太原晋阳西山大佛松动岩体边坡地震稳定性研究

SEISMIC STABILITY OF LOOSENED ROCK SLOPE OF GRAND BUDDHA ROCK MASS IN WEST JINYANG MOUNTAIN IN TAIYUAN

根据太原晋阳西山大佛所处的地形地貌、地质构造、气象水文条件和场地工程地质条件,分析影响大佛边坡岩体稳定性的主要因素,建立大佛松动岩体边坡稳定性分析概化模型,提出大佛边坡岩体所处的主要工况类型。运用拟静力法和极限平衡法分析地震和降雨多种工况组合条件下大佛松动岩体边坡的顺层抗滑动稳定性和抗倾覆稳定性。分析结果表明,单独在地震荷载作用下,大佛陡崖岩体不会发生顺岩层的滑动破坏;但是在排水不畅条件下松动岩体裂隙充水对大佛陡崖边坡的抗滑稳定性会有非常大的影响;在裂隙水压力和水平地震力联合作用下,大佛陡崖不能保持稳定;在地震荷载作用下,大佛陡崖松动岩体存在向外倾覆崩落的危险。这些研究结果可为大佛松动岩体的加固整修提供依据,并可为类似石质文物边坡稳定性分析提供借鉴。

Jinyang west mountain Grand Buddha,with significant value of culture and history,was excavated in the Permian sand rock mass on a steep slope 1 400 years ago.At present,the steep slope of the Grand Buddha is in a dangerous situation because of its broken and loosened rock mass.According to the conditions of topography,geological structure,climate,hydrology and engineering geology,the main factors influencing the slope stability of the Grand Buddha rock mass are discussed;the generalized model of the slope for stability analysis is set up,and the main working situations of the slope are put forward.By pseudostatic and limit equilibrium analysis,anti-slip and anti-overturning stability of the steep slope with broken and loosened rock mass under the main working situations affected by earthquake and rainfall are analyzed.The analytical results show that the bedding slide of the rock mass on the steep slope will not occur if there is only seismic load acting on.However,the water filling in the cracks of the loosened rock mass will greatly weaken the anti-slip and anti-overturning stability of the slope;the steep slope will not keep stable under water pressure and horizontal seismic force.Moreover,the loosened rock mass of the steep slope has the overturn risk under seismic load.These results offer a base for the mending of the broken and loosened rock mass of the Grand Buddha,and can also be a reference to the stability analysis of similar lithoid cultural relics.