煤矿长距离斜井TBM(盾构)施工基础理论

It is very important for the construction of multi-pair inclined-shafts or similar shafts at huge coalmines under the conditions of shaft length over 6km with dip angle of 6°to investigate the characteristics of deformations and segment – geo-material interaction by Tunnel Boring Machine (TBM). In this project, the stability of segment structures is in detail analyzed and the effect of water-proof is also examined at the phases of TBM construction and shaft operation, respectively. The damage and abrasivity of cutter-head and cutting tools are carefully studied due to TBM driving along long-distance inclined shaft. The safety prediction and monitoring system are developed at the two stages of TBM construction and shaft operation. The process of stress re-distribution induced by back-filling (pea gravel + grouting) is disclosed by the examination of specific practicability to shaft-lining structure system under the conditions of complex geological strata. All these effects aim to present a feasible evaluation model of segment-lining stability along the directions of ring and driving axis, develop the controlling principles of its stability and obtain the useful technologies to inclined shaft at huge coalmines at the various stages of TBM construction and shaft operation. Finally, a system of risk control and hazard monitoring for TBM construction and safety operation in inclined shaft coalmines is established.

斜长6km以上、坡度6°的煤矿斜井TBM施工且井壁采用管片衬砌的工程，在国内外尚无先例。开展斜井TBM施工的特殊井壁（管片衬砌）-地层相互作用机理及其变形规律的研究，揭示斜井角度对TBM施工期和矿井运营期的管片衬砌结构稳定性及防水性能的影响，进行长距离斜井TBM掘进对刀盘结构影响和刀具磨损机理及煤矿斜井TBM施工期与运营期安全预测、监测方法等基础性课题研究，对解决神华新街能源公司台格庙矿区多对斜井建设和类似条件下千万吨级以上特大型矿井建设，具有重要理论意义和工程实用价值。本项目将揭示TBM（盾构）施工中围岩（地层）-支护（管片+回填层）相互作用机理，阐明回填层（豆砾石+灌浆层）应力均匀化过程及井壁结构（管片+回填层）对复杂地层条件和斜井角度的特殊适应性，获得管片衬砌结构在TBM施工期和运营期的环向与纵向稳定性规律、控制原理及技术；建立煤矿斜井TBM施工和安全运营过程风险控制和病害监测系统。

煤矿长距离斜井TBM（盾构）施工面临着复杂地层、长距离、大埋深、大角度、下行等因素引起的特殊关键技术及其基础理论问题。针对施工中遇到的井筒-地层相互作用、管片衬砌结构稳定及其防水性能、刀具破岩及磨损机理、掘进与运营安全的预测监测方法等问题，本项目综合采用理论分析、数值模拟、实验室物理模拟实验与现场工程试验研究相结合的研究手段，进行了弹塑性条件下斜井围岩-支护（管片+回填层）的全过程解析，确定了斜井围岩弹塑性变形的空间分布特征，揭示了井筒-地层相互作用机理及其变形规律；运用弹塑性力学、隧道力学等基础理论得出围岩-管片衬砌结构和锚喷支护结构的位移、应力和应变的解析解，采用FLAC3D软件对TBM施工过程进行了全过程的数值模拟，采用ANSYS有限元软件对管片衬砌结构在非对称荷载作用下的内力进行了数值计算，揭示了斜井角度对TBM施工管片衬砌结构稳定性其防水性能的影响规律；针对台格庙斜井围岩4种介质条件分别研究其各自破岩机理，建立盘形滚刀破岩力的计算公式，建立刀盘与工作面相互作用力学模型；采用PFC3D数值模拟研究破岩过程的切削、破岩机理的数值动态过程，通过相似模拟实验，验证数值模拟中对滚刀间距和刀盘推力变化规律的合理性，提出了长距离斜井TBM掘进对刀盘结构设计理论；通过一系列岩石力学实验，得出地层参数与岩石磨蚀性CAI之间的关系，进而建立了基于地层参数和掘进参数的刀具磨耗预测模型，阐述了刀具磨损的机理和预测方法；通过建立的BOTDR光纤应变与顶板沉降变形关系的模型并进行试验研究，研发了斜井TBM施工管片衬砌结构光纤监测实施方案，揭示了煤矿斜井TBM掘进与运营安全的预测、监测方法。项目研究期间培养了一大批青年教师和研究生，取得了丰富的研究成果，为神华台格庙矿区的斜井TBM施工提供了可靠的理论与技术支持，为煤矿斜井开拓方式的推广与应用打下坚实的理论基础。