The Rock Mass Structural Plane Information Extraction And Evaluation Of Rock Mass Structure For Dam Rock Excavation

The rock mass,which is suffered from repeated geological processes during a long geological history,subjected to deformation and destruction,formed a certain rock composition and structure,is a special structure occured in a certain geological environment."Rock mass structure control theory" consider the rock mass structure can not only reflect the history of the structural evolution of the rock mass,while controlling the deformation and failure characteristics of the rock mass.A large number of structural planes will be exposed in the process of rock excavation in hydropower project.The development degree and scale of structural plane are divided into five classes,and the IV and V level is smaller structural plane,lots of which occur in the rock mass,directly affect the mechanical properties of the rock mass and stress distribution,and affect the failure mode of rock mass in a large extent,play a very important role in the stability of rock engineering.Therefore,it is the foundation and key in rock mass engineering geological evaluation and optimization engineering design to obtain the development degree,distribution status and combination condition of these structures correctly and reasonably.The thesis takes the dam rock mass structural plane information acquisition as the main route.The dam rock mass structural plane investigation is mainly according to the grading of structural planes to grading hierarchical collection,and for the II and III structure surface,is using 3D laser scanner as well as the total station to interpret the large crack.Furthermore,the paper focuses on the IV and V structure surface acquisition method and then take a engineering evaluation to the dam rock mass.In view of the actual engineering conditions of the IV and V level structure plane at the hydropower station site excavation of dam rock surface,and previous research on structural plane,the method of structure plane trace length and the occurrence is proposed.Using the camera to obtain the field dam rock mass information,and then correcting and artificial recognition the structure plane to obtain the structure plane trace length information.The stereographic projection method is used to measure the different ladder structure plane;the joints of study area were grouped and the geometric parameters of the group structure including angle,inclination are statistical analyzed;the distribution and statistical characteristics of these parameters is obtained.implementing to produce the random number of the probability distribution of each structure planes occurrence and then using a program to assign occurrence for unmeasured occurrence of structural plane of the same group,obtaining the complete information(relative coordinates,occurrence);Combined with related information processing software,to obtain parameters of rock tie spacing of structural planes,volumetric joint count JV,structure surface density,rock fragmentation characteristics,rock quality index RQD and trace length information,and comprehensive evaluation of rock mass structure.