Journal of Changjiang River Scientific Research Institute ›› 2025, Vol. 42 ›› Issue (1): 177-185.DOI: 10.11988/ckyyb.20231018

• Rock-Soil Engineering • Previous Articles     Next Articles

Mechanical Characteristics and Damage Constitutive Model of Quartzite under Freeze-thaw Cycles

HOU Zhao-xu1,2(), LIU Xian-feng1,2,3(), WANG Tong1,2, ZHANG Jun1,2, YUAN Sheng-yang1,2, HU Jin-shan4   

  1. 1 School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
    2 Key Laboratory of High-Speed Railway Engineering of Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China
    3 School of Civil Engineering, Xinjiang Institute of Engineering, Urumqi 830023, China
    4 China Railway First Survey and Design Institute Group Co., Ltd., Xi’an 710043, China
  • Received:2023-09-18 Revised:2024-01-09 Published:2025-01-01 Online:2025-01-01
  • Contact: LIU Xian-feng

Abstract:

There are a large number of rock slopes in the difficult and dangerous mountainous areas of southwest China. Long-term freeze-thaw action deteriorates the mechanical properties of the rock mass, leading to decreased slope stability. To study the damage degradation law of rock mass under freeze-thaw action, uniaxial compression tests were conducted on low-porosity quartzite from a high and steep slope in the southwest hazardous mountainous area. The mechanical deterioration and energy evolution were analyzed. Based on the energy evolution law, a method for determining the complete compaction point of rock was proposed. A piecewise damage constitutive model of the rock in consideration of the compaction section was established by taking the complete compaction point as the piecewise point. Results show that early freeze-thaw cycles have little effect on the quartzite. However, when the number of freeze-thaw cycles exceeds 40, the mechanical properties of quartzite deteriorate significantly, and the failure mode gradually changes from shear failure to a combination of tensile and shear failure. The point corresponding to an elastic energy consumption ratio K (ratio of dissipated energy to elastic energy) of 1.2 is determined as the complete compaction point. The strain corresponding to the complete compaction point increases linearly with the increase in freeze-thaw cycles. The proposed piecewise damage constitutive model matches well with experimental data and more accurately describes the deformation and failure characteristics of freeze-thaw damaged quartzite.

Key words: freeze-thaw cycles, quartzite, mechanical degradation, energy evolution, complete compaction point, piecewise damage constitutive model

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