钙芒硝盐岩多场耦合作用下蠕变的温度效应研究  

Temperature effect on creep of glauberite salt rock under multi-field coupling

作　　者：杨玉良 梁卫国[1,2] 杨晓琴 曹孟涛[1,2] 李静[1,2] 肖宁 YANG Yuliang;LIANG Weiguo;YANG Xiaoqin;CAO Mengtao;LI Jing;XIAO Ning(College of Mining Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Key Laboratory of In-situ Property-improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学矿业工程学院,山西太原030024 [2]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《煤炭学报》2020年第3期1070-1080,共11页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51504159)。

摘　　要：为了研究温度-溶浸-应力耦合作用下钙芒硝盐岩蠕变的温度效应,利用自主研发的三轴岩石力学试验机,进行了围压4 MPa、轴压5 MPa、不同温度(30,60,90℃)、不同渗透压(3,2,1 MPa)条件下的三轴蠕变试验,并在试验前后对试件进行CT扫描,分析了不同蠕变过程中温度对钙芒硝蠕变变形的影响。结果表明:溶浸连通过程,对钙芒硝盐岩蠕变变形起主要作用的是渗透压和温度,渗透压越小且温度越高,蠕变应变越大;饱水蠕变过程,温度和有效应力是影响蠕变变形特性的主要因素,随温度的升高蠕变应变逐渐增大,但其增加幅度逐渐减小。在72 h的饱水蠕变过程中,渗透压为2 MPa时,30,60,90℃条件下的蠕变应变分别为0.0095×10^-2,0.0144×10^-2,0.0195×10^-2,渗透压为3 MPa时,分别为0.001×10^-2,0.003×10^-2,0.007×10^-2;排水蠕变过程,影响钙芒硝蠕变变形的主要因素是温度-溶浸-应力作用的历史过程对钙芒硝固体骨架力学性能的弱化程度和温度对蠕变过程的热损伤作用,随温度的升高蠕变应变和其增加幅度都逐渐增大;基于非线性流变力学理论,对广义开尔文模型进行改进,根据蠕变试验结果,采用曲线拟合法对改进后模型的参数进行反演识别,结果与实测数据吻合效果良好,说明改进后的模型可以较好的描述钙芒硝在温度-溶浸-应力耦合作用下的排水蠕变过程。In order to study the temperature effect on the creep of glauberite salt rock under tempera-ture-solubility-stress coupling,a self-developed multi-functional rock testing machine was used to conduct the triaxial creep tests under the confining pressure of 4 MPa,the axial pressure of 5 MPa,the infiltration pressure of 3,2 and 1 MPa and the temperatures of 30,60 and 90℃.Also,the CT scan of the specimen was performed before and after the test.The effect of temperature on the creep deformation of different creep processes of glauberite salt rock was analyzed.The results show that the main factors affecting the creep deformation characteristics of the glauberite salt rock are the infiltration pressure and temperature in the creep stage of hydraulic connection(CSHC).The smaller the infiltration pressure and the higher the temperature,the greater the creep strain.In the creep stage with pore water pressure(CSPWP),the temperature and the effective stress are the main factors affecting creep deformation characteristics.With the increase of temperature,the creep strain gradually increases,and its increment gradually decreases.After 72 h of CSPWP,the creep strain values at 30,60 and 90℃are respectively 0.0095×10^-2,0.0144×10^-2,0.0195×10^-2 when the infiltration pressure is 2 MPa,and 0.001×10^-2,0.003×10^-2,0.007×10^-2 when the infiltration pressure is 3 MPa.In the creep stage after drainage(CSAD),the deformation characteristics of glauberite is dominated by the heating damage and the loading history of dissolution under multi-field coupling and the softening degree of mechanical properties of solid skeleton.The creep strain and its increment increase gradually with the increase of temperature.Based on the theory of nonlinear rheological mechanics,the generalized Kelvin model is improved.According to the creep test results,the parameters of the improved model are identified by curve fitting method.The results show that the improved model is appropriate to describe the CSAD under the coupled action of temperature,d

关 键 词：钙芒硝盐岩 温度效应 蠕变 溶浸作用 

分 类 号：TD315[矿业工程—矿井建设]