Graded broken stone repeated load experiment elastoplasticity yield point stress determining method

Abstract

The invention relates to a graded broken stone repeated load experiment elastoplasticity yield point stress determining method. The method is characterized in that according to the deformation processof granule materials such as graded broken stone under the repeated load effect, a stability analysis method is used; the stability of graded broken stone under the repeated load effect is evaluatedthrough plastic strain; a plastic strain rate model and a rebound strain model of the graded broken stone under the repeated load effect are built; by analyzing the relationship between the plastic strain rate and the rebound strain and the SMP yield criterion, a calculation model of the yield stress along with the change of the load intensity and the load times is provided. The yield stress and the elastic-plastic state of granule materials under different load intensity and load action times can be judged; the conditions are provided for elastic-plastic stress strain calculation; the foundation is laid for realizing the application of a graded broken stone elastic-plastic model. The experiment method and the parameter obtaining method are convenient; the model composition part representative significance is defined; the elastic-plastic yield point yield stress calculation process is concise.

Description

technical field [0001] The invention belongs to the technical field of road engineering, and in particular relates to a method for determining elastic-plastic yield point stress in a repeated load test of graded gravel. Background technique [0002] Graded crushed stone is a typical base or subbase material for road engineering flexible pavement due to its good deformation traceability, crack barrier, water permeability and renewability. However, graded crushed stone has the characteristics of loose particles, weak stress diffusion ability under load, large plastic deformation, and significant elastoplasticity. The use of elastic models for the design and calculation of graded crushed stone structure layer is different from its actual effect. The conventional elastic model is not enough to reflect the characteristics of graded crushed stone, so it is necessary to use an elastic-plastic model to characterize the elastic-plastic characteristics of graded crushed stone. [000...

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Problems solved by technology

The stress at the yield point is an important judgment to determine when plasticity occurs, and the conventional yield surface also lacks relevant instructions and guidance, and the state of the structure cannot be clarified, which seriously affects the analysis of the structural performance bearing capacity and the evaluation of the long-term performance of the structure. and forecast

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