The new composited foundation of the pile-diaphragm wall has high horizontal bearing capacity.There is social and economical significance for the research of the structure.The theories of deformation and mechanical behaviours of new combined foundation under large area loading are analyzed.The checking computations of stability of combined foundation are proposed.Inter force and deformation is calculated based on programming of theory of the finite element,and comes up with some elements impacting on bending moment and displacement.At the same time,the force and deformation properties of the whole combined foundation and the single piles-wall foundation are calculated for comparison.Calculation results show that the stress shape of combined foundation is"belly shaped"and the deformation of foundation is the overall tilt deformation;the maximum of bending moment is in near the connected point of the piles and the wall;in influencing factors,degree of large area loading is the foremost,the wall height,pile diameter,pile number are following behind it.The change of pile length,especially when the pile is up to 10 m,has little effect on the combined foundation.The mechanical properties are different between single piles-wall and the whole combined foundation.The overall stress of combined foundation is more obvious,and shows rigid deformation. But the stress of single piles-wall concentrates in the wall under the ground 5 m,and shows flexure deformation.The whole combined foundation has the higher horizontal bearing capacity compared with the single piles-wall.%桩地下连续墙新型组合基础具有较高的水平承载力,对于其结构的理论研究具有重要意义.文章对堆载下新型组合基础的受力及变形性状进行理论分析,提出组合基础的稳定性验算方法,基于有限元原理编程对组合基础进行内力变形计算,分析了各因素对组合基础弯矩及位移的影响,对整体组合基础与单片桩墙基础受力及变形性状进行计算对比.结果表明:堆载下组合基础结构受力呈"大肚形",变形呈整体倾斜变形,在桩墙连接点处附近弯矩最大;在诸多影响因素中,堆载荷载大小对基础的影响最大,其次是墙高、桩径、桩数的改变,桩长的改变尤其是当桩长达到10 m后,对组合基础的影响较小;单片桩墙基础与组合基础受力性状不同,组合式桩墙结构的整体性受力更为明显,偏刚性变形,而单片桩墙结构受力主要集中在上部5m深度内的墙体,呈挠曲变形,两者相比整体组合基础的水平承载力更高.
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