流塑淤泥地层中大型泵房的沉井施工

Construction of Open Caisson for Large Pump House in Current-formed Silt Soil

在流塑淤泥地层中进行泵房的沉井施工,容易产生突沉、偏移、反涌、超沉不止及施工过程难以控制等问题。扬州第五水厂取水泵房的沉井施工采用振冲碎石桩处理地基,不仅降低了地基的淤泥液化指数,而且碎石桩对沉井下沉也起到了支撑和导向作用。该施工方案的成功应用表明,在相似土层中通过改变碎石桩的长度、直径、桩距等手段调整地基承载力,使沉井在淤泥中的下沉过程成为一个可控工艺,具有施工简单、成本低的优点。

Some problems, such as sudden sinking, deflection, mud gush, constant subsidence and difficult control may occur in the construction of open caisson for pump house in current-formed silt soil. The vibro-stone column process was used in the construction of open caisson for the water intake pump house in Yangzhou Fifth Waterworks. The mud liquefaction coefficient can be decreased, and the stone columns can effectively prop and guide the caisson sinking. The successful application of the process in this construction scheme shows that the sinking of open caisson in silt soil can be controlled through regulating the load hearing capacity of foundation by changing the length and diameter of stone columns and their spacing in the similar soil. The process is simple in construction and low in cost.