泥浆护壁条件下缺陷混凝土防渗墙抗渗特性研究

Study on impermeability characteristics of defected concrete cutoff wall under mud protection wall conditions

水利水电工程在深厚覆盖层中修建防渗墙时,泥浆护壁已经成为确保槽孔稳定的重要手段,槽孔内的泥浆在压力差的作用下会向槽孔地层土体渗透,进而在槽孔壁面上形成泥皮。本文结合已有泥浆渗透形成泥皮的抗渗性能试验研究成果,在确定了覆盖层土体与混凝土之间泥皮渗透系数的基础上,建立稳定的渗流计算模型,并对防渗墙混凝土存在局部缺陷时,是否存在泥皮条件下的防渗墙抗渗性能进行计算分析,进一步讨论了泥皮对于缺陷混凝土防渗墙抗渗能力的影响。

When a cutoff wall is built for the water conservancy and hydropower project in the overburden layer,the mud protection wall has become an important means to ensure the stability of the slot.The mud in the slot will permeate to the soil of the slot stratum under the action of pressure difference,and then it forms a mud skin on the wall of the slot.The impermeability performance test research result of existing mud penetration mud skin formation is combined in the paper.A stable seepage calculation model is established on the basis of determining the mud skin permeability coefficient between soil and concrete of the overburden layer.When the cutoff wall concrete has local defect,whether there is cutoff wall impermeability performance under the mud skin condition is calculated and analyzed.The influence of the mud skin on the defected concrete cutoff wall impermeability ability is further discussed.