Unsaturated soil direct-shear test device with function of controlling suction by negative pore water pressure

A test device and negative pore technology, applied in the direction of testing the strength of materials by applying stable shear force, can solve the problem that the structure of direct shear instrument is complex, it is difficult to truly reflect the suction state of natural unsaturated soil, and increase the airtightness of pressure chamber To achieve the effect of avoiding the airtightness of the pressure chamber, simple structure and simple structure of the instrument
CN103234840BInactive Publication Date: 2015-01-07SHANGHAI UNIV
7 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
SHANGHAI UNIV
Publication Date
2015-01-07
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses an unsaturated soil direct-shear test device with a function of controlling the suction by the negative pore water pressure. The unsaturated soil direct-shear test device comprises a direct-shear apparatus, a soil body water content change measurement system, and a positive and negative pressure conversion system, wherein the soil body water content change measurement system is composed of a dryer, a water container and a weight sensor; the positive and negative pressure conversion system is composed of a positive pressure control meter, a negative pressure control meter, a pressure converter and an air compressor; the loading system comprises a vertical load loading system and a horizontal load loading system; and the bottom surface of a lower shear box and the upper surface of a base oppositely slide in parallel through a sliding pair. By using the unsaturated soil direct-shear test device disclosed by the invention, a natural state of an unsaturated soil body is really reproduced when the suction is controlled; the effect of the suction of unsaturated soil on the shearing strength can be accurately tested; and meanwhile, the structure of the common unsaturated soil direct-shear apparatus at present is simplified. The unsaturated soil direct-shear test device disclosed by the invention is simple in structure, convenient to operate and easy to grasp.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a civil engineering geotechnical test device, in particular to a test device for the influence of the suction change of unsaturated soil on its strength, which is applied to the geotechnical test of geotechnical engineering. Background technique

[0002] Most of the earth's surface is in an arid or semi-arid zone, so most of the soil encountered in geotechnical engineering is in an unsaturated state, such as sandy soil, silt, collapsible loess, expansive soil, tropical residual soil, etc. Soil, it is very necessary to study the properties of unsaturated soil. In particular, sandy soil and silt soil have larger permeability coefficients and are more easily affected by rainfall or atmospheric evaporation. The surface layer of natural slopes and artificial slopes is mostly unsaturated sandy soil and silt soil. During the rainfall process, rainwater seeps into the soil and the groundwater level rises, which increases the saturatio...

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