下压荷载作用下桩—桶基础结构设计及数值模拟  

Design and numerical simulation of pile-bucket foundation under compressive loading

作　　者：刘文白[1] 王大山[1] 赵龙[1] 

机构地区：[1]上海海事大学海洋环境与工程学院,上海201036

出　　处：《岩土工程学报》2010年第S2期216-219,共4页Chinese Journal of Geotechnical Engineering

基　　金：上海市教育委员会科研项目(07ZZ99);上海海海事大学校级重点学科建设项目(A290209002);浙江省科技计划面上项目(2008C23023);国家自然科学基金(50909057)

摘　　要：运用ABAQUS软件分析不同尺寸的桩—桶基础在相同下压位移时的下压荷载的变化,并对桩—桶基础进行结构设计。桩—桶基础的主要尺寸包括桶顶以下入土桩长(L3),桶半径(R)及桶壁高(H),不同尺寸的桩—桶基础在地基土达到破坏时的极限荷载各不相同,增加L3,R及H能提高基础的抗压承载力;R的变化对基础的抗压承载力最大,其次是L3的变化,最后是H的变化。通过变化桩—桶基础结构的几何尺寸可以得到结构不同的承载力,以分析结构内力变化的规律,若其他尺寸不变,桶径增大1.67倍,桩—桶基础极限抗压承载力可提高60%,桶高增大40%,基础极限承载力可提高5%,桩长增长一倍,基础极限承载力提高33%,故桶径的变化对桩—桶基础的承载力影响最大。为了将桩与桶两者的工程优势充分发挥出来,并考虑到工程经济性原则,从而设计出几何尺寸合适的桩—桶基础结构,使其承载力性能高,结构内力相对小且分布均匀。Variation of the pressure-loading on the pile-bucket foundation with different sizes under the same displacement are analyzed with ABAQUS,and the design of pile-bucket foundation structure is carried out.Main dimensions of the pile-bucket foundation are showed as follows:buried pile length(L3),bucket radius(R) and bucket wall height(H).The ultimate pressure loading of pile-bucket foundations is various with different sizes of foundations.The enhancement of L L3,R and H leads to the improvement of pressure-loading bearing capacity of foundation.The influence of change R is most significant to the pressure-loading bearing capacity of foundation,and the change of L3 takes the second place,and the change of H goes the last.By comparing pile-buckets with different sizes,different structural pressure-loading bearing capacities can be achieved,so that the inner stress distribution of structure can be studied.By enlarging the diameter of bucket by 1.67 times while maintaining the two other dimensions,the bearing capacity can be enhanced by 60%;the bearing capacity can be enhanced by 5% when the height of bucket is enlarged by 40%;the bearing capacity can be enhanced by 33% when the pile length is doubled,which means the variation of bucket diameter affects the pile-bucket foundation bearing capacity most.By comparing engineering economy with engineering performance of the structure,the pile-bucket foundation with reasonable size can be analyzed so as to enhance the pressure-loading capacity of the structure,and make inner stress be more homogeneously distributed.

关 键 词：下压荷载 桩—桶基础 数值模拟 结构优选 

分 类 号：TU470.3[建筑科学—结构工程]