This invention belongs to the field of flood drainage and seepage technology for valley ash dumps. It proposes a composite flood drainage and seepage
system and method for use in power
plant valley ash dumps. The invention includes a
drainage ditch set along the direction from the
flood control dam towards the initial dam of the ash dump. The
drainage ditch includes a flood drainage
culvert at the bottom of the ash dump, a seepage
ditch and a flood
drainage ditch located above the flood drainage
culvert. The bottoms of the seepage
ditch and the flood drainage
ditch share a common
pool wall with the upper part of the flood drainage
culvert. The adjacent side walls of the seepage ditch and the flood drainage ditch also share a common
pool wall. This effectively reduces the foundation treatment area and
land occupation, as well as the amount of steel reinforcement and concrete used, thus lowering the project cost. Simultaneously, the flood drainage ditch has an opening at its upper part and a cover plate placement groove. A seepage
pipe is installed at the end of the drainage ditch away from the
flood control dam. This
system is suitable not only for flood drainage and seepage when upstream floodwaters flow into the ash dump along the slopes of both banks, but also for flood drainage and seepage under conditions of high rainfall.