一、前言有些用水平铺盖作防渗的土坝,在运用中由于水平防渗起不到予期的效果,而采用垂直防渗作补强处理,在工程布置上则成为既有水平又有垂直的两种防渗措施,对垂直防渗墙下游的铺盖,由于渗透坡降的加大而必须加厚,而防渗墙上游的原铺盖仍有一定的作用,另外在多年的运用期间,上游的淤积对防渗亦有一定的防渗效果,计算简图如下: I. INTRODUCTION Some earth dams which are used for seepage prevention with horizontal coverings will not achieve the expected effect due to horizontal seepage prevention and will be treated with vertical seepage prevention for reinforcement treatment. The project layout will be both horizontal and vertical Of the two anti-seepage measures, vertical cut-off wall downstream of the cover, due to the increase of infiltration slope must be thickened, and the cut-off wall upstream of the original bedding still have a role, in addition to many years of use, the upstream The siltation of impermeable seepage also has some anti-seepage effect, the calculation is as follows: