Feng Jihao, Shi Hao, Rong Chuanxin, Song Lei, Long Wei, Liu Jianpeng, Wei Di, An Gangjian
School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, 232001, People's Republic of China.
State Key Laboratory for Geomechanics & Deep Underground Engineering, School of Mechanics & Civil Engineering, China University of Mining and Technology, Xuzhou, 221116, People's Republic of China.
Sci Rep. 2025 Jan 13;15(1):1873. doi: 10.1038/s41598-025-85839-w.
Research investigating the complex mechanical properties and energy evolution mechanisms of frozen calcareous clay under the influence of multiple factors is crucial for optimizing the artificial ground freezing method in shaft sinking, thereby enhancing construction quality and safety. In this study, a four-factor, four-level orthogonal test was devised, taking into account temperature, confining pressure, dry density, and water content. The complex nonlinear curvilinear relationship between deviatoric stress, volume strain, and axial strain of frozen calcareous clay under different interaction levels was analyzed. The sensitivity of each factor to the peak volume strain was explored, and the energy evolution mechanism of frozen calcareous clay during the triaxial compression process was analyzed. The findings are summarized as follows: (1) The deviatoric stress-axial strain curves demonstrate the strain-hardening characteristics of frozen calcareous clay specimens. Furthermore, as temperature decreases, the hardening degree increases. (2) Sensitivity analysis indicates that the factors' influence on peak volumetric strain ranks as follows: dry density > confining pressure > temperature > water content. Under the various interactions, specimens exhibit significant volumetric shrinkage. When the temperature remains constant, peak volumetric strain is negatively correlated with dry density but positively correlated with confining pressure. (3) Input energy density, elastic strain energy density, and dissipated energy density of frozen calcareous clay all increase with axial strain. (4) When temperature is held constant, both peak input energy density and peak dissipated energy density rise with increasing confining pressure. Meanwhile, peak elastic strain energy density shows a linear increase with higher confining pressure and lower temperatures.
研究多因素影响下冻结钙质黏土的复杂力学特性及能量演化机制，对于优化立井施工中的人工地层冻结法、提高施工质量与安全至关重要。本研究设计了一个四因素、四水平的正交试验，考虑了温度、围压、干密度和含水量。分析了不同交互水平下冻结钙质黏土的偏应力、体积应变和轴向应变之间复杂的非线性曲线关系。探讨了各因素对峰值体积应变的敏感性，并分析了冻结钙质黏土在三轴压缩过程中的能量演化机制。研究结果总结如下：(1) 偏应力-轴向应变曲线表明冻结钙质黏土试样具有应变硬化特性。此外，随着温度降低，硬化程度增加。(2) 敏感性分析表明，各因素对峰值体积应变的影响排序为：干密度＞围压＞温度＞含水量。在各种交互作用下，试样表现出明显的体积收缩。当温度保持恒定时，峰值体积应变与干密度呈负相关，与围压呈正相关。(3) 冻结钙质黏土的输入能量密度、弹性应变能密度和耗散能量密度均随轴向应变增加。(4) 当温度保持恒定时，峰值输入能量密度和峰值耗散能量密度均随围压增加而升高。同时，峰值弹性应变能密度在较高围压和较低温度下呈线性增加。
