Method for determining equivalent resilience modulus of roadbed top surface by considering viscoelastic property and wet-force coupling of roadbed soil

Abstract

The invention discloses a roadbed top surface equivalent resilience modulus determination method considering the viscoelastic property and wet-force coupling of roadbed soil. The method specifically comprises the following steps: establishing a two-dimensional finite element model of a pavement structure through numerical software; determining the basic parameters in a solid mechanics module of the numerical software, and determining the boundary conditions; defining the driving dynamic load as a weak form partial differential equation, and giving an initial value; inputting a dynamic resilience modulus and viscosity coefficient equation of the roadbed related to the compaction degree, the humidity and the pressure; completing the finite element calculation, and acquiring the change relation of roadbed top surface deflection at the intersection position of the roadbed surface and the load center line along with the loading time, wherein the peak value is the maximum deflection of the roadbed top surface under the action of the dynamic load; establishing an elastic half-space estimation model, and obtaining a corresponding dynamic resilience modulus, namely the equivalent resilience modulus of the top surface of the roadbed. The method is closer to the real condition of the roadbed, the accuracy of performance prediction of the active-service roadbed is improved, a reliable basis is provided for a road maintenance decision, and the determination process is simple and reliable.

Description

technical field [0001] The invention belongs to the technical field of road engineering, and relates to a method for determining the equivalent resilience modulus of the roadbed top surface in consideration of roadbed soil viscoelastic properties and wet-force coupling. Background technique [0002] The subgrade structure bears the traffic dynamic load transmitted from the road surface, and the subgrade soil receives different dynamic loads at different depths, and different dynamic loads have different effects on the modulus of resilience of the subgrade soil. Under the action of moving load, the duration of the dynamic load in the subgrade will also be different, and the modulus of resilience of the subgrade soil will be different under different loading durations. At the same time, the overlying pressure of subgrade soil at different depths is different, resulting in different confining pressures, and different confining pressures will also affect the modulus of resilienc...

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Problems solved by technology

[0003] The modulus of resilience of subgrade soil can only represent the value of modulus of resilience at a certain point on the top surface of the subgrade, and the equivalent modulus of resilience of the top surface of the subgrade is the equivalent value of the modulus of resilience of the subgrade structure; Considering the viscoelastic properties of the subgrade soil and the wet-force coupling research on the equivalent rebound modulus of the subgrade top surface, the determination of the equivalent rebound modulus of the subgrade top surface is not accurate, and the preventive measures are not taken in time, which leads to the wetting of the subgrade structure Deformation, the problem of shortening the service life

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