Research On Mechanical Properties Of HUI Type Composite Steel Sheet Pile And Its Engineering Applicatio

With the acceleration of urbanization in China,the transformation of old cities has brought about the development of great underground urban space,and foundation pit engineering has become one of the important geotechnical engineering topics.Combined steel sheet pile has the advantages of green environmental protection and fast construction speed,and also integrates the water-stopping effect of steel sheet pile and the advantages of large stiffness of H-beam,so it has good performance and economy.In this paper,a new HUI composite steel sheet pile is designed,and the numerical simulation software PLAXIS 3D is used to simulate the deformation effect of foundation pit excavation on adjacent buildings with different stiffness,different distances and different angles,and analyze the changes of horizontal displacement and vertical settlement of buildings after foundation pit excavation.The main research contents and achievements are as follows:1.According to the characteristics of Larsen IV.steel sheet pile and H type steel,a new HUI type composite steel sheet pile is designed,and the stiffness of the designed five HUI type composite steel sheet piles is calculated,and the results show that the HUI type composite steel sheet pile type 4 has the largest stiffness.HUI type composite steel sheet pile type 4 is adopted,which is used for the support form of foundation pit excavation.2.In order to verify whether the supporting structure meets the requirements,a combination of numerical simulation and theoretical calculation is used to verify whether it is suitable for the foundation pit used in this paper.HUI type composite steel sheet pile 4 was used for the numerical simulation of shallow foundation pit excavation in this paper,and the verification was carried out through theoretical calculation.Verify the suitability of this sheet pile for shallow foundation pits.3.PLAXIS 3D is used to establish the three-dimensional finite element model of foundation pit and adjacent buildings,and analyze the change law of horizontal and vertical displacement of adjacent buildings with different stiffness after excavation of foundation pit.The simulation results show that after the same depth of excavation of the foundation pit,when the stiffness of the building with different stiffness is the same distance from the foundation pit and the angle between the horizontal centerline and the foundation pit,the greater the stiffness,the smaller the horizontal displacement and vertical settlement of the building,and vice versa.4.In order to study the change law of horizontal displacement and vertical displacement of buildings at different distances from the foundation pit or at different angles from the horizontal centerline of the foundation pit,the angle between the horizontal centerline of the building and the foundation pit and the distance between the building and the foundation pit are changed in numerical simulation.The numerical simulation results show that only the angle between the horizontal centerline of the building and the foundation pit or only the distance between the building and the foundation pit are changed,and the horizontal and vertical displacements of the building will change.