Quantitative study of unlocking mechanisms of rock mass containing a locking section: insights from DIC and IR techniques

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics Pub Date : 2025-08-13 DOI:10.1016/j.tafmec.2025.105172

Xianghua Liu , Ke Zhang , Kai Zhang , Rencai Lin , Wenhuan Li

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引用次数: 0

Abstract

To study the unlocking mechanisms of the rock mass containing a locking section, sandstone specimens with two edge flaws are prepared and subjected to uniaxial compression tests, considering flaw inclinations of 30°, 45°, and 60°. The whole failure process of these specimens is monitored by the digital image correlation (DIC) method and infrared radiation (IR) technique. The flaw inclination exerts a substantial influence on the mechanical properties and failure pattern. The step-path failure is found in the case of α = 30°, while the retaining-wall failure is observed in the case of α = 45° and 60°. The relative displacement extraction, extended from the DIC, is applied to identify and quantitatively analyze the cracking behavior. Based on the relative displacement across the flaw, the locking effect is found to be weaker in the specimens with α = 30° than in those with α = 45° and 60°. According to the relative displacement within the locking section, two unlocking modes are identified: slow unlocking, characterized by a stable development in the relative displacement, and rapid unlocking, characterized by a stable and then exponential change in the relative displacement. By the IR monitoring, the thermal anomaly points are uniformly distributed in the specimens with α = 30° but progressively concentrated toward the failure planes in the specimens with α = 45° and 60°. The spatiotemporal characteristics of IR temperature fields are quantified by the discrete statistical method and the novel spatial distribution statistical method, standard deviational ellipse (SDE). The quantitative indicators, including standard deviation, skewness, and SDE parameters, exhibit stable development in the specimens with α = 30° but pronounced stagewise development and significant variability in the specimens with α = 45° and 60°.

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含锁段岩体解锁机制的定量研究：DIC和IR技术的见解

为了研究含锁段岩体的解锁机理，制备了具有两个边缘缺陷的砂岩试件，分别考虑缺陷倾角为30°、45°和60°，进行了单轴压缩试验。采用数字图像相关（DIC）方法和红外辐射（IR）技术对试件的破坏全过程进行了监测。缺陷倾斜度对材料的力学性能和破坏形态有较大的影响。当α = 30°时出现阶梯破坏，当α = 45°和60°时出现挡土墙破坏。应用从DIC扩展而来的相对位移提取方法对裂纹行为进行识别和定量分析。通过相对位移分析，发现当α = 30°时，锁紧效应弱于当α = 45°和60°时的锁紧效应。根据锁定段内的相对位移，确定了两种解锁模式：缓慢解锁和快速解锁，前者的特征是相对位移稳定发展，后者的特征是相对位移先是稳定而后呈指数变化。红外监测发现，热异常点在α = 30°试样中分布均匀，在α = 45°和60°试样中逐渐向破坏面集中。采用离散统计方法和标准偏差椭圆（SDE）空间分布统计方法量化了红外温度场的时空特征。标准差、偏度、SDE等定量指标在α = 30°时表现为稳定发展，在α = 45°和60°时表现为明显的阶段性发展和显著的变异性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Theoretical and Applied Fracture Mechanics 工程技术-工程：机械

CiteScore

8.40

自引率

18.90%

发文量

435

审稿时长

37 days

期刊介绍： Theoretical and Applied Fracture Mechanics'' aims & scopes have been re-designed to cover both the theoretical, applied, and numerical aspects associated with those cracking related phenomena taking place, at a micro-, meso-, and macroscopic level, in materials/components/structures of any kind. The journal aims to cover the cracking/mechanical behaviour of materials/components/structures in those situations involving both time-independent and time-dependent system of external forces/moments (such as, for instance, quasi-static, impulsive, impact, blasting, creep, contact, and fatigue loading). Since, under the above circumstances, the mechanical behaviour of cracked materials/components/structures is also affected by the environmental conditions, the journal would consider also those theoretical/experimental research works investigating the effect of external variables such as, for instance, the effect of corrosive environments as well as of high/low-temperature.