Abstract:Based on the extremely complex surrounding environments and karst development sites, the selection of foundation type of water treatment project is discussed. The highest applicability of cast-in-place pile foundation is given. The distribution of karst is judged by supplementary investigation of one pile and one hole, and the pile length is determined according to the principle of the embedded rock depth at the pile tip. Based on the problems such as over-pouring, loss and cross-hole of concrete that occurred during the pile test process, the effects of different treatment methods are analyzed and discussed. The jumping pile driving scheme from outside to inside, from having karst caves to having no karst caves, from large to small, from many to few, and from deep to shallow is proposed, and the treatment schemes such as the full sleeve without pull-out treatment for medium and large karst caves, the over-poured concrete treatment for small karst caves, and the pre-grouting treatment for karst caves that cannot be clearly identified are put forward in order to give the good technical support for pile forming in the large scale. Finally, the experience in the investigation, design and construction of karst caves is summarized. It is concluded that the karst distribution has strong uncertainty, and the advanced exploration is a necessary prerequisite for formulating a treatment scheme for karst caves. During the design and construction process, the dynamic adjustments still need to be made according to the actual situation of the cave to ensure the treatment effect, the depth of the pile tip entering the rock and the integrity of the pile forming.
