Random Field Analysis of Gradation Parameters of Liquefiable Saturated Silt in Nanning, Guangxi

Abstract

The fine particle content and particle gradation have a significant influence on the liquefaction characteristics of saturated silt fine sand. In order to further study the regional easy-liquefaction silt fine sand particle gradation parameters (d₁₀, d₃₀, d₆₀, p_0.075, C_u, C_cdistribution law, spatial variability and spatial trend characteristics, based on the study of 68 preliminary liquefied fine sands in the Quaternary strata in Nanning. The results show that the statistical distributions of the five parameters of the initial liquefaction gradation are all in accordance with the Gaussian distribution; the initial liquefaction silt is uneven soil (96% of the C_uvalue is greater than 5, and 93% of the C_cvalue Less than 2), and the fine particle content p_0.075is less than 60%, which is prone to liquefaction; with the increase of depth, d₁₀, d₃₀, d₆₀, C_chave an increasing trend, The value ofp_0.075has a tendency to decrease along the depth, and the value of C_uhas no obvious trend change. The random field theory is introduced to analyze the coefficient of variation of parameters. Compared with the traditional method, the coefficient of variation of d₁₀, d₃₀, d₆₀, p_0.075, and C_uare reduced by 5.6%, 7.8%, 2.9%, 1.6%, 2.9%, 5.7%. The obtained results reveal the distribution law, spatial variability and spatial trend characteristics of gradation parameters of silt sand in Nanning area, which can provide basic data for the later analysis of dynamic liquefaction of silt sand in Nanning.