加固软土路基的现浇X形混凝土桩力学特性  

Mechanical Property for Cast-in-situ X-shaped Concrete Pile of Reinforced Soft Roadbed

作　　者：张敏霞[1,2] 刘汉龙[1,3] 丁选明[1,3] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河南理工大学土木工程学院,河南焦作454003 [3]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《中国公路学报》2011年第5期11-17,共7页China Journal of Highway and Transport

基　　金：江苏省自然科学基金创新学者攀登项目(BK2008040);江苏省"青蓝工程"科技创新团队项目

摘　　要：通过截面几何特性分析和足尺模型试验,从理论分析和模型试验等多角度研究了现浇X形混凝土桩的力学特性。分析了X形桩截面3个参数对其截面力学效应的影响,并与等面积和等周长的素混凝土方形桩、圆形桩作了对比。结合试验结果,并针对X形桩有别于传统桩型的过度充盈反而削减承载力的特点,提出X形桩极限承载力计算公式。理论分析结果表明:从增大侧表面积、减少桩身混凝土用量的角度分析,X形桩优于方形桩,方形桩优于圆形桩。足尺模型试验结果表明:在相同的荷载条件下,与等面积圆形桩相比,X形桩沉降量小、侧摩阻力高;实测极限状态时X形桩承载力比等面积圆形桩提高了32%。Through geometric property analysis and full scale model test, special mechanical property of the cast-in-situ X-shaped concrete pile was studied by theoretical analysis and model tests. The influences of three geometric parameters of X-shaped pile cross-section on mechanical effects of cross-section were analyzed, and were compared with same case of quadrate pile and circular pile in same area and same perimeter respectively. According to the test results, the fullness depreciation coefficient was brought forward and analyzed in calculating ultimate bearing capacity. Aimed at the characteristic of X-shaped pile which was different from bearing capacity depreciation due to fullness of tradition pile, the calculated formula of ultimate bearing capacity was proposed. Theoretical analysis results show that the X-shaped pile is better than the quadrate pile,and the quadrate pile is better than the circular pile from the point of view of reducing concrete and augmenting skin area. Full scale model test results show that compared with circular pile in same area, the settlement of the X-shaped pile is small, the lateral friction is large under the same load condition; compared with the circular pile in the same area, bearing capacity of the X-shaped pile increases by 32% under the measured ultimate state.

关 键 词：道路工程 软土路基 足尺模型试验 现浇X形混凝土桩 异形力学特性 

分 类 号：U416.1[交通运输工程—道路与铁道工程]