摘要
借助自主设计的由加载控制系统、应变采集系统、电阻同步采集系统以及红外成像系统等组成的多参数、同步监测系统,研究了充填体在单轴压缩过程中的应力-应变、电阻率以及温度变化规律,分析了充填体在破坏失稳应力-应变、电阻率以及热效应异常前兆特征,并对比了不同监测信息对同一事件破坏的敏感度和差异性。结果表明:充填体的电阻率和热红外信息时空演化进程与其压缩变形破坏整个过程基本相符,且具有明显的阶段性;在整个加载破坏过程中,观测到的电阻率前兆信息点要早于热红外前兆点、应力前兆点;与应力-应变、温度变化相比,电阻率变化规律具有明显的反对称性;电阻率变化规律能详细地表现充填体受压过程中每个阶段内部结构变化特征,而热红外信息则主要体现充填体塑性屈服前的表面结构温度演化特性。运用多参数评价充填体加载破坏前兆特征,能克服单纯考虑某一参数变化方法预警可信度低、错误率高的缺点。该方法是一种能全面、精准地掌握采场充填体稳定状态的有效方法。
The stress-strain, resistivity and temperature variations of backfill materials in the whole process of uniaxial compression are studied using a self-designed synchronous monitoring system, which is composed of the loading control system, strain measurement system, the resistivity collection system and the thermal infrared（TIR） observation unit. The precursory anomaly characteristics of the stress-strain, resistivity and TIR are observed before backfill body failure. The sensitivity and difference of different monitoring systems to the same failure event are also compared. The results show that the time-space evolution process of the resistivity and TIR is quite close to the whole process from compression deformation to failure of backfill body, showing apparent staged characteristics. The precursory information point of resistivity occurs prior to the TIR and the stress points. The resistivity variation has an apparently anti-symmetry feature in the process of compression, compared to the stress-strain relation and temperature variation. The variation of resistivity can give a detailed description of the internal structure change at every phase during compression. However, the TIR information mainly represents the surface temperature evolution during the process of compression before plastic yielding of the backfill. The multiparameter methodology used to evaluate the precursory information during loading process can overcome the disadvantages of early-warning approach, say low reliability and inaccuracy. The proposed method is an effective one in determining the stable state of backfill body.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第2期399-406,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51504256)
金属矿山安全与健康国家重点实验室基金资助(No.zdsys006)
国家重点基础研究发展计划(No.2013CB227903)~~
关键词
胶结充填体
压缩破坏
前兆信息
多参数
cemented backfill body
compression failure
precursor information
multiparameter
