热-力耦合作用下砂质泥岩的单轴蠕变特性及本构方程研究  

Study on Uniaxial Creep Characteristics and Constitutive Equation of Sandy Mudstone Under Thermal-Mechanical Coupling Effect

作　　者：曹孟涛[1,2] 武鹏飞[1,2] CAO Mengtao;WU Pengfei(College of Mining Engineering,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China;Key Laboratory of In-situ Modified Mining Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi 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：《矿业研究与开发》2021年第2期87-93,共7页Mining Research and Development

基　　金：国家自然科学基金资助项目(51904196).

摘　　要：为了研究深部地下工程的稳定性,以砂质泥岩为研究对象,采用YDY-100高温单轴蠕变机开展了恒定应力(60%σc)、不同温度(25℃、50℃、100℃、150℃)条件下100d的蠕变试验,并引入温度对蠕变特征参数的影响,建立了改进型Burgers模型。研究结果表明:在低温作用下,砂质泥岩呈黏性固体特征,但随着温度的升高,其逐渐呈现黏性流体特征,蠕变特征更加明显,具体表现为:随着温度的升高,瞬态蠕变阶段的历经时间、蠕变应变增量逐渐增加,稳态蠕变率呈指数增加趋势;25℃时,砂质泥岩稳态蠕变率为4.23e-6/d,而在50℃、100℃、150℃温度作用下,砂质泥岩的稳态蠕变率分别增加到5.34e-6/d、1.16e-5/d、3.96e-5/d,分别为25℃条件下的1.26倍、2.47倍、9.36倍;改进型Burgers模型能够较好地拟合不同温度条件下砂质泥岩的蠕变特征,拟合结果表明,弹性模量E1随着温度增加而线性减小,弹性模量E2、黏性系数η1、η2随着温度增加而非线性减小。In order to study the stability of deep underground engineering,taking sandy mudstone as the research object,the YDY-100uniaxial high-temperature creep testing apparatus was adopted to conduct the creep tests of the sandy mudstone under the conditions of constant stress(60%σc)and four different temperatures(25℃,50℃,100℃,150℃)in 100days and the thermal effect on the creep parameters was introduced to build the improved Burgers model.The results show that,under the action of low temperature,sandy mudstone presents the characteristics of viscous solid,but with the increase of temperature,it gradually presents the characteristics of viscous fluid.The creep characteristics are more obvious,and the specific performance is as follows.With the increase of temperature,the time and creep strain increment in transient creep stage gradually increase,and the steady-state creep rate presents an exponential trend.The steady-state creep rate of sandy mudstone is 4.23e-6/d at 25℃,and it increases to 5.34e-6/d at 50℃,1.16e-5/d at 100℃,and 3.96e-5/d at 150℃,respectively,which are 1.26times,2.47times,and 9.36times of that at 25℃,respectively.The improved Burgers model can fit the creep characteristics of sandy mudstone well at different temperatures,and the fitting results show that the elastic modulus E1 decreases linearly with increasing the temperature,but the elastic modulus E2and viscosity coefficientη1andη2decrease nonlinearly with the increase of temperature.

关 键 词：砂质泥岩 热力耦合 蠕变 BURGERS模型 

分 类 号：TD313[矿业工程—矿井建设]