水体浸润作用下含原生裂隙岩石剪切性能及破断规律研究

原生裂隙和水体会改变岩石物理力学特性,易诱发地质灾害。因此,水—裂隙作用下岩体失稳破坏行为特征成为当前地下岩土工程领域重要研究内容之一。基于D-P准则提出了不同含水条件下裂隙岩石断裂破坏临界条件,分析了原生裂隙影响下岩石可能存在的新生裂隙发育扩展形态,并对含水红砂岩开展剪切试验。结果表明,在本次试验范围内,含水裂隙岩样与预制原生裂隙以20°角为界呈分段式演化,随裂隙倾角增大,演变趋势由正相关转为负相关,20°时含水裂隙岩样抗剪强度最大;随含水率增大,水体浸润对岩样抗剪性能损伤弱化程度的增量减小,在含水率1.213%之后,随含水率继续增大,对岩样抗剪性能损伤弱化程度由增转降,可知饱和含水对裂隙岩样损伤弱化程度小于非饱和含水。剪切破坏面破坏形态呈现出剪切破坏—剪切破坏主导的拉剪复合破坏—拉剪复合破坏—拉伸破坏主导的拉剪复合破坏的变化趋势。研究结果可对多因素叠加影响下岩石破坏诱发突水事故的研究提供参考。

Damage and fracture behavior and spatio-temporal evolution of acoustic emission of sandstone before and after laser radiation

Laser technology holds significant promise for enhancing rock-breaking efficiency.Experimental investigations were carried out on sandstone subjected to laser radiation,aiming to elucidate its response mechanism to such radiation.The uniaxial compressive strength of sandstone notably decreases by 22.1%–54.7%following exposure to a 750 W laser for 30 s,indicating a substantial weakening effect.Furthermore,the elastic modulus and Poisson ratio of sandstone exhibit an average decrease of 33.7%and 25.9%,respectively.Simultaneously,laser radiation reduces the brittleness of sandstone,increases the dissipated energy proportion,and shifts the failure mode from tensile to tension-shear composite failure.Following laser radiation,both the number and energy of acoustic emission events in the sandstone register a substantial increase,with a more dispersed distribution of these events.In summary,laser radiation induces notable damage to the mechanical properties of sandstone,leading to a substantial decrease in elastic energy storage capacity.Laser rock breaking technology is expected to be applied in hard rock breaking engineering to significantly reduce the difficulty of rock breaking and improve rock breaking efficiency.

数值分析方法在微波辅助破岩中的应用

主要介绍了几种与微波照射岩石相关的数值模拟研究。微波照射加热预处理岩石可改变矿石性质,使岩石强度降低,改善矿物解离能力,提高破岩效率。随着计算机模拟技术的发展及应用,运用数值模拟软件进行微波破岩研究,可以通过改变微波照射时间、功率密度、脉宽、岩石种类等因素,能得到微波照射下裂隙周围应力变化情况及微裂纹的萌生和发展规律,并可更好地分析微波照射下晶体颗粒边界破坏过程,有利于从微观角度揭示微波辅助照射致使岩石损伤破坏机理。