吹填淤泥土真空预压沉降计算修正系数的分析

同天然软土相比,吹填淤泥土初始含水量高,初始孔隙比甚至超过3。通过对比国内不同行业的相关规范可知,软土地基设计阶段的沉降计算尤其是沉降修正系数取值难以适用于吹填淤泥土。通过对天然软土地基沉降计算进行分析,研究了吹填淤泥土采用真空预压处理下的沉降特点。结果表明,吹填淤泥土沉降修正系数的取值范围幅度远大于规范给定的取值范围。对不同地区吹填土沉降数据进行分析,从实例角度验证吹填淤泥土沉降计算修正系数取值范围;对吹填淤泥土沉降与厚度关系曲线进行拟合,得出沉降量与吹填层厚度的比值在初步设计阶段可按吹填厚度的30%考虑。

Analysis of modified coefficients for calculating dredger fill sludge settlement under vacuum preloading

Compared with natural soft soil， dredger fill sludge has high initial moisture content (100%) and high initial void ratio, even more than three. By comparing the different relevant norms， it is indicated that the settlement calculation and the settlement value of the modified coefficients of the soft soil in design phase are inadequate to the dredger fill sludge. The settlement characteristics of the dredger fill sludge under vacuum preloading is analyzed by comparing the settlement calculation of the natural soft ground. The analysis results show that the range of the modified coefficients of the dredger fill sludge is much larger than that given in the norms. Additionally， the settlement data of the dredger fill sludge collected from different regions have been analyzed to verify the range of the settlement modified coefficients. Fitting the relationship curves between the measured settlement and thickness of the dredger fill sludge, thus it is concluded that the ratio of the settlement and thickness in 30% of the hydraulic reclamation thickness can be taken into account in the preliminary design phase.