Study On Bearing Capacity Of Reinforced Strip Foundation

With the progress of science and technology,engineering technology has also made a qualitative leap.In the field of water conservancy,railway,highway,and other engineering constructions,reinforced soil technology is widely used.The reinforced soil technology has multiple advantages;these advantages are: the low cost of projects,the technology required for construction is not complex and can be applied in many fields,so it has been widely used in many engineering fields.Therefore,it is significant to study the reinforced foundation’s reinforcement mechanism and its action law in the foundation.In previous studies on the reinforced foundation’s bearing capacity,reinforcement is relatively single,and most of them are flat reinforcement,while the research on three-dimensional reinforcement is rare.This paper takes this as the breakthrough point,transforms various reinforcement forms,first carries on the indoor model test to various reinforcement sizes and shapes,and then carries out the numerical simulation to the working condition based on the discontinuous medium’s discrete element.Finally,utilize the theoretical analysis method to put forward the bearing capacity formula to the strip foundation reinforced foundation to analyze the foundation bearing capacity,foundation failure mode,and reinforcement soil effect of different reinforcement shapes.The mechanism was studied.The main work of this paper is as follows:(1)The indoor model tests were used to investigate the variety of test schemes of flat reinforcement and surrounding reinforcement;seven test conditions were conducted.The influence of the reinforcement layers number,length,and reinforcement method on the foundation bearing capacity,the distribution of earth pressure within the soil,and the foundation’s failure mode are studied.The results of the model tests show that: the increase of reinforcement length can improve the foundation bearing capacity and may play the role of spreading earth pressure;the increase of reinforcement layers can improve the soil’s strength under the foundation and form the overall stress mechanism.Under the same test conditions,the surrounding reinforcement can reduce the soil movement to both sides of the foundation more than the flat reinforcement and enhance its bearing capacity.The improvement of soil strength under the foundation and different reinforcement modes can affect the foundation failure mode because of the influence on the development of the failure surface on both sides of the foundation’s lower part.(2)The experimental conditions were simulated by PFC2 D.Based on the model test,the reinforced foundation model of strip foundation with different reinforcement shapes is established.The displacement variation law and particle contact interface law of soil particles in the foundation under different reinforcement conditions are obtained.The reinforcement reduces the soil displacement and delays the lower part foundation’s damage by reducing the soil’s lateral sliding on both sides.Reinforcement improves the soil particles’ contact force phenomenon concentrated in a certain area;when there is no reinforcement,the distribution of the soil particles’ contact force under the lower part of the foundation is more uniform;because of the restraint effect of the vertical reinforcement.The surrounding reinforcement has less effect on the lateral sliding of the soil.Obviously,it makes the internal soil integrity of the surrounding reinforcement better,so the bearing capacity is stronger.It is found that reinforcement can decrease the soil displacement and delay the lower part foundation’s damage by reducing the lateral sliding of the soil on both sides.In addition,In the case of the unreinforced model,the reinforcement can greatly improve the phenomenon of the soil particles’ contact force which is concentrated in a certain area,so that the distribution of the contact force of the soil particles on the lower part of the foundation is more uniform;because of the restraint effect of the vertical reinforcement,the surrounding reinforcement can reduce the lateral sliding of the soil The confinement effect of the reinforcement is more obvious,which makes the integrity of the soil in the surrounding reinforcement better.(3)Combined with the model test and PFC2 D numerical simulation,the effect of reinforcement on the foundation’s bearing capacity and the foundation’s failure mode are obtained.The lateral pressure of the soil reinforced part is analyzed,combined with the unreinforced foundation’s bearing capacity formula,the bearing capacity formula of reinforced strip foundation is proposed.Through the calculation of the test results,the adopted bearing capacity formula is verified.