Abstract
Artificial freezing ground method has been widely used in tunnels, metro and other projects, in the connecting passage in metro, the artificial frozen soil wall, which is formed by artificial freezing method, is often used as temporary support. The artificial frozen soil wall is in the joint action of pressure and bending moment, for it takes the upper pressure and lateral earth pressure at same time, so there may be tensile stress in the profile, which may cause brittle failure. At present, some scholars have carried out researches on the tensile strength with different test methods, but they are insufficiency and have a certain difference in stress state between the specimen and the actual support structure. A bending test instrument was designed and manufacture, which satisfies the code’s requirements, and reduces the error caused by poor contact between the specimen and loading device. Bending test on artificially frozen soils was launched using this instrument, and the test on influence law of moisture content and freezing temperature on artificially frozen soils’ strength was also launched. The conclusions can provide a reference for design and construction.
Highlights
In 1955, the artificial freezing method construction technology was first applied to the construction of the Kaixi Linxi ventilating shaft excavation construction project
Ma Qinyong[4] and Zhao Jingfeng[5] refer to the method for determining the tensile strength of rocks, and use the split method and the Brazilian split test to determine the tensile strength of frozen soil, respectively
Based on the uniaxial compression test equipment for frozen soil, this paper designs and manufactures the artificial frozen soil bending test equipment, which can meet the requirements of the bending test and reduce errors caused by poor contact between the test specimen and the loading device
Summary
In 1955, the artificial freezing method construction technology was first applied to the construction of the Kaixi Linxi ventilating shaft excavation construction project. In engineering design and construction, like brittle materials such as rock and concrete, the tensile strength of frozen soil is a very important mechanical indicator. The frozen soil wall is under the joint action of bending, or the lateral bending effect, and the section may have a tensile stress zone For this kind of stress state, it is easy to cause unpredictable brittle damage and cause engineering accidents. Ma Qinyong[4] and Zhao Jingfeng[5] refer to the method for determining the tensile strength of rocks, and use the split method and the Brazilian split test to determine the tensile strength of frozen soil, respectively This method applies linearity along the diameter of the cylindrical sample, the load causes tensile stress failure in the radial direction of the sample, and the tensile strength is analyzed by elastic theory. Using a bending test to determine its bending (that is, bending tensile) strength compared to the uniaxial tensile method and the splitting method to determine its tensile strength more in line with the material's actual stress
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
