The results of the stability study of dam foundation , including the effects of ground stresses on the stability of base masses and long-term stability and strength of weak intercalations , especially of clayey ones, are presented. It is proved that the considerable tectonic stresses exist even in red rock layers with slight folds and a gentle terrain and that the stability of masses are directly affected by local stress relief. It is found that sedimentary rock behaves like rheology. A method of deter-mining long-term strength of rheological rock is suggested.

Based on the large-scale triaxial experimental resulte, some troublenesses in the E-μ model for big granular media widely used in our country are analysed . It is indicated that the relationship used in the model (σ1-σ3)f = R (σ1-σ3)u l is unnecessary and the semilogarithmic relationship between uf and σ3 is not unique. In order to inprove this model, a more convenient formula is suggested.

GJP-1 Program is used for three –dimensional elasto-static finite element analysis related to joints, which is the first stage result of three-dimensional nonlinear finite element analysis aimed at subject of rock and soil mechanics. Intact media and discontinuities are modeled by a twenty-node isoparametric finite elements and a sixteen-node isoparametric joint elements respectively, which can be subjected to nodal forces, gravity loads, uniformly or nonuniformly distributed loads acting perpendicularly or obliquely on any faces of elements properties for different elements. GJP-1 has an ability to generate and adjust meshes and to check input data autpmatically, and provides user with frotal solution and subblock triangular resolution in order to solve larger problems with medium or small computer. Several simple problems are solved with GJP-1 for illustrating and testing purposes. Comparison is made between the computational results and the theoretical solutions.

First in this paper, two types of apparatus in laboratories, the simple shear plastometer and the relaxation plastometer, and the methods of simple shear testing and relaxation testing are introduced. Then according to the test results of thin interbedded clayey seams in rock, the upper yield value f3-ritical stress suggested by Dr. Tan Tjongkie is the limit long-term stress to rocks or soils. For engineering purposes it is important to know their long-term creep strength.\

This paper, according to characters of breaking rock of excavators, deals with the influrnces of physic-mechanical properties and occurrences of rock on the excavatability of rock under the condition of muti-cut breaking performed on a large-scale section. According to analyses of in-situ data, a preliminary plan for excavatable classification under the use of excavators is put forward in terms of geological survey, which depends upon hardness and intactness and grindability of rock.

The assembling of a borehole deformeter is introduced in detail. Surface processing of transducers and the art of sticking strain gauges and the techanological process of operation and the requirements for performance check are presented. The operating method of 36-2 borehole deformeters used in field measurements for stresses in rock is stated.

In this paper, it is discussed the effect of amorphous iron, silica and aluminiuim on microstructure and mechanical property of soil. The research indicates that the linkage between the aggregates of soil and structural strength are strengthened by the amorphous materials if. A little of amorphous materials in the soils, the contents of water, the voids ratio will be higher that than of nothing in it. The mechanical properties will be changed while the physical-chemical circumstance are varied.

The engineering mechanical properties of the soil are under the influence of the various factors. The microstructure character of the soil is one of the main factors, concerned by engineering technicians and scientists in recent years. In this paper, the historical development of the microstructure research for the soil is simply retraced. It is mentioned that some contents and results of microstructure research in foreign country and the research results of various representive soil of recent years in our country. Furthermore, the viewpoints about the further research of the microstructure is proposed by the author.