基于含水率的昆明软土盾构隧道太沙基土压力计算方法

Natural Water Content Based Terzaghi Earth Pressure Calculation Method of Shield Tunnels in Kunming Soft Soil

文章以昆明市轨道交通四号线工程地质资料为基础,结合现有文献资料,通过采用线性回归、非线性拟合等统计学分析方法,分析了昆明地区软土的含水率与其物理力学指标间的相关关系,建立了回归分析方程,并给出了相应的相关系数。结果表明:昆明地区软土的工程性质在天然孔隙比、天然含水率、天然容重、有机质含量等方面均与常见的淤泥质土不同,其中粉质粘土和泥炭质土的含水率与其天然密度间的相关性较好;通过采用非线性拟合方式得出的粉质粘土含水率与其粘聚力、内摩擦角的相关性较好,而泥炭质土的相关性一般,故根据统计学方法给出了相应的取值表;提出了通过含水率计算昆明软土竖向土压力的计算方法,该方法因考虑了该土层含水量较高的特点而具有一定的研究价值。

Based on the engineering geological data of Kunming Rail Transit Line 4,combined with the existing literature data,this paper analyzed the correlation between the water content of soft soil and its physical and mechanical indexes in Kunming area by using the statistical analysis methods such as linear regression and nonlinear fitting,established the regression analysis equation and gave the corresponding correlation coefficients.The results show that the engineering properties of soft soil in Kunming area are different from those of the common silt soil in terms of natural porosity ratio,natural water content,natural bulk density and organic matter content,among which the water content of silty clay and peat soil has a good correlation with their natural density.The water content of silty clay obtained by the non-linear fitting method has a good correlation with its cohesive force and internal friction angle,while the correlation of the peat soil’s is not so good,so the corresponding value table is given according to the statistical method.Based on this,the calculation method for calculating the vertical earth pressure of Kunming soft soil by water content is proposed,which has certain research value due to considering the high water content of the soil layer.