钢管护坡桩力学性能与回收技术现场试验研究

Field Test Study on Mechanical Performance and Recycling Technology of Steel Pipe Pile for Slope Protection

以北京市某典型基坑工程场地条件为背景,对可回收式锥形钢管护坡桩力学性能与回收关键技术进行现场试验。研究桩身应变-弯矩变化规律、桩后地表沉降分布特征、桩顶水平位移、桩顶竖向位移及钢管桩回收相关技术。结果表明:钢管护坡桩抗弯性能好,桩身变形小,可有效抵抗桩后土体的作用,安全可靠,满足承载力要求;桩孔采用护筒护壁形式,可防止拔桩过程中塌孔,减小地层损失,从而减小拔桩过程对基础变形的影响;采用黄油作为桩身隔离剂,同时采用外裹薄膜形式,有利于钢管桩回收,可以重复周转使用。

Based on the site conditions of a typical foundation excavation project in Beijing, field tests were conducted on the mechanical properties and key recycling technologies of recyclable conical steel pipe piles for slope protection. The change law of the strain-bending moment of the pile, the distribution characteristics of the ground surface settlement behind the pile, the horizontal displacement of the pile top , the vertical displacement of the pile top, and the related recycling technology of steel pipe pile were studied. The results show that the steel pipe pile for slope protection has good bending resistance and the deformation of the pile is small, which can effectively resist the action of the soil behind the pile. It is safe and reliable, and meets the requirements of bearing capacity. The pile hole adopts the protection tube form , which can prevent the hole collapse during the pile-pulling process, reduce the ground loss and reduce the impact of the pile-pulling process on foundation deformation. Butter was used as an isolating agent for pile body , and the form of outer coating was used , which is beneficial to the recycling of steel pipe pile and can be used repeatedly.