大面积堆载预压处理滩涂地基沉降分析及固结度推算

Settlement Analysis and Solidification calculation of Large area Heap Load Preloading Treatment of Tidal Flat Foundation

在预压堆载过程中,滩涂地基总沉降、差异沉降、水平位移、固结度等指标变化,以及最终固结度是否满足相关要求,是工程建设中的关键问题。为研究堆载预压对此类地基的作用过程以及处理效果,通过对宁德市某大道工程堆载预压全程的地基沉降过程进行分析,并对地基最终固结度进行推算,得出:地基堆载预压过程中,深层分层沉降变化基本保持一致,且在某一载荷下发生显著沉降;地基邻水侧深层土无水平位移,中上层土横向位移较大,而无水侧土体各层均存在水平位移;预压过程地基存在以不排水为主伴随剪胀的状态,随预压时间增长,土体完成结构重排固结,并逐渐转化为排水为主的状态。同时,双曲线法适合用于推算滩涂地基最终沉降量计算,拟合度极高。

The ability of differential settlement,horizontal displacement and consolidation to meet the operational needs of the project was a key issue in its construction.In order to explored the effect of mound precompression on such foundation,the changes of foundation were analyzed by the monitoring data of deep stratified settlement,deep horizontal displacement,pore water pressure,surface settlement and groundwater level of a thoroughfare project in Ningde City during the whole process of mound precompression in this study.Furthermore,the hyperbolic method was used to predicted the final settlement of the foundation,and obtained the following conclusion.On the one hand,the change in settlement of deep stratified layers during precompression of the foundation mound remained essentially uniform and significant settlement occurred at a load.On the other hand,there was no horizontal displacement of the deep layer of soil on the adjacent side of the foundation,the lateral displacement of the middle and upper layers of soil was larger,while there was horizontal displacement of all layers of soil on the waterless side.In the pre-pressing process,the foundation existed in a state where no drainage was mainly accompanied by shear expansion,and with the growth of pre-pressing time,the soil completed structural re-arrangement and consolidation and gradually transforms into a drainage.The soil completed the structural re-drainage and gradually transforms into the drainage state with the increase of pre-pressing time.