Abstract
Floor heave and water inrush accidents are likely in fault-traversing roadways above highly confined aquifers. In this paper, the deflection curve equation for the key floor stratum of a fault-traversing roadway in the Zhaogu no. 2 coal mine was derived based on the cantilever beam model, and the line strain in the failure zone, ε, was introduced to characterize the relationship between floor heave and deformation of deep intact rock layers. Then, three- dimensional pre-grouting technology was established for floor reinforcement. Analysis indicated that the rock surrounding the fault-traversing roadway was highly fractured, increasing the risk of water hazards. Numerical UDEC simulations showed that the plastic zone of the roadway was greater due to the faults; the floor heave, in this case, was 2.6 times greater than without faults. However, water pressure applied to the floor had a limited impact on deformation of the surrounding rock. The measured maximum deflection of the stratum was 644 mm, and the line strain ε in the failure zone in the floor was 67 mm, which resulted in a difference of 3.5% compared with the modelled results. The apparent resistivity in the grouted areas, observed through comprehensive geophysical explorations, was increased, suggesting that the grouting reinforcement had been successful.
Zusammenfassung
Unfälle durch Sohlhebung und Wassereinbruch sind nicht unwahrscheinlich bei Fahrbahnen, die Verwerfungen über stark gespannten Grundwasserleitern queren. In dieser Arbeit wurde die Gleichung der Verformungskurve für die Hauptbodenschicht einer störungsüberquerenden Fahrbahn in der Zhaogu-Nr. 2 Kohlemine abgeleitet auf der Grundlage des Kragträger-Modells. Die Linienbelastung in der Bruchzone ε wurde eingeführt, um die Beziehung zwischen der Sohlhebung und der Verformung tiefer intakter Gesteinsschichten zu beschreiben. Anschließend wurde eine dreidimensionale Vorverpressungstechnologie zur Bodenverstärkung eingeführt. Die Analyse ergab, dass das Gestein, das die störungsüberquerende Straße umgab, stark gebrochen war, was das Gefahrenrisiko von Wassereinbrüchen erhöhte. Numerische UDEC-Simulationen zeigten, dass die plastische Zone der Fahrbahn aufgrund der Verwerfungen größer war. Die Sohlhebung war in diesem Fall 2,6-mal größer als ohne Verwerfungen. Der auf den Boden ausgeübte Wasserdruck hatte jedoch einen begrenzten Einfluss auf die Verformung des umgebenden Gesteins. Die gemessene maximale Biegung der Schicht betrug 644 mm, und die Linienverformung ε in der Bruchzone im Boden betrug 67 mm, was zu einer Differenz von 3,5 % im Vergleich zu den modellierten Ergebnissen führte. Der scheinbare spezifische Widerstand in den abgedichteten Bereichen, der durch umfassende geophysikalische Untersuchungen beobachtet wurde, erhöhte sich, was darauf hindeutet, dass die Verpressungsverstärkung erfolgreich gewesen war.
Resumen
Los accidentes por levantamiento del piso y de irrupción de agua son altamente probables en rutas que atraviesan fallas sobre acuíferos altamente confinados. En este artículo, la ecuación de la curva de desviación para el estrato clave del piso de una ruta que atraviesa fallas en la mina de carbón n° 2 en Zhaogu, se obtuvo en base al modelo de viga en voladizo; se introdujo la tensión de línea en la zona de falla, ε, para caracterizar la relación entre el levantamiento del piso y la deformación de las capas de roca intactas profundas. Luego, se estableció la tecnología tridimensional de pre-lechada para el refuerzo del piso. El análisis indicó que la roca que rodeaba la ruta estaba muy fracturada, lo que aumentaba el riesgo de peligros hídricos. Las simulaciones numéricas de UDEC mostraron que la zona plástica de la carretera era mayor debido a las fallas; la elevación del piso, en este caso, fue 2,6 veces mayor que sin fallas. Sin embargo, la presión del agua aplicada al piso tuvo un impacto limitado en la deformación de la roca circundante. La desviación máxima medida del estrato fue de 644 mm, y la tensión de línea ε en la zona de falla en el piso fue de 67 mm, lo que resultó en una diferencia de 3,5% en comparación con los resultados modelados. La aparente resistividad en las áreas con lechada, observada a través de exploraciones geofísicas exhaustivas, aumentó, lo que sugiere que el refuerzo de la lechada había sido exitoso.
抽象
底鼓和突水事故可能发生于高承压含水层上断层穿越的巷道。基于悬臂梁模型,推导出赵固2号矿断层穿越巷道底板关键层的挠度曲线方程,引入破坏区的线应变(ε)来表征深部完整岩体的底鼓与变形关系。然后,建立了三维预注浆底板加固技术。分析显示,被断层穿越巷道的围岩高度破裂,突水风险增大。UDEC数值模拟表明,由于断层影响,巷道塑性区增大,底鼓量比没有断层时大2.6倍。施加于底板上的水压作用对围岩变形影响有限。实际测得地层最大挠曲644毫米,破坏区底板线应变(ε)67毫米,实测结果与模拟结果差异3.5%。综合地球物理勘探也显示,灌浆区视电阻率提高,灌浆加固效果显著。
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This study was funded by National Natural Science Foundation of China (CN) (Grant number 2013CB227903).
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Xu, Y., Zhang, E., Luo, Y. et al. Mechanism of Water Inrush and Controlling Techniques for Fault-Traversing Roadways with Floor Heave Above Highly Confined Aquifers. Mine Water Environ 39, 320–330 (2020). https://doi.org/10.1007/s10230-020-00670-1
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DOI: https://doi.org/10.1007/s10230-020-00670-1