In this paper, an equivalent continuum model for rock mass which consists of joints and rock is proposed by averaging the stress and strain of rock mass in a volume element. Using the theory of damage mechanics and fracture mechanics, the damage tensor, effective stress tensor and damage strain ,etc. of rock mass are defined, propagation equation of damage is developed. Furthermore, the damage fracture model for jointed rock mass is established. The fracture mode of joints is studied by model tests.

Ryugyong Hotel in Pyongyang, DPRK, is a 105-storey skyscraper with a high of 323.55m and its foundation mainly consists of fine-grained sandstone, siltstone and silty slate clay. The former involves about 50% of the total formation. A modified borehole jack was used to measure the Young' s modulus of the base rock. Unlike Goodman Jack suggested by ISRM, BJ-110 Borehole Jack gives the true rock modulus directly without any correction. The results show that the elastic modulus of fine-grained sandstone ranges from 6-14GPa, and those of siltstone and silty slate clay about 21GPa and less than 3GPa respectively. The settlement observation was carried out during construction. According to the total weight and the settlements observed, the average calculated modulus of the foundation is about 6GPa, approximately coincidents with the measured one To obtain the average modulus of the foundation before construction, a method will be introduced in this paper.

The entire and partial safety evaluation problems of rock slope are studied under the simplest condition. In order to predict the potential unsafety factors and their location in rock mass, the concepts of zero-force element and zero-force boundary are given, and then, illustrated by the example that the maximum height exist in the rapid slope.

In this paper, the mapping between reference region and physical region is built in advance by harmonic function, and which is extended to the transformation between triangular regions. Then all of the nodal coordinates in physical region are obtained by the numerical solutions of two Dirichlet’s problems through F.E.A. Finally, it is detailed that some sub-regions are combined a real region with joints or holes, according to their top logic relationships. The flow-chart of program and calculating examples are given in this paper.

The deformation failure of the galleries in unfavorable rock formations in Jinchuan is well-known in China, which is the crux affecting the production costs and the mining construction of Jinchuan Nonferrous Metal Company. The company, for many years, has invited a great number of researchers from dosens of scientific institutes, univeisities and engineering design departments to tackle this crux problem, centering on controlling the earth pressure on the galleries and obtained a certain number of significant achievements. However, to have a real grasp of the earth pressure law of Jinchuan unfavorable rock formations and to make a set of measures to control effectively the pressure acting on the galleries in a ruptured rock mass with a high geostress, one must carry out further thorough research. What is described in this paper is an example to tame the deformation failure of the Jinchuan galleries in a high-stressed ruptured rock mass by means of secondary supporting method using the spout anchorge supporting system.

Numerical technique of determining utilization coefficeint of explosion energy is given through mechanical analysis on explosion of the spherical charge in rocks. The computing examples showed that the utilization coefficeint of energy is about 50% in the blasting mainly for rupturing rocks, and the energy transmission ratio is about 40%. In addition, the closer wave impedances of both rock and explosive, the higher the utilization coefficeint of energy.

Surrounding rocks of GPSH ( Guangzhou Pumped Storage Hydroplant) are treated as isotropic medium or orthotropic jointed rocks. Directed back analyses of measured displacements from observation section in access gallery and exhaust gallery of main transformer house are made by simplex acceleration method. A number of mechanical parameters of rock mass and in-situ ground stresses are obtained and compared with measured data.

Riedel Shear is a common reverse phenomenon in geological research, which goes against the theoretical failure criterion in rock mechanics. From the point of view of strain-stress theory, the mechanism of this structure mode is discussed in this paper in combination with the systimatical analysis to a typical practice case.

This paper describes the correlativity between physical-structural characteristics and wave velocities in kaolinite. The relationships between density, water content and wave velocities, dynamic elastic modulus, dynamic shear modulus are mainly discussed, and their relational expressions are given. In addition, the influence of structural property of kaolinite to wave velocities and dynamic mechanical parameters are analyzed.

In order to measure elastic modulus of rock in a borehole, Type BEM-1-D76 Jack was developed by our institute. In this paper, working principle, targets and measuring method of this jack are introduced. It's practical applications in a region with high stress are given. In addition, the jack are compared with other similar jacks in abroad. It is shown that Type BEM-1-D76 Jack is a new effective instrument for measuring deformation behavior of rock mass.

Model HA-1 Soil Thermal Parameter Finder ,developed by Inst. of Rock and Soil Mech. Academia Sinica, is fitted out with an automatic system of data acquisition and processing which takes a KC-85 micro-computer as its principal part. This automatic system can make real-time data acquisition and processing and print and plot testing results automatically, thereby the soil thermal parameters will be determined rapidly and accurately. This paper deals briefly with the composition, function, interface principle of the system 11s well as the essentials of programming.