ordinates (33,40)

Point B� Point B▪ 10m away from point A

▪ Co-ordinates (23,40)

� Point C▪ 20m away from point A

▪ C0-0rdinates (13,40)

� Velocity-time variation

� Displacement-time variation

� Acceleration-time variation

0.06

0.08

0.1

Velocity [m/s]

Chart 3

Point A

Point B

Point C

0 0.2 0.4 0.6 0.8 1 1.2

-0.02

0

0.02

0.04

dynamic time (s)

0.03

0.04

0.05

Velocity [m/s]

Chart 1

Point A

Point B

Point C

0 0.2 0.4 0.6 0.8 1 1.2

-0.01

0

0.01

0.02

dynamic time (s)

0.02

0.025

0.03

Velocity [m/s]

Chart 1

Point A

Point B

Point C

0 0.2 0.4 0.6 0.8 1 1.2

-5e-3

0

5e-3

0.01

0.015

dynamic time (s)

0.015

0.02

Velocity [m/s]

Chart 1

Point A

Point B

Point C

0 0.2 0.4 0.6 0.8 1 1.2

-5e-3

0

5e-3

0.01

dynamic time (s)

9e-3

0.012

0.015

Velocity [m/s]

Chart 2

Point A

Point B

Point C

0 0.2 0.4 0.6 0.8 1 1.2

-3e-3

0

3e-3

6e-3

dynamic time (s)

3

4

Acceleration [m/s2]

Chart 1

Point A

Point B

Point C

0 0.2 0.4 0.6 0.8 1 1.2

-1

0

1

2

dynamic time (s)

4e-3

5e-3

6e-3

Displacement [m]

Chart 5

Point A

Point B

Point C

-0.3 0 0.3 0.6 0.9 1.2

-1e-3

0

1e-3

2e-3

3e-3

dynamic time (s)

� Tunnel depth

� Tunnel diameter

� The depth of the tunnel from the surface

� The depths chosen;

� 6m (d)� 6m (d)

� 12m (2xd)

� 18m (3xd)

� 24m (4xd)

� 30m (5xd) d=diameter

0.07

0.08

0.09

0.1

velocity vs depth

0

0.01

0.02

0.03

0.04

0.05

0.06

0 5 10 15 20 25 30 35

VE

LO

CIT

Y (

m/s

)

DEPTH (m)

A

B

C

0.2

0.25

0.3

displacement vs depth

0

0.05

0.1

0.15

0.2

0 5 10 15 20 25 30 35

Dis

pla

cem

en

t (m

)

Depth (m)

A

B

C

6

7

8

9

acceleration vs depth

0

1

2

3

4

5

6

0 5 10 15 20 25 30 35

Acc

ele

rati

on

(m

/s²)

Depth (m)

A

B

C

� Velocity of the soil particles decrease in proportion

with the tunnel depth

� Acceleration also decrease with the tunnel depth� Acceleration also decrease with the tunnel depth

� Displacement increases as tunnel depth increases

� The value was max at A and min at C

� The tunnel diameter chosen were

*6m

*7m*7m

*8m

� The depth was kept as constant 6m in all the above

cases.

0.35

0.4

0.45

0.5

velocity vs diameter

0

0.05

0.1

0.15

0.2

0.25

0.3

0 1 2 3 4 5 6 7 8 9

Ve

loci

ty (

m/s

)

Diameter (m)

A

B

C

0.25

0.3

0.35

displacement vs diameter

0

0.05

0.1

0.15

0.2

0 1 2 3 4 5 6 7 8 9

Dis

pla

cem

en

t (m

)

Diameter (m)

A

B

C

6

7

8

9

acceleration vs diameter

0

1

2

3

4

5

6

0 1 2 3 4 5 6 7 8 9

Acc

ele

rati

on

(m

/s²)

Diameter (m)

A

B

C

� Velocity, acceleration and displacement increase as

tunnel diameter increase from 6m to 8m

� The magnitude was max at point A and min at point � The magnitude was max at point A and min at point

C

� Analytical model

� Charge-Distance Relationship

This relationship is known as the Propagation Law, This relationship is known as the Propagation Law,

developed in the U.S. Bureau of Mines Bulletin 656

•The charge weight per delay was 10.54 poundsThe charge weight per delay was 10.54 pounds

•The distance from the charge is 7m

•The value was fund to be 0.0914m/s and this was

comparable with the value obtained from numerical

analysis, 0.092m/s

� Similar study on PLAXIS

� Case study in Iran Ahwaz city

� The geologic conditions were comparable, clay

soil

� Model was 6m diameter tunnel at a depth of

12m

� The frequency of the train was assumed ranged

between 70-80 Hz

� The average peak particle velocity of the present

study due to train traffic was 0.0004m/s

� The average peak particle velocity for the above � The average peak particle velocity for the above

work was 0.0006m/s

� Velocity of the soil particle decreases as the tunnel

depth increases

� Acceleration of the soil particle decreases as the � Acceleration of the soil particle decreases as the

tunnel depth increases

� Displacement increases as the tunnel depth

increases

� The velocity, the displacement and the acceleration

increases as the tunnel diameter increases

� The magnitude for the velocity, displacement and � The magnitude for the velocity, displacement and

the acceleration was maximum at point A, lesser at

point B and least at point C

� 1. M.S. Pakbaz, R. Mehdizadeh, M. Vafaeian and K. Bagherinia N.; Numerical

prediction of subway induced vibrations: Case study in Iran Ahwaz city, Journal of

Applied Sciences 9(11); 2001-2015 (2009).

� 2. Hamid Reza Netaji, Morteza Ahmadi, Hamid Hashemolhosseini.; Numerical

analysis of ground surface vibration induced by underground train movement, analysis of ground surface vibration induced by underground train movement,

Tunnelling and Underground Space Technology 29,1-9 (2012).

� 3. D. Clouteau, M. Arnst, T.M. Al-Hussaini and G. Degrande.; Freefield vibrations

due to dynamic loading on a tunnel embedded in a stratified medium, Journal of

Sound and Vibration, 283(1-2):173-199 (2005).

� 4. Seung-Ryull Kim.; Some experience from the soft ground tunnelling in urban

area, Seminar on “The State of the art Technology and Experience on

Geotechnical Engineering in Korea and Hong Kong-28 March 2008, 2008

Geotechnical Division, The Hong Kong Institution of Engineers.

� 5. G. Lombaert, G. Degrande.; Experimental validation of the numerical

prediction model for freefield train induced vibrations by in situ experiments, Soil

Dynamics and Earthquake Engineering 21,485-497 (2001).

� 6. J.A. Forrest, H.E.M. Hunt.; A three-dimensional tunnel model for calculation of

train-induced ground vibration, Journal of Sound and Vibration, 294(4-5):706–736 train-induced ground vibration, Journal of Sound and Vibration, 294(4-5):706–736

(2006).

� 7. D. Grothe, P. Reinders.; Advanced vibration management in quarries using a

predictive blast vibration model, European Federation of Explosives Engineers,

ISBN 978-0-9550290-1-1 (2007).