桩筏结构加固路桥过渡段深厚淤泥地基的现场试验研究

Experimental study on pile-raft structure reinforcing deep silt foundation of transition section between bridge abutment and embankment

摘要: 针对采用"预应力管桩+钢筋混凝土板"的桩筏结构加固处理高速铁路路桥过渡段的深厚淤泥地基,选择两处过渡段开展现场试验,基于实测结果分析桥台地基土的侧向位移和孔隙水压力、桩筏结构的沉降、桥台基桩的弯矩和侧向位移的变化特点及其产生原因,研究过渡段打入管桩对邻近桥台地基的影响、靠近过渡段的路基填土对桩筏结构稳定性的影响、台后路基填土对桥台基桩的侧向影响。结果表明:过渡段打入管桩会挤压邻近的桥台地基,若不采取其他措施,宜等管桩全部打完5个月后再开始钻进靠近管桩的桥台冲孔灌注桩孔;靠近过渡段的路基填土使桩筏结构先上浮然后不均匀下沉;采用桩筏结构对过渡段的淤泥地基进行加固处理后,台后路基填土仍会使下卧淤泥侧向移动而挤压桥台基桩,使桥台基桩偏移。

Abstract: The pile raft structure of prestressed pipe-pile and reinforced concrete slab was applied in reinforcing the deep silt foundation of the high-speed railway transition section between bridge abutment and embankment.The field tests were performed,including lateral displacement and pore water pressure of the abutment foundation,settlement of the pile-raft structure and bending moment and lateral displacement of the abutment pile.Based on the measured data,the effects of driving pipe-piles on the ab...