锦屏一级水电站左岸高边坡工程整体稳定性的模型试验研究

介绍锦屏一级水电站高边坡工程整体的模型试验方法,以检验和评价该工程的整体实效与稳定性。根据现场高边坡实际开挖工程、已完成支护及工程地质等条件,建立三维地质力学模型,采取施加上部荷载和底部动荷载方式,模拟和测试该边坡在上部山体正常荷载作用下边坡工程的稳定性、爆破振动荷载作用下的边坡工程稳定性,以及超常荷载作用下边坡工程的破坏过程与安全度。试验与分析结果表明,正常荷载应力作用下,该高边坡工程变形较小,边坡无破坏且稳定;在下部爆破振动工况下,未出现边坡及支护开裂与破坏,而在不断增加的超载作用下,边坡最终发生开裂和失稳破坏,且裂缝主要出现在锚固区之外。试验给出边坡变形及破坏的全过程,定量分析边坡变形和应力变化规律,探明边坡应力、变形及破坏趋势。研究结果表明,前期完成的高边坡支护工程是有效的,整个边坡在目前工况下是稳定的,并对边坡安全提出建议:后期边坡工程应有足够锚固强度,避免损伤岩体,加强长期现场监测与信息反馈。此模型试验具有重要的工程意义及实际价值。

MODEL TEST RESEARCH ON GLOBAL STABILITY OF LEFT BANK HIGH SLOPE OF JINPING I HYDROPOWER STATION

The model test method employed in Jinping I Hydropower Station on the whole high slope is presented to evaluate the actual effects. A new upside load with bottom dynamic load test method for the slope modeling is also proposed to simulate and analyze the stability of high slope under upwards normal load，the dynamic impact effect under blasting wave；and the failure process and the safety degree of slope under overload are also given. The test results show that the deformation of high slope engineering is small without slope failure under the normal load；and there is no crack and thus the slope will not fail. In addition，with reinforced structures under bottom with dynamic blasting load at construction site，the slope will also not fail，but slope cracks and possible failure are traced mostly outside the reinforced zone of slope under increasing overload ultimately. The complete processes of deformation and failure are verified by the test. The stress distribution，deformation characteristics and failure trend of the high slope are achieved. The deformation and failure caused by the maximum principal stress in slope are also simulated. The geostress effect and mechanical mechanism under unloading are studied. The results show that reinforcements adopted in the slope are effective and acceptable，and the global high slope is stable during construction. The further techniques for slope safety are therein suggested：anchorage structures should be highly effective，the slope rock damage should be avoided，and field monitoring and information feedback should be implemented perennially in later period for slope engineering. It can be found that the model test is also effective for other high slope projects.