深部复合挤压地层双护盾TBM护盾卡机致灾机理及主动防控技术研究

Double-shield TBM (tunnel boring machine) was adopted in deep buried long tunnel construction more and more. While for the deep composite extrusion stratum, the double-shield TBM is ineffective due to the uncertainty of the extruded stratum deformation mechanism, the unsuitability of the traditional judging criterion of rock large deformation, the absence of discriminant criteria for shield blocking, and the scarcity of theory and technology for active prevention and control. The frequently occurring problem is shield blocking, which may affect the safety of personnel and equipment, cause the delay of project construction. Based on the complex loading and unloading stress path of surrounding rock, the laboratory test and numerical simulation will be conducted to explore the mechanism of extrusion deformation in deep composite strata. The PFC-FLAC coupling technology and refinement model will be applied to study on the mechanism of shield blocking induced problems, and then to establish the discriminant criterion of shield blocking in deep composite extrusion stratum. Research on the effect law of surrounding rock rapid support method and its efficiency will be performed on the basis of simple supported beam theory and mold bag grouting technique, combined with physical model and numerical experiment, to form the active prevention and control theory and technology of double-shield TBM in deep composite extrusion stratum. Considering the actual working conditions of double-shield TBM in deep composite extrusion stratum, this study has scientific and practical significances in improving and completing mechanism and prediction of TBM shield blocking and in enhancing the disaster prevention and construction safety of deep boring engineering.

双护盾TBM在深埋长隧洞工程中愈来愈多被采用，挤压地层变形机理不清、传统围岩大变形判别标准对该设备不适合、护盾卡机判别准则缺失、卡机灾害主动防控理论及技术罕见，使得双护盾TBM在面临深部复合挤压地层时束手无策，常发生护盾卡机灾害，威胁人员设备安全的同时延误工程建设。拟从围岩复杂加卸载应力路径出发，进行岩石室内和数值仿真试验，阐释深部复合地层挤压变形机理。借助PFC-FLAC耦合技术和精细化模型，研究护盾卡机孕育致灾机理，建立深部复合挤压地层双护盾TBM卡机灾害判别准则。基于简支梁理论和模袋灌浆技术，结合物理模型与数值试验，研究围岩快速支护方法及效用影响规律，构建围岩快速支护及扩挖组合的深部复合挤压地层双护盾TBM卡机灾害主动防控理论和技术。本研究更贴合深部复合挤压地层双护盾TBM卡机实际，对完善TBM卡机机理及预测判别，提高深部工程灾害防治、施工安全等方面具有重要的科学和应用价值。

双护盾TBM在深埋长隧洞工程中愈来愈多被采用，挤压地层变形机理不清、传统围岩大变形判别标准对该设备不适合、护盾卡机判别准则缺失、卡机灾害主动防控理论及技术罕见，使得双护盾TBM在面临深部复合挤压地层时束手无策，常发生护盾卡机灾害，威胁人员设备安全的同时延误工程建设。针对这一问题，系统研究了双护盾TBM掘进过程中围岩复杂加卸载应力路径，归纳整理了地下洞室开挖围岩主应力及方法变化规律。基于该规律，进行了岩石复杂应力路径下室内和PFC数值仿真试验，阐述了深部复合地层挤压变形机理。进行了PFC-FLAC耦合技术的研究，并建立了双护盾TBM掘进过程PFC-FLAC的精细化模型，研究了双护盾TBM掘进过程围岩裂化屈服的机理；依托多雄拉隧洞双护盾TBM卡机工程案例，采用FLAC3D建立了卡机洞段的精细化数值仿真模型，研究揭示了双护盾TBM掘进过程中围岩与护盾接触关系变化、塑性区演化、TBM所需克服摩阻力的变化，从最大推力和所需克服摩阻力角度揭示了护盾卡机孕育致灾机理。利用随机岩体、地应力赋值的方法，考虑围岩与护盾预留变形量值，进行了大量的数值仿真实验，建立了深部复合挤压地层双护盾TBM卡机灾害判别准则。最后，基于简支梁理论和模袋灌浆技术，结合物理模型、数值试验和现场试验，研究了围岩快速支护方法及效用影响规律，构建了围岩快速支护及扩挖组合的深部复合挤压地层双护盾TBM卡机灾害主动防控理论和技术。本研究更贴合深部复合挤压地层双护盾TBM卡机实际，对完善TBM卡机机理及预测判别，提高深部工程灾害防治、施工安全等方面具有重要的科学和应用价值。