高铁盐渍土地区溶陷特性的预测模型及因素敏感性分析

近年来,高速铁路在西北地区建设中遇到大量的盐渍土路基,而盐渍土路基很容易发生溶陷变形,这对高速铁路的平顺性有着极为不利的影响。结合兰新铁路第二双线的盐渍土溶陷病害实例,使用改进的普通固结仪开展单因素溶陷试验,以其试验结果为基础,通过正交设计方法开展多因素交互作用下的盐渍土溶陷试验;采用SPSS软件对试验结果开展逐步回归分析,并根据分析结果中方差大小,消除不显著因素,建立溶陷系数简化预测模型,并对所得预测模型进行验证,确定影响氯盐渍土溶陷预变形的因素敏感性。研究结果表明:影响盐渍土的溶陷系数的敏感性因素由高到低排序依次为压实度,轴向压力,含盐量以及轴向压力与压实度的相互作用,影响所占比例分别为0.463,0.172,0.140,0.092。

Prediction Model and Factor Sensitivity Analysis of Melt-sinking Characteristics of Saline Soil Area of High-speed Railway

In recent years, a large number of saline soil subgrade is encountered in the construction of the high-speed railway in the northwest of China, and the melt-sinking deformation of the saline soil subgrade is likely to occur with very unfavorable influence on the smoothness of the high-speed railway. With reference to a melt-sinking problem in the second double-line of Lanzhou-Xinjiang railway, improved consolidation instrument is used to conduct single factor experiments. According to the test results, the karst subsidence test of saline soil under the interaction of multiple factors is carried out by using orthogonal design method. The SPSS software is used to perform stepwise regression analysis of the test results. According to the variance of the analysis results, non-significant factors are eliminated, a simplified prediction model of the collapse coefficient is established and verified, and the sensitivity of the factors affecting the pre-deformation of the chlorine saline soil is determined. The results show that the sensitive factors affecting the coefficient of saline soil subsidence from high to low are compactness, axial pressure, salinity and interaction between axial pressure and compaction, and their affecting proportions are 0.463, 0.172, 0.140 and 0.092 respectively.