Stability Analysis For Rock Slope Of Xishan Grand Buddha In Taiyuan

Engineering geology plays a vital role in the damages of lithoid cultural-relics. In China, research on engineering-geology problems in the protection of lithoid cultural-relics has been conducted since 50s of last century. The stability problem of lithoglyph in scarp has drawn great concern since many factors are involved, including regional geology structures, engineering geology, hydro-geology and so on.In our country, Xishan Buddha is the first open-air stone buddha, with incalculable historical, cultural, artistic, and high socio-economic value. However, the domestic protection work of stone cultural relics is still at an early stage, and the techniques and experience are not mature and rich.In this paper, Jinyang grand Buddha in Taiyuan city is taken as an example for research. According to the properties of topography, geological structures, climate, hydrology and engineering geology, analysis for influencing factors of the Buddha slope was performed and the main working-conditions were presented. Site investigation reveals that the Buddha slope stands upright and the rock-masses are composed of thick Permian-sandstone, which dips slightly inwards the slope face. Affected by both the incision of regional joints and the load relief to free face, the rock of the Buddha slope becomes loosened blocks. To better understand the potential failure modes, FLAC-2D based on strength reduction method was employed to model the deformation of the Buddha slope. The modeling results reveal that the localized deformation of the rock-masses may trigger reversing of rock beddings, which make the back-slope convert to dip slope. In this situation, the Buddha slope is potential to plane failure. Furthermore, pseudo-static together with limit equilibrium methods was applied to analyze of the plane failure and toppling failure under different working-conditions.The analytical results illustrate that plane failure will not occur when the slope is affected only by seism. However, water-filling into cracks of the loosened rock-masses may greatly contribute to the potential plane failure. When horizontal seism-force and hydro-static pressure are coupled, the Buddha slope can hardly keep stable. Additionally, the loosened rock-masses are prone to toppling failure when influenced by seism force. Summarily, the analytical results are reliable and effective when FLAC in combination with limit equilibrium method are employed to explore the slope stabilities of lithoglyphs in scarps.