城市内河汛期堤防边坡稳定性研究

Study on Stability of Embankment Slope of Urban Inland River in Flood Season

根据许昌市某内河堤防断面构建概化数值分析模型,通过变水头渗透试验测得堤防土体渗透系数,通过剪切试验获得土体粘聚力和内摩擦角参数.计算了不同水位堤防渗流场及水力梯度变化规律;进而分析堤防背水坡稳定性.结果表明,两种工况最大水力梯度均出现于溢出点附近且小于临界水力梯度,随着水位增长,堤防内水力梯度明显提升,边坡安全系数显著下降,其中Janbu法计算最高水位安全系数接近临界值.

A generalized numerical analysis model is constructed based on a Embankment Section of an inland river in Xuchang.The permeability coefficient and shear strength parameters of soil is measured through variable head permeability test and shear test.The characteristics of seepage and Hydraulic gradient field at different water level are studied.Then,the stability of downstream slope is analyzed based on the seepage field.The results show that the maximum hydraulic gradient appears near the overflow point below the critical hydraulic gradient.With the increase of water level,the hydraulic gradient in the embankment increases while the slope safety factor decreases significantly.The safety factor of the highest water level calculated by Janbu method is close to the critical value.