Characterization of permanent deformation of fine-grained subgrade soil under intermittent loading. Issue 139 (December 2020)

• Record Type: Journal Article
• Authors: Nie, Rusong; Mei, Huihao; Leng, Wuming; Ruan, Bo; Li, Yafeng; Chen, Xixi
• Is Part Of: Soil dynamics and earthquake engineering. Issue 139(2020)
• Publication Date: 2020-12
• Subjects: Permanent deformation -- Repeated load triaxial test -- Intermittent loading -- Pore water pressure -- Accumulated plastic strain -- Shakedown concept; Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2020.106395
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: Understanding the permanent deformation characteristics of subgrade soils under traffic loads can provide a basis for subgrade design and evaluation. During repeated load triaxial (RLT) tests, accurate simulation of traffic loads is critical. RLT tests on silt under continuous loading and intermittent loading (cycles of continuous loading and intermittent stage) were performed using an RLT apparatus. The effects of the intermittent stage on the development of axial strain, pore water pressure and accumulated plastic strain were analyzed, and the dynamic behaviors of accumulated plastic strain under intermittent loading were also studied. The results show that the existence of the intermittent stage plays an active role in dissipating pore water pressure and improving the ability of the specimen to resist permanent deformation. Based on shakedown concept, an expression of critical stress and a prediction model for the accumulated plastic strain of silt under intermittent loading were proposed. The research results provide reference values for understanding the permanent deformation characteristics of silt. Highlights: The ε p ~ N curves present three categories: stable, critical and destructive. The equations of plastic shakedown and plastic creep limits reflecting the effect of S r was proposed. A prediction model of accumulated plastic strain with the number of load cycles for plastic creep behaviour was established.