水泥土桩在我国滨海相软土或海洋吹填土地基处理中应用广泛，但其在腐蚀地基土中会发生表层强度降低的劣化现象，劣化的发生将影响水泥土桩的使用寿命。拟以滨海相软土场地形成的水泥土桩为研究对象，揭示其在竖向工作荷载条件下承载性状演化过程并预测其长期承载力。研究手段有室内模型试验、化学成分分析、数值模拟和理论分析。研究场地形成的水泥土桩，在竖向工作荷载条件下，由于场地中侵蚀离子导致水泥土桩劣化而引起的承载性状变化问题是申请项目的主要特色。主要研究内容包括，确立室内加速劣化试验方法（建立达到相同劣化程度时侵蚀离子浓度与侵蚀时间的等效关系）；劣化水泥土桩桩身强度特性及基于复合材料强度理论的长期强度预测与验证；劣化水泥土桩承载性状演化规律及机理、长期承载力的预测与验证。研究成果可为工程设计提供依据，并具有一定的理论意义。申请项目采用的研究思路和方法可为盐渍土等腐蚀场地形成的加固体的劣化问题的研究提供参考。

The cement-soil pile is widely used in the treatment of marine soft soil or marine fill soil foundation, but the surface strength could degrade in the corrosive soil, which will affect the service life of cement-soil pile. By researching the cement-soil pile formed in marine soft soil sites, the evolution process of its bearing characteristic under vertical working load is revealed and the long-term bearing capacity can be forecasted. The research methods include laboratory model test, chemical analysis, numerical simulation and theoretical analysis. The evolution process of bearing characteristics of Cement-soil pile formed in marine soft soil site could be changed caused by the erosion of erosive ion, which is the main feature of this application project. In this paper，the main contents include: the establishment of the indoor accelerated degradation test method (the equivalent relationship between the erosive ion concentration and the time when the same degree of deterioration is achieved), the strength characteristics of deteriorated cement-soil pile and the prediction and verification of the long-term strength based on the theory of the composite material strength, the evolution law of cement-soil pile bearing characteristic in the process of deterioration. the prediction and verification of pile-soil interaction mechanism and support force of the soil against the pile under vertical working load condition. The assessment method on durability of the cement-soil pile in site of marine soft soil is proposed. The results of research can provide not only the basis for engineering design, but also certain theoretical significance. The ideas and methods in the research can be used as references in the study of the deterioration of the solidified body formed in the corrosive sites such as saline soil.