填海软基处理工程现场监测成果与加固效果分析

Analysis of Field Monitoring Results and Reinforcement Effects in Reclamation and Soft Soil Foundation Treatment Project

针对某填海软基处理工程软基处理方法与现场监测项目,对堆载预压法加固处理淤泥软基的表层沉降、分层沉降、孔隙水压力等监测成果及加固效果进行了分析,结果发现,堆载施工期沉降约占总沉降的65%,加荷间歇期沉降随时间近似呈线性增加；满载预压期沉降约占总沉降的35%,沉降随时间近似呈抛物线增加。从分层来看,表层6m淤泥层沉降占总沉降比例平均值为53.9%,是沉降发生的主要部分,而淤泥层下卧层沉降占总沉降量比例平均值为22.8%,预估地基沉降应考虑下卧层沉降。淤泥表层与底层超静孔压比中间层消散快,满载6个月时不同深度淤泥超静孔压消散约80%,满载8个月时超静孔压消散约85%～90%。场区淤泥加固后,物理力学性质及强度均得到明显改善,加固效果十分明显。

Soft soil foundation treatment methods and field monitoring schemes in the reclamation and soft soil foundation improvement project were introduced,and the monitoring results of the surfacial settlement,layered settlement,and pore water pressure and reinforcement effects of soft silty soil foundation with preloading method were analyzed.The results showed that（1）the settlement during the loading construction period is accounted for 65%of the total settlement,and the settlement during the loading intermittent period increases linearly with time.The settlement during the full load pre-compression period is accounted for 35%of the total settlement,and it shows an approximately parabolic increasing with time;（2）the settlement in the surfacial silt from 0to 6mis accounted for 53.9%of the total settlement,where the settlement mainly occurs,while the settlement in the underlying layer of silt is accounted for 22.8% of the total settlement,and the estimated foundation settlement should consider the settlement in the underlying layer of silt;（3）the excess pore water pressures in the surfacial and bottom silt layers dissipate faster than that in the middle layer.The excess pore water pressure at different depths dissipates by 80%after six months of full load,and it dissipates by 85%to 90% after eight months of full load;and（4）the physical and mechanical properties and strength of silt improve significantly after reinforcement,indicating an obvious reinforcement effect.