航城地区位于闽江下游,靠山沿江,海浅湾处因各类腐植土、淤泥质土和沼泽土的沉积,形成的软土地质分布起伏较大,地质剖面如图1。此外还有许多废弃河道、大小池溏,这些地方低洼积水、淤泥上无覆盖层,原有地层遭到不同程度的破坏,工程地质变坏。实践证明在这基底起伏较大或覆盖层较薄甚至无覆盖层的软土地基上,预制圆形混凝土沉井基础具有占地面积小、挖土量小、施工设备简单、操作方便、对邻近建筑物影响小等优点,是一种因地制宜、便于施工的地基基础处理方法,对小城镇的多层房屋及工业厂房具有一定的适应性。基础工程 The Hangcheng area is located in the lower reaches of the Minjiang River, and it is surrounded by mountains. Along the shallow sea, the formation of soft soils fluctuates due to the deposition of various types of humus, silt, and swamp soil. The geological profile is shown in Figure 1. In addition, there are many abandoned river channels, large and small pools, where there are no overburdens on the low-lying water and silt, and the original strata have been destroyed to varying degrees and the engineering geology has deteriorated. Practice has proved that the prefabricated circular concrete caisson foundation has a small footprint, small amount of excavation, simple construction equipment, easy operation, and proximity to soft foundations with large base undulations or thin or even non-overburden coverings. The advantages of small buildings and other advantages are a ground-based treatment method that suits the local conditions and facilitates construction. It has certain adaptability to multi-storey houses and industrial plants in small towns. Basic engineering