Study On Depth Effect Of Lateral Pressure Characteristic Parameters Of Deep Buried Fine Sand Layer

The mechanical properties of fine sands have attracted much attention from geotechnical engineers.With the increasing scale of infrastructure construction,more and more geological problems related deep-buried fine sands with a depth of over 100 meters emerged and they are particularly prominent.Deep side pressure test,a kind of effective in-situ test methods,can be used to evaluate the properties of soil under 135 m depth which is far deeper than other in-situ test(e.g.prospecting,drilling,etc.).Compared with other in-situ tests,Deep side pressure test features economic,suitable and its test results are more reliable,However,fewer researchers focused on the deep side pressure test technology,and the relevant specifications are rarely described.This article employs the side pressure model test as the main method of research,with the help of laboratorial soil test,comparison with the other in-situ test and the test under the different depth of practical buried deep silty sand,load-bearing characteristics,the change rule of load-bearing characteristics of the deep silty sand layer and evaluation standard for related research are explored and discussed.Solving the shortage of testing technology for deep buried fine sand layer will have a global and far-reaching impact on the development of in-situ testing technology.Based on the Hutong Yangtze River Bridge 29 Pier section,and combined with the indoor side pressure model test,the original data of the field test obtained by the in-situ test and the indoor main test.The research work and the results of this paper are showed as follows:(1)The model in the side pressure test room is designed to simulate the stress state of sand soil under natural conditions,The relationship between the lateral pressure modulus and the density and the rule along the depth are obtained through the analysis of the auxiliary lateral pressure test.(2)The engineering profile of hutong Yangtze river bridge is introduced,and the lateral pressure modulus data of the 4th series soil layer under the engineering environment is obtained through on-site lateral pressure test.(3)The correlation and comparative analysis between the results of the side pressure test and the data of the standard penetration test,consolidation test and other indoor tests were carried out.The applicability of the model test design is verified,which provides a reference method for correction of large error of test data in side pressure test under deep overburden.