江滩深厚软土地基堆载预压稳定分析和评价

STABILITY ANALYSIS AND EVALUATION OF DEEP THICK SOFT CLAY ON FLOOD PLAIN DURING SURCHARGE PRELOADING

为准确评价某炼油厂油罐区江滩堆载预压工程的安全稳定性,根据工程监测数据和施工中出现的险情,采用Geo Studio边坡分析软件,分别用四种计算方法,分析了堆载期的边坡稳定,评估了地基加载过程中的安全状态。计算与监测数据对比表明只有考虑强度增长的分析方法才能真实反映预压期地基的实际安全状况,设计中宜采用此种方法,而Bishop有效应力法和有限元耦合分析法过高估计了地基安全值。对于有淤泥软弱夹层的堆土预压工程,只有复合滑动面法才能找出局部浅层滑移的最小安全系数,而石化规范中圆弧滑动面法则计算偏大,不能反映堆土施工过程中的最危险状态。

In order to accurately evaluate the safety and stability in preloading of oil tank area on flood plain, GeoStudio slope analysis software was used according to the engineering monitoring data and the dangerous situation in the construction. Four stability analysis method were used to evaluate the stability during the preloading and the safety of the process of loading the foundation. The comparison between calculation and monitoring data shows that only the analysis method considering the strength increase can reflect the actual safety condition of the foundation during the preloading. The Bishop effective stress method and the finite element coupling analysis method overestimate the safety value of the foundation. So the method considering the strength increase should be adopted in the de- sign. For the preloading engineering with silt and weak interlayer, only the composite slip surface method through the silt interlayer carl find out the minimum safety factor of local shallow slip. The calculated results of the circular slip surface method in petrochemical specification are too large and can not reflect the most dangerous state in the process of preloading.