Elasto-plastic solution of deformation in circular soft rock tunnel based on double yield surface model
LI Hao
BAI Hai-bo
WU Jian-jun
MENG Qing-bin
WANG Ying-chao
ZHAO Hui-ming
HUANG Wei-xing
MA Kai
ZHENG Lei
Abstract：The radial displacement of the soft rock roadway has great influence on the coal mine production.Based on double yield surface model,using the conventional triaxial test data of a mudstone,the loading surfaces which were expressed by the first and the third main plastic strain(εP1,εP3) as the hardening parameter were fitted.According to the verified hypothesis of complete loading,the non-associated flow rule of the mudstone material was derived,and the surrounding rock plastic zone scope and radial displacement solution were obtained.The results show that:① the form of two loading surfaces of the mudstone material are quadratic function,and the coefficients can be expressed as a linear function of εP1 or εP3,and the value of the plastic strain increment component is determined.② the derived non associated flow law contains a constant term,the reason is that in the process of loading,it will first reach the loading surface of the εP3,when P1 happens to be 0,εP3 is the value of the constant.③ in this paper,the authors consider the rock characteristics of strain nonlinear softening,rule out the subjective cognition of " assumed flow rule" and others,get the analytical solution of the range of plastic zone and radial displacement,obtain the linear fitting formula between the range of plastic zone,radial displacement and excavation radius under the condition of constant stress.
Keywords：double yield surface modelloading surfacenon associated flow rulenonlinear strain softeningcircular tunnelelasto-plastic solution
Publication Date：2017-01-01
Pages：9( 833-841 )