Method for determining maximum dry density of natural-gradation sand and gravel materials for damming

Abstract

The invention relates to the technical field of sand and gravel material soil tests, and discloses a method for determining the maximum dry density of natural-gradation sand and gravel materials for damming. The method comprises the following steps: preparing density barrels according to the size of the sand and gravel material, digging a groove in a test site, laying fine sand on the bottom surface of the groove, and performing static rolling, leveling and compaction; arranging the density barrels at intervals in an extension direction of the groove, and marking positions of center points of the density barrels; manually mixing raw materials according to test required gradation, sequentially filling the density barrels and the groove around the density barrels with the raw materials, performing forward and backward driving vibration rolling for 26 times, performing precise calculation to determine residual rolling times, performing driving vibration rolling again, performing barrel top leveling after rolling completion, measuring the volume of each density barrel, weighing the mass of the sand and gravel materials in each density barrel, and then performing calculation to obtain the maximum dry density of the sand and gravel materials. The method adopts a more reasonable rolling manner, and can rapidly and accurately determine the maximum dry density of the sand and gravel materials, thereby avoiding damage to relevant equipment.

Description

technical field [0001] The invention relates to the technical field of sand and gravel material geotechnical tests, in particular to a method for determining the maximum dry density of the original gradation sand and gravel material for dam construction. Background technique [0002] The maximum dry density of sand and gravel is a key parameter in determining relative density index and construction quality control. Due to the size effect, the indoor relative density test cannot well reflect the actual situation of fully graded gravel materials on site, especially now that large-scale machinery and equipment are widely used in water conservancy projects, so that relative density often occurs in on-site rolling tests and on-site construction inspections. An unreasonable phenomenon with a density greater than 100%. It is an effective way to solve the above-mentioned unreasonable phenomenon to carry out large-scale relative density tests on the original gradation of sand and gr...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved is: the existing rolling method can easily cause the density barrel to tilt, which will lead to inaccurate test results and even damage the vibrating roller.

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