灌注桩桩端后压浆效果的室内模型试验

摘要

通过室内模型试验，对桩端后压浆灌注桩进行静载试验以及开挖观察，探讨了加固体的性状以及压浆参数对单桩承载力特性的影响，分析了灌注桩荷载传递特点和桩端阻、侧阻随荷载增加的变化趋势。经试验发现：压浆量、压浆压力以及岩土的可灌性是影响加固体性状的主要因素；浆液上返与桩周土作用形成的复合桩身形式对桩侧摩阻力影响较大，桩侧扩径效果明显处其侧摩阻力提高幅度大；桩端后压浆改变灌注桩承载力特性，常规桩表现出摩擦型端承桩性质，桩端压浆后表现出端承桩特性。%Through indoor model test about the pile-grouted, actualized static load test and excavation of observation of the pile, this paper discussed the impaction of the size and solid form and grouting parameters for the characteristics of single pile bearing capacity, analyzed the load transfer characteristics and changes trend of the pile tip resistance, lateral load resistance with the load increased. The result shows that grouting quantity, grouting pressure, perfusion character of stratum are the main factors influencing the solid characters. The composite pile formed by the slurry backwash to the soil around the pile has greater impact on the pile of lateral friction. The more the diameter of the pile expands, the more the side of lateral friction increases. Post-grouting at end of pile changes the bearing characteristic of pile, conventional pile exhibits the character of friction-end bearing pile, the pile of post-grouting at end exhibits the character of end bearing pile.