长江济益公堤河湖相淤泥质软基堤防裂缝成因分析

Analysis on the Cause of Formation of Cracks in a River-lacustrine Silty Soft Embankment

为监控和治理长江沿岸某堤防的安全稳定性,基于2个水位年、42个不同部位的水平位移、垂直位移及其力学参数监测数据分析了该堤防裂缝形成的原因,并利用数值模拟方法分析了其稳定性。结果表明,堤防裂缝随着时间的增长逐渐向下游延伸,并存在堤防背水坡位移量大于迎水坡位移量,上游裂缝宽度大于下游堤顶裂缝的问题;堤防沉降速率与长江水位变化具负相关性,水位上涨,沉降速率减慢,水位下降,沉降速率增大,反映渗透扬压力对坝体作用的基本规律;水位升降、结构性软土、上部结构荷载三者的综合作用导致了堤顶裂缝的产生,影响堤防的稳定性。治理时应注意软弱地基的处理,适当加大背水坡的反压。

In order to monitor and control the safety and stability of a embankment along the Yangtze river, based on the monitoring data of horizontal displacement, vertical displacement and mechanical parameters of 2 water level years and 42 different parts, the cause of the formation of cracks in the embankment was analyzed, and its stability was analyzed by numerical simulation method. The results show that the cracks of the embankment extend to the downstream gradually with the increase of time, and the displacement of the back water slope of the embankment is larger than that of the head water slope, and the width of the upstream crack is larger than that of the top of the downstream embankment. There is a negative correlation between the embankment settlement rate and the water level change of the Yangtze river. The water level rises, the settlement rate slows down, the water level drops, and the settlement rate increases, which reflects the basic law of the effect of seepage uplift pressure on the dam body. The comprehensive action of water level rise and fall, structural soft soil and superstructure load leads to the crack on the top of the embankment and affects the stability of the embankment. Attention should be paid to the treatment of soft foundation and increase the back pressure of the slope.