By means of 3D FEM non-linear analysis of an arch dam having a dam toe with developed geological structure, the influence is discussed of temperature，seepage，terrain and geological flaws in the foundation on the arch dam and mechanical behaviors of foundation when the dam is working. The distribution of the displacement field，and the stress field of the arch dam with complex foundation and characteristics of the transmission of forces are given. The mechanism of the generation，form and development of plasticity domain in dam and bedrock are analyzed.

Mechanism of some serions rock caving cases in rock bolted coal roadway is very complex. There are mainly two reasons：the one is the uncertainty of physical parameters and mechanical characteristics of surrounding-rock，and the other is that various calculation models used for analyzing the stability of surrounding-rock in roadway only partly reflect the mechanical behaviors of surrounding-rock. To improve design approach based on safety coefficient and to consider stochastic factors as mentioned above，based on a model of loose weight for rock-mass of underground pressure theory and a principle of resistance force development in structure supported by rock-bolt，the paper researched calculation methods of resistance force and load in limite state equation which was used to calculated stability degree of surrounding-rock in coal supported by rock-bolt. A stability reliability degree for surrounding-rock of a underground roadway in coal supported by rock-bolt has been calculated，and the conclusion is that failure probability about l0 percent of surrounding-rock in a rock-bolt supported coal roadway is acceptable.

Factors that should be taken into account in shield selection were analyzed and the flow-chart of shield selection was established in this paper. The cutting mechanism of cutterhead was also described. Then，one of shield advancing cases of Guangzhou metro No.2 was illustrated to describe the shield selection and ground adaptability. The conclusions were that full face disc cutters are not suitable for completely weathered rock No.6 and No.8 but suitable for slightly weathered rock No.9 with advancing speed 0.5 mm/d and 2～4 mm/d respectively. On the contrary，the full face rip teeth cutters are suitable for rocks No.6 and No.8，and not for slightly weathered rock No.9，with the advancing speed 8～10 mm/d and 4～7 mm/d，respectively.

Aiming at the characteristics and current situation of model experiment，sources of experimental errors are analyzed from the point of view of equivalent theorem，equivalent material，boundary condition，temperature and humidity. The experimental errors are divided into three types：controllable，amendable and unavoidable. The pattern of movement distribution caused by compression and splitting on the model boundary is studied. Theoretical solutions are suitable to amend the abnormal curve of measured experimental data and helpful to improve the accuracy of model experiment.

It is an important measurement in decreasing mining-caused land destruction by building super-high bench dumping-site. Foundation loading，stability analysis，mud-rock-flow and water control are key factors in decision making. By the new study，a great scale dumping-site in Qijiagou of Changba，which is 400 m high has been built. Meanwhile，mechanism of foundation loading，technology of determining the limit height of dumping-site，corresponding stability analysis，and a new method of controlling mud-rock flow by controlling small and tiny grains have been developed. The first sluiceway of dumping-site has been built successfully in our country. Afterward，these techniques have been developed widely in Miaoergou dumping-site of Nanfen. Better effects have been obtained. Therefore，this technique can be used widely for reference in other mines.

Rock-like materials have high compressive strength，but low tensile one. Testing study is made on a express highway for improving these material characteristics to meet the engineering requirement. The prestressed concrete girder is pulled，and three types of load，that is，the fixed load in the middle of the girder，well-distributed and point loads on the girder，are exerted. The working characteristics of prestressed concrete girder under the states of elasto-placticity are discussed. Experience for the design of prestressed concrete girder has been accumulated and mechanical behaviors of rock-like materials have been investigated.

Under the condition of inverted filter protection，the crack self-healing of dispersive clay core for a reservior in Xinjiang Province is systematially investigated. Results show that the dispersive clay can be used to build core directly without improvements. Even the perfoliate crack can be self-healed if a good filter is provided downstream of the core.

In this paper，the drilling core examination data of 192 DJM piles in the Suzhou-Jiaxing-Hangzhou freeway project are analyzed. The adjusting indices and standards of construction quality in drilling core examination of DJM piles are discussed.

A large number of rock mass quality classification systems have been put forward in the world. Recent advances in this field at home and abroad are reviewed systemically in this paper. The relationship between rock mass structure， rock mass quality and its classification is summarized. Finally，a relation of interrelation，comparison and conversion among the main rock mass quality classification systems are proposed.

The figure of Rankine active earth pressure in clayey soil is corrected. And the cohesion stress region in it is conformed. Various incorrect statements of cohesion on that part are put right. At last，the steps in design of retaining wall in clayey soil are given.