TBM破岩震源超前探测不良地质实时精确成像和岩体质量动态评价理论研究

Major disasters, such as water inrush, mud burst, collapse, TBM blockage and even machine crash, often occur in the tunnel constructed using TBM. The main reason is that the TBM environment is extremely complex and effective theories and methods used for unfavorable geology real-time advanced detection in the tunnel constructed by TBM are still lacking both at home and abroad. To solve this problem, seismic exploration of TBM rock-breaking source were studied, the predictive idea of revealing the propagation characteristics by forward viscoelastic media, characterizing the geological structure by inverse time migration, and multi-parameter comprehensive evaluation of rock mass quality has been formed. Firstly, the wave field characteristics and propagation law of TBM rock breaking under the condition of viscoelastic medium will be revealed, and we will study the high-precision data processing method of TBM rock breaking source, and then, break through the problem of equivalent source wavelet estimation after reconstruction of complex signal of TBM rock fragmentation source, propose the multi-scale variable grid least squares inverse time migration method and break through the frequency domain full waveform inversion theory and method based on reconstructed seismic records, and rock mass quality of multi-parameter comprehensive evaluation which are characterized by indoor test and machine learning method method will be established. Through the research of this project, we intend to solve the problem of low accuracy of advanced exploration of TBM rock-breaking source and the inability to evaluate the quality of rock masses, and achieve accurate prediction of adverse geology and rock mass quality within 100m in front of the tunneling face, and provide scientific and effective theoretical guidance and technical support for safe and effective TBM excavation.

TBM施工隧道经常发生突水突泥、塌方及卡机甚至机毁人亡等重大灾害事故，其主要原因是TBM环境极为复杂，国内外尚没有适合TBM隧道的不良地质实时超前探测与岩体质量动态评价理论与方法。针对该难题，深入研究TBM破岩震源超前探测方法，形成“粘弹性介质正演揭示传播特征、逆时偏移精确刻画地质构造、多参数综合评价岩体质量”的研究思路。首先揭示粘弹性介质下TBM破岩震源波场特征及传播规律，研究TBM破岩震源高精度数据处理方法，突破TBM破岩震源复杂信号重构后等效震源子波估计难题，提出基于多尺度可变网格的最小二乘逆时偏移方法，突破基于重构地震记录的频率域全波形反演理论与方法，以室内试验和机器学习方法为特色，建立岩体质量多参数综合评价方法。通过本项目研究，拟解决TBM破岩震源超前探测准确度低、无法评价岩体质量的难题，实现掘进面前方100m范围内不良地质及其岩体质量的较准确预报，为TBM安全高效掘进提供指导。

TBM施工隧道经常发生突水突泥、塌方及卡机甚至机毁人亡等重大灾害事故，其主要原因是TBM环境极为复杂，国内外尚没有适合TBM隧道的不良地质实时超前探测与岩体质量动态评价理论与方法。针对该难题，深入研究TBM破岩震源超前探测方法，以“正演揭示传播特征→逆时偏移刻画地质构造→波速评价岩体质量”为脉络开展了研究攻关。首先，依托工程现场实测了TBM破岩震源特征，揭示了不良地质体破岩震源地震波场传播特征，形成了“破岩震动先导传感+波场信息阵列测量”观测方式，并改进了适应TBM破岩震源观测模式的波束定向方法，提高了前向传播的能量；进而提出了以光滑互相干干涉为核心的TBM破岩震源波场特征恢复方法，研究了基于高阶累积量的等效震源子波提取方法、改进了约束盲反褶积方法，形成了TBM破岩震源地震超前探测高精度数据处理流程，在此基础上创新了隧道环境下的最小二乘逆时偏移成像方法，有效改善了成像质量；特别针对隧道探测模式偏移距和数据量过小，全波形反演波速计算不准确的问题，提出了基于波速校正和正则化的隧道全波形反演方法，降低了反演的多解性，提升了波速反演效果，最终，以波速为桥梁，基于震机岩关系模型实现了前方岩体质量的动态评价。通过本项目研究，创新并发展了TBM破岩震源超前地质预报方法与技术，研究成果在云南高黎贡山隧道、新疆某工程等TBM施工隧道中得到成功应用，为TBM安全高效掘进提供了指导。