Study On Soil Pressure Model Of Deep Foundation Pit Support

With the rapid development of urban construction and construction industry,underground space has been developed and utilized as an important resource of the city.Foundation pit project also develops accordingly.More and more problems are revealed as the foundation pit develops.For example,the design theory is far from enough to meet the needs of the actual project.Many practices indicate that there is a great difference between theoretical and practice.The calculation of earth pressure is one of the most obvious problems.The classical earth pressure theory,such as Rankine and Coulomb,is very different from the earth pressure in actual engineering.In this paper,the soil pressure was studied by the monitoring results of the Castle for All Seasons in Kaifeng(open around)and Huiyuan community project(buildings around).The distribution model and calculation formula of soil pressure are presented.The main achievements are as follows:(1)Analyze the monitoring results of Castle for All Seasons in Kaifeng(open around)and Huiyuan community project(buildings around).The displacement variation pattern and soil pressure distribution of the support structure are discussed.Compare the actual measured displacement and soil pressure and the theoretical calculation value.The results show that both the development law and the numerical value,the theoretical calculation and actual monitoring value are very different.(2)A finite element method based on the internal force and deformation mechanism of foundation pit is discussed.Two engineering examples were simulated by using finite element software ABAQUS.The reliability of the finite element method is verified by comparing the numerical simulation results with the measured results.(3)According to the results of the monitoring and finite element analysis,the soil pressure distribution model of open around project and existing buildings around project is discussed.For the open around project,the soil pressure distribution is divided into two parts.Above 0.3H,the distribution law and the value of soil pressure are consistent with Rankine earth pressure.Below the 0.3H,the distribution law of soil pressure is consistent with Rankine earth pressure,but the numerical value is less than Rankine earth pressure.For the existing buildings around project,the soil pressure is consistent with Rankine earth pressure.Due to the grating effect of the pile foundation of the building,the numerical value is less than Rankine earth pressure.(4)The above method is used to calculate the earth pressure.The soil pressure distribution pattern of the supporting structure under two conditions is determined.The calculation formula of earth pressure is put forward in stages.The results are compared with the measured results,the pressure values and the simulated values.It is proved that the new calculation formula of soil pressure is reliable.It provides reference for similar foundation pit engineering support.