厚松散层下高压注浆上覆地层变形光纤监测研究

Research on Optical Fiber Monitoring of Overlying Stratum Deformation under High-Pressure Grouting in Thick and Loose Strata

摘要: 为揭示厚松散层条件下高压注浆过程中地层内部变形的发育层位与变化特征，以安徽某矿区地面定向钻孔高压注浆工程为背景，采用分布式光纤监测技术对钻孔全剖面地层变形进行连续监测，结合不同层位应变响应特征，分析注浆扰动作用下地层变形发育特征。研究表明：分布式光纤监测技术能够实现厚松散层条件下注浆过程地层内部变形的全钻孔、连续化、高精度监测，有效识别地层变形发育位置，为注浆影响范围评价提供了新的技术手段。监测结果显示，高压注浆扰动引起多个层位地层发生不同程度变形，其中关键变形区主要分布于380~480 m深度范围。地层变形总体以压缩应变为主，局部发育拉应变，表明注浆过程中浆液扩散主要通过充填孔隙裂隙和挤密压缩周围地层实现，其变形传递过程具有明显的向上衰减与分段变形的特征。研究揭示了关键变形层位形变发育演化过程，可为高压注浆参数优化、浆液扩散范围评价以及矿区水害防治工程设计提供重要技术支撑。

Abstract: To investigate the development horizons and variation characteristics of stratum deformation during high-pressure injection in a thick loose layer, this study focuses on a directional surface borehole grouting project in a mining area of Anhui. Distributed fiber monitoring technology was employed to continuously measure deformation across the entire borehole profile. By combining strain response features from different horizons, the development characteristics of stratum deformation under grouting disturbance were analyzed. The research shows that distributed fiber monitoring can achieve full-hole, continuous, and high-precision monitoring of internal stratum deformation during the injection process under thick loose layer conditions, effectively locating deformation zones and providing a new technical means for evaluating the injection influence range. Monitoring results indicate that high-pressure injection disturbance caused varying degrees of deformation in multiple layers, with key deformation areas mainly distributed within the depth range of 380~480 m. Overall, stratum deformation was dominated by compressive strain, with local development of tensile strain, indicating that grout diffusion primarily occurs by filling pores and fractures and compacting the surrounding strata. The deformation transmission process exhibits clear upward attenuation and segmented characteristics. This study clarifies the deformation evolution process in key horizons, which can provide important technical support and a scientific basis for optimizing high-pressure injection parameters, evaluating grout diffusion range, and designing water hazard prevention engineering in mining areas.