预应力锚杆担梁排桩在基坑支护中的应用

Application of prestressed anchor rod spreader beam row pile in foundation pit support structure

基坑侧壁采用锚杆排桩围护结构时,由于施工成桩时的桩身垂直度与压入点位移误差很大,桩沿基坑侧壁平面凹凸不平,且贴靠点处存有空隙,相邻各桩的相对位移差值远超出结构分析变形的允许值,致使计算模型失真。提出了一种新型围护结构——预应力锚杆担梁排桩围护结构。此结构无连续腰梁、冠梁,将传统的排桩结构整体改成独立的双桩单元结构体,较好地符合计算模型假定。通过对比分析及工程实例,阐述了预应力锚杆担梁排桩围护结构具有安全可靠、节省造价、操作简便、缩短工期等特点。

When the side wall of the foundation pit is supported by anchor rod row pile retaining structure,the displacement deviation of the vertical degree of pile body and the compression point are very large,and each pile is uneven along the side wall of the foundation pit,and there is a gap at the point where the pile is attached. The relative displacement difference of the adjacent piles is far beyond the allowable value of the structural analysis,resulting in the distortion of the calculation model. In order to solve the above problems,a new type of retaining structure was proposed,that is,prestressed anchor rod spreader beam row pile retaining structure. This structure has no continuous waist beam and crown beam,and the traditional row pile structure is transformed into an independent double pile unit structure,which is well in line with the assumption of the calculation model. Through comparison and analysis and engineering examples,the characteristics of the prestressed anchor rod spreader beam row pile retaining structure were explained including safety,reliability,cost saving,simple operation and shortening construction time.