STUDY OF SHEAR CREEP CHARACTERISTICS OF GREENSCHIST DISCONTINUITIES
SHEN Mingrong1,2,ZHANG Qingzhao2
(1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;2. Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)
Abstract:Based on the characteristics of high depth and high stress in diversion tunnel of Jinping II hydropower station,the gray marble containing greenschist discontinuities from the slope and underground rock cavern is selected as research object;and the shear creep test is carried out for the samples with greenschist discontinuities. The test results are analyzed and the rheological behaviors of greenschist discontinuities are discussed. The creep characteristics and mechanical laws of rock mass discontinuity under different normal stresses are studied;and the creep rate characteristics of discontinuities are investigated. Results show that the creep curves have obvious three stages. On this basis,the improved Burger model is selected for the analysis of creep test results;and a discussion on modified Burger model for describing the shear creep characteristics of discontinuities is presented.