模拟深海环境砂土地层的材料配比试验研究

为了研究可近似模拟琼州海峡深海环境下砂土地层的相似材料，基于正交试验法，以重晶石粉/标准砂、黏结剂浓度、凡硅比和石膏含量作为4个控制因素，对不同配比相似材料的物理力学参数的变化规律进行了分析. 首先确定标准砂、重晶石粉作为骨料，凡士林和硅油作为黏结剂，石膏粉作为调节剂，其次基于正交试验原理设计25组相似材料配比，分别进行密度试验、直剪试验、压缩试验以及渗流试验，得到了重度、内摩擦角、黏聚力、压缩模量以及渗透系数等物理力学指标，通过极差和显著性分析，研究了各个控制因素对材料参数的影响规律，并对25组试验结果进行了去异常点的多元线性回归分析. 研究结果表明:相似材料重度受重晶石粉/标准砂比值的影响最大，石膏的比例是控制压缩模量的主要因素，内摩擦角和黏聚力无主要控制因素，重晶石粉的比重主要控制着渗透系数的大小；适用于深海环境砂土地层条件下的相似材料配比为重晶石粉/标准砂0.4，黏结剂浓度4.5%，凡硅比3∶1，石膏含量3%. 

Experiments on Material Proportions for Simulating Sandy Layer in Deep Sea

In order to obtain the material proportions that can simulate the sandy layer in the deep sea of Qiongzhou Strait, using on the orthogonal experiment method, the physical and mechanical parameters of different material proportions were analyzed with four control factors of barite powder/standard sand, binder concentration, silicon ratio and gypsum content. Firstly, standard sand or barite powder is used as aggregate, petroleum jelly and silicone oil as binders and gypsum powder as modifier. Secondly, 25 groups of material proportions were designed on the basis of orthogonal experiment principle, and types of tests of density, direct shear, compression and seepage were performed to obtain physical and mechanical indices such as weight density, internal friction angle, cohesion force, compression modulus, and permeability coefficient. Through the range analysis and significance analysis, the influence of control factors on the material parameters was explored, and a multivariate linear regression analysis of test results was carried to eliminate outliers. The results show that the weight density is most affected by the ratio of barite powder to standard sand; gypsum content is the leading factor to control the compression modulus; the internal friction angle and cohesion force have no major controlling factors; and the proportion of barite powder mainly affects the permeability coefficient. The appropriate material proportions for the sandy layer in deep sea environment are barite powder /standard sand of 0.4), binder concentration of 4.5%, silicon ratio of 3∶1, and gypsum content of 3%.