库水位周期波动对抗滑桩加固效果影响研究

以安康水库东岸马家坡滑坡为研究对象,采用现场调查、室内试验、数值模拟等方法,对比分析了岩土体物理力学性质在不同饱水-失水循环次数下的劣化趋势,验证支护设计的合理性及安全性,研究水库水位周期性波动对于抗滑桩加固效果的影响。得出主要结论如下:(1)滑体及滑带的主要成分即强风化千枚岩在饱水-失水循环条件下,物理力学性质产生明显的劣化现象,呈现出先快速下降后缓慢下降的趋势;(2)坡体中前部设置抗滑桩后,坡体稳定性有了较大的提高,但随着水位变化次数增多,抗滑桩的加固效果不断弱化,且弱化速度为先快后缓;(3)随着水位循环次数的增加,位移及塑性应变带逐渐后移至滑坡后缘处,滑带处桩身受到的作用力最大且其值缓慢增大。

Study on the reinforcement effect of anti-slide pile with reservoir water level fluctuation

Taking the landslide in AnKang reservoir as the research object,we adopt field investigation,laboratory test and numerical simulation to analyze the physical indexes and mechanical properties parameters of the rock under different water-dehydration cycles,and verify the rationality and safety of the supporting design. The effect of periodic fluctuation of reservoir water level on the reinforcement effect of anti-slide piles is studied. The main conclusions are as follows:(1) Under the water-dehydration cycle,the physical and mechanical properties of the strong weathering phyllite show the deterioration phenomenon,and there is a tendency to decrease slowly after the first rapid descent; (2) The stability of slope with the pile installed is improved greatly. With the increase of water level, the effect of anti-slide piles is weakened,and the speed is fast and then slow;(3) As water level cycles increases,the displacement and plastic strain bands gradually move to the trailing edge of the landslide,and the maximum force of the pile at the sliding zone is increased slowly.