路堤下水平加筋体与散体材料桩复合地基极限承载力

Limit Bearing Capacity of Composite Foundation Reinforced with Geosynthetic and Granular Pile Under Embankment

针对路堤荷载下水平加筋体与散体材料桩复合地基的极限承载力计算问题,分析了水平加筋体、路堤和地基之间的相互作用,得到了三者的作用力关系以及速度关系;研究了散体材料桩对地基承载力的影响,得到了考虑桩体置换率、地基土固结度影响的复合地基土体强度指标的计算公式;根据极限分析理论,从能量平衡角度推导出了地基极限承载力计算公式;对实际路堤工程设计计算进行了研究,搜索出最危险滑动面以及路堤极限高度。最后,通过工程实例,对比了路堤极限高度计算值和实测值,并分析了筋材极限强度发挥系数、固结度等因素对地基极限承载力的影响。结果表明:计算值与实际情况很接近,结果较为理想。

Aimed at the problem of calculation for limit bearing capacity of composite foundation reinforced with geosynthetic and granular pile under embankment,the reciprocities among the horizontal reinforcement,embankment and foundation were analysed and their forces and velocities were got.Through studying the influence of granular pile on bearing capacity of composite foundation,the formulas about strength of composite foundation were obtained which considered pile replacement ratio and consolidation degree.The formulas of limit bearing capacity of composite foundation reinforced with geosynthetic and granular pile were deduced based on the energy balance method of limit analysis theory.Authors studied the design of field embankment engineering,and searched the most dangerous slide surface and the limit height of embankment by using optimization method.Finally,through practical engineering,authors compared the calculated values and field test values of limit height of embankment and analyzed the influences of several factors,such as limit strength coefficient of geosynthetics,consolidation degrees on limit bearing capacity of composite foundation.Results show that calculated values of the limit height agree well with the practice.