桩间距和布桩形式对微型桩受力的影响

摘要

建立了独立式、连系梁式及承台式微型桩支护体系模型,探讨了不同布置形式及桩间距下,各类型微型桩体系的受力特性.研究结果表明,相同荷载下承台型微型桩抗滑效果好,其最大桩身弯矩分别为独立式和连系梁式微型桩的1.36倍和1.35倍;梅花形布桩形式下,同类型微型桩的桩身最大弯矩约为矩形布桩形式微型桩的1.02倍;桩间距取1.5～2.0 m更有利于微型桩体系抗滑效果的充分发挥;最佳的微型桩布桩形式为承台式微型桩呈梅花形布桩,桩间距为1.5～2.0 m.%The models of independent micropile,micropile with coupling beams and micropile with pile cap are built up,and the mechanical characteristics of all these three types of micropile supporting systems are analyzed under the condition of different pile arrangements and pile spacings.The results show that the anti-slide effect of micropile with pile cap is better under the same load condition,whose maximum bending moment is 1.36 and 1.35 times as that of independent micropile and micropile with coupling beams respectively.The maximum bending moment of micropiles with plum blossom shape arrangement is almost 1.02 times as that of micropiles with rectangular symmetry arrangement.The pile spacing of 1.5～2.0 m is in favor of fully exerting of the anti-slide effect of micropiles.Thus,it is concluded that the best pile arrangement form is the micropile with pile cap with the arrangement of plum blossom shape,and the recommended pile spacing is 1.5～2.0 m.