连云港港区深厚淤泥地基筑堤数值分析
Numerical analysis of breakwater construction on soft clay in harbor area of Lianyungang Port
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摘要: 连云港徐圩港区淤泥层深厚,土质条件差,拟在淤泥地基上修筑斜坡堤。准确开展筑堤后地基固结预测分析,可优化设计,并为港区后期建设提供技术支撑。采用能较好反映超软淤泥性质的修正剑桥模型,模拟斜坡堤分级施工过程,采用不同涂抹效应参数进行计算,通过与实测结果对比以确定海上排水板施工的合理涂抹参数。计算结果表明,当涂抹区井径比s=5,渗透系数降低比kh/ks=5时,原位监测结果与数值模拟结果吻合较好。要满足油气管廊基础对工后沉降的要求,应保障排水板施工质量,同时堤身预压时间不低于13个月。Abstract: The ground in Xuwei harbor area of Lianyungang Port is the deep soft clay, and its engineering property is poor. On the soft ground the breakwater is proposed to be constructed. Predicting the consolidation settlement of the ground of the breakwater accurately can give a design optimization and provide technical support for the harbor construction. The modified Cam-clay model is used as the constitutive model for soils, and the staged-construction of the breakwater is simulated. A systematic parametric study is conducted, and the results are back-calculated to determine the extent and permeability of smear zone with respect to installation of offshore PVDs. The numerical results reveal that when the extent ratio is 5 and the permeability ratio kh/ks is 5, the in-situ observed results agree well with the numerical ones. In order to meet the requirements of the post-construction settlement of oil pipeline foundation, the construction quality of PVDs should be controlled, and the preloading time of the breakwater should be more than 13 months.