墙前水位骤降挡土墙稳定不利水深取值问题分析研究

以水工挡土墙为研究对象,探讨提出墙前墙后水位骤降过程的模拟方法并建立墙前与墙后水位降幅的关系,设定多种墙前与墙后水位降幅比值及过程水深变化来模拟不同的水位降落速度及过程,分析了3个工程实例挡墙在不同水位降幅比值情形下稳定性和墙基边缘垂直正应力状态随不同过程水深的变化趋势,结果表明,稳定安全系数最小值对应水深绝大部分是发生在墙前水位降落过程中某一过程水深,墙前不利过程水深随水位降幅比值的提高而变小,墙后不利过程水深则相反。文中初步探讨性提出的墙前墙后水位降幅比和墙后初始最大水深取值原则、不利过程水深与墙高比建议值,可供墙前水位有骤降情况的挡土墙工程设计参考。

Study on Water Depth Determination for the Stability of Retaining Wall

Taking hydraulic retaining wall as the study object,the paper presents simulation of water level rapid drop processes before and after the wall and establishes a drop relation between water levels before and after the wall.The drop speeds and processes of different levels are simulated by setting various drop ratios and process depth changes.Meantime,the wall stability at different drop ratios is analyzed,and a study is made on the change trend of vertical positive stress at the foundation edge with different process depths through three project cases.It is indicated that in most cases the minimum stability safety factor corresponds a certain process depth during water dropping before the wall.The unfavorable process depth before the wall decreases with the increase of drop ratio,while it is opposite after the wall.In conclusion,the paper put forward the valuing principle of water level drop ratio before and after the wall and the initial maximum depth after the wall,as well as the recommended ratio between unfavorable process depth and wall height,which can be referenced by design of retaining wall with rapid water drop before the wall.