以修正劍河模式探討隧道開挖之地盤反應行為研究

• Main Author: 蕭伊珍
• Other Authors: 李煜舲
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/07375841186532361930

碩士 === 中華大學 === 土木工程學系碩士班 === 88 === During processing the tunnel excavation and support construction on the soft rocks, the major controlling variables of the timing of setting up the support system are the pre-estimation and control of ground response. Among them, the advancing effects of tunnel excavation and the effects of without-supported distance are the most prominent. To make a comprehensive understanding of this issue, the Modifies Cam-Clay model that considers the strain hardening and is installed in the finite element programming is considered. The main purpose of this research is to examine the interaction between the convergence of rock mass and the confinement of support system. The analysis results of the behavior of tunnel excavation are as following: the stimulating the relation between the advancing effects of tunnel excavation and the without-supported distance, the analysis of non-linearity ground response behavior, and the design of needed supporting pressure. The results obtained of analysis are the ground response curve, the distribution curves of radial displacement, of radial stress and of tangential stress, and the stress path diagram with and without supported system. Before applying the Modified Cam-Clay Model, first the linear elastic model and the elastic-perfectly-plastic model (Mohr-Coulomb failure criteria) is investigated. When it comes to the numerical stimulation of tunnel excavation, the five parameters of Modified Cam-Clay Model (l、k、eo、M and Pco) will be analyzed and examined. As for the with-supported system, the research of the equilibrium point between the ground response curve and the support reaction curve when with different support timing and different support system is considered and simulated. While in the case of tunnel excavation analysis, the advancing effect will be measured according to the model relative parameters, which decides the without-supported distance. Then, by comparing the results of numerical calculation and measurement, we will find that applying Modified Cam-Clay Model to soft rock tunnels can not only get a preliminary convergence, but also handle the non-linearity ground reactive behavior.