Study On Calculation Method Of Settlement And Stability Of New And Old Roadbed Combination Part In Loess Area

The differential settlement of the new and old roadbed and the stability of the combined part are the technical problems faced in the loess area highway reconstruction.In this paper, based on Tong Xi, Xi Bao highway reconstruction project, through field investigation and theoretical analysis, model test and numerical analysis, it has been studied in many aspects. The main contents are as follows:1、Through theoretical analysis, the stress distribution of the new and old roadbed in the loess area is studied, and the corresponding calculation formula and the corresponding applicable conditions are obtained.2、On the basis of the above theoretical calculation, the settlement and deformation of the new and old roadbed in the highway reconstruction project in the loess area are calculated, including the settlement of the new roadbed and the additional settlement of the old roadbed, and the settlement deformation law is obtained.3、In view of the foundation deformation characteristics of the loess area highway reconstruction, select the appropriate settlement control standard, respectively, during the construction and post construction settlement control, proposed several suggestions of reducing post construction differential settlement and increasing the combination part splicing quality of new and old roadbed in the loess area highway reconstruction.4、According to the theory of step type combined with the new and old roadbed, the design scheme and the excavation scheme of the new and old roadbed are given, and the design model is proposed and the corresponding solution is given, and it was illustrated through concrete example.