Analysis of mechanical behaviors of big pipe roof for shallow buried large-span tunnel

作     者：Li Jian Tan Zhongsheng Yu Yu Guo Xiaohong 

作者机构：Second Highway Consultants Co. Ltd.China Communications Construction Company Ltd. School of Civil EngineeringBeijing Jiaotong University The Second Survey and Design Institute of China Railway 

出 版 物：《Engineering Sciences》 (中国工程科学（英文版）)

年 卷 期：2013年第11卷第6期

页      面：32-37页

学科分类：081406[工学-桥梁与隧道工程] 08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0814[工学-土木工程] 082301[工学-道路与铁道工程] 0823[工学-交通运输工程] 

基　　金：Major Science and Technology R&D Program of Ministry of Railways(No.2005K001-D(G)-2) 

主　　题：shallow burying mining underpass construction loess tunnel pipe roof deformation monitoring mechanical behavior 

摘      要：A series of researches on mechanical behaviors of big pipe roof for shallow large-span loess tunnel were carried out based on the Wenxiang tunnel in Zhengzhou—Xi an Special Passenger Railway. The longitudinal deformations of the pipe roofs were monitored and the mechanical behaviors of the pipe roofs were analyzed at the test section. A new double-parameter elastic foundation beam model for pipe roof in shallow tunnels was put forward in Wenxiang tunnel. The measured values and the calculation results agreed well with each other,revealing the force-deformation law of big pipe roof in loess tunnel:At about 15 m in front of the excavating face,the pipe roof starts to bear the load;at about 15 m behind the excavating face,the force of the pipe roof tends to be stabilized;the longitudinal deformation of the whole pipe roofs is groove-shaped distribution,and the largest force of pipe roofs is at the excavating face. Simultaneously,the results also indicate that mechanical behaviors of pipe roof closely relate to the location of the excavation face,the footage of the tunnelling cycle and the mechanics parameters of pipe roof and rock. The conclusions can be reference for the design parameter optimization and the construction scheme selection of pipe roofs,and have been verified by the result of numerical analysis software FLAC3Dand deformation monitoring.