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CBR numerical test method based on graded crushed stone in three-dimensional state

A three-dimensional state, numerical test technology, applied in CAD numerical modeling, electrical digital data processing, special data processing applications, etc. Problems such as micromechanical properties of particles in stone

Active Publication Date: 2021-05-14
CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In addition, the above-mentioned graded gravel CBR indoor test method and the existing CBR numerical test method have the following defects: (1) the traditional test method can only obtain the relationship between aggregate and CBR through repeated large numbers of tests; (2) the traditional indoor The test method can only obtain the CBR value of the graded crushed stone, but cannot obtain the microscopic mechanical properties of the internal particles of the graded crushed stone during the test; (3) The existing CBR numerical test method is based on a two-dimensional model. Converted to a disc-shaped unit with a certain thickness, the interlocking effect between the crushed stones and the distribution characteristics of the voids cannot be considered

Method used

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  • CBR numerical test method based on graded crushed stone in three-dimensional state
  • CBR numerical test method based on graded crushed stone in three-dimensional state
  • CBR numerical test method based on graded crushed stone in three-dimensional state

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Embodiment 1

[0082] Example demonstrates the specific implementation process of the present invention with limestone crushed stone, the basic physical properties of crushed stone are shown in Table 1, and the micromechanical parameters are shown in Table 2.

[0083] Table 1 Optimum moisture content of graded gravel

[0084] Dry density (g / cm3) 2.31 2.334 2.346 2.338 2.334 Average moisture content (%) 3.78 4.41 4.83 5.37 5.84

[0085] Table 2 Micromechanical parameters

[0086]

[0087] Step a: Through the WALL command in PFC3D, respectively establish the bottom surface (circular wall) and side wall (column wall) of the test mold, such as figure 1 As shown, gravel particles are generated according to the actual gradation, and physical properties such as gravel density are endowed. According to the test results and fitting curve, the optimal moisture content of graded gravel is 4.85%, and the maximum dry density is 2.346g / cm 3 . The simulated graded grave...

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Abstract

The invention discloses a CBR numerical test method based on graded crushed stone in a three-dimensional state. Firstly, the mesoscopic parameters of the simulated specimen are assigned values, and then the simulation of the loading process of the CBR experiment is carried out, so that the indenter penetration amount and penetration force can be obtained. The relationship curve, and then through the CBR conversion formula, the penetration force corresponding to the penetration amount of 2.5mm in the model results can be converted into a CBR value. This method truly reproduces the CBR test of graded crushed stone in three-dimensional state, overcomes the deficiency that the two-dimensional model cannot describe the crushing and spatial distribution of crushed stone, and can quickly and accurately obtain the CBR value of graded crushed stone, and can real-time To track the change law of meso-mechanical properties of graded crushed stone particles during the CBR test.

Description

technical field [0001] The invention belongs to the technical field of road engineering, in particular to a CBR numerical test method based on graded gravel in a three-dimensional state. Background technique [0002] Graded crushed stone is a typical road base material, and the CBR (California Bearing Ratio) index is usually used to evaluate its strength and design the material composition. The basic principles and steps of the graded crushed stone CBR indoor test method are as follows: (1) prepare the specimen according to the maximum dry density and optimum water content; (3) Carry out the penetration test on the specimen soaked in water; (4) Arrange and calculate the penetration test results to obtain the CBR value. At present, there have been applications for CBR numerical two-dimensional test method for graded crushed stone, but there is no report on the three-dimensional numerical test method for graded crushed stone. [0003] Compared with the two-dimensional test, ...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F30/20G06F111/10G06F119/14
CPCG06F30/20G06F2119/06
Inventor 张军辉李崛郑健龙
Owner CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY