预制高强混凝土薄壁钢管桩力学特性与生产工艺

Mechanical property and productive technology of precast thin-wall steel and spun concrete composite pile

预制高强混凝土薄壁钢管桩（TSC桩）是在钢管内浇筑混凝土,经离心成型,混凝土抗压强度不低于80MPa,能够承受较大竖向荷载和水平荷载的新型基桩制品.在公称直径、钢管厚度、混凝土厚度相同时,TSC-Ⅱ型的桩身极限弯矩高于TSC-Ⅰ型,二者比值不变;公称直径、钢管材质相同时,随着钢管厚度的增大,桩身极限弯矩显著增大,并且随着TSC公称直径的增大,差值也增大.当钢管采用该规格中的最大壁厚时,TSC-Ⅰ型桩的极限弯矩是同规格C型PHC管桩的2.1～2.7倍,TSC-Ⅱ型桩的极限弯矩是同规格C型PHC管桩的2.7 ～3.4倍,TSC桩轴向承载力设计值是同规格C型PHC管桩的1.4～2.6倍.TSC桩的生产工艺主要包括钢管成型、混凝土搅拌和布料、离心成型、养护、检验等工序,其特殊的构造形式对钢管成型、布料和养护制度均提出了较高要求.

Precast thin-wall steel and spun concrete composite pile （TSC） is a new type of foundation pile with higher capacity for vertical load and horizontal load, which is produced by pouring concrete into steel pipe, and spinning. Compressive strength of concrete used in TSC is not less than 80 MPa. Keeping same nominal diameter, same thickness of steel tube and concrete, uhimate bending moment of TSC- Ⅱ is higher than that of TSC- I . Keeping same nominal diameter and same type of steel, the higher thickness of steel is, the higher ultimate bending moment of TSC. And the difference is greater with the increase of thickness of steel pipe. With maximum thickness of steel tube in this nominal diameter,ultimate bending moments of TSC- I and TSC-Ⅱ are 2. 1 - 2. 7,2. 7 - 3.4 times of C type of pretensioned spun concrete pile （PHC） respectively, and design value of axial capacity of TSC is 1.4 - 2. 6 times of C type of PHC . Productive technology of TSC includes steel pipe forming, concrete mixing and pouring, spinning, curing and quality inspecting mainly. More requirements for shape of steel pipe, concrete pouring and curing are put forward because of special conformation of TSC pile.