Method for evaluating relative compactness of quartz soil based on light dynamic penetration test index

Abstract

The invention discloses a method for evaluating the relative compactness of quartz soil based on a light dynamic penetration test index. The quartz soil sample taken back at the site is dried, and theRhod, max, Rhod, min of each type of quartz soil sample is determined by a geotechnical test. D50, Cu, Dri is set to calculate the Rhodi of each type of quartz soil sample under various Dri; the penetration hammering numbers of each type of quartz soil sample under different Rhodi and the cumulative penetration depth of the probe after each hammering were measured respectively, the hammering number of each type of quartz soil sample-accumulated penetration depth scatter plot was plotted respectively, each set of test data points in each figure is fitted into a straight line, and the slope ofeach straight line is the pindex, i of such quartz soil sample under Dri; the formula is shown in the description. A scatter plot is drawn; the expressions of the formula and Dri are shown in the description. The relative compactness of the predicted quartz land based on the method is more consistent with the actual situation.

Description

technical field [0001] The invention relates to a method for evaluating the relative compactness of quartz soil, and more specifically, relates to a method for evaluating the relative compactness of quartz soil based on a light dynamic penetrating test index. Background technique [0002] Filling construction has many applications in engineering construction, such as lowland reclamation, roadbed, wharf construction, etc. Most of the raw materials for filling are coarse-grained quartz soil, including quartz gravel and coarse quartz sand. During the construction process, it is necessary to ensure that the filling soil has good compaction, so as to avoid the subsidence, damage and even liquefaction of the foundation in the future. Therefore, it is very important to propose a method that can quickly and accurately predict the degree of compaction of quartz soil foundations. [0003] For non-cohesive soils such as quartz gravel and quartz sand, the relative compactness D r It ...

AI Technical Summary

Problems solved by technology

Compared with the DIN standard, the light-duty dynamic penetrometer of the GB standard has the same penetration energy, but there is a big difference in the diameter and shape of the probe.

All of these will lead to different penetration indicators of field tests

Therefore, if the existing empirical formulas for dynamic penetrometers in ASTM and DIN specifications are used to evaluate the test results of light-duty dynamic penetrometers specified in GB specifications, there will be a large difference between the predicted value and the actual value

In addition, most of the existing empirical formulas do not consider the influence of soil particle size and gradation, resulting in a decrease in calculation accuracy. For example, for coarse-grained soils such as quartz gravel and quartz coarse sand, the more uneven the soil sample, the less The smaller the particle size, the easier it is to enter the intergranular pores due to the vibration of the hammer, which will increase the degree of compaction of the foundation soil and increase the penetration resistance.

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