Jointed Rock Mass Mechanical Parameters Studied

Rock mass is the synthesis of an intact rock and it's joint. Mechanical property of rock mass depends mainly on those of the intact rock and the joint, and it is never a simple overlap of the two. Joint is the relatively weak part as regards to mechanical intensity. Its existence breaks the continuity and integrity of rock mass. Meanwhile, the joint itself, as a part of rock mass, is rather complicated both geometrically and mechanically. The joint plays a key role in controlling both the Mechanical property and stability of rock mass. Therefore, research on structure characteristics is the basis of reasonable evaluation towards mechanical property of rock mass; field investigation and quantitative analysis are the critical link to surrounding rock classification and stability analysis. Reasonable determination of mechanical parameters of jointed rock is of great significance to the design and construction of rock mass engineering as well as the deformation and stability of rock mass.Combined the Fu Long tunnel of Shen Zhen, this paper takes jointed rock which influences the stability of surrounding rock as it's object of study. The main research is as follows:(1)Analyze the data of joint through stereographic projection based on geological sketch and investigation of joint, determine the influences of joint's geometric parameter on the stability of tunnel surrounding rock.(2)Analyze the mechanical property of joint, summarize the constitutive model and strength theory of intact rock, and discuss a composite equivalent model of jointed rock.(3)Make laboratory experiment of field sampling rock to get mechanical parameters, and determine mechanical parameters of jointed rock mass by experience compensation.