吹填土地基长期沉降与预测技术

Prediction technology and long-term settlement of dredger fill foundation

以天津港某吹填土地基加固工程为依托,以现场监测和数值模拟为主要手段,对吹填土地基加固期(施工期)和使用期(长期)沉降进行现场监测,确定吹填土地基施工期和长期沉降的发生发展特性;运用有限元软件对施工期监测结果进行拟合,确定吹填土长期沉降的数值预测模型;并通过该模型分析吹填土地基长期沉降的发生机理。研究结果表明:文中提出的数值模拟方法可有效模拟吹填土地基的施工期和长期沉降,但由于未考虑土体的次固结沉降,长期沉降模拟结果偏小,二者相差16.7%;排水板打设区的土体孔隙水压力消散较快,固结效率高;排水板下卧层软土的持续固结变形是造成吹填土地基长期沉降较大、时间较长的主要原因。

Based on the reclamation engineering in Tianjin port,we adopted in-site test and numerical analysis methods to monitor the settlement in consolidation period(construction period)and service period(long-time)of the dredger fill foundation,and determined the occurrence and development characteristics of the construction period and long-time settlement.We used the finite element software to fit the monitoring results during construction period,determined the numerical prediction model for long-time settlement of dredger fill,and analyzed the mechanism of long-time settlement of dredged fill foundation by this model.The research results show that the numerical simulation method in this paper can effectively simulate the dredger fill foundation construction period and long-time settlement,but because of not considering the secondary consolidation settlement,the simulation results of long-time settlement is small,the difference between them is about16.7%,the pore water pressure dissipates rapidly and the consolidation efficiency is high in the drainage plate area,the continuing consolidation deformation of thesoftclaybelowthedrainageplateisthemainreasonofthelargelong-timesettlementandlongtimeofdredgerfillfoundation.