在饱和软土地基上施工房屋、桥梁、涵闸等的明挖基坑时,为防止饱和土中水的渗流引起边坡滑塌而影响施工,必须采取多种防治措施,用降水法施工是经常采用的措施之一。降排水的方法有明沟排水、轻型井点降水、喷射井点降水、电渗排水及大井管降水等方法,这些都是有效的办法,但都需要一整套机具和设备。在一般中小型工程或较浅基础从地下静水位向下10m以内施工时,我们采用了无砂混凝土滤水井降水。50年代无砂混凝土仅用于墙体保温,后来无砂混凝土用于打水井、坝坡反滤等方面,但用于房屋、桥梁的基坑降水施工还是 When constructing excavation foundation pits, such as houses, bridges, culvert gates, etc. on saturated soft soil foundations, in order to prevent slopes from sliding due to seepage of water in saturated soil and affect construction, various prevention and control measures must be taken, and construction by precipitation method is often One of the measures taken. There are methods for lowering drainage such as open drainage, light well precipitation, jet well point precipitation, electroosmotic drainage, and large well pipe precipitation. These are effective methods, but all require a complete set of equipment and equipment. In the construction of general small and medium-sized projects or shallow foundations within 10m below the groundwater level, we used precipitation from sand-free concrete filtration wells. In the 1950s, no sand-free concrete was used only for wall insulation. Later, no sand concrete was used for water wells, dam slopes, and other aspects of filtration. However, the construction of foundation pits for houses and bridges was still conducted.