黄土地基螺杆桩桩身参数对承载力影响研究

依托中兰客专引入兰州枢纽螺杆桩处理黄土地基项目，通过现场竖向静载试验确定单桩极限承载力，并与数值模拟结果进行对比验证，分析螺杆桩的荷载传递特性，研究螺杆桩桩身参数变化对其承载性能的影响。结果表明：螺纹段长度占比、螺距和螺牙宽度对承载力影响较为显著，螺纹叶片端部厚度对桩身承载力影响较小；螺杆桩最优螺纹段长度占比为0.6～0.7，螺距为0.35～0.40 m，叶片宽度为50～60 mm。

Study on Influence of Screw Pile Parameters on Bearing Capacity at Loess Foundation

Based on the project of loess foundation treatment by screw pile in Lanzhou hub on Zhongwei—Lanzhou Passenger Dedicated Line, the ultimate bearing capacity of single pile was determined by field vertical static load test, and verified by comparing with the result of numerical simulation, and then the load transfer behavior of screw pile was analyzed; secondly, how the change of the screw pile parameters influence its bearing capacity was studied. The result shows that the ratio of thread section length, the thread pitch and width have obvious influence on bearing capacity, and the thickness of threaded blade end has little influence. In this project, the optimal ratio of thread section length on screw pile is 0.6~0.7, the thread pitch is 0.35~0.40 m, and the blade width is 50~60 mm.