Study On Soil Calibration And Force Deformation Characteristic Of Corrugated Steel Pipe Culvert Based On Particle Flow Code

With the continuous improvement of highway infrastructure in Western China,culvert as an important part of highway engineering,its construction needs are gradually increasing.Among many different culvert structures,corrugated steel pipe,as a special structure,have been widely used in highway traffic construction in our country because of its flexibility,environmental protection,light weight,large deformation resistance and centralized production.However,for the design and construction of corrugated steel pipe culverts,engineers and technicians in China usually refer to the foreign design codes and experience,lacking the corresponding mature design and construction codes.Moreover,most of the existing studies on the interaction between corrugated steel pipe culvert structure and soil are based on the finite element analysis of continuous medium,ignoring the inherent characteristics of soil —discreteness.Particle Flow Code(PFC3D),as a professional software for mechanical analysis of rock and soil,can well simulate the macroscopic mechanical properties of rock and soil,but there is still a big gap in the mechanical analysis of continuum structure in geotechnical engineering.Under the above background,firstly,based on the development platform of Particle Flow Code(PFC3D),the macroparameters and micrparameters calibration of sandy soil was studied by compiling the triaxial simulation test program of flexible boundary with Fish language,and the shear failure process of sandy soil was analyzed and studied from the perspective of micromechanics.By comparing and analyzing the laboratory tests,the feasibility of the triaxial simulation test model with flexible boundary and the rationality of the calibration parameters were verified.The effects of effective modulus,stiffness ratio,rolling friction coefficient and other Micro-Parameters on the macro-mechanical properties of sandy soil are obtained,as well as the evolution of such micromechanics as internal contact force chain,displacement field and microscopic fabric distribution of sandy soil in the process of shear.It was convenient to effectively calibrate the filling parameters of corrugated steel pipe culvert in the later stage.Secondly,continuous structures such as bars,plates and cylindrical shells were constructed by particle flow code,and the force and deformation under the condition of linear elasticity were simulated,compared with ABAQUS.The contact model was improved by extending the contact detection distance when simulating the force and deformation of the spatial continuum structure.The feasibility and rationality of using the modified contact model to simulate the force and deformation of the continuous corrugated steel pipe structure were verified.Finally,based on the soil calibration and the verification of the force and deformation of the corrugated steel pipe structure,the force and deformation of the corrugated steel pipe culvert at different filling heights and the distribution law of the earth pressure were discussed.The simulation results of the force and deformation of the corrugated steel pipe culvert were compared with the previous research results,which verified the feasibility and rationality of the particle flow method in simulating the force and deformation of the corrugated steel pipe culvert.At the same time,the research results also could expand the application prospect of the particle flow method for the study of the interaction between soil and structure in geotechnical engineering,and have certain reference value for the later study and analysis of the force and deformation of the interaction between other structures and soil in geotechnical engineering.