CFG桩施工工艺在工程中的应用

Application of CFG Pile Construction Technology in a Project

鉴于工程座落的地基为粉土层,属中软土,其承载力不能满足设计要求,故根据以往的实践经验及岩土工程勘察报告的建议,选用CFG桩复合地基进行地基处理,采用了长螺旋钻孔、管内泵压混合料灌注成桩施工工艺。详细说明了CFG桩复合地基在工程所在地区软土地基处理的设计参数及施工工艺。单桩竖向抗压载荷试验显示,所抽检的8根桩的单根竖向极限承载力均不小于1 200kN,地基承载力提高了130%～140%,总沉降量均小于10mm;在2#楼54根桩的桩身的完整性检测中,47根为Ⅰ类桩(完好桩),7根为Ⅱ类桩,表明桩的完整性较好。由此可见,在该区选用CFG桩复合地基进行地基处理是切实可行的。

Because of the foundation of a project is silty soil,a kind of medium-soft soil,its bearing capacity is not satisfied to design requirements.Based on practical experiences and the geotechnical engineering exploration report of the project,the CFG pile composite foundation treatment has been selected and long auger boring,in-pipe pump pressurized mixed material grouting piling technology adopted.The paper described the CFG pile composite foundation design parameters and construction technology used in the project site in detail.The single pile vertical compressive load test results have demonstrated that the spot tested 8 piles single vertical ultimate bearing capacities are all not less than 1200kN,foundation bearing capacity increased 130%~140%,total settlements are all less than 10mm.In pile integrity inspection of 54 piles of No.2 building,47 are classed in category I（intact）,7 in category II,indicated the good integrity of piles.Thus it can be seen,CFG pile composite foundation treatment is practical in the area.