Classification Of Weathered Rock Mass And Seismic Stability Analysis For Jinyang Grand Buddha Slope In Taiyuan

Jinyang Grand Buddha in Taiyuan, built in Beiqi Dynasty, is the earliest large stone statue found by far in our country and has significant value in history and culture. It was destroyed due to the war at the end of Yuan Dynasty. When it was found again in 1980, the Buddha is only a headless and fragmented body. Now, the cultural-relic department determines to repair the Buddha and recondition its vicinity. This will be beneficial not only to the protection of rare cultural-relics but also to the development of local tourism-economy. Based on the repair project of the Buddha,, the classification of weathered rock mass, the influence of structure faces on the earthquake motion in a rock slope are studied in this thesis. Furthermore, some new conceptions and methods on the seismic stability of rock slope are also put forward in this paper.Considering the dual requirement of cultural relic for appearance and stability, the index system for weathering degree evaluation of rock mass is proposed based on the external characteristic, the rock structure and the physical and mechanical properties of rock mass. The relationship between weathering grades and the physical and mechanical properties of rock mass is studied and the evaluation standard was put forward according to the relationship. Furthermore, analytic hierarchy process and fuzzy mathematics theory were applied to evaluate the weathering grade of rock mass of Buddha in accordance to the evaluation standard. The analytic results indicate the rock mass of Buddha is differently weathered.The numerical simulation with software UDEC for the influence of structure faces on the earthquake motion of rock slopes are carried out systematically in this paper. The influences of the variations in the factors such as the damp ratio of rock mass, the stiffness, positions, occurrence(insert with the slope and parallel with the slope) of structure faces, and unloading depth on the earthquake motion in a rock slope were summarized by the numerical simulation results. Based on the conclusion mentioned above, some valuable laws are developed.Two different concepts of dynamic stability of slope were proposed. The first is used to describe the stability of slope under the constant seismic load; The second is used to describe the seismic load that the slope can sustain.Dynamic time-history method and quasi-static method were used to analyze the stability of key blocks on Buddha slope respectively. By comparing the results of the two different methods, It is found that quasi-static method overestimate the stability of slope, but the critical acceleration calculated by the two methods is not far off. Thus, a new method that combines the merits of the two methods is put forward to assess the seismic stability of rock slope. And the analytical results illustrate that plane sliding failure will not occur when the slope is affected only by seism. However, When horizontal seism-force and hydro-static pressure are coupled, the Buddha slope can hardly keep stable.