SIMULATION OF MULTIPLE-STEP LOADING TRIAXIAL COMPRESSION TEST ON A MUDSTONE BY A NEW DAMAGE MODEL Paper No.294
作者单位：TokyoUniversity of Science YokohamaNational University
会议名称：《ISRM-Sponsored International Symposium on Rock Mechanics:"Rock Characterisation,Modelling and Engineering Design Methods"(SINOROCK2009)》
会议日期：2009年
学科分类：08[工学] 080104[工学-工程力学] 0815[工学-水利工程] 0801[工学-力学（可授工学、理学学位）]
关 键 词：Multiple-step loading triaxial compression test Mudstone Damage model
摘 要：Multiple-step Loading Triaxial Compression Test（ML-TCT）,permits determination of a failure envelope by testing a single rock specimen in a series of consolidation and shearing *** appropriate rocks,this technique allows determination of strength parameters from fewer specimens than does conventional triaxial testing,which requires three or more specimens to determine a failure ***,because of accumulated damage in the specimen with repeated cycles of axial loading/unloading,the shear strength is prone to be underestimated. Therefore,a Multiple-step Loading Damage（MLD） model was proposed to simulate ML-TCTs with various stress *** the MLD model,the damage accumulated in the specimen by the repeated cycles of axial loading/unloading is represented by the plastic axial strains. Two series of ML-TCTs were carried out on a sedimentary soft rock of *** the first series repeated steps of axial loading-unloading were made under the constant effective confining pressures,σ = 0.4,0.6,1.0,1.2,1.6,2.0 MPa,to determine all geotechnical parameters to describe the MLD *** the second series,repeated cycles of axial loading-unloading were made under different effective confining pressures to verify the MLD *** kinds of stress paths were attempted,three tests were done in increasing effective confining pressures in a stepwise manner and two tests were done in decreasing fashion. The MLD model built to simulate ML-TCTs on the mudstone with various stress *** model is comprised of five relationships,and is prepared on the basis of the results obtained from the first series of *** model allows prediction of peak deviator stress and the relevant excess pore water pressure due to previous plastic deformations in the specimen for mudstone. The verification of the MLD model was made using two *** the first one,comparisons were made between the experimental results of ML-TCTs and the calculated results of ML-TCTs with the id