钢管+Hat钢板桩新型组合支护结构研究

Study on supporting effect of steel tube and Hat composite steel sheet pile

为解决传统拉森钢板桩支护刚度不足的问题,提出一种由钢管与Hat型钢板桩交叉组合使用的新型组合支护结构(Pile-Hat type steel sheet pile-Composite,简称PHC),其既有钢管桩抗弯刚度大的优势,又有钢板桩止水挡土的优点。同时,针对PHC支护结构可能存在的问题,展开了截面刚度、结构选型、施工工艺等方面研究,并以马鞍山某基坑工程为算例,得出桩顶水平位移与地表最大沉降值的偏差在15%左右,表明该组合支护结构设计合理。最终总结了钢管+Hat型钢板桩的刚度计算、等效截面计算和桩体选型方法,提出组合支护结构的施工工艺和注意事项,对提高地下工程施工质量和安全具有一定意义,也为该组合支护结构的实际应用与推广提供参考。

In order to solve the problem of insufficient rigidity of the rigidity of the traditional Lason steel plate piles,a new combination support structure used by the cross combination of steel pipe and Hat steel plate pile is proposed by this paper,PHC support structure for short.It has the advantages of large section modulus,stiffness and good sealing effect of steel sheet pile.In view of the possible problems of the support structure,the section stiffness,structure selection,construction technology and other aspects of the study were carried out.By taking the actual foundation pit project as an example,the deviation of the high value reduction of the horizontal displacement of the pile roof and the maximum value reduction of the surface is about 15%,indicating that the combination support structure design is reasonable.The method of stiffness calculation,equivalent section calculation and the combined structure selection were summarized,and finally the construction technology and matters for attention of combined supporting structure were obtained.It is of certain significance to improving the quality and safety of underground engineering,and also provides a reference for the actual application and promotion of the combination support structure.