Earth and stone material grading optimization method based on fractal theory and physical mechanics test

Abstract

The invention provides an earth and stone material grading optimization determining method which comprises the following steps of: changing granularity fractal dimension of earth and stone materials for the earth and stone materials with particle distribution meeting fractal distribution characteristics; preparing a grading earth and stone material sample with different particle size distribution functions; establishing a function relationship of extreme value dry density, modulus of compression, shearing strength and grading granularity fractal dimension through a field or indoor test; and regulating the granularity fractal dimension to obtain earth and stone material grading with a better filling relationship, easier compactness, higher modulus and strength. The earth and stone material grading optimization determining method can be used for a particle grading optimization design of rockfill materials and natural sand gravel materials.

Description

technical field [0001] The invention relates to an optimization method for earth-rock material gradation based on fractal theory and physical mechanics test, and belongs to the technical field of earth-rock dam construction in the water conservancy and hydropower industry. Background technique [0002] Earth-rock dam is the oldest and most widely used dam type in the world. Since the construction of Bikou 100m-level core rockfill dam in the 1970s, a number of 200m-level high earth-rockfill dam projects such as Xiaolangdi, Pubugou and Shuibuya have been built, and a relatively complete dam design and construction technical specification has been formed. . Because earth-rockfill dams have the advantages of strong adaptability to topographic and geological conditions, good earthquake resistance, and good economic indicators, a number of 300m-level core rockfill dams such as Lianghekou, Shuangjiangkou, and Changheba are already under construction, such as Mei, Gushui, A batch ...

AI Technical Summary

Problems solved by technology

Although the construction of earth-rock dams has achieved great success, and the dam construction technology has also made great progress, there are still many technical problems such as the determination of the gradation of earth-rock materials, which are only listed in the "Code for Design of Roller-Compacted Earth-rock Dams (DL / T 5395‐ 2007) Article 4.1 and Article 6.3 of "Code for Design of Concrete Faced Rockfill Dams (DL / T 5016-1999)" stipulate that the content of particles smaller than 5mm should not exceed 20%, and the content of particles smaller than 0.075mm should not exceed 5%. Still in the experience stage

For gradation evaluation, currently there are only gradation indicators applicable to coarse-grained soils with a maximum particle size of 60mm or less, that is, the standard for good gradation if the coefficient of inhomogeneity Cu is greater than 5 and the coefficient of curvature Cc is within the range of 1-3 , but these indicators mainly describe the width and continuity of the gradation distribution of granular materials, and cannot reflect the mesoscopic collocation between particle components. Even if different gradation curves have similar indicators, their compaction densities can be completely different, which leads to The mechanical properties of rockfill produce huge differences

Images