沁水煤田采空区场地高速铁路路基灾变机制与防控

There is a safety risk in high-speed railway passing through the goaf site of the Qinshui coalfield in Shanxi Provence. It is the key to ensure the safe operation and maintenance of high-speed railways for adopting the method of intelligent, dynamic security monitoring, situation judgment and emergency response. According to the mining conditions in the Qinshui coalfield, some typical geological models are built, and the surface deformation mechanism and the spatial-temporal evolution rule are studied. The prediction model for the overburden and surface movement deformation in the goaf site is established, and the accuracy prediction theory of the residual deformation is proposed. The interactions among the rock and soil overlying the goaf, the high-speed railway subgrade, and the engineering environment under the action of the cyclic dynamic load of the high-speed railway are studied, the mechanism and law of the activation deformation of the ground over the goaf are revealed, and the criteria and the evaluation system for the activation deformation are also established. The high-precision multi-source monitoring network system of “space-sky-earth-depth” is built, an early warning model is proposed, and a graded early warning indicator system is established. Then a visualization system for data collection and management, ground safety early warning assessment, and safety monitoring information release is developed. The harmful deformation types are divided, a quick and accurate identification method is studied, and a rating code for disasters is constructed. The evaluation system for harmful deformation prevention and control effects is established, and a deformation control method for long-term safety operation is proposed. The measures for prevention and control of disasters are proposed to ensure the safety and stable operation of high-speed railways.

高速铁路通过沁水煤田采空区场地存在重大安全风险。要确保高速铁路平安运维，智能、动态化的安全监测、态势研判及应急处置是关键。依据沁水煤田采矿条件，构建采空区场地典型工程地质概化模型，研究地表变形机制及时空演化规律，建立采空区覆岩及地表移动变形的时空预测模型，提出采空区场地剩余变形精准预测理论；研究高速铁路循环动荷载作用下采空区上覆岩土体、高速铁路路基、工程环境的相互作用，揭示采空区地基活化变形演变机理与规律，建立采空区地基活化变形判据及评价体系；构建“天-空-地-深”的高精多源监测网络体系，提出预警模型，建立分级预警指标体系；研发数据的采集与管理、地基安全预警评判和安全监测信息发布的可视化系统；划分有害变形类型，研究快捷精准辨识方法，构建灾变等级评判标准，建立有害变形防控效果的评价体系，提出高速铁路长期安全运维的有害变形控制方法和灾变防控工程对策，保证高速铁路安全平稳运行。

山西沁水煤田的长期开采，已形成约2300平方公里的采空区，对高铁运维存在重大安全风险。项目采用现场调研、数值模拟、相似试验、理论分析等方法开展了如下研究工作：（1）在研究沁水煤田采空区场地工程地质特征基础上，建立了载荷扰动下的采空区覆岩结构力学计算模型，揭示了长壁采空区地表剩余变形机制，明晰了采空区地表剩余变形与覆岩结构之间的关系；基于机器学习和现场实测等技术手段，建立了采空区覆岩与地表剩余变形的时空预测模型，提出了采空区场地剩余变形的精准预测理论。（2）揭示了采空区地基活化变形演变机理，提出了高铁采空区地基活化判据；建立了车辆-轨道-路基-采空区地基力学耦合模型，分析了列车轴重、速度、采矿条件等因素对采空区地基动力响应的影响规律；确定了影响高铁采空区地基“活化”的5大因素和19个因子，建立了高铁采空区地基“活化”分级评判体系；构建了与循环振次有关的采空区地基土体修正H-D动本构模型；研发了采空区场地拟动力加载试验系统。（3）提出了采空区场地InSAR-LiDAR-CORS-BH（天-空-地-深）多源融合监测与数据处理方法，建立了路基变形的高精多源监测网络体系；构建了高铁安全运维预警指标体系，给出了预警指标分级标准，建立了组合赋权-模糊综合评判的高铁安全运维稳定性评价模型；研发了高铁采空区点云监测数据处理分析系统和地基灾变多级预警系统，实现了高铁地基安全的动态监测分析。（4）提出了由附加变形、剩余变形、活化变形和路堤变形四部分组成的最终沉降变形计算方法，建立了有害变形防控效果的评价体系；揭示了采空区地基渗透注浆机理，优化了采空区地基注浆压力、注浆速率、注浆孔间排距以及处治范围等参数；研发了采空区地基注浆处治的绿色节能环保型浆液；提出了高铁长期安全运维的有害变形控制方法和灾变防控工程对策。研究成果为采空区场地高铁路基变形控制与灾变防控提供理论支撑。