Method for determining optimal cohesive frozen moisture content of cohesiveless soil

A cohesive soil and measurement method technology, which is applied in the field of soil mechanical performance testing in geotechnical engineering, can solve problems such as easy tilting, failure to make shapes, and easy scattering of triaxial samples, so as to achieve cohesion reduction, Solve the effect of easy to scatter and easy to tilt

Active Publication Date: 2015-05-20
SHAOXING UNIVERSITY
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for measuring the optimum cohesive frozen water content of cohesive soil, so as to solve the defects in the prior art that the triaxial sample is easy to scatter and tilt after forming, and even cannot be formed.

Method used

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  • Method for determining optimal cohesive frozen moisture content of cohesiveless soil
  • Method for determining optimal cohesive frozen moisture content of cohesiveless soil
  • Method for determining optimal cohesive frozen moisture content of cohesiveless soil

Examples

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Embodiment 1

[0042] In the k5+150~k6+200 section of a high-speed railway, the roadbed has local sandy soil, which is a typical cohesive soil. Since the subgrade will be subjected to cyclic dynamic loads from trains, it is necessary to carry out triaxial mechanical properties testing of the reshaped sand. In order to prepare high-quality triaxial samples, the optimum cohesive freezing moisture content of the cohesive soil should be determined by direct shear test first.

[0043] For above-mentioned example, adopt the assay method of a kind of cohesive-free soil optimum cohesive freezing moisture content of the present invention, measure, comprise the steps:

[0044] (1), dry soil preparation:

[0045] According to the number N and dry density R of the designed direct shear samples, calculate the mass M of the dry state of the cohesive soil required for the direct shear test 2 .

[0046] N 2 =2*n 1 *n 2

[0047] m 2 =N 2 *3.14*(D / 2) 2 *h*R

[0048] Among them, n 1 is the number o...

Embodiment 2

[0079] Embodiment 2: application embodiment.

[0080] The optimal cohesion freezing water content that embodiment 1 measures is used for the sample preparation of cohesionless soil triaxial sample, specifically as follows:

[0081] 1. Preparation of mixed soil materials:

[0082] According to the design sample dry density R, the number of triaxial samples N 1 and the number of auxiliary direct shear samples N 2 , to calculate the mass M of the cohesionless soil in the dry state required for the triaxial specimen and the auxiliary direct shear test 1 and M 2 .

[0083] According to the optimum coagulation freezing water content W measured in Example 1, calculate the mixing water quality M added 3 = M 1 *W, for mixing to prepare cohesion-free soil mixture.

[0084] 2. Freezing of mixed soil materials:

[0085] Freezing the mixed non-cohesive soil material after mixing, preferably, the freezing temperature is -10°C, and the freezing time is 24 hours.

[0086] 3. Single s...

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Abstract

The invention discloses a method for determining optimal cohesive frozen moisture content of cohesiveless soil, and belongs to the technical field of mechanical property testing of a soil body. The method comprises the following steps: (1) preparing dry soil; (2) preparing mixed soil materials; (3) fabricating a frozen-state direct shear sample; (4) carrying out a frozen-state direct shear test; (5) carrying out a room-temperature state direct shear test; (6) calculating a friction angle and cohesive force; and (7) carrying out comprehensive assessment. According to the method disclosed by the invention, the cohesive force and friction angle of the cohesiveless soil are obtained by the room-temperature state direct shear test and the frozen-state direct shear test; the optimal cohesive frozen moisture content of the cohesiveless soil is determined; and under the premise of adopting a tri-axial sample fabricating method for increasing the cohesive force of the cohesiveless soil in the sample fabrication process and reducing the friction angle in the freezing process, the defect that the tri-axial sample in the prior art is easy to scatter and incline, and is difficult to be fabricated into a standard cylinder after being formed can be overcome.

Description

Technical field: [0001] The invention relates to a method for measuring the optimal cohesive frozen water content of non-cohesive soil, which belongs to the field of soil mechanical performance testing in the discipline of geotechnical engineering. Background technique: [0002] Cohesionless soil represented by sandy soil is one of the main components of the foundation of buildings and structures. At present, the testing of the mechanical properties of cohesionless soils is usually done through conventional triaxial tests, in which the soil is made into a cylindrical standard triaxial specimen for loading testing. Therefore, making high-quality remodeled cohesion-free soil samples is a prerequisite for this test. [0003] However, since the cohesive soil has no cohesive force and the friction angle is large, the triaxial sample is easy to scatter and tilt after being formed by the traditional sample preparation method, and it is even impossible to make a shape, which is not...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N19/10
Inventor 张芳王伟李娜雷璐璐张旻玉
Owner SHAOXING UNIVERSITY
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