MESOSCALE NUMERICAL STUDY ON THE TUNNELING-INDUCED GROUND RESPONSE IN A SANDY COBBLE STRATUM CONSIDERING THE ROCK ORIENTATION ANGLE

被引：0
|
作者：
Zhang P. [1 ,2 ]
Liu Z.-H. [1 ]
Qi J.-L. [1 ]
Du X.-L. [3 ]
机构：
[1] School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing
[2] Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong
[3] Key Lab of Urban Security and Disaster Engineering, Ministry of Education, Beijing University of Technology, Beijing
来源：
Gongcheng Lixue/Engineering Mechanics | 2022年 / 39卷 / 10期
关键词：
ground response; mesoscale finite element method; rock orientation angle; sandy cobble stratum; tunnel excavation;
D O I：
10.6052/j.issn.1000-4750.2021.04.0314
中图分类号：
学科分类号：
摘要：
In engineering practice, oval or subcircular pebbles are distributed in ground at different orientation angles. It investigates the effect of the rock orientation angle on the ground response during tunneling in sandy cobble stratums, with special attention to the material meso-structure. By treating the ground material as a composite of rock blocks and soil matrix, mesoscale numerical models were established. A series of simulations were carried out to model the tunnel excavation using the mesoscale models. By comparing the ground stress between the simulation results and the theoretical values, the applicability of the mesoscale models was verified. Based on this, the ground response during tunnelling in a sandy cobble stratum is analyzed from the viewpoint of stress distribution and deformation performance. The simulation results show that, with the increase of the orientation angle from 0° to 90°, both the shape and extension of the plastic zone changes, and the vertical stress in the soil mass at the tunnel side increases gradually. Under given conditions, the maximum surface subsidence increases linearly with the increase of the rock orientation angle at a relative rate of 5.17% per 10°. The width coefficient of the surface settlement trough first increases and then decreases. When the rock orientation angle is 30°, the width coefficient of the surface settlement trough reaches the maximum value. The relationship between the maximum subsidence Smax(z) with the depth z can be described by a power function. The relationship between the width coefficient of the subsurface settlement trough i(z) with the depth z can also be described by a power function. © 2022 Tsinghua University. All rights reserved.
引用
收藏
页码：48 / 60
页数：12
相关论文
共 32 条
  • [1] ZHANG P, JIN L, DU X L, Et al., Computational homogenization for mechanical properties of sand cobble stratum based on fractal theory [J], Engineering Geology, 232, pp. 82-93, (2018)
  • [2] DU X L, ZHANG P, JIN L, Et al., A multi-scale analysis method for the simulation of tunnel excavation in sandy cobble stratum [J], Tunnelling and Underground Space Technology, 83, pp. 220-230, (2019)
  • [3] LIN Q T, LU D C, LEI C M, Et al., Model test study on the stability of cobble strata during shield under-crossing, Tunnelling and Underground Space Technology, 110, 9, (2021)
  • [4] WANG Zhenfeng, Study on ground surface settlement due to metro shield tunneling in sand cobble stratum, (2012)
  • [5] MA Hui, GAO Mingzhong, ZHANG Jiankang, Et al., Theoretical model developed for equivalent elastic modulus estimation of cobblestone-soil matrix, Rock and Soil Mechanics, 32, 12, pp. 3642-3646, (2011)
  • [6] MOU Di, Research on distribution law and engineering properties in sand and gravel strata, (2015)
  • [7] ZHANG Shu, TANG Huiming, Research on soil-rock mixture stochastic model based on meso-structural statistical characteristics [J], Yangtze River, 46, 16, pp. 48-52, (2015)
  • [8] XU W J, YUE Z Q, HU R L., Study on the meso-structure and meso-mechanical characteristics of the soil-rock mixture using digital image processing based finite element method [J], International Journal of Rock Mechanics and Mining Sciences, 45, pp. 749-762, (2008)
  • [9] ZHANG Pei, DU Xiuli, JIN Liu, Et al., Study on the orientation angel of rock long axis on the micromechanical properties of soil-rock mixture, Engineering Mechanics, 35, 8, pp. 64-72, (2018)
  • [10] GAO M Z, ZHAO J, LI S W, Et al., Theoretical model of the equivalent elastic modulus of a cobblestone-soil matrix for TBM tunneling [J], Tunnelling and Underground Space Technology, 54, pp. 117-122, (2016)
1234