Chen Lei, Han Jinchi, Zhang Shuguang, Jin Jiaxu, Jia Baoxin, Liu Jiashun, Tang Jupeng
Ordos Institute of Liaoning Technical University, Ordos, 017004, China.
School of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China.
Sci Rep. 2025 Apr 1;15(1):11084. doi: 10.1038/s41598-025-96352-5.
Rock creep is essentially a process of damage accumulation. According to the damage evolution of rock under creep conditions, the TAW2000 triaxial test system is used to carry out triaxial creep test on red layer soft rock taken from Yibo Tunnel in Leshan, Sichuan Province, China, and analyzed the creep deformation rule under different confining pressures. Meanwhile, based on the Nishihara model and Weibull distribution function and Perzyna viscoplastic theory, an improved viscoelastic-plastic creep model which can describe the whole process of rock creep failure was established. The critical point damage variable is defined by dividing the creep stage, so that the acceleration creep start time can be determined more accurately. The results show that: (1) The model curves in this paper fit well with the test data, indicating that Weibull distribution function is feasible to describe rock creep damage, and the accuracy and rationality of the model in this paper are verified. (2) Based on Perzyna viscoplastic theory, a more accurate viscoplastic strain expression was established to describe accelerated creep. (3) By defining the critical point damage variables of different creep stages, the relationship between rock creep deformation and damage can be better reflected, which makes up the shortcoming that Nishihara model cannot describe accelerated creep, and enriches the creep constitutive theory of rock materials.
岩石蠕变本质上是一个损伤累积的过程。依据岩石在蠕变条件下的损伤演化，利用TAW2000三轴试验系统对取自中国四川省乐山市宜柏隧道的红层软岩进行三轴蠕变试验，并分析了不同围压下的蠕变变形规律。同时，基于西原模型、威布尔分布函数和佩尔兹纳粘塑性理论，建立了一个能够描述岩石蠕变破坏全过程的改进粘弹塑性蠕变模型。通过划分蠕变阶段定义临界点损伤变量，从而能够更准确地确定加速蠕变起始时间。结果表明：(1) 本文的模型曲线与试验数据拟合良好，表明威布尔分布函数用于描述岩石蠕变损伤是可行的，验证了本文模型的准确性和合理性。(2) 基于佩尔兹纳粘塑性理论，建立了更准确的粘塑性应变表达式来描述加速蠕变。(3) 通过定义不同蠕变阶段的临界点损伤变量，能够更好地反映岩石蠕变变形与损伤之间的关系，弥补了西原模型不能描述加速蠕变的不足，丰富了岩石材料的蠕变本构理论。
