Experimental Study On Normal Closure Deformation Model Of Filled Rock Joint

Joints of different scales are widely present in rock masses and are the main factors that affect the mechanical properties of rock masses and control the stability of rock mass engineering.It is also the main channel for groundwater seepage in the rock mass.Under the action of external load,normal closed deformation will occur,causing microscopic changes in the joints,and then causing seepage.Among natural joints,rock joints mostly exist in the form of filled rock joints,and the filling medium has a great influence on deformation.Therefore,it is of great significance to study the normal closure deformation characteristics of filled rock joints.In this paper,the preparation of the article has the 5th to 10 th Barton standard profile line appearance characteristics of 6 kinds of cement rock joints specimens,a total of 52 groups,and 8 kinds of quartz sand as the filling medium filling degrees of rock specimen preparation,filling the method to make tests,and for the filling and packing methods of rock joints to stress and closed to the deformation curve is analyzed,The main research results are as follows:(1)Analyzing the normal stress-normal closed deformation curve of non-filled rock joints,it is found that the normal closed deformation curve of joints presents a typical nonlinearity,and the normal closed deformation appears to be fast first as the normal stress increases.Growth,then a slow upward trend;(2)Analyzing the normal stress-normal closed deformation curve of the filled rock joints,it is concluded that for the filled rock joint specimens with the same joint surface roughness,the normal closed deformation of the joints shows a gradually increasing trend as the filling degree increases;The entire deformation process can be divided into two stages: the first stage is mainly the compression deformation of the voids between the quartz sand particles,and the deformation is relatively rapid;the second stage is the crushing deformation of the quartz sand particles and the deformation of the rock joint specimen itself Slower;(3)In combination with the results of the indoor test,the normal closed deformation model of the filled rock joint was established on the basis of considering the filling degree and the surface roughness of the joint,and then verified by the indoor test data.The verification result is good and the model has high accuracy.