基于COMSOL的洛河治理工程中河道岸坡安全稳定性分析研究

Analysis and research on the safety and stability of river bank slope in Luohe River control project based on COMSOL

针对洛河治理工程中的河道岸坡,利用COMSOL有限元软件,引入渗流与安全稳定系数理论,研究了不同工况下岸坡渗流与安全稳定性。分析了不同河道水位下水压从坡底部至顶部逐渐增大,水位6 m的最大水压相比于4 m时增大了11.2%,浸润线均呈水平状态,坡脚底部处的等效应力随水位增大,量值逐渐降低,但分布面积扩散。降雨工况下常规降雨强度时坡体水压分布基本一致,流网分布呈均匀,强降雨强度时坡脚底部水压力增大显著,呈条状分布,最大流速是常规降雨强度下的6倍,达到30.8 cm/s。获得了不同水位下岸坡安全稳定系数与河道水位呈反比关系,但坡脚处位移量与河道水位呈正相关,水位增大,滑动体愈倾向于外侧坡面。分析了降雨强度增大,安全稳定系数降低,强降雨强度250 mm/d下岸坡稳定系数逼近于1,滑动面附近坡体内位移值随降雨强度增大而变大,降雨强度20 mm/d时为0.15 m。论文为河道治理过程中岸坡安全稳定性分析评价提供一定参考。

The COMSOL finite element analysis(FEA)is introduced the theory of seepage and safety stability coefficient under different working conditions in order to study the bank slope of the Luohe River control project.It was analyzed that the water pressure at different water levels gradually increased from the bottom to the top of the slope.The max water pressure increased by 11.2%at the water level of 6 m compared to that at 4 m.The infiltration lines were all horizontal.The equivalent stress at the bottom of the slope foot increased as the water level increasing,but the distribution area diffuses.Under normal rainfall intensity,the water pressure distribution of the slope body is basically identical,and the distribution of the drift network is uniform.Under strong rainfall intensity,the water pressure at the bottom of the slope foot increases significantly,showing a stripe distribution,and the maximum flow velocity 30.8 cm/s is 6 times that of the conventional rainfall intensity.The safety and stability coefficient of bank slope under different water levels is inversely proportional to the river water level,but the displacement at the foot of the slope is positively related to the river water level.As the water level increasing,the sliding body tends to the outer slope surface.It concludes that as the rainfall intensity increasing,the safety stability coefficient inversely decreases,and the stability coefficient of the bank slope close to 1 under the strong rainfall intensity 250 mm/d.When the rainfall intensity is 20 mm/d,the displacement value of the slope body near the sliding surface is 0.15 m.The results can provide some reference for the analysis and evaluation of bank slope safety and stability in the course of river regulation.