深基础施工中,经常采用井点降水系统来降低地下水位。这种施工方法由于能保持基坑土壤干燥,防止流砂产生,改善施工条件,减小基坑边坡,减少挖上数量,并由于土体固结而使坑底土层更为密实,因而,工程实践中得到了广泛的应用。但是,由于井点降水时,周围地下水位表现为漏斗状曲线,愈近井管水位愈低,影响半径可达数十米;加上建筑物四周土层结构的差异,四周各套井点降水设备实际降水能力的不均匀,以及四周原始地下水位与地下水量的不同,这一切导致井点降水时井点系统周围土层产生不均匀沉降。降水时间愈长,沉降差异越大。在城市兴建房屋,由于土地紧张等缘故,不少新建工程是在原有建筑物附近建造的。当新建工程基础采用井点降水法施工时,由于地 In deep-rooted construction, well-point precipitation systems are often used to reduce groundwater levels. This construction method can keep the soil in the foundation pit dry, prevent the generation of quick sand, improve the construction conditions, reduce the slope of the foundation pit, reduce the number of excavation, and make the pit bottom soil layer denser due to consolidation of the soil. It has been widely used in practice. However, due to the well-point rainfall, the surrounding groundwater level shows a funnel-shaped curve, the lower the near-well water level is, the influence radius can reach several tens of meters; plus the difference in the soil structure around the building, the surrounding wells are dewatering. The inconsistency of the actual precipitation capacity of the equipment and the difference between the original groundwater level and the groundwater volume all lead to uneven settlement of the soil around the well point system when the well point is dewatered. The longer the precipitation time, the greater the difference in settlement. In the construction of houses in cities, due to land tenseness and other reasons, many new construction projects were built near the original buildings. When the new project foundation is constructed by the well-point precipitation method,