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Study on shield tunneling behaviors by kinematic shield model(シールド機動力学モデルによる掘削中のシールド機挙動に関する研究)

氏名 サラムーン アピチャート
学位の種類 博士(工学)
学位記番号 博乙第174号
学位授与の日付 平成13年3月26日
学位論文の題目 Study on shield tunneling behaviors by kinematic shield model (シールド機動力学モデルによる掘削中のシールド機挙動に関する研究)
論文審査委員
 主査 助教授 杉本 光隆
 副査 教授 海野 隆哉
 副査 教授 丸山 久一
 副査 助教授 大塚 悟
 副査 助教授 阿部 雅二朗

平成12(2000)年度博士論文題名一覧] [博士論文題名一覧]に戻る.

TABLE OF CONTENTS

Chapter 1 Introduction p.1
1.1 General p.1
1.2 Literature review p.2
1.2.1 Face stabilization and ground movements p.2
1.2.2 Finite element implementation for shield tunneling works p.7
1.2.3 Field measurement and centrifuge model test p.17
1.2.4 Model of shield tunneling work p.20
1.3 Objectives of this study p.29
1.4 Organization of this research work p.30

Chapter 2 Mechanized Shield Tunneling Work p.32
2.1 Shield tunneling works p.32
2.1.1 General aspect of shield tunneling method p.32
2.1.2 Shield tunneling machinary and applicable soil types p.33
2.1.3 Ground responses caused by shield tunneling p.35
2.2 Shield tunneling control system p.42
2.2.1 Control system for face stabilization p.42
2.2.2 Control system for computation amount of excavated soil volume p.47
2.2.3 Back filling control p.48
2.2.4 Tail sealed control p.49
2.2.5 Shield directional control system p.51

Chapter 3 Model of Loads Acting on Shield p.52
3.1 Forces and their positions p.52
3.1.1 Self-weight of the shield p.52
3.1.2 Forces on the shield tail p.54
3.1.3 Jack force p.58
3.1.4 Force at the face p.59
3.1.5 Earth pressure acting on the shield periphery p.67
3.2 Summations of forces, moments and cutter torque p.69
3.3 Summary p.71

Chapter 4 Simulation Algorithms p.72
4.1 General p.72
4.2 Simulation techniques p.73
4.3 Indexes of shield tunneling behavior p.75
4.3.1 Curvature on the vertical plane p.75
4.3.2 Tilt angle on the vertical plane p.77
4.3.3 Curvature on the horizontal plane p.77
4.3.4 Tilt angle on the horizontal plane p.79
4.4 Summary p.79

Chapter 5 Sensitivity Analyses p.80
5.1 Data used in the analyses p.80
5.1.1 Number of radial element on the front face p.82
5.1.2 Number of circumferential element on the front face p.82
5.1.3 Number of circumferential element on the shield periphery p.85
5.1.4 Number of longitudinal element on the shield periphery p.85
5.1.5 Influence of time interval between two successive steps p.85
5.1.6 Steady state of the shield during excavation p.88
5.2 Simulation of shield tunneling behavior p.88
5.3 Sensitivity analyses p.93
5.3.1 Parameters of force on the shield tail p.93
5.3.2 Parameters of force at the face p.96
5.3.3 Parameters of the ground reaction curve p.100
5.3.4 Parameters of frictional force p.103
5.3.5 Parameters of the shield operations p.105
5.3.6 Parameters of the copy cutter p.109
5.4 Summary p.112

Chapter 6 Application of Shield Loads Model to Shield Tunneling Work p.114
6.1 Shield tunneling site test p.114
6.1.1 Shield tunnling site description p.114
6.1.2 Raw measured data p.119
6.2 Filtering the raw measured data p.124
6.3 Input data p.125
6.3.1 Validations of ground properties p.125
6.3.2 Data used in the simulation p.132
6.4 Simulation of the shield tunneling behavior p.134
6.4.1 Influence of simulation condition on shield tunneling behavior p.134
6.4.2 Shield tunneling behavior p.136
6.4.3 Forces acting on shield during excavation p.139
6.5 Summary p.144

Chapter 7 Conclusions and Recommendations p.146
7.1 Conclusions p.146
7.2 Recommendations for further studies p.148

References p.149

Author Publications p.159

Appendix A Forces on shield tail p.161
Appendix B Ground displacement caused by shield tunneling p.172
Appendix C Earth pressure acting on shield p.179
Appendix D Non-linear least square method p.185
Appendix E Alignment of shield tunnel p.193
Appendix F FE analysis of shield tunneling p.198
Appendix G Reverse analysis p.215
Appendix H Transformation matrices p.217

 The closed type shield tunneling methods have been recently developed together with the computer aided automatic control system of the shield and the tunneling operations to minimize the ground surface settlement. However, some automatic control systems are based on an empirical relationship and the precise theoretical background has not yet been studied. This means that the present automatic shield control systems control the shield to move it back on a planned alignment after snake-like motions, instead of the escape of the snake-like motions. Consequently, it is difficult to control the shield particular in complicated geological structure and to predict the required capacity of the shield. Therefore, a theoretical approach is necessary to cope with the above mentioned problems.
 The purpose of this study is to establish the model of the loads acting on the shield based on the existing model and to develop an algorithm to simulate the shield behaviors during excavation.
 The theoretical loads acting on the shield is modeled especially taking account of the forces on the shield tail, the earth pressure at the face due to the local collapse of the ground at the front face and the force acting on the shield skin plate due to the loosening earth pressure at the shield crown.
 The simulation algorithms were developed to simulate the shield tunneling behaviors and the tunnel alignment parameters based the equilibrium conditions. The optimized solution was assured by the use of Levenberge Maquardt's scheme. The computer programs, in FORTRAN 77, were developed in order to solve the problem.
 The sensitivity analyses of the developed model were carried out to examine the influence of the model parameters to the shied tunneling behaviors. The analyses were examined in both the straight and curve alignments and also for the difference of soil types either sandy or clayey ground.
 Furthermore, the applicability of the model was validated by applying it to the shield tunneling site test. To escape the errors of the shield tunneling site test data obtained by real time high accuracy measuring data system, the filtering process was applied prior to proceed the analysis. The model parameters were determined based on 2D FE analysis, the reverse analysis, the empirical value and the engineering practice.
 Through the study, the results indicate that the model parameters should carefully be handled and the measured data should be filtered prior to apply in the model. The forces on the shield tail should be taken into account in order to predict the shield tunneling behaviors precisely. The earth pressure due to the local collapse of the ground at the face and around the shield is found to influence to the shield tunneling behaviors. The results also discover that the ground displacement around the shield is a predominant factor in determining of the earth pressure acting on the shield. Finally, the model of the loads acting on the shield is successfully verified by the overall agreement between the simulation results and the observation data.

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