摘要
为探讨冻融对寒区工程岩石剪切蠕变特性的影响,以吉林省辉白隧道花岗岩为研究对象,对经历不同冻融循环次数的试样开展细观特征分析和剪切蠕变试验。试验结果表明:(1)随着冻融次数的增加,试样裂隙、孔隙不断扩展,岩石表面损伤现象愈发明显;(2)试样主要以中小孔隙为主,孔隙度随着冻融次数的增加呈非线性增长趋势;(3)随着冻融循环次数增加,蠕变变形量和蠕变速率逐渐增大,而蠕变时长、破坏应力和长期强度均呈现明显降低趋势。根据试验结果,进行冻融岩石非定常蠕变参数的表达,提出了冻融岩石损伤黏性元件,构建了花岗岩冻融剪切蠕变本构模型。将蠕变试验曲线和理论模型拟合曲线进行对比,验证了模型的正确性和适用性。通过对蠕变参数进行敏感性分析,研究了其对花岗岩蠕变变形的影响,并给出了蠕变参数随冻融循环次数的变化规律。该研究结果对于寒区岩体工程长期稳定性评价具有指导意义。
To study the effect of freeze-thaw on the shear creep characteristics of engineering rocks in cold regions,the granite samples from Huibai tunnel in Jilin province were taken as the research object,and the microscopic characteristics and shear creep tests of samples under different freeze-thaw cycles were carried out.The results show that:1)With the increase of freeze-thaw cycles,the cracks and voids in the samples develop continuously,and the damage of rock surface becomes more and more obvious.2)The pores in the sample are mainly composed of small and medium pores,and the porosity increases nonlinearly with the increase of freeze-thaw cycles.3)With the increase of freeze-thaw cycles,creep deformation and creep rate increase gradually,while creep time,failure stress and long-term strength decrease obviously.According to the test results,expressions of unsteady creep parameters of freeze-thaw rocks are established,the damage viscous element of freeze-thaw rock is proposed,and the freeze-thaw shear creep constitutive model of granite is constructed.By comparing creep test curve with theoretical model fitting curve,the correctness and applicability of the model are verified.Through sensitivity analysis of creep parameters,the influence of creep parameters on granite creep deformation is studied,and the variation law of creep parameters with the number of freeze-thaw cycles is given.The research results have guiding significance for long-term stability evaluation of rock mass engineering in cold regions.
作者
张峰瑞
姜谙男
杨秀荣
申发义
ZHANG Feng-rui;JIANG An-nan;YANG Xiu-rong;SHEN Fa-yi(Institute of Road and Bridge Engineering,Dalian Maritime University,Dalian,Liaoning 116026,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第2期509-519,共11页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51678101)
中央高校基本科研业务费专项资金(No.3132014326)
吉林省交通运输项目(No.2017ZDGC-2)。
作者简介
第一作者:张峰瑞,男,1990年生,博士研究生,主要从事岩土工程稳定性分析的研究工作。E-mail:zhangfengmi@dlmu.edu.cn;通讯作者:姜谙男,男,1971年生,博士,教授,博士生导师,主要从事岩土工程稳定性分析和多场耦合方面的研究工作。E-mail:jiangannan@163.com E-mail:zhangfengrui@dlmu.edu.cn。
