Papers by Author: Han Peng Wang

Abstract: Based on engineering geological conditions and measured data of the in-situ stress at a hydropower station, 3D geological models under each affecting factor are calculated by means of finite element computing tools ABAQUS and MATLAB. Then, a multivariate regression model is created between the measured and calculated value of in-situ stress at measurement points, and the optimal regression coefficient of the model is found. Consequently, the distributions of initial in-situ stress of this area are obtained. It is the first time to take into account the independence and internal relations among each stress components. Thus, the more reasonable distributions of initial in-situ stress of this area are obtained. The results indicate that the 3D calculating in-situ stress field is reasonable.

Abstract: As the implementations of the western development in China, more and more tunnels will get through the western mountains in China. In order to economize the construction costs, a new type of underground structural form called branching-out tunnel must be applied. The failure process of the branching-out tunnel under lateral overload action is also greatly complicated, which is related with the depth of the mountains, the branching-out angle, the in-situ stress field, the thickness of the middle wall and so on. This paper uses the 3D-physical model of geo-mechanical model tests to study the stability and failure process of this complicated structure, especially the part of the middle wall. The physical model is built up in a new kind of analogy material. In the process of the whole experiments, different lateral pressures imposed on both of the lateral planes of the physical model. According to different lateral pressures, we have attained the change of the stress and displacement field and looked into the failure process of the pivotal positions in the branching-out tunnel. We also use finite element method analysis software RFPA (Realistic Failure Process Analysis) to simulate the whole failure process of the branching-out tunnel. Finally, we have got the load-bearing safety reliability of this complicated structure through comparative analysis of physical modeling and numerical simulation.

Abstract: It is very important to choose a similar material which simulates rock mass correctly in geo-mechanics model test. In this paper, we introduce similar material research status and analyze the principle of selecting and compounding. According to the experiences of similar material research, we develop a new similar material (we call it iron barites sand cementation material, abbreviate IBSCM) through hundreds of compounding experiment. This similar material is made up of iron ore powder, barites powder, sand, rosin, alcohol and gypsum powder. Iron ore powder, barites powder and sand are main materials, the solution of rosin and alcohol is glue, and gypsum powder is regulator. Specimen mechanics tests show that different rock mass can be simulated by the model materials with different materials compounding. The new similar material is easy to buy and its price is cheap, and it has some advantages, such as high density, stable performance, easy dryness, and easy cutting. The new similar material can simulate a lot of rock mass, so it is an ideal similar material. At last, we apply this new type similar material to tunnel geo-mechanical model test and gain the ideal result.