格宾堤防边坡动态水头下的浸润过程及稳定全状态函数

Infiltration process and stable full-state function of the quasi-dynamic head of the gabion embankment slope

格宾支挡在堤防工程中起重要支护作用,长期水位变化使其出现安全性计算模糊等问题。为此,通过室内模型试验及数值模拟,对格宾支挡边坡动水浸润过程及稳定状态进行了研究。结果表明:1)格宾支挡边坡的动态水位浸润主方向表现为由坡脚向坡体内的分散辐射状,区别于素土边坡的圆弧形,且平均浸润速度仅为后者的0.3~0.5倍;2)格宾结构与坡体耦合稳定性好,动态浸润过程中无超孔隙水压和基底绕流现象;3)建立了4种工况下动水浸润边坡的稳定全状态函数,发现格宾支挡边坡(有格宾有基岩)稳定性系数随水位变化幅度最小。研究结果明晰了动水条件格宾挡墙边坡稳定性变化的浸润特征,为堤防边坡工程的施工设计及运行监控提供了理论指导。

The gabion support plays an important role in the embankment project,and the long-term water level changes cause the safety calculation ambiguous.Therefore,the dynamic water infiltration process and stable state of the gabion retaining slope are studied through indoor model tests and numerical simulations.The results show that:(1)The infiltration characteristics of the gabion retaining slope under static and dynamic water conditions are different,and the infiltration rate and direction differ from the plain soil slope.The main direction of dynamic water level infiltration of the gabion-supported slope shows a scattered radial shape from the toe of the slope to the slope body,which is different from the arc shape of the plain soil slope,and the average infiltration rate is only 0.3-0.5 times of the latter.(2)Compared with the mortar rubble retaining method,the coupling effect between the gabion retaining wall and the slope soil is better,the slope deformation convergence time is short,and the transition time from the saturated area to the unsaturated area in the slope is relatively stable.During the dynamic infiltration process,the pore water pressure increases nonlinearly with the water level rise and shows a gradual decrease in steps as the water level decreases.There is no excess pore water pressure and the phenomenon of flow around the basement.(3)The stable full state functions of the dynamic water infiltrated slope under four working conditions are established,and it is found that the stability coefficient of the slope with gabion support(with gabion and bedrock)changes the smallest with the water level,compared with the slope without gabion support.The stability at static water level is increased by a factor of 1.7 to 2.4 compared to the slope without the gabion support.The research results clarify the infiltration characteristics of the stability change of the gabion retaining wall slope under the dynamic water condition and provide theoretical guidance for the construction design and operation monitoring of the embankment slope engineering.