ANALYSIS OF REASONABLE EXCAVATION SEQUENCE AND STRESS CHARACTERISTICS OF PORTAL SECTION OF SHALLOW TUNNEL WITH UNSYMMETRICAL LOADINGS
LIU Xiaojun1,2,ZHANG Yongxing1,2
(1. College of Civil Engineering,Chongqing University,Chongqing 400045,China;2. Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China)
Abstract:The portal section of shallow tunnel with unsymmetrical loadings is a typical three-dimensional problem,the main initial geostress of which is gravity stress. The relatively real initial geostress can be obtained by accurately simulating the topographical and geologic conditions,which can increase the reliability of the calculation result.
Analysis of three-dimensional simulation in the excavation process of portal section of shallow tunnel with unsymmetrical loadings of Laozhai tunnel in Guizhou province of Xiamen—Chengdu Expressway is conducted by using the fast Lagrangian analysis of continua in 3 dimensions(FLAC3D) program. Comparing excavated shallow part firstly with excavated deep part firstly by the annular pilot heading conservation core soil method,the changes of deformations and stresses of rock mass and supporting structure of Laozhai tunnel in different excavation sequences are obtained. Actual tunnel excavation sequence is optimized by comparison;and the rationality of excavation scheme is explained by the method of released load and the method of principal stress trace. Finally,through analyzing and calculating the measured data of three measured sections in site,the stress characteristics of surrounding rock and supporting structure of Laozhai tunnel portal section are obtained. The analysis results can provide technical guidance for the design and construction of Laozhai tunnel and the tunnel which has the similar topographical and geologic conditions.
刘小军1,2,张永兴1,2. 浅埋偏压隧道洞口段合理开挖工序及受力特征分析[J]. 岩石力学与工程学报, 2011, 30(S1): 3066-3073.
LIU Xiaojun1,2,ZHANG Yongxing1,2. ANALYSIS OF REASONABLE EXCAVATION SEQUENCE AND STRESS CHARACTERISTICS OF PORTAL SECTION OF SHALLOW TUNNEL WITH UNSYMMETRICAL LOADINGS. , 2011, 30(S1): 3066-3073.
王祥秋,杨林德,高文华. 高速公路偏压隧道施工动态监测与有限元仿真模拟[J]. 岩石力学与工程学报,2005,24(2):284-289. (WANG Xiangqiu,YANG Linde,GAO Wenhua. Dynamic monitoring and FEM simulation analysis of an expressway tunnel with unsymmetrical loadings[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(2):284-289.(in Chinese))
[2]
丁文其,王晓形,李志刚,等. 龙山浅埋大跨度连拱隧道施工方案优化分析[J]. 岩石力学与工程学报,2005,24(22):4 042-4 047. (DING Wenqi,WANG Xiaoxing,LI Zhigang,et al. Optimal analysis of construction schemes for shallow large span Longshan twin tunnel[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(22):4 042-4 047.(in Chinese))
Your browse does not support frame!