中文摘要：

为了揭示盐水环境下水泥土桩的劣化效应及其对道路复合地基沉降的影响,通过室内模型试验研究了黄河三角洲盐水环境下水泥土的劣化效应,分析了水泥土劣化深度和未劣化部分抗压强度的演化规律。通过对已有水泥土劣化研究成果进行总结分析,提出了基于水泥土早期强度试验的盐水环境下水泥土桩全寿命周期承载力实用预测方法;同时,通过模型试验和数值模拟研究了水泥土桩劣化对复合地基沉降的影响。研究结果表明：在加固地下水矿化度高的软弱地基时,水泥土桩会从外向内逐渐劣化;水泥土劣化对搅拌桩承载力的影响较大,会增大复合地基沉降,而且桩体缺陷将加剧水泥土桩的劣化效应。为了保证路基的持久稳定并控制其长期沉降,在盐水环境下水泥土桩复合地基设计中须考虑水泥土劣化的影响。

英文摘要：

In order to reveal deterioration effect of soil-cement pile in saltwater environment and its influence on road composite foundation settlement, the deterioration effect of soil-cement in Yellow River Delta in saltwater environment was investigated by model test. The deterioration depth of soil-cement and evolution laws of compressive strength in non-deteriorated regions were analyzed. Based on the conclusion of previous researches on soil-cement deterioration, a practical prediction method for entire life-cycle bearing capacity of soil-cement piles in saltwater environment was proposed based on soil-cement early strength test. At the same time, influence of deterioration of soil-cement pile on composite foundation settlement was investigated by model test and numerical simulation. The results show that during reinforcing the soft subsoil with high salinity groundwater, soil-cement piles are deteriorated from outside to inside. Deterioration of soil-cement has a great influence on bearing capacity of mixed pile, which increases settlement of composite foundation. Furthermore, the pile defects will aggravate deterioration effect of soil- cement pile. In order to ensure sustainable stability of subgrade and control its long-term settlement, deterioration of soil-cement should be considered during the design of composite foundation in saltwater region.