向阳圩海塘围堰堤坝沉降特性原位实测及稳定性分析

In situ test of cofferdam dyke settlement character and analysis on long time stability of dyke at Xiangyangxu bank

以上海市向阳圩海塘围堰主堤为工程背景,在大量原位实测的基础上通过对各测试结果的统计分析研究了软土海滩围堰堤坝及地基沉降位移特性。结果表明:围堰堤坝及地基沉降具有显著的时效特性,沉降与时间的相关关系可用负指数时效特性曲线拟合;各测点位移值随时间具有明显突变变化,整个沉降时域可分为快速沉降时域区及缓慢沉降时域区。同时,在充分考察了沉降速率随时间变化特性的前提下提出了用该参量预测堤坝稳定时间及最终沉降位移的建议。

On the background of main cofferdam dyke at Shanghai Xiangyangxu bank cofferdam project, and based on mass in situ tests, this paper studies the cofferdam dyke and foundation settlement characters at soft ground beach by statistic analyzing each test result. It shows that: cofferdam dyke and foundation settlements have obvious secular characters, and the time-settlement relationship can be fitted by negative exponent secular character curve; the settlement value of each measuring point has obvious time mutation change, and the whole settlement time domain can be divided into fast settlement time domain and slow settlement time domain. At the same time, based on sufficient consideration on the character of settlement speed change with time, this paper recommends that this parameter can be used to predict stabilization time and final settlement of dyke. The results will give valuable reference to the prediction and appraise of foundation settlement caused by same type dyke or ground loading.