基于标准压缩模量和液限推求地基土全压力段压缩模量的分析方法

An analysis method for calculating compression modulus of foundation soil based on standard compression modulus and liquid limit

以京沪高铁深厚地层细粒土固结试验数据为基础,以e-lgp曲线包含分式函数的复合函数表达和土体液限与压缩指数的线性关系为依据,提出了基于土体基本物性指标标准压缩模量E1？2和液限wL推求正常固结原状地基土全压力段压缩模量的简化方法,其适用性得到了京津城际铁路试验数据的验证。结果表明,Harris函数能较好地描述土体压缩的e-lgp曲线特征,E1？2和wL能分别反映曲线低压力段割线斜率和高压力点切线斜率,建立的地基土压缩模量估算方法具有良好精度,其中,100-1 000 k Pa常压力段的误差均值仅为7.89%,高压力段约为13.70%,只在低压力段变异性较大;研究成果提供了缺少e-lgp曲线情况下简便快速获取土体压缩模量的新途径。

Based on the consolidation data of deep fine-grained soils distributed along the Beijing-Shanghai high-speed railway, a simplified method is proposed for determining the compression modulus of the undisturbed normally consolidated foundation soils using standard compression modulus E12 and liquid limit wL, in which the composite function expression containing the segmental function of the e-lgp curve and the linear relationship between liquid limit and compression index are also adopted. It is shown that the Harris function can describe the e-lgp curve characters well, and E12 can reflect the secant slope of the low-pressure section of the compression curve, while wL can reflect the tangent one of the high pressure section. The compression modulus estimation method of foundation soil yields good results for all levels of pressure, namely, the average error is just 7.89% in the commonly used pressure section of 100-1 000 k Pa, and in the high pressure section is about 13.70%, whereas significant error occurs only in the low pressure section. The study results provide a new approach to rapidly obtain the compression modulus of soil in the case that the e-lgp curve is lacking.