Statistical Analysis Of Soil Parameters And Research Of Random Characteristics In Jiangsu Coastal Area

Jiangsu coastal area is one of the most development region in Jiangsu Province,which is an important growth pole of Jiangsu Province.Acceleration of the development of Jiangsu coastal areas is conducive to optimize the industrial upgrading and upgrade the overall strength of the Yangtze River Delta region.Although a large amount of exploration work has been carried out in the coastal areas of Jiangsu,the analysis of the engineering geological conditions and the engineering properties of rock and soil is still not perfect.The reliability design method can not be applied in geotechnical engineering,mainly because the variability of soil parameters obtained by traditional statistical theory of random variables is too large,and the calculated failure probability is too large to reflect the real safety of the project.Therefore,statistical analysis of the characteristics of physical and mechanical indexes and the spatial variability of soil in Jiangsu coastal area has very important practical significance for understanding the engineering characterist:ics of soil and the application of reliability theory in geotechnical engineering in Jiangsu coastal area.Based on the coastal exploration data of Jiangsu Province,this paper draws up the soil profile in Jiangsu coastal area,and analyzes the change of soil layers in Jiangsu coastal area.The Q4 and Q3 strata in Jiangsu coastal area are divided,and the physical and mechanical parameters of each stratum are analyzed and compared.The soils of Q4 stratum in Lianyungang are different from those in Yancheng and Nantong,and the engineering geological properties of Q4 stratum in Lianyungang properties are poor.There are few differences in soil properties of Q3 stratum in Jiangsu coastal area.The physical and mechanical indexes of soft soil in three areas of Lianyungang,Yancheng and Nantong are analyzed statistically.The local empirical formula is obtained by analyzing the correlation between indexes.Compared with the other two areas,Lianyungang soft soil has the characteristics of high water content and high compressibility.There are significant correlations between the main physical indexes of soft soil in coastal areas,and between physical and compressive indexes.The physical and mechanical properties of silt soil in Yancheng and Nantong are analyzed statistically.The differences are not obvious.At the same time,the correlation between the soil indexes is analyzed to prove that the main physical indexes have good linear relationship.The correlation between the physical and mechanical indexes is insignificant,but with a good trend.Based on the random field theory,the vertical and horizontal soil profile model of random field in Jiangsu coastal area is established with the CPT data and laboratory test index of the coastal areas of Jiangsu Province,and the stationeriness and ergodic of soil profile are tested.Static cone tip resistance and wall friction of soil in Jiangsu coastal area have the trend component along the depth direction.This paper discusses the method of removing the trend component,which can be eliminated by the linear regression method.Moreover,the influence of trend component on soil parameter variability is analyzed.The advantages and disadvantages of the calculation methods and the improved calculation method of correlation distance are compared and analyzed.The influence of soil thickness,calculation method,calculation parameter and trend component on the correlation distance is further analyzed.The results show that more than 60%of the total thickness of the soil layer is used to calculate the thickness of the soil layer,and the calculated distance has a high degree of credibility.The correlation distance is calculated by recursive space method and correlation function method using tip resistance and side friction data of cone penetration test,and the calculated results are in good agreement.The vertical correlation distance of the soil layers in the Q4 strata in Jiangsu coastal area is statistically analyzed.The results show that the vertical correlation distance of each soil layer has a certain regionality,and the vertical correlation distance of the soil layers in the Q4 strata in Jiangsu coastal area is obtained.The vertical correlation distances of typical soil layers in different regions of Jiangsu coast are compared,which has certain regional differences.The horizontal correlation distance of each soil layer in Jiangsu coastal area is calculated by laboratory test indexes.