不同因素对堆石坝地基防渗墙应力应变影响分析

Analysis of Influence of Various Factors on Stress and Strain of Impervious Wall of Rockfill Dam Foundation

为了掌握面板堆石坝防渗墙的受力变形特点,通过数值计算方式,分析覆盖层类型、材料属性、坝趾和防渗墙距离对防渗墙受力和变形的影响。研究结果表明,防渗墙变形值受覆盖层特性影响较大,变形值随着覆盖层刚度的增加而减小,垂直变形值的规律与此相似;防渗墙应力应变受墙体材料的影响较大,选择塑性混凝土作为防渗墙材料能够在较大程度上降低墙体所受压应力,压应力峰值可降低至3.2MPa以内,且防渗墙在工作期间的垂直应力σ_(z)和最大主应力σ_(1)与普通混凝土防渗墙相比只有其1/3~1/4;防渗墙的变形随着坝趾和防渗墙间距离的增大而减小,防渗墙中间部位水平位移峰值降低近1cm;增大坝趾和防渗墙间的距离,能够较好地改善防渗墙受力情况。

In order to master the stress and deformation characteristics of the cutoff wall of concrete faced rockfill dam,the influence of the overburden type,material properties,dam toe and the distance between the cutoff wall on the stress and deformation of the cutoff wall is analyzed through numerical calculation.The research results show that the deformation value of the cutoff wall is greatly affected by the characteristics of the overburden layer,and the deformation value decreases with the increase of the overburden layer stiffness,and the law of vertical deformation value is similar to this;the stress and strain of the cutoff wall are greatly affected by the wall material.Choosing plastic concrete as the cutoff wall material can greatly reduce the compressive stress of the wall,and the peak compressive stress can be reduced to less than 3.2MPa,and the vertical stress of the cutoff wall during the working periodσ_(z) and maximum principal stressσ_(1).Compared with ordinary concrete cutoff wall,it is only 1/3~1/4;the deformation of the cutoff wall decreases with the increase of the distance between the dam toe and the cutoff wall,and the peak horizontal displacement of the middle part of the cutoff wall decreases by nearly 1 cm;increasing the distance between the dam toe and the cutoff wall can improve the stress of the cutoff wall.