长期库水作用下星光三组倾倒变形体稳定性研究

Stability of Xingguangsanzu Toppling Deformation Body Under Long Term Influence of Reservoir Water

基于室内岩土体试验,结合FLAC3D数值模拟分析,对星光三组变形体稳定性演化趋势进行分析,研究结果表明:砂岩抗剪强度指标随着干湿循环次数n及饱水时间d的增加而降低,循环次数和饱水时间分别大于25次和40 d后,其抗剪强度逐渐趋于稳定;库水位稳定在540 m和600 m水位时,岸坡整体处于稳定状态,随着干湿循环次数的增加,稳定性不断降低。循环次数达25次时,岸坡位移出现突变,循环次数达30次时,剪应变增量带在极强倾倒区已经完全贯通,初步判断极强倾倒区在干湿循环25次~30次间存在失稳破坏的可能。

This paper analyzes the evolution trend of the stability of the Xingguangsanzu deformation body based on indoor rock and soil tests and FLAC3 D numerical simulation analysis.The research results are as follows.The shear strength index of sandstone decreases with the increase of the number of dry and wet cycles and the saturation time.After a number of cycles and the saturation time are greater than 25 and 40 days,the shear strength gradually stabilizes.When the reservoir water level is stable from 540 m and 600 m,the bank slope is in a stable state.With the increase of the number of dry and wet cycles,the maximum displacement of the bank slope gradually increases,and the increase in shear strain continues to expand backward.The stability continues to decrease.When the number of cycles reaches 25,the bank slope displacement has abrupt changes.When the number of cycles reaches 30,the shear strain increment zone has been completely penetrated in the extremely strong toppling zone.It is preliminarily judged that the extremely strong toppling zone exists between 25~30 times of dry and wet cycles.