采动覆岩变形多场光纤神经感知与安全保障体系构建研究

地下煤层开采引起煤层上覆岩体的变形、破坏与垮落,若采动覆岩变形破坏监测预警和应急处置不当,往往会导致工作面发生冒顶、突水、瓦斯突出和冲击地压等开采灾害事故。为保障开采工作面的本质安全,需要对煤层采动覆岩变形进行全实时动态感知与全过程智能预警。大量的现场监测试验研究结果表明,煤层上覆岩土体的变形破坏存在不连续和非线性变化特点,因此,如何突破覆岩变形的时空不连续观测瓶颈,实时准确地获取煤层上覆岩土体的多场数据,已成为采动覆岩变形破坏机理研究的关键一环。基于分布式光纤感测技术,对煤层采动过程上覆岩土体的变形场、温度场、渗流场和地电场进行了系统性研究,详细介绍了各物理场的作用机理、观测技术、研究现状以及发展趋势,并分析了基于DAS技术的矿山工程微震研究方向,以期为实现矿山地下空间的“透明化”探测提供理论支撑;通过构建井上井下一体化协同的光纤感知神经网络,建立一套集感知–传输–处理–预警–决策–应急于一体的煤层采动覆岩安全保障体系,该体系由实时感知、可靠传输、智能处理、即时预警和应急决策五大模块构成,可实现采动覆岩变形破坏全过程的动态感知和多场实时数据的关联分析与评价,进而为保障煤层开采全周期安全提供技术支撑,研究成果同时可为开采矿区范围内的地质环境监测评价与修复治理提供参考依据。

Distributed Discrimination of Strain and Temperature Based on Brillouin Dynamic Grating in an Optical Fiber

This paper reviews distributed discrimination of strain and temperature by use of an optical fiber based on fiber optic nerve systems. The preliminary method based on multiple resonance peaks of the Brillouin gain spectrum in a specially-designed fiber is firstly introduced. The complete discrimination of strain and temperature based on the Brillouin dynamic grating in a polarization maintaining fiber is extensively presented. The basic principle and two experimental schemes of distributed discrimination based on fiber optic nerve systems are demonstrated. The performance of the high discriminative accuracy （0.1 ~C-0.3 ~C and 5 kte-12~te） and high spatial resolution （-10 cm） with the effective measurement points of about 50 for a standard system configuration or about 1000 for a modified one will be highly expected in real industry applications.