| Ci Ha Xia Hydropower Station, location at Ciha Gorge Canyon of Hainan autonomous prefecture in Qinghai province, Its dam height is about 250m, the initial list of dam type of panel (heart wall) rock-fill dam, equipped capacitor is 1800 to 2000MW. 3~# deformable rock was located in underside dam site of Ci Ha Xia hydropower stations by the side of the right bank of the toe board slope. Its geological conditions is complex,the deformation is diversity, and then it is a complex geological body.3~# deformable rock of Ci Ha Xia Hydropower Station was discussed in this paper. It analysis the rock mass structure characteristic, the boundary condition and the mechanism of deformation of the slope on the base of inside investigation of geoengingeering conditions and signs of deformation. Afterwards, stress-strain and stability of slope were comprehensively studied with the geology analyze, the limit equilibrium method and finite element. At last,Through analytical the stability of 3~# deformable rock, put forward the availability and the processing measure with difference zones finally. The key contents and conclusions are as follows:1. Through field investigation, Preliminary study on 3~# deformable rock slope's structure characteristics are comprehended , The researching consists of the advantages of structural surface occurrence, trace length and thickness of rock. At last, the type of the slope's structure is arrived.2. Based on the signs of deformation of slope, considering the characteristic of rock mass structure, the boundary condition and the mechanism of deformation is analyzed. It's proposed that the type of the slope deformation is creep-sliding and fracturing mode.3. Using the geology analyze and the Limiting Equilibrium Methods, a more comprehensive analysis was carried out to this slope's stability. the slope face of the excavation platform. Stability analysis of the results shows that in the natural state,â… ,â…¡two areas are stable, in spite of a significant reduction in the stability factor in the seismic and stormy state, but the partial failure of the existence of possible after the excavation,â…¡area high probability of damage. In conclusion, FEM numerical analogue analysis method is used on deepening simulation study and comparison analysis of stress and deformation felds on the natural and engineer excavation conditions.Numerical analysis is obtained in good agreement with the above assessment. Then it commented the reasons that caused the deformation and failure from the view of the mechanism and internal origin. So this provided comprehensive and objectively estimation for the stability of the naturally slope and engineering slope in the dam area.4. A synthetical analysis on utilizable deformable rock is conducted by several kinds of methods, for example, project analog study, analyses on results of rock mechanics properties. For theâ… ,â…¡a different Engineering Geology Division, combined with the results of slope stability evaluation, it is proposed the availability of 3~# deformable rock,â…¡area as a dam foundation surface should be directly excavation, and at this stageâ… a rea can be used after treatment.5. Combine with the availability ofâ… area rock,the support measure is advised pertinency. Anchoring as a basic method on the whole, strengthening the weak and soft zone as a major means, taking water interception and drainage and setting protective structure as an assistant. On the basis, put forward the optimization design with difference zones. In addition, some monitoring points should be set up in the key component of slope to monitor the deformation and displacement during the construction and operation.
|
PDF Full Text Request