Numerical Simulation Study On Soil Arching Effect

It is well-known that urban underground engineering plays more and moreimportant role in cities. However, there are so many accidents occurred duringunderground construction that urban production and life are in threaten. It bringsserious influence in society, and has caused wide attention of social. So, reducing oravoiding the accidents to the least is the crucial thing for urban undergroundengineering.Soil arching effect exists widely in geotechnical engineering. The essence of soilarching is the transfer of stress by developing the shear strength of soil. Thecompressive strength of soil can be developed by making use of soil arching effect, aswell as reduce the engineering cost.With the development of computer technology, numerical simulation has becameone of the most important means in analyzing the soil arching effect. The essentialproblem is that the stress paths can be considered in constitutive model for soil,especially plastic deformation formed when p reducing. However, constitutive modelsof many commercial software are Mohr-Coulomb Model, Cam-clay Model etc.Whensimulating the tunnel excavation, they have some limits. Therefore, numericalsimulation of soil arching effect using stress-path constitutive model is necessary.Then, the catastrophe mechanism and the evolution law can be obtained. The work ofthis paper are shown as follows:1. The trial stress return mapping algorithm applied to elastic-plastic constitutivemodel with many loading surfaces was proposed. And the three-dimensionalconstitutive model for concrete and the stress-path constitutive model of soil wereused on ABAQUS platform by compiling a subroutine program of finite element(UMAT).2. Base on the three-dimensional elastic-plastic constitutive model for Concrete,simulated the axial compression of concrete materials and reinforced concretecolumns, the size effect of concrete material and the three-dimensional mechanicalproperties of reinforced concrete columns were analyzed.3. Based on the stress path constitutive model for soil and three-dimensionalelastic-plastic constitutive model for concrete, author simulated the excavation of thetunnel and foundation ditch, proposed criteria for the classification of deep buriedtunnel and shallow buried tunnel, the tunnel surrounding rock disturbance affectingthe scope of analytical methods, as well as soil arch analysis method of foundationsupport.