摘要
传统型钢水泥土搅拌桩(SMW工法桩)具有施工便捷、造价经济等优势,但其侧向刚度主要由型钢独立承担,故存在着侧向刚度不足、水平变形较大等缺陷。本文针对传统SMW工法的缺陷,提出改由直线型钢板桩和窄翼H型钢组合而成的方形格构作为水泥土搅拌桩的加筋体,将搅拌桩中大部分水泥土置于方形格构内部,使得水泥土由传统工法中置于型钢外侧的单向拉弯受力状态变为型钢外包约束的三向受压状态,充分发挥了水泥土抗压强度远大于抗拉、抗剪强度的特性,从而大幅提高承载中水泥土的侧向刚度贡献。本文首先提出了组合格构式型钢水泥土搅拌桩的型钢布置形式与施工方法。其次,在讨论不同型钢布置形式的简化计算模型的基础上,提出新型工法桩的抗弯承载力和抗弯刚度的计算方法。最后通过算例分析与讨论,验证了新型工法桩相对于传统工法桩的抗弯刚度与抗弯承载力均得到了大幅提高。
The traditional SMW pile has many advantages including convenient construction,economical cost,but the lateral stiffness is mainly assumed by the steel.There are some defects,such as weak lateral stiffness and large horizontal deformation.To improve the above defects of traditional SMW pile,a kind of combined and latticed SMW pile was proposed to replace the rectangular lattice composed of linear steel sheet pile and narrow-wing H-beam as the reinforcement of cement-soil mixing pile.Most of the cement soil in the mixing pile was placed inside the square lattice to make the stress state of cement-soil change from unidirectional tension-bending to three-dimensional compression state confined by section steel envelope in traditional construction method.This gave full play to the characteristics that the compressive strength of cement-soil was far greater than the tensile and shear strength with greatly improving the lateral stiffness contribution of cement-soil in bearing capacity.The layout of section steels and the construction method about this new pile was put forward,and the calculating method for the flexural bearing capacity and bending stiffness were brought forward for considering the different layout of section steels.A case study demonstrated that the new method had a great improvement in the flexural capacity of the pile comparing the traditional SMW method.
作者
吴定宇
张鹏
董韬
李俊才
WU Dingyu;ZHANG Peng;DONG Tao;LI Juncai(College of Transportation Science & Engineering,Nanjing Tech University,Nanjing 210009,China)
出处
《南京工业大学学报（自然科学版）》
CAS
北大核心
2019年第1期112-120,共9页
Journal of Nanjing Tech University(Natural Science Edition)
基金
国家自然科学基金面上项目(41372295)
关键词
组合格构式
SMW工法桩
抗弯承载力
抗弯刚度
combined and latticed
SMW pile
flexural bearing capacity
bending stiffness
