软土地区预应力管桩施工质量事故分析及处理

ANALYSIS AND DISPOSAL OF CONSTRUCTION QUALITY ACCIDENT FOR PRESTRESSED CONCRETE PIPE PILES IN SOFT SOIL AREA

预应力管桩在软土地层施工由于施工速度快、施工效率高,应用较为广泛,但软土层具有含水量高、强度低、稳定性差等特点,预应力管桩施工会出现管桩上浮、偏位、损伤、断裂等质量事故。带地下室的高层建筑由于需要进行基坑土方开挖,挖土机械扰动土层、碰撞管桩,更易造成质量事故的发生。针对典型软土地区湖州地区管桩施工出现的质量事故,进行事故原因分析并介绍了事故处理方法。经加固处理后,检测及沉降观测显示:处理后的管桩均符合设计要求,并且建筑物沉降较小、沉降均匀,均符合设计要求。

Prestressed pipe pile is widely used in soft soil area due to its fast construction speed and high efficiency. However, the pipe piles are prone to floating, deviation, damage and fracture due to high water content, weak strength, poor stability for soft soil.As foundation excavation is needed for high-rise building with basement, construction accidents are more likely to occur when foundation soils are disturbed or piles are crashed.In light of project cases in typical soft soil of Huzhou Region, the paper showed conventional construction process of the pipe piles for high-rise building with basement and common pipe pile quality construction accidents, also analyzed the causes of the accident, and introduced treatment methods for the accident.Later detection and settlement observation indicated that the treated pile could meet the design requirements, and the building settlement was minor and even.