Expansive soil direct shear test device and shear strength measurement method

A test device and shear strength technology, applied in the direction of applying stable shear force to test material strength, measurement device, strength characteristics, etc., can solve the impact of expansive soil effective stress shear strength index, dry density dry density change, etc. question

Active Publication Date: 2019-06-28
CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
View PDF9 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The prior art adopts the above-mentioned loading device, structure and method, which has the following defects: due to the use of loading plates and permeable stones with the same size and area to apply different overlying loads to the sample before immersion, at this time, the s...

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Expansive soil direct shear test device and shear strength measurement method
  • Expansive soil direct shear test device and shear strength measurement method
  • Expansive soil direct shear test device and shear strength measurement method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0068] See attached figure 1 a. An expansive soil direct shear test device of the present invention includes a strain-type direct shear apparatus and a loading plate 4, and the loading plate 4 is provided with a limit structure. When the sample is placed in the shear box 1 of the strain-type direct shear apparatus Before soaking in water, when the loading plate 4 is installed on the shear box 1 of the strain-type direct shear apparatus, the limit structure controls the bottom surface of the loading plate 4 to achieve gapless contact with the sample 3, but no load is applied to the sample;

[0069] The loading plate 4 is composed of a lower cylinder and an upper cover. The diameter of the upper cover is larger than that of the lower cylinder. A positioning boss is formed between the cylinder of the lower cylinder and the bottom surface of the upper cover to make the horizontal The cross-section is in a "T"-shaped structure; the diameter of the lower cylinder of the loading plate i...

Embodiment 2

[0072] Samples of undisturbed expansive soil and disturbed soil were collected at the site of Baise Expressway in Guangxi, and basic physical properties and engineering properties were tested. The indoor test results show that the plasticity index of the expansive soil samples of Baise Expressway is 33.5% and the free expansion rate is 63%. According to the current expansive soil classification standards for highways, the soil samples taken are medium expansive soils. Using the expansive soil direct shear test device and shear strength test method of the present invention, sample preparation and direct shear test are performed on Guangxi expansive soil. The specific implementation steps are as follows:

[0073] According to the initial dry density is 1.40g / cm 3 , Saturation 85%, 75%, 60%, 55%, 50% configure five soil samples with different moisture content. The compacted test piece was prepared by the method of static pressure sample preparation to ensure that the top surface of...

Embodiment 3

[0078] Samples of undisturbed expansive soil and disturbed soil were collected at the site of Baise Expressway in Guangxi, and basic physical properties and engineering properties were tested. The indoor test results show that the plasticity index of the expansive soil samples of Baise Expressway is 33.5% and the free expansion rate is 63%. According to the current expansive soil classification standards for highways, the soil samples taken are medium expansive soils. Using the expansive soil direct shear test device and shear strength test method of the present invention, sample preparation and direct shear test are performed on Guangxi expansive soil. The specific implementation steps are as follows:

[0079] According to the initial dry density is 1.60g / cm 3 , Configure the ring cutter soil sample with saturation of 95%, 90%, 85%, 80%, 75%. The disturbed soil test piece was prepared by static pressure sample preparation method to ensure that the surface of the test piece was ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Outer diameteraaaaaaaaaa
Outer diameteraaaaaaaaaa
Heightaaaaaaaaaa
Login to view more

Abstract

The invention provides an expansive soil direct shear test device and a shear strength measurement method. The device comprises a strain type direct shear instrument and a loading plate, wherein the loading plate is provided with a limiting structure and a pressure sensor; a larger overlying load is applied before a sample is soaked in water, the limiting structure controls the bottom surface of the loading plate to be contacted with the top surface of porous stone at the upper part of the sample, and the sample is not affected by the overlying load. The measurement method comprises steps as follows: static-pressure sample preparation is carried out according to geotechnical test rules of roads, the sample is soaked in water in constant volume, vertical expansive force is measured, a direct shear test is performed with the vertical expansive force as the overlying load, and effective cohesion and effective internal friction angle of experimental expansive soil are obtained. The test device and the method have the advantages of being simple, convenient to operate, reasonable in structure and economical and guarantee consistent micro-structure before sample shear under the action ofdifferent overlying loads in the direct shear test, so that the problem that shear strength parameters of expansive soil cannot be accurately obtained for a long time in the field is solved, and accurate design parameters are provided for civil engineering structure design of the expansive soil.

Description

Technical field [0001] The invention discloses a direct shear test device and a method for measuring the shear strength of expansive soil; it belongs to the technical field of geotechnical test measurement. Background technique [0002] Expansive soil spreads to more than 40 countries on six continents in the world. China is one of the countries with the most extensive distribution of expansive soil. This special soil exists in 26 provinces, autonomous regions, and municipalities directly under the Central Government. Compared with ordinary clay, expansive soil is rich in montmorillonite And its mixed layer minerals, when the moisture content increases and accepts a small constraint, it will produce expansion deformation and a sharp decline in strength; and when its swelling is subject to certain constraints, it will produce non-negligible expansion of the surrounding soil and structures Additional stress. Therefore, expansive soil excavation and filling slopes in highways, rail...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N3/24G01N3/02
Inventor 张锐赵旭郑健龙蔡树生兰天龙明旭
Owner CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap