Zhejiang Hangwen Railway Company
浙江杭温水平岩层隧道内滞后型岩爆频发,但目前对于其孕育机理和时空倾向性研究不足。故采用有限差分软件,通过地应力测试和统计现场岩爆资料的方法,研究分析滞后型岩爆时空特征机制。结果表明:(1)滞后型岩爆具有明显的时空倾向性特征。近70%的滞后型岩爆时间上发生在该区开挖6～30 d,空间上滞后于掌子面30～100 m之间；且多发生中等岩爆,岩爆等级及可能性随时空变化呈现倒“V”形趋势。(2)硬岩在高地应力环境中具有明显的延性与时效变形特征；在卸荷条件下,应力释放率的逐渐增加是诱发滞后型岩爆的最主要因素。(3)开挖一定距离后,隧道周边不同位置处都出现应变能突变,且保持较高的应变能密度,易发生等级较高的岩爆。上述结果为以后预测滞后型岩爆和施加相应支护措施提供了依据。
Delayed rockburst occurred frequently in HangWen Railway’s horizontal rock tunnel in Zhejiang Province, but there are few studies on its gestation mechanism and space-time tendentiousness. Therefore, taking the time-dependent deformation of tunnel surrounding rock induced delayed rockburst as the core, the characteristics and mechanism of delayed rockburst are studied and analyzed by means of in-situ stress test and statistical field rockburst data. The results show that : (1)Delayed rockburst has obvious time-space tendentiousness characteristics. Nearly 70 % of the delayed rockburst occur in the excavation of 6 ~ 30 days in this area, and lag the palm faces of 30 ~ 100 m in space.The delayed rockburst mostly occurs in medium rockburst, and the rockburst grade and possibility show an inverted 'V ' trend with time and space. (2)Hard rock has obvious ductility and time-dependent deformation characteristics in high in-situ stress environment. Under unloading conditions, the stress releasing rate is the most important factor inducing delayed rockburst.(3)After a certain distance of excavation, strain energy mutations occur at different locations around the tunnel, and a high strain energy density is maintained, which is prone to high-level rock burst.The above results provide a basis for predicting delayed rockburst and applying corresponding supporting measures in the future.
张均清,唐潮,刘宇,等. 高地应力水平岩层隧道滞后型岩爆时空倾向性机制分析[J]. 科学技术与工程, , ():复制