"Study on the Influence of TBM operation on its behavior in H&V Shield"
by Castillo Felix Corina Alejandra
Civil Engineering Department
Student Number: 12323988

1. Introduction:
The objectives of this study were to run a
Sensitivity

analysistounderstandF3rR

theinfluence of a tunnel boring machine on ahorizontal and vertical movement shield, and tocompare the shield tunneling behaviors between
the simulation results and the observed data toverify the model.
A Shield tunneling method is any method inwhich a solid cylinder or shield is push forward
throughtheground with

thepurposeoftunneling construction. This shield is calleda Tunnel Boring Machine or TBM.
A Vertical and Horizontal shield is a

Table 1. Parameters

tunneling machine using two bodies, with crosssections that can be changed continuously from horizontal to vertical multi-circular shapeor vice versa, for simultaneous construction of multiple tunnels.
2. Sensitivity Analisys
In the other hand, a sensitivity analysis has the objective to make quantitatively clear
the characteristics of operational parameters on H&V shield behavior.
The parameters analyzed are on Table 1, which are (from left to right): copy cutter range
and copy cutter length, crease angle and pitching angle, jack thrust force and the ground.

2.1 Type 1
For this Type the effective rate was modified.
For the biggest impression was presented on the shield bahavior where we can check thatcase (d) (presented with the lowest effective rate) stops its results even before the 10

meters distance is reached. This isbecause the effective rate affects theexcavation speed or velocity, the lower
the rate, the slowest it becomes, andtherefore

thedistancereachedisshorter.
Graph 1. Velocity vs. distance, case (d)2.2 Type 2
For Type 2, the study was divided in Type 2.1 with



00.5

1

an alpha value 0.5 and 2.2 with an alpha value 1.

 cv

 cv

0.5 cv

0fp

0

We can appreciate the influence of this value on thecrease and pitching angle on Table 2.
Therefore,fp(pitching angle) has a tendency

to be reduced the higher is the  value. The
reduction of thefp

means a change on the vertical

 cv

0.5 cv

Table 2. Alpha effect on crease ( cv ) andpitching (fp)angle.

angle, and when the machine starts to go upwards, the velocity is reduced, and therefore
the distance.
The Crease angle influences the pressure on the front and rear part of the machine, butjust on the Right Body, since the Left Body does not present an inclination angle on thevertical direction. The reason for this influence is that this inclination angle, led toa bigger area for the pressure to act.

In case (a), Graph 2, the jack trust
value is equal to 0.4, and for Case (b),Graph 3, 0.6 on the left body of thef y (min)2.3 Type 3-300-200-1000100200300

Graph 2. Case (a)was calculated as: 1 minus the force of theleft body. Even tough these were thef y (min)machine. While the force of the right body,-300-200-1000100200300

Graph 3. Case (b)values used on the calculating programs, the real value is in percentage, therefore, whenthe value 0.6 is mentioned, it actually means a 60% of the jack thrust force maximum capacity.
First of all, we can see that the distance reached in Graph 2 case (b) is larger, butthat even in this case, the 20 meters are not reached. The reason was because in order tocompensate the jack force and the force acting at the face, the force acting on the periphery
was increased, therefore reducing the velocity, the jack force also had an effect on thedirection of the machine as we can appreciate on the screen, turning to left when the jackforce is bigger on the right body, and vice versa.

2.4 Type 421

2324Plan(L)
Plan(R)
Cal(L)
Cal(R)

22x (m)x (m)Type 4 corresponds to the21Plan(L)
Plan(R)
Cal(L)
Cal(R)

222324analysis

oftheground

2525

26

26-20

02040
Distance(m)

6080

-20

100

02040
Distance(m)

60

80

100

parameters. The case (a) on
Graph 4 represents a stiff

1010Plan(L)Plan(R)
Cal(L)
Cal(R)

0-5

type ground (SPT-N valuePlan(L)
Plan(R)
Cal(L)
Cal(R)

5y (m)y (m)5equal to 30), while the case0(b) are the results of doing-5-10

the analysis on a very stiff

-10
-20

020

40

60

80

100-20020z (m)

4060

80

100

type of ground (SPT-N valuez (m)40403030Calculated distance (m)Calculated distance (m)equal to 50).
2010

Both cases presented a20

very

10similar

behavior.

shieldThe

most00significant difference for-10-10-200204060

Planed distance (m)Distance

80

100

-20

02040
Planed distance (m)Distance

60

80

100

thisparameteristhedistance reached, as we canappreciate on the Graph 4,

Graph 4.

Case a)Case b)wherecase (b),withastiffer ground, duplicatedthe distance reached. This brings us the conclusion that when the ground is stiffer, therotation of the machine comes more easily and therefore reaches a longer distance.

3. Conclusions
Of the four principal parameters that were analyzed for this study we can conclude as
next:
1)

The effective rate of the copy cutter machine is important to reduce the friction

generated because of the contact between the machine and the ground. This is importantbecause the friction reduces the velocity.
2)

The  value, which only affects the Right body, affects the pressure area due tothis inclination. For this reason, a bigger  value means bigger pressure against thetunneling machine, reducing the velocity too.
3)

A large jack force is required to increase the velocity. Also, the jack moment iseffective for rotating the shield.
4)

The stiffness actually helps the machine, permitting the rotation more easily,

increasing the velocity ant therefore also the reached distance.
These parameters of the Tunneling Boring Machine, therefore, have an influence on theHorizontal and Vertical shield machine that should be considered in order to optimize theexcavation work.