Characterization And Engineering Application Of Deconstructing Evolution Of Refined Artificially Prepared Structural Clay

Soft clay is widely distributed in coastal areas,lakes,inland rivers and other areas,due to the particularity of the geographical location and formation method of soft clay,it has the characteristics of high water content,large pore size and large amount of compression deformation,this causes engineering problems such as slow foundation drainage and consolidation and large settlement.At the same time,soft clay has obvious yield strength when loaded,showing deformation and failure caused by sudden pore collapse,this property will cause great harm to the project.In order to explore the failure mechanism of soil structure and the law of deconstruction and evolution,many scholars have conducted research on it by artificially preparing structured soil.How to ensure the accuracy of the physical indicators of artificially prepared structured soil samples is the basis for exploring the failure mechanism of soil structure and the law of deconstruction.On this basis,an elastoplastic constitutive model that can consider the law of deconstruction and evolution of soil is established to solve the problem of effective calculation and prediction of construction settlement of structural soft soil engineering,therefore,this article will conduct research from the following five aspects:?1?In view of the current artificially prepared structured soils that do not consider the effect of cement hydration on the void ratio of the soil samples,and have not verified the consistency ratio between the actual pores of the artificially prepared samples and the target pore ratios,this paper focuses on the artificially prepared macroporous structured soils,the actual void ratio evolution characteristics.By using urea as an additive to form macroporous structural soil,two structural soils with different void ratios?1.5,1.7?and different cement contents?4%,6%?were prepared,and the cement hydration products and The influence of water bath penetration on the actual void ratio of the sample,the variation law of the actual void ratio deviation caused by infiltration when the samples are in a constant temperature water bath for 7d,10d,15d and 20d is discussed,and a plan for controlling the actual void ratio of artificially prepared structured soils in a reasonable range is given.?2?One-dimensional compression was used to test artificially prepared structured soils with different initial void ratios?1.5,1.7?and different cement contents?4%,5%,6%,7%?,and the initial void ratio and cement content were analyzed.The influence of these two factors on the performance of soil structure.?3?Quoting structural damage parameters,interpreting the evolution process of the soil cemented skeleton in the one-dimensional compression process through the parameter change law,the influence of the initial void ratio and the cement content on the structural damage parameter change law is analyzed in detail,and the structural stress sharing ratio is analyzed.Quantitative processing,the structural damage parameter expression is given.?4?Based on the structural characteristics test of Bothkennar and Pisa clays and two typical deconstruction functions based on measured data,the deconstruction and evolution of artificially prepared structured soils with different cement content under a single initial void ratio were discussed,and based on this Two artificially prepared structured soil deconstruction functions with a single variable?cement content?are established.?5?The above yield function criterion for the lower load surface is used as a reference,the failure law of soil structure is introduced,an elastoplastic constitutive model that can characterize the failure law of the structure is established,and the UMAT subroutine based on ABAQUS is developed.Based on the Ariake Sea in Japan^[88],the structural soft soil foundation is characterized by an elastoplastic constitutive model based on the upper and lower load surfaces and considering the structural failure evolution.The finite element ABAQUS is used to numerically calculate the engineering condition of embankment construction on soft soil foundation.