摘要
为探究不同含水状态矸石胶结充填体(gangue cemented backfill,简称GCB)能量演化规律及损伤破坏机制,制备了干燥、自然和饱水(含水率分别为0%、10%和25%)3种状态的GCB试样。基于单轴压缩试验获取的应力-应变曲线,分析了GCB试样的能量演化规律,提出了能量强化/弱化系数,揭示了GCB试样的损伤演化机制,并建立了全应力-应变曲线的分段式损伤本构模型。结果表明:干燥与自然状态GCB试样应力-应变曲线表现出明显的“四阶段”特征,而饱水状态GCB试样仅存在“三阶段”特征;GCB试样由干燥到饱水状态,弹性模量和峰值强度呈指数函数递减,含水状态对充填体强度的弱化机制可分为物理效应、化学效应和结构效应;干燥作用对充填体能量有强化作用,对耗散能的强化占主导地位,饱水作用对充填体能量有弱化作用,对弹性应变能和总应变能的弱化占主导地位;GCB试样由干燥向饱水状态的转变过程中,破坏形态主要经历拉伸破坏―拉剪混合破坏―V字形剪切破坏的转变,并伴有块体的脱落;不同含水状态GCB试样的变形破坏均为同一类型的损伤演化过程,但含水率增加会促进充填体损伤的发展,建立的不同含水状态GCB试样的分段损伤本构模型能够较准确地描述GCB试样的受载损伤破坏过程。研究结果可为深入探究矸石胶结充填体的力学行为及稳定性提供理论参考。
To investigate the energy evolution and damage mechanisms of gangue cemented backfill(GCB)with varying water content,we prepared dry,natural,and saturated GCB samples(with water contents of 0%,10%,and 25%,respectively).Using the stress-strain curves obtained from uniaxial compression tests,we analyzed the energy evolution laws of the GCB samples,proposed an energy strengthening/weakening coefficient,revealed the damage evolution mechanisms,and established a segmented damage constitutive model for the total stress-strain curve.The results show that the stress-strain curves of GCB samples in dry and natural states exhibit distinct“four-stage”characteristics,whereas GCB samples in a saturated state display only“three-stage”characteristics.The elastic modulus and peak strength of GCB samples decrease exponentially from the dry to the saturated state.The weakening mechanism of backfill strength due to water content can be categorized into physical,chemical,and structural effects.The drying effect strengthens the energy of the backfill,primarily through the enhancement of dissipated energy.The saturation effect weakens the energy of the backfill,predominantly through the reduction of elastic strain energy and total strain energy.During the transition from dry to saturated state,the failure modes of GCB samples mainly undergoes a transformation from tensile failure,tensile-shear mixed failure and V-shaped shear failure,accompanied by block detachment.The deformation and failure of GCB samples with different water contents follow the same type of damage evolution process.However,increased water content promotes the development of backfill damage.The established segmented damage constitutive model of GCB samples with different water contents accurately describes the load damage and failure processes of GCB samples.The research results can provide theoretical reference for further studies on the mechanical behavior and stability of gangue cemented backfill.
作者
杨科
于祥
何祥
侯永强
张连富
YANG Ke;YU Xiang;HE Xiang;HOU Yong-qiang;ZHANG Lian-fu(School of Mining Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Institute of Energy,Hefei Comprehensive National Science Center,Hefei,Anhui 230031,China)
出处
《岩土力学》
北大核心
2025年第1期26-42,共17页
Rock and Soil Mechanics
基金
国家重点研发计划资助项目(No.2019YFC1904304)
国家自然科学基金重点资助项目(No.52130402)。
关键词
含水状态
矸石胶结充填体
能量演化
分段损伤本构模型
单轴压缩
water content state
gangue cemented backfill
energy evolution
segmented damage constitutive model
uniaxial compression
