摘要
为研究冻融循环作用下砂岩的蠕变特征,建立一种可以描述冻融岩石材料的全过程蠕变模型。选取鲁中地区地下矿洞黄砂岩为研究对象,进行了不同次数的冻融循环试验(冻融温度范围-20~20℃),开展了冻融砂岩的三轴压缩蠕变试验,并基于建立的非线性黏塑性模型和西原模型原理,建立了一种用来描述冻融岩石的非线性蠕变模型,通过数学微积分求导方法和元件叠加原理推导了模型的本构方程和蠕变方程。结合试验数据,利用最小二乘法进行参数认证,并通过Origin软件进行曲线拟合。结果表明:1)冻融循环对地下矿洞砂岩蠕变变形产生较大影响,随着冻融循环次数的增加,砂岩蠕变变形不断增大,破坏时间缩短;2)在同一载荷下,稳态蠕变率随着冻融循环次数的增加而增大;在冻融循环次数一定时,稳态蠕变率随着载荷的增大呈现出非线性的增长;3)建立的非线性蠕变模型,可以较好地表述冻融砂岩的衰减蠕变、稳态蠕变和加速蠕变特征。试验曲线与拟合曲线对比发现吻合程度较高,拟合效果相对理想,从而验证了模型的正确性和合理性。
To study the creep characteristics of sandstone under freeze-thaw cycles,a creep model describing the whole process of rock materials under freeze-thaw cycles was established.In this paper,the yellow sandstone in the underground mine in central Shandong was selected as the research object,and the freeze-thaw cyclic tests(freeze-thaw temperature range-20—20℃)were carried out at different times.The triaxial compression creep tests of the freeze-thaw sandstone were carried out.Based on the Bingbam model and the principle of Xiyuan model,a non-linear creep was established to describe the freeze-thaw rocks.The constitutive equation and creep equation of the variable model were deduced by calculus derivation method and element superposition principle.Based on the test data,the least square method was used to authenticate the parameters,and the curve was fitted by Origin software.The results show that:1)Freeze-thaw cycles have a great influence on creep deformation of sandstone in underground mine.With the increase of freeze-thaw cycles,the creep deformation of sandstone increases and the failure time shortens.2)Under the same load,the steady-state creep rate increases with the increase of the number of freeze-thaw cycles;When the number of freeze-thaw cycles is constant,the steady-state creep rate increases nonlinearly with the increase of the load.3)The established non-linear creep model can better describe the characteristics of attenuation creep,steady-state creep and accelerated creep of frozen-thawed sandstone.Comparing the experimental curve with the fitting curve,it was found that the degree of coincidence was high and the fitting effect was relatively ideal,which verified the correctness and rationality of the model.
作者
王永岩
冯学志
王浩
崔立桩
刘亚琦
WANG Yongyan;FENG Xuezhi;WANG Hao;CUI Lizhuang;LIU Yaqi(College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266061,China)
出处
《青岛科技大学学报（自然科学版）》
CAS
2020年第6期44-50,共7页
Journal of Qingdao University of Science and Technology:Natural Science Edition
基金
国家自然科学基金资助项目(51374134,51674149).
关键词
冻融循环
矿洞砂岩
三轴蠕变
蠕变模型
freeze-thaw cycle
cave sandstone
triaxial creep
creep model
