| In the process of large-scale construction of railway,highway,water conservancy and hydropower and other infrastructure construction in China,due to the influence of the original complex geological conditions and the deep excavation project,the various types of geological disasters are more prominent,which seriously restricted the infrastructure projects' construction and operation.Among them,the stability of unstable rock has become a problem that has plagued the engineering community.At the same time,the stability of unstable rock under the coupling of water and rock has also become a hot topic in the study of geology,land and related scientific research institutes.Therefore,it is necessary to study the stability of unstable rock mass under the coupling of water and rock,and it is necessary to study the prevention and control engineering of geological disasters such as unstable rock and rock slope.In this paper,an efficient means is used to monitor the unstable rock mass in the Feng four sections of the Si Mian shan towns in Jiangjin District,Chongqing City.The seasonal effects of the deformation and development of the target unstable rock are studied by means of theoretical analysis,laboratory test and numerical simulation.At the same time,the influence mechanism of water on the stability of unstable rock mass is analyzed,and the stability analysis is carried out on this basis.Finally,based on the results obtained from the experiment,the stability of the unstable rock mass after coupling with water and rock is verified by numerical simulation.The main results of this paper are as follows:(1)The volume of the monitored unstable rock mass is 258.3193m3 by using the 3D real reproduction technique,and according to the classification of landslide,collapse(unstable rock)and debris flow scale,the unstable rock mass is small unstable rock body;During the monitoring period,the coordinate values of the monitoring deformation blocks on the parent rock did not change with time.The change of the coordinates in the Y and Z directions of the deformation monitoring block on the unstable rock mass showed a monotonic trend;The unstable rock mass in the deformation of the development process,sliding to the empty side.According to the position variation of the structural hatching,the unstable rock body can be considered as dumping type unstable rock body.(2)Based on the time series analysis theory,the data of the monitoring data of the unstable rock mass obtained by the three-dimensional laser real-time replicating technique are analyzed.The results show that the change of the monthly coordinates in the Y and Z directions in the whole space coordinate system established by the scanner Monotonic periodic changes in the law,while the X direction is irregular irregularities.There are obvious seasonal effects in the deformation of the unstable rock mass,that is,in the annual flood season,the displacement changes soared.(3)After the sandstone specimen is coupled with water rock,the overall density decreases,and the mineral distribution within the specimen tends to be uniform;After the specimen is treated by the water,the damage variable increases with the distance from the axis;The compressive strength,elastic modulus,peak strain and other mechanical parameters of the sandstone specimen are reduced in different degrees after being treated by water;The main consideration of the deterioration of the mechanical parameters of the sandstone specimen is due to the dissolution reaction of the different mineral components inside the specimen,forming new secondary pores on the one hand and increasing the original pores on the other hand.(4)The numerical simulation of the unstable rock mass after excavation is carried out by using ANSYS.After calculation,the deformation and internal stress distribution of the unstable rock mass are obviously changed;The energy release rate of the tip of the main structure of the unstable rock mass after the coupling with water rock is obviously increased,and the structural plane is more obvious. |
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