A 3D finite element simulation model for TBM tunnelling in soft ground     

Thomas Kasper  Günther Meschke 《国际地质力学数值与分析法杂志》2004,28(14):1441-1460

  相似文献   

GIS中直线元内插点精度及对误差带的影响   总被引：1，自引：0，他引：1  

魏峰远  邰茜 《测绘学院学报》2005,22(3):232-234

基于误差传播定律，考虑参数r误差影响，推导了线元内插点的精度计算公式，讨论内插点精度对线元误差带的影响，并对影响的结果进行了分析，得到了一些有益的结论。  相似文献   

Relationship of Uncertainty and Line Segment for Between Polygon Segment Spatial Data in GIS     

LIU Chun TONG Xiaohua 《地球空间信息科学学报》2005,8(3):183-188

The mathematic theory for uncertainty model of line segment are summed up to achieve a general conception, and the line error hand model of εσ is a basic uncertainty model that can depict the line accuracy and quality efficiently while the model of εm and error entropy can be regarded as the supplement of it. The error band model will reflect and describe the influence of line uncertainty on polygon uncertainty. Therefore, the statistical characteristic of the line error is studied deeply by analyzing the probability that the line error falls into a certain range. Moreover, the theory accordance is achieved in the selecting the error buffer for line feature and the error indicator. The relationship of the accuracy of area for a polygon with the error loop for a polygon boundary is deduced and computed.  相似文献   

A Procedure for Determining the Reaction Curve of Shotcrete Lining Considering Transient Conditions   总被引：6，自引：0，他引：6  

P. P. Oreste 《Rock Mechanics and Rock Engineering》2003,36(3):209-236

Summary The mechanical behaviour of a shotcrete lining is analysed in this paper using the convergence-confinement approach. A calculation procedure is presented which is able to provide the reaction curve of a lining with increasing stiffness, by taking into account the variability due to time of the shotcrete stiffness and strength, as well as the face advancement rate. The proposed procedure is also able to provide the change of the safety factor of the lining in time. This results to be a very useful tool for understanding the behaviour of this widely used support and for assigning its thickness to guarantee stability (also in transient conditions), with a known safety factor, during tunnel excavation. Received May 25, 2001; accepted July 18, 2002; Published online January 21, 2003 Acknowledgements The author would like to thank Prof. S. Pelizza and Dr. S. Xu for the help given during the preparation of this paper. The help of the Editor G. Barla is also acknowledged. Authors' address: Dr. P. P. Oreste, Department of Earth Resources and Land, Politecnics di Torino, corso Duca degli Abruzzi 24, 1-10129 Torino, Italy; e-mail: oreste@polito.it  相似文献   

深厚表土层地面注浆加固过程中井壁应变变化规律     

付厚利 《岩土力学》2003,(Z1)

分析了深厚表土层地面注浆加固过程中井壁的受力特点,介绍了金桥矿副井表土段地面注浆加固过程中井壁的应变观测结论,提出了深厚表土层井壁外注浆加固工程的井壁安全保证核心技术。  相似文献   

隧道支护结构荷载作用的随机反演   总被引：7，自引：0，他引：7  

朱永全  张清 《岩土力学》1996,17(2):57-63

提出荷载－结构模式进行随机反分析方法，从隧道支护结构变形反算对应的荷载作用，可反推围岩抗力系数和覆土荷载的分布情况，以及作用于支护结构上各部位的外荷载。提出了以实测位移为基础的样条函数插值．以插值位移补充大量的实测值，满足了反分析所需众多的已知位移数。通过一施工实例对该方法的可行性进行了检验。  相似文献   

The effect of an interface boundary layer on the resonance properties of a buried structure     

Y. S. Karinski  V. V. Shershnev  D. Z. Yankelevsky 《地震工程与结构动力学》2004,33(2):227-247

This paper presents a model for the analysis of the diffraction of plane waves at a cavity in an infinite homogeneous linear elastic medium supported by a segmented lining. An elastic boundary layer is introduced between the cavity lining and the infinite medium. The boundary layer is simulated by ‘elastic boundary conditions’ in which the stress is proportional to the relative displacement of the lining and of the surrounding medium boundary. A closed‐form analytical solution of the problem was obtained using the Fourier–Bessel series, the convergence of which was proven. It was shown that the number of series terms required to obtain a desired level of accuracy can be determined in advance. Using amplitude–frequency response analysis it was shown that the boundary layer produces additional ‘pseudo‐resonance’ frequencies that depend on the layer properties. These frequencies are almost identical to the eigenvalues obtained from the simple analysis of a segmented elastically supported lining. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

SH波对无限介质土中衬砌结构的动应力集中     

周香莲  周光明 《岩土力学》2004,25(Z2):366-368

运用复变函数法和保角映射法对无限介质土中的衬砌结构进行分析.通过引入两个势函数将弹性介质的控制方程解耦成两个Helmholtz方程.利用所得势函数的通解,得到无限土介质和衬砌结构的位移和应力的表达式,利用无限介质与衬砌结构之间的连续性条件和衬砌结构内边界上的边界条件,可确定波函数展开式中的末知系数,并给出动应力集中系数的数值结果.  相似文献   

A new numerical approach to the hyperstatic reaction method for segmental tunnel linings     

Ngoc Anh Do  Daniel Dias  Pierpaolo Oreste  Irini Djeran‐Maigre 《国际地质力学数值与分析法杂志》2014,38(15):1617-1632

This paper proposes a numerical approach to the hyperstatic reaction method (HRM) for the analysis of segmental tunnel linings. The influence of segmental joints has been considered directly using a fixity ratio that is determined on the basis of the rotational stiffness. The parameters necessary for the calculation are presented. A specific implementation has been developed using a FEM framework. This code is able to consider the three‐dimensional (3D) effect of segment joints in successive rings on the tunnel lining behaviour. The present HRM allows one to take an arbitrary distribution of segment joints along the tunnel boundary into consideration. In addition, the rotational stiffness of segment joints has been simulated using nonlinear behaviour, as it is closer to the true behaviour of a joint than linear or bilinear behaviour. The numerical results of three hypotheses on ring interaction, which allow the 3D effect of a segmental tunnel lining to be taken into account, have been compared with data obtained from the shield‐driven tunnel of the Bologna–Florence high‐speed railway line project. The numerical results presented in the paper show that the proposed HRM can be used to effectively estimate the behaviour of a segmental tunnel lining. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

软岩隧道中双层初期支护的应力情况分析     

姚正源 《探矿工程》2018,45(7):73-76

两水隧道穿越的地层主要岩性为炭质千枚岩,地质情况较差,围岩破碎度高,节理发育。自2009年两水隧道开工建设以来,隧道工程问题层出不穷,出现了初期支护开裂、破坏,甚至出现二衬开裂、掉块,仰拱隆起等严重的隧道结构破坏现象,施工进度缓慢。在进口桩号为DK359+712～ DK359+742段采用双层初期支护和单层二次衬砌的支护方式,取得了良好的效果。通过应力情况分析为炭质千枚岩隧道的支护选型提供了依据。  相似文献