预应力混凝土管桩桩基承载力影响分析

对PHC管桩单桩竖向承载力和水平承载力性状特征进行了规律分析,研究了水平抗力系数的比例系数m的主要影响因素,结合PHC管桩桩基现场原位试验,进行了经济型比较分析.结果表明:针对夹有碎石填土层和基岩风化带,锤击法相对静压法具有更大的适用性;为保证桩端顺利进入持力层和选择合适的桩长,在施工前,应在未探明地质条件处采用超前钻;PHC管桩灌芯后水平极限承载力可提高50%以上;单桩水平抗力系数的比例系数m主要取决于桩侧地基土的性质,桩体刚度对其的影响呈非正相关关系;PHC管桩费用采用每吨承载力平均费用公式进行经济分析是可行的,可以达到节省投资的目的.

Analysis of Bearing Capacity of Pre-stressed Concrete Pipe Pile

This paper analyzes the characteristics rules for the vertical bearing capacity and horizontal bear- ing capacity of single pile, and studies scale factor m of the horizontal resistance coefficient. Combined with the in-sire tests of PHC pile foundation, the comparative analysis economically is carried out. The results show that, aiming at backfill soil with gravel and bedrock weathering zone, compared with static pressure method, hammering method has greater applicability. In order to ensure the smooth entry of the pile-end into the bearing layer and choose the appropriate pile length, the advanced drill should be applied in the place with unproven geological conditions before PHC pile construction. The horizontal ultimate bearing capacky increases more than 50% when PHC pipe pile is filled with concrete. The proportional coefficient m of horizontal resistance coefficient of the single pile depends mainly on the properties of the pile-side foun- dation soil. The impact of pile rigidity on coefficient m is not positively correlated. For economic analysis of the PHC pipe pile cost, the average cost formula of the bearing capacity per ton is feasible, which can save the investment.