高速铁路桩网复合地基加筋垫层刺入变形研究

Research on Reinforced Cushion Stabbing Deformation of High Speed Railway Pile-net Composite Foundation

设计了能够准确反映桩网复合地基各部位受力变形特性的室内缩尺模型试验,研究了桩网复合地基加筋网垫的荷载传递规律及土工格栅受力及应变特点。通过试验发现,桩头上穿的影响范围为桩径的2.5倍,且格栅应变呈现"M"形分布。应用压力分布传感器探明了加筋垫层和桩-土接触界面的压力分布,从而深化了对桩网复合地基加筋垫层受力变形和荷载传递规律的认识,为现有理论及计算方法的优化提供了数据支撑。

A scale laboratory modeling test was designed and carried out. This test can accurately reflect the stress and deformation characteristics of different parts of pile-net composite foundation. The research focused on the load transfer laws of pile-net composite foundation reinforced cushion and the stress and strain characteristics of geogrid.Test results show that the influence range of pile head is 2. 5 times of the pile diameter,and the grid strain presents M-shape distribution. By pressure sensors,the pressure distributions of reinforced cushion and pile-soil contact interface were tested. The deformation and load transfer laws of reinforced cushion were further understood through the test. The results provide data to support the optimization of the existing theories and calculation methods about pile-net composite foundation.