doi:10.16186/j.cnki.1673-9787.2020070038

Received:2020/07/10

Revised:2020/09/03

Published:2022/05/15

Research on cumulative dynamic deformation characteristics of compacted silty sand under different initial static shear stresses

YANG Liguo1,2, SHAO Shengjun1

1.Institute of Geotechnical Engineering， Xi’ an University of Technology， Xi ’an 710048 ， Shaanxi， China;2.Department of Civil and Traffic Engineering， Yellow River Conservancy Technical Institute， Kaifeng  475003 ， Henan， China

Abstract: In order to study the effect of initial static shear stress on the dynamic deformation and damping ratio of compacted silty sand,a series of cyclic dynamic shear tests of total 5 000 cycles were carried out by using a hollow cylindrical torsion shear apparatus. The results showed that:(1) When the small dynamic shear stress acted , the small initial static shear stress could tighten the soil and reduce the axial cumulative dynamic deformation. However, under the action of large dynamic shear stress,the existence of initial static shear stress could aggravate the development of axial cumulative deformation.(2) In the initial stage of cyclic loading , the inclination of the hysteresis loop increased sharply with the number of vibrations, and the area of the hysteresis loop decreased sharply. However, with the number of vibrations increasing,the hysteretic curves of different initial static shear stresses gradually tended to coincide. (3) The initial static shear stress had little effect on the damping ratio of the compacted silty sand, which gradually decreased to the same level with the increase of vibration times. The research results could provide references for controlling the initial static shear stress and reasonably determining the damping ratio in the design of foundation or subgrade which was easily affected by large dynamic stress for a long time.

Key words:initial static shear stress;silty sand;cumulative dynamic deformation;hysteresis loop;damping ratio

不同初始静剪应力下压实粉砂土动变形特性研究_杨利国.pdf