高地应力下花岗质片麻岩蠕变损伤模型研究  

Creep Damage Model of Granitic Gneiss under High Ground Stress

作　　者：钟祖良[1,2] 王南云 任玉琪 李洋 Zhong Zuliang;Wang Nanyun;Ren Yuqi;Li Yang(School of Civil Engineering,Chongqing University,Chongqing 400045,P.R.China;National Joint Engineering Research Center of Geohazard Prevention in Reservoir Area,Chongqing 400045,P.R.China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]库区环境地质灾害防治国家地方联合工程研究中心,重庆400045

出　　处：《地下空间与工程学报》2021年第3期759-767,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家重点研发计划(2018YFC1504802);国家自然科学基金(41972266)。

摘　　要：高海拔地区深埋隧道的花岗质片麻岩在高地应力条件下具有较强的蠕变力学特性,易导致隧道结构开裂,对结构的安全性和耐久性影响较大。在花岗质片麻岩基本力学特性试验的基础上,对其开展了高围压下的三轴蠕变试验。研究表明:随着围压的增大,轴向蠕变量减小显著,环向蠕变量受影响较小;不同围压下的加速蠕变阶段,环向蠕变效应均比轴向更显著;破裂面倾角随围压的增大逐渐减小。基于蠕变试验结果,分析了花岗质片麻岩的损伤演化规律,提出了指数型损伤变量,将传统Burgers蠕变模型改进为能够描述加速蠕变段的全损伤蠕变模型,并推导了一维和三维蠕变损伤方程,利用加速蠕变阶段的试验数据对模型进行了参数识别,拟合效果较好。Granitic gneiss in deep-buried tunnels at high altitudes has strong creep mechanical properties under high geostress conditions,which lead to cracking of tunnel structures easily and has a great impact on the safety and durability of structures.The triaxial creep test under high confining pressure is carried out based on the test of basic mechanical properties of granitic gneiss.The research shows that with the increase of confining pressure,the axial creep decreases significantly,and the circumferential creep is less affected;in the accelerated creep stage under different confining pressure,the circumferential creep effect is more significant than the axial creep effect;the angle of fracture surface decreases with the increase of confining pressure.Based on the creep test results,the damage evolution law of granitic gneiss is analyzed,and the exponential damage variable is proposed.The traditional burgers creep model is improved to the full damage creep model which can describe the accelerated creep section,and the one dimension and three-dimension creep damage equations are derived.The parameters of the model are identified by the test data in the accelerated creep stage,and the fitting effect is good.

关 键 词：高地应力 花岗质片麻岩 蠕变规律 损伤模型 参数识别 

分 类 号：TU458[建筑科学—岩土工程]