大型填海造地人工岛工程土体沉降预测数值分析

Numerical analysis in soil settlement prediction of a large-scale marine reclamation artificial island project

在大型填海造地人工岛建设工程中,土体沉降是影响整个场区后期安全运营的重中之重.为了分析填海造地工程中土体沉降的因素,利用土体微观结构分析方法中的扫描电镜法(SEM),对场区具有代表性的淤泥、淤泥质粉质黏土、粉质黏土、黏土等6种土样进行研究.通过观察不同深度处的SEM图,得到影响土体沉降的结构特征.同时结合Terzaghi一维及Biot二维固结理论两种数值计算方法,建立一维及二维蠕变模型并对比两种固结理论的数值计算结果,预测工程竣工后土体沉降规律.分析结果表明,土体本身的微观结构特征是影响场区沉降量的本质因素,两种数值分析方法得到的沉降规律和趋势基本一致.

In an artificial island construction project based on the large-scale marine reclamation land,the soil settlement is the most important factor affecting the later safe operation of the whole field.To analyze the factors of the soil settlement in a marine reclamation project,the SEM(scanning electron microscopy)method of the soil microstructural analysis method is used to test and study six soil samples such as the representative silt,mucky silty clay,silty clay and clay in the field.The structural characteristics of soil settlement are obtained by observing the SEM charts at different depths.Combined with Terzaghi one-dimensional and Biot two-dimensional consolidation theory numerical calculation method,one-dimensional and two-dimensional creep models are established and the numerical results of two kinds of consolidation theories are compared to predict the settlement rule of the soil after completion of the project.The analysis results indicate that the micro-structural characteristics of the soil itself are the essential factors affecting the settlement quantity of the field.The settlement rule and trend of two numerical analysis methods are basically consistent.