基于能量耗散与释放的充填体失稳尖点突变预警模型

A cusp catastrophe warning model for instability of backfill based on energy dissipation and release

在充填体失稳预警研究中,以声发射前兆特征作为材料失稳预警标志已得到众多学者的一致肯定。然而,声发射前兆特征具有多种形式,这对充填体的失稳预警有一定的影响。基于此,建立了一种形式固定的充填体失稳预警模型。首先,以能量演化特征为切入点,基于尖点突变理论构建了充填体失稳预警模型,随后针对不同灰砂比充填体开展单轴压缩声发射验证试验。试验结果表明,耗散能突变与可释放弹性应变能突变所构成的区间可描述充填体的预警状态,将其定义为预警区间。不同灰砂比充填体预警区间唯一,模型具有较好的灵活性及普适性。以振铃计数率等认可度高的声发射特征参数的前兆特征对得出的预警区间的合理性进行验证,验证结果表明,根据模型求出的预警区间与声发射参数的前兆特征所处时间高度一致,进一步验证了该方法的合理性及普适性,可为充填体的失稳预警研究提供一种新的思路。

In the study of early warning of backfill instability,the acoustic emission precursory characteristics have been recognized by many scholars.However,there are many forms of acoustic emission precursory characteristics,which have certain influence on the early warning of the backfill instability.Based on this,this paper attempts to establish a fixed form of early warning model of the backfill instability.First of all,based on the energy evolution characteristics and cusp catastrophe theory,an early warning model of backfill instability is constructed,and then the uniaxial compression acoustic emission verification test is carried out for backfill with different ash sand ratios.Experimental results show that the early warning state of backfill can be described by the interval composed of the catastrophe of dissipative energy and the catastrophe of releasable elastic strain energy,and the interval is defined as early warning interval.Moreover,the early warning intervals of backfill with different cement-sand ratios are unique,implying the model is extremely flexible and universal.The precursory characteristics of acoustic emission characteristic parameters with high recognition such as ringing counting rate are employed to verify the reasonableness of the early warning interval.It is found that the early warning interval calculated from the model is highly consistent with the time of the precursory characteristics of acoustic emission parameters,further proving the rationality and universality of this model and providing a new idea for the early warning of instability of backfill.