Abstract
The mechanical properties of loess-steel interface are of great significance for understanding the residual strength and deformation of loess. However, the undisturbed loess has significant structural properties, while the remolded loess has weak structural properties. There are few reports on the mechanical properties of loess-steel interface from the structural point of view. This paper focused on the ring shear test between undisturbed loess as well as its remolded loess and steel interface under the same physical mechanics and test conditions (water content, shear rate and vertical pressure), and explored the influence mechanism of structure on the mechanical deformation characteristics of steel-loess interface. The results show that the shear rate has little effect on the residual strength of the undisturbed and remolded loess-steel interface. However, the water content has a significant influence on the residual strength of the loess-steel interface, moreover, the residual internal friction angle is the dominant factor supporting the residual strength of the loess-steel interface. In general, the residual strength of the undisturbed loess-steel interface is greater than that of the remolded loess specimen (for example, the maximum percentage of residual strength difference between undisturbed and remolded loess specimens under the same moisture content is 6.8%), which is because that compared with the mosaic arrangement structure of the remolded loess, the overhead arrangement structure of the undisturbed loess skeleton particles makes the loess particles on the loess-steel interface re-adjust the arrangement direction earlier and reach a stable speed relatively faster. The loess particles with angular angles in the undisturbed loess make the residual internal friction between the particles greater than the smoother particles of the remolded loess (for example, the maximum percentage of residual cohesion difference between undisturbed and remolded loess specimens under the same vertical pressure is 4.29%), and the intact cement between undisturbed loess particles brings stronger cohesion than the remolded loess particles with destroyed cement (for example, the maximum difference percentage of residual cohesion between undisturbed and remolded soil specimens under the same vertical pressure is 33.80%). The test results provide experimental basis for further revealing the influence mechanism of structure, and parameter basis for similar engineering construction.
Highlights
640,000 square kilometers of loess are distributed in China, which is the most representative regional special soil in China
The undisturbed loess interface shear specimen is pressed into the loess vertically by the ring knife until the ring knife cylinder is filled with loess specimen
The dry density and water content of the remolded loess specimen are controlled to be the same as those of the undisturbed loess specimen, and the remolded loess specimen is compacted by the remolded loess specimen preparation
Summary
640,000 square kilometers of loess are distributed in China, which is the most representative regional special soil in China. Results suggested that the structure had an important influence on the mechanical deformation properties of loess [13, 14]. The structure of undisturbed loess has a great influence on its mechanical characteristics in the process of extrusion and shear. After the destruction of undisturbed soil, its mechanical characteristics transit to those of remolded soil, that is, the structure is gradually lost. The structural reduction or disappearance of the undisturbed loess is a manifestation of the transition from the mechanical properties of the undisturbed loess to the remolded loess soil. During the construction of pile foundation and the exertion of bearing capacity, the structure of undisturbed soil around pile will affect the mechanical effect of pile-soil interface. It is necessary to study the influence of structure on the mechanical characteristics of soil-steel interface
Sign-in/Register to view highlights & summary 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.
