岩石节理面应力–渗流耦合剪切流变试验系统的研制与应用

Development and application of a hydro-mechanical coupling shear creep testing machine for rock joints

为了研究岩石节理面在不同应力和渗流耦合条件下的长期力学特性,自主研制岩石节理面应力-渗流耦合流变试验系统,主要由主机、垂向、剪切伺服加载系统、剪切盒、渗流控制系统以及数据动态采集系统等部分组成,通过配备专门设计的剪切盒装置,能保证节理面在剪切或者剪切流变试验过程中提供最大5 MPa渗透压力,试样的密封方面既考虑了胶套在围压的作用下对试样周围的包裹实现防渗,同时采用主动与被动加载相结合的方式,满足圆形压头与立方体岩样紧密贴合,使得试验过程中节理面在应力渗流耦合剪切流变过程中不发生侧向渗漏。剪切加载可以实现上下任意一块试样固定,而对另一块进行剪切,也可以实现2个方向同时产生剪切位移;满足常法向应力(CNL)、常法向位移(CNV)下结构面剪切或剪切流变试验研究;并实现结构面剪切条件下渗透率的动态测量;该试验机还可开展结构面应力-渗流耦合作用下不同水力梯度和渗透压的剪切流变试验,并开展含节理面花岗岩在不同边界条件下的各类试验,验证了该系统的准确性和可靠性,为节理面应力-渗流耦合剪切流变特性研究提供了支撑,对丰富和完善岩石节理面应力-渗流耦合流变特性理论研究有一定的指导作用。

In order to study the hydro-mechanical coupled shear rheological mechanisms of rock joints,a hydromechanical coupled shear rheological testing system for rock joints was independently developed.The test system is equipped with a specially designed shear box device,which can ensure that the maximum water pressure of 5 MPa can be provided in the process of shear test.The wrapping of the rubber sleeve around the specimen under the action of the confining pressure,and the combination of active and passive loadings are adopted to meet the tight fit between the circular indenter and the cubic rock sample to ensure that there is no leakage during shear test.Shear displacement can be produced in both directions simultaneously.Shear rheological test of joints can be carried out under servo control of constant normal stress(CNL)and constant normal displacement(CNV).Dynamic permeability of rock joints under different shear conditions can be conducted.Furthermore,hydro-mechanical coupled shear rheological test of structural planes under different hydraulic gradients and water pressures can be carried out.The accuracy and reliability of the system are verified by various tests of granite with different joint faces under different boundary conditions of hydraulic gradient and hydraulic pressure.The testing system provides a support for the study of hydro-mechanical coupled shear creep properties of rock joint,and has a certain guiding role in enriching and improving the theoretical study of rheological properties of rock joints.