Graded broken stone dynamic resilience modulus rapid prediction method considering particle crushing

Abstract

The invention discloses a graded broken stone dynamic resilience modulus rapid prediction method considering particle crushing. The method specifically comprises the steps: determining multiple groups of physical property parameters of graded broken stones under the conditions of different gradation, different compaction degrees and different water contents; respectively measuring the dynamic resilience moduli of a plurality of groups of graded broken stones according to a dynamic triaxial test, predicting by adopting a three-parameter model, and fitting the three-parameter model to obtain model fitting coefficients k1, k2 and k3 based on the dynamic resilience moduli of each group of graded broken stones obtained by the dynamic triaxial test; and determining the contribution ratio of all the physical property parameters of each group of graded broken stones to the fitting parameters k1, k2 and k3 of the three-parameter model, and determining the correlation between the fitting parameters k1, k2 and k3 of the model and all the physical property parameters by adopting a stepwise multivariate regression analysis method to obtain a rapid prediction formula. According to the method, the dynamic resilience moduli of the graded broken stones can be conveniently and accurately obtained, design and construction of the graded broken stones in a pavement structure are scientifically guided, and the engineering quality is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of road engineering, and relates to a method for quickly predicting the dynamic rebound modulus of graded crushed stones considering particle crushing. Background technique [0002] As the graded crushed stone material for the subgrade transition layer and cushion layer, due to the relatively uniform gradation and the relatively small contact area between particles, particle breakage is prone to occur under the combined action of load stress and environmental factors, resulting in the deterioration of the crushed stone gradation and mechanical properties. The properties are attenuated, and its ability to resist deformation is reduced accordingly. If gravel materials with unreasonable gradation, poor angularity, and severe crushing are selected, the subgrade structure after overlaying will experience different degrees of settlement and deformation, which will not only fail to improve the performance of the su...

AI Technical Summary

Problems solved by technology

Due to the essential difference between the static calculation and the dynamic response of the structure, the fast prediction results such as the CBR conversion and the look-up table method proposed earlier based on the static modulus are no longer applicable to the current road design, and it is impossible to accurately control the site construction. guide

At the same time, the test method for the elastic modulus of granular materials (Appendix D) proposed in the new version of the specification requires the use of an expensive dynamic triaxial tester; in addition, the gravel material used for the test is loose, the preparation of the specimen is difficult, and the results are highly discrete. These factors limit the application of dynamic triaxial tester in road engineering

In the existing literature (such as the mesoscopic thermodynamic mechanism of the crushing evolution path of granular materials, Shen Chaomin et al., 2019.1), the research on the evolution law of the elastic modulus of graded gravel under different molding methods and moisture content conditions is not in-depth, and it is difficult to accurately and quickly Prediction of Dynamic Resilience Modulus of Graded Crushed Stone

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