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| A modified thermo-elasto-viscoplastic constitutive model for soft rock considering the effect of confining stress |
| XIONG Yonglin1，2，ZHU Hehua1，2，ZHANG Sheng3，YE Guanlin4，ZHANG Feng5 |
| (1. State Key Laboratory of Disaster Reduction in Civil Engineering，Tongji University，Shanghai 200092，China；2. Key Laboratory of Geotechnical and Underground Engineering，Ministry of Education，Tongji University，Shanghai 200092，China；3. School of Civil Engineering，Central South University，Changsha，Hunan 410075，China；4. Department of Civil Engineering，Shanghai Jiaotong University，Shanghai 200240，China；5. Department of Civil Engineering，Nagoya Institute of Technology，
Nagoya 466–855，Japan) |
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Abstract Large amount of triaxial shear experimental evidences show that the mechanical behaviour of soft rock is dependent on the confining stress. The strain softening and shear dilation of soft rock were reduced with the increase of the confining stress. When the confining stress is large enough，the strain hardening and shear contraction occur. The original thermo-elasto-viscoplastic model for soft rock has different parameters for different confining stresses and is therefore difficult to be applied to engineering problems. In order to describe the mechanical behaviour of soft rock with one set of parameters，the original constitutive model was modified to consider the confining stress dependence. The parameters of the modified model have explicit physical meanings and can be determined from triaxial tests. The accuracy of the modified model was verified by comparing with the simulated results and experimental data.
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2016, Vol. 35 
