The role of dilatancy in shallow overburden tunneling
作者机构:Department of Urban ManagementKyoto UniversityNishikyo-KuKyoto 615-8540Japan Department of Civil EngineeringYokohama National UniversityYokohamaKanagawa 240-8501Japan
出 版 物:《Underground Space》 (地下空间(英文))
年 卷 期:2019年第4卷第3期
页 面:181-200页
核心收录:
学科分类:081406[工学-桥梁与隧道工程] 08[工学] 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:Ministry of Education Culture Sports Science and Technology MEXT
主 题:Shallow tunnels Dilatancy Overburden Ground reaction curve Stress path
摘 要:The mechanical behavior of sandy ground during shallow circular tunneling is explored for various overburden heights H(=0.5D,1.0D,1.5D and 2.0D;D is the diameter of the tunnel)and various dilatancy coefficients(w//=0,1/3,1/2,and 1;/and w are the internal friction angle and dilation angle,respectively)through finite difference *** ground is modeled as a linear elastic-perfectly plastic material that employs the Mohr-Coulomb yield criterion and obeys the non-associated flow *** ground reaction curve is applied in conjunction with the stress path as a conceptual tool for interpreting the mechanical response of the ground to *** is revealed that,at a certain relaxation value,a yield zone develops during tunneling and extends to the *** relaxation value increases with increases in the overburden and w//values for the cases of less shallow tunnels(i.e.,H=1.0D,1.5D and 2.0D),while for the shallowest case(H=0.5D),the extent of the yield zone to the ground surface is not sensitive to the w//*** shear strain due to tunneling also increases with an increase in the w//***,the w//value affects the radial displacement and the surface settlement due to *** magnitudes of the surface settlement and the radial displacement at the tunnel crown both decrease with an increase in the w//*** relative difference in the displacement at the tunnel crown between the upper bound and lower bound values,w//(at the last computed stage),increases with an increase in the overburden *** is recommended,therefore,that careful consideration be given to the dilatancy angle in the case of relatively less shallow tunnels.