Numerical Analysis Of Different Excavation Methods Of Yongshouliang Tunnel

Under the condition of shallow buried Yongshouliang tunnel soft rock,explore the tunnel excavation method,adopt geological analysis method and engineering analogy method to support the design of Yongshouliang tunnel,and use elastoplastic theory to analyze the stress of the tunnel surrounding rock Based on the previous experience of tunnel surrounding rock control,three theories of surrounding rock control of Yongshouliang tunnel were analyzed.The stress state after the excavation of the face of Yongshouliang tunnel was analyzed through existing theories.Conduct a theoretical analysis of the construction process of the invert arch.Through domestic tunnel construction experience,four tunnel excavation methods are proposed:(1)Full-section excavation method;(2)Three-step excavation method;(3)Half-side wall excavation method;(4)CRD excavation method.The construction process,construction machinery configuration and blasting scheme of these four construction methods are compared through the construction project,and it is concluded that the full-section excavation is the most time-saving and convenient,followed by the stepped excavation method,the half-wall guide Both the excavation method and the CRD excavation method are time-consuming and mechanically diverse.The finite difference software FLAC3 D was used to simulate and analyze the four excavation methods,and the displacement contours and principal stress contours of the surrounding rock of the four schemes for excavation were obtained respectively,and the displacement impact range after stepped excavation was the smallest,The full range excavation displacement has the largest influence range.During the simulation analysis,the displacements and displacement rates of the arches,elevations,left and right sides of the model were calculated at intervals of 5m,and the curves were drawn,and the variation laws of the tunnel surrounding rock displacements and displacement rates under different excavation methods were obtained.After comparing the four excavation methods,it is concluded that the stepped excavation method is more suitable for this geological condition,which provides a theoretical analysis for the project under this geological condition and also has reference significance for similar projects.The paper has 47 pictures,19 tables and 52 references.