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%.