US 12,222,330 B2
Large-scale direct shear apparatus for direct shear test of multi-size cylindrical undisturbed soil samples
Zhibo Chen, Fuzhou (CN); Jinyang Cai, Fuzhou (CN); Hui Yang, Fuzhou (CN); Yongning Xie, Fuzhou (CN); Xuming Zeng, Fuzhou (CN); and Shenggui Pan, Fuzhou (CN)
Assigned to FUZHOU UNIVERSITY, Fuzhou (CN); and EAST CHINA SURVEY AND DESIGN INSTITUTE (FUJIAN) CO., LTD., Fuzhou (CN)
Appl. No. 18/704,944
Filed by FUZHOU UNIVERSITY, Fuzhou (CN); and EAST CHINA SURVEY AND DESIGN INSTITUTE (FUJIAN) CO., LTD., Fuzhou (CN)
PCT Filed Jul. 21, 2022, PCT No. PCT/CN2022/107016
§ 371(c)(1), (2) Date Apr. 26, 2024,
PCT Pub. No. WO2023/071315, PCT Pub. Date May 4, 2023.
Claims priority of application No. 202111277195.0 (CN), filed on Oct. 30, 2021; and application No. 202111277276.0 (CN), filed on Oct. 30, 2021.
Prior Publication US 2024/0418616 A1, Dec. 19, 2024
Int. Cl. G01N 3/24 (2006.01); G01N 3/02 (2006.01); G01N 33/24 (2006.01)
CPC G01N 3/24 (2013.01) [G01N 3/02 (2013.01); G01N 33/24 (2013.01); G01N 2203/0025 (2013.01); G01N 2203/005 (2013.01); G01N 2203/0284 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A large-scale direct shear apparatus for direct shear test of multi-size cylindrical undisturbed soil samples, comprising an external frame, a sample shear box, a horizontal loading device, a vertical loading device, and a control system, wherein the sample shear box is disposed in a middle of the external frame, and the sample shear box comprises upper and lower shear boxes and a cylindrical shear box, both the upper and lower shear boxes are provided with circular through-holes in the middle, and the cylindrical shear box is disposed in a middle of the upper and lower shear boxes and pass through the upper and lower shear boxes, the horizontal loading device comprises a horizontal drive motor equipped with a horizontal load sensor, a horizontal mechanical loading mechanism, and an upper shear box connecting structure, the horizontal drive motor is installed on an inner wall of a first side of the external frame, a first end of the horizontal mechanical loading mechanism is connected to an output end of the horizontal drive motor, and a second end of the horizontal mechanical loading mechanism is in contact with a side of the lower shear box, a first end of the upper shear box connecting structure is fixed to an inner wall of a second side of the external frame, and a second end of the upper shear box connecting structure is in contact with the upper shear box to apply shear force to the sample in the sample shear box, the vertical loading device comprises a vertical drive motor equipped with a vertical load sensor and a vertical mechanical loading mechanism, the vertical drive motor is installed on a lower side wall of a top of the external frame, an upper end of the vertical mechanical loading mechanism is connected to an output end of the vertical drive motor, and a lower end faces the sample in the sample shear box to apply vertical pressure to the sample, the control system is electrically connected to the horizontal load sensor, the horizontal drive motor, the vertical load sensor, and the vertical drive motor to collect loaded load data and control output loading pressure and shear rate, the direct shear apparatus is applied to indoor direct shear test of multi-size cylindrical undisturbed soil samples and direct shear test of cylindrical remolded soil samples of the same size;
wherein the sample shear box is placed on a base, and a bottom of the base is provided with a slide rail cooperating with the sample shear box, wherein the sample shear box is allowed to slide along the slide rail to a test station for direct shear test after the sample is installed;
wherein the control system comprises:
a data acquisition module for automatically collecting test data according to a set time interval required for the test;
a standard consolidation module for applying a set axial pressure to the sample for sample consolidation;
a standard shear module for setting shear rate, shear displacement, time interval, and test termination conditions, and controlling the horizontal and vertical drive motors to operate for the direct shear test;
a quick shear module for setting normal stress, shear rate, shear displacement, time interval, and test termination conditions, and controlling the horizontal and vertical drive motors to operate for quick shear test;
a cyclic shear module for setting a number of cycles, shear rate, shear displacement, time interval, and test termination conditions, and controlling the horizontal and vertical drive motors to operate for cyclic direct shear test; and
a rheological shear module for setting normal stress, horizontal stress, time interval, and test termination conditions, and controlling the horizontal and vertical drive motors to operate for rheological shear test;
wherein the sample shear box comprises an upper shear box square solid frame and a lower shear box square solid frame stacked together, middle parts of the upper and lower shear box square solid frames are both provided with circular through-holes, and circular annular adapter sleeves of different sizes are nested in the circular through-holes of the upper and lower shear box square solid frames from large to small, the sample shear box is equipped with a plurality of cylindrical shear boxes of different sizes, the plurality of cylindrical shear boxes of different sizes are compatible with diameters of the circular through-holes or different circular annular adapter sleeves to accommodate different sample sizes, the plurality of cylindrical shear boxes are disposed in the middle parts of the upper and lower shear box square solid frames and penetrate through the upper and lower shear box square solid frames; and guide connecting blocks are provided on both sides of the upper and lower shear box square solid frames to prevent lateral movement of the cylindrical shear box during the test and ensure that the cylindrical shear box moves along a shear direction.