Study On Failure Mode And Bearing Capacity Of Foundation With Lateral Constraint Applied In Silt

The basis for the lateral deformation suppression effect is a new type of composite foundation.For a long time,the bearing capacity of this new type of foundation was calculated according to the formula of bearing capacity of composite foundations with scattered points.The application in the silty soil area of Zhengzhou shows that the calculated value is lower(13 to 32%)than the static load test value.At present,there are few theoretical studies on the working properties and bearing capacity of this new type of foundation,and the research is still confined to the idea of a scatter-like composite foundation.This article is based on the ground-based basic form of lateral deformation restraint,which is often used in the silty soil foundation in Zhengzhou,and is full of short piles.Through the physical model test and three-dimensional numerical simulation,the failure morphology of the structure with constrained lateral deformation and the failure mechanism of this new foundation were studied,and static analysis was carried out.The main knowledge gained is as follows:(1)In the physical model indoor experiment,a scale model was used.The area replacement rate m was set as a variable,and the axial stress of the structure was attenuated with increasing depth.With the increase of the replacement ratio,the stress ratio between the structure and the foundation soil decreases,the bearing effect of the foundation soil between the structures becomes stronger,the bearing capacity of the foundation increases,and the failure modes of the samples with different area replacement rates are analyzed and summarized.(2)In the numerical simulation,a model with a size of 40×40×20m is used for the simulation test.According to the profiles in different directions,the numerical simulation during the simulation loading process is used.Analyze and study the stress distribution of the new foundation in the elastic state,the deformation characteristics under the limit load,the plastic deformation distribution area of the foundation under the action of the destructive load,combined with the major principal stress and the shear strain increment,and infer this The new type of foundation destruction surface morphology.(3)Based on the results of physical experiments and numerical simulations,the damage patterns of this foundation are deduced: 1.Peripheral impact shear failure of the foundation-Internal X-shaped shear failure;2.At the half height of the side cells,horizontal shear cracks are formed.The destruction of this new type of foundation is a superposition of the above two mechanisms.Based on this,the calculation formula for bearing capacity of this new foundation was deduced.In order to verify the correctness,rationality and suitability of this formula,five engineering examples in Zhengzhou were used to verify the results.The results showed that the calculated value was different from the measured value by 5%.The engineering application example also shows that the settlement deformation value is within the specified range.In this paper,the calculation of the bearing capacity for the first time according to the failure mode reveals the internal stress and strain mechanism of this new type of foundation.In the future application of the project,through adjustment of the area replacement rate,emphasis will be placed on strengthening the stress concentration,large deformation portion,under the premise of controlling economic costs,the foundation bearing capacity can be effectively improved.