关键词: 砂土, 蠕变, 微观结构, 级配, 地面沉降

Abstract: The sand layers exhibit the characteristics of creep to some degree during the land subsidence. In this paper, we studied the
characteristics of sand deformation, using one-dimensional compression test under the condition of 4 MPa and extracted the
microstructure of sand by improving the test device. Through analyzing the creep characteristics and microstructures of 8 sand samples,
the following conclusions are obtained: sands with a single size have higher possibility to lead to sudden deformations and sands broken
which cause the slippage and position change of sands; The characteristics of deformation of sands are closely related to the grading of
sands which have higher possibility to cause more deformations and sudden changes when the sands size is large; Using the formal
factor of sands from micro-perspective to analyze the sands particles, we found that the smaller the formal factor of sands is, the higher
possibility of broken and the larger deformations of sands are.

Key words: sands, creep, microstructure, grading, land subsidence