This paper presents a rapid and effective calibration method of mesoscopic parameters of a threedimensional particle flow code(PFC3D)model for sandy cobble soil.The method is based on a series of numerical tests and t...This paper presents a rapid and effective calibration method of mesoscopic parameters of a threedimensional particle flow code(PFC3D)model for sandy cobble soil.The method is based on a series of numerical tests and takes into account the significant influence of mesoscopic parameters on macroscopic parameters.First,numerical simulations are conducted,with five implementation steps.Then,the multi-factor analysis of variance method is used to analyze the experimental results,the mesoscopic parameters with significant influence on the macroscopic response are singled out,and their linear relations to macroscopic responses are estimated by multiple linear regression.Finally,the parameter calibration problem is transformed into a multi-objective function optimization problem.Numerical simulation results are in good agreement with laboratory results both qualitatively and quantitatively.The results of this study can provide a basis for the calibration of microscopic parameters for the investigation of sandy cobble soil mechanical behavior.展开更多
This paper focuses on theoretical analytical models to calculate the limit support pressure and vertical earth pressure on the cutting face for tunnels.The failure zone is divided into two parts:a sliding failure zone...This paper focuses on theoretical analytical models to calculate the limit support pressure and vertical earth pressure on the cutting face for tunnels.The failure zone is divided into two parts:a sliding failure zone and an upper loosen zone,and the limit support pressure calculation equation is derived.To verify the rationality of the theoretical model,it was compared with the existing theory,numerical simulation,and centrifugal test,and then the parameter analysis was carried out.The results show that the results of this paper agree well with the existing theory,numerical simulation,and centrifugal test.The inclination angle of the proposed mechanism is determined based on the results of the existing centrifuge test,and the recommended inclination angle is between 52°+φ/2 and 54°+φ/2.The method is proven to be safe and accurate.It can provide a theoretical basis for similar projects.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Grant No.51978019)the Beijing Natural Science Foundation(No.8222004).
文摘This paper presents a rapid and effective calibration method of mesoscopic parameters of a threedimensional particle flow code(PFC3D)model for sandy cobble soil.The method is based on a series of numerical tests and takes into account the significant influence of mesoscopic parameters on macroscopic parameters.First,numerical simulations are conducted,with five implementation steps.Then,the multi-factor analysis of variance method is used to analyze the experimental results,the mesoscopic parameters with significant influence on the macroscopic response are singled out,and their linear relations to macroscopic responses are estimated by multiple linear regression.Finally,the parameter calibration problem is transformed into a multi-objective function optimization problem.Numerical simulation results are in good agreement with laboratory results both qualitatively and quantitatively.The results of this study can provide a basis for the calibration of microscopic parameters for the investigation of sandy cobble soil mechanical behavior.
基金The authors gratefully acknowledge the financial support provided by the National Natural Science Foundation of China(Grant Nos.51978019 and 51978018)Natural Science Foundation of Beijing Municipality,China(Grant Nos.8222004 and 8222005).
文摘This paper focuses on theoretical analytical models to calculate the limit support pressure and vertical earth pressure on the cutting face for tunnels.The failure zone is divided into two parts:a sliding failure zone and an upper loosen zone,and the limit support pressure calculation equation is derived.To verify the rationality of the theoretical model,it was compared with the existing theory,numerical simulation,and centrifugal test,and then the parameter analysis was carried out.The results show that the results of this paper agree well with the existing theory,numerical simulation,and centrifugal test.The inclination angle of the proposed mechanism is determined based on the results of the existing centrifuge test,and the recommended inclination angle is between 52°+φ/2 and 54°+φ/2.The method is proven to be safe and accurate.It can provide a theoretical basis for similar projects.
