(1. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，Chengdu，Sichuan 610059，China；2. China Railway Second Engineering Group Co.，Ltd.，Chengdu，Sichuan 610031，China)
Abstract：The failure mechanism of tunnel is more complex under the high geostress and high ground temperature action for deep hard rock tunnel. Loading-unloading triaxial tests on granite under different temperatures were carried out. The complete stress-strain curves of rock，mechanical parameters of rock，and macro failure types under different temperature conditions were analyzed in detail. The results show that there is a temperature threshold value of 60 ℃–100 ℃. The failure is from ductile to brittle with the temperature increase if the temperature does not exceed the threshold value. Temperature enhanced the brittle damage of hard rock. Shear is the dominant failure mode with the temperature increase. Then based on the test，thermo-mechanical coupling calculation was carried out. The thermal effect of excavation unloading for hard rock tunnel was calculated by using a brittle constitutive model and energy release rate index. The mechanical response to tunnel excavation was analyzed under different ground temperatures. The plastic zone，stress index and energy release value were compared quantitatively under different ground temperatures. The calculation showed that temperature increase would make rockburst intensity increase，and shear zone increase. The result of calculation and test data is consistent，and the analysis could benefit the understanding of brittle failure under high ground temperature.
李鹏举，冯光明，李守彦，等. 温度影响下大理岩脆塑性转换的机制分析[J]. 煤炭科学技术，2010，38(9)：23-25.(LI Pengju，FENG Guangming，LI Shouyan，et al. Analysis of fragility plasticity conversion mechanism of marble under temperature influences[J]. Coal Science and Technology，2010，38(9)：23-25.(in Chinese))
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2013, Vol. 32 
