大口径反循环施工方法的泥砂排除方式有泵吸式和气举式。为防止孔壁坍塌,需向孔内注水并使之高于地下水位,使岩粒和水同时排到孔外。在反循环钻进吸入条件较好、水源不断的情况下,可单独使用泥浆泵排除泥砂。在吸入条件不稳定、发生断水的复杂条件下,多采用 Sediment removal methods for large-caliber reverse-circulation construction methods include pump suction and air lift. In order to prevent the hole wall from collapsing, it is necessary to inject water into the hole and make it above the groundwater level, so that the rock particles and water are discharged to the outside of the hole at the same time. In the reverse circulation drilling inhalation is better, the water continuously, the mud can be used alone to exclude mud. In the inhalation of unstable conditions, the occurrence of complex conditions of water, the more use