基于孔压消散改进模型的土体孔隙水压力预测  

Prediction of pore water pressure based on improved pore pressure dissipation model in soil

作　　者：蔡国军[1] 刘晓燕[1] 刘路路 刘松玉[1] 李学鹏[1] CAI Guojun;LIU Xiaoyan;LIU Lulu;LIU Songyu;LI Xuepeng(Institute of Geotechnical Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学岩土工程研究所,江苏南京211189

出　　处：《南京工业大学学报（自然科学版）》2021年第4期492-496,共5页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：国家重点研发计划(2020YFC1807200);国家自然科学基金(41877231,42072299)。

摘　　要：固结系数在评估土体工程特性方面具有重要作用,孔隙水压力是孔压静力触探技术中评价土体水平固结系数的重要指标。目前,基于孔压静力触探试验计算固结系数的方法比较费时,为了提高孔压静力触探技术在低渗透黏土中的工作效率,本文基于不完全孔隙水压力试验数据,结合早期与后期双曲线拟合法,建立孔压消散改进模型。以上海浦东新区黏土场地为例,计算得到的孔隙水压力与时间曲线截距与斜率分别为0.943和0.003,通过比较孔隙水压力计算值与试验值得到其相关系数均大于0.99。此外,对消散时间小于消除50%孔隙水压力所需时间的数据进行预测,预测结果相关系数为0.9967,表明本文提出的孔压消散改进模型预测孔隙水压力的精确度较高,能够节约大量工程勘察时间,能有效拓展孔压静力触探试验在岩土工程勘察中的应用。The coefficient of consolidation plays an important role in the evaluation of soil engineering properties.Pore water pressure is the key to evaluate the coefficient of consolidation in pore pressure cone penetration test.In order to improve the efficiency of piezocone penetration test in low permeability clay,an improved model of pore pressure dissipation was established based on incomplete pore water pressure test data,combined with the early and late hyperbolic fitting method.Taking the clay site in Pudong New Area of Shanghai as an example,the intercept and slope of the calculated pore water pressure-time curve were 0.943 and 0.003,respectively.By comparing the calculated value of pore water pressure with the measured value,the correlation coefficient between the calculated value and the measured value was greater than 0.99.In addition,when the data of dissipation time less than half of pore pressure dissipation time was predicted,the correlation coefficient of prediction result was 0.9967,which meaned that the improved pore pressure dissipation model proposed in this paper had high accuracy in predicting pore water pressure.Thus,it can save lots of engineering investigation time,and therefore can effectively expand the application of pore pressure static cone penetration test in geotechnical engineering investigation.

关 键 词：上海黏土 孔隙水压力 孔压消散改进模型 孔压静力触探 

分 类 号：TU413[建筑科学—岩土工程]