煤田地质与勘探2025，Vol.53Issue(7)：141-153,13.DOI:10.12363/issn.1001-1986.25.04.0288
低渗灰岩注浆压力跃变机理与调控工艺研究
Mechanisms behind grouting pressure jumping in low-permeability limestones and techniques for grouting pressure control
摘要
Abstract
[Background]The exploitation of the Carboniferous-Permian coalfields in China is gradually transitioning toward coal seams in lower formations.In this context,issues including the confined water hazards in the floor and karst water preservation become increasingly pronounced.During the advanced surface treatment of karst water hazards in coal seam floors,the unclear patterns of matching between grout selection and grouting pressure control lead to empiric-al parameter selection,thereby yielding poor performance of grouting reinforcement.[Methods]This study aims to deal with the phenomena of rapid pressure rise with a limited grout volume in the low-permeability argillaceous limestones within the top part of the Ordovician limestones in the Xin'an Coalfield,Western Henan.It investigated three typical grout types applied in surface treatment engineering of the Mengjin Coal Mine in the Xin'an Coalfield:pure cement grout,clay grout,and clay-cement grout through a range of experiments on the grouting pressure at the borehole head,static rheological characteristics,liquid-phase particle size distribution,zeta potential,electrical conductivity,microscop-ic morphology,and element distribution of the three grout types.Based on the flocculation mechanisms of cement and clay particles,this study analyzed pressure rise differences of three grout types from the physical and chemical perspect-ives.[Results and Conclusions]Positively-charged cement particles and negatively-charged clay particles were prone to form three-dimensional reticular flocs due to strong electrostatic attraction.Consequently,the clay-cement grout exhib-ited large particles(sizes:＞600 μm).Furthermore,particles with sizes greater than 100 μm accounted for 78％of the total.These particles easily blocked up fractures.Compared to the cement grout,the clay-cement grout showed de-creased electrical conductivity of 1.87 mS/cm.As a result,clay particles were observed to encapsulate cement particles post-mixing.The cement grout,characterized by small particle sizes,lower static yield stress,and low viscosity,can eas-ily pass through narrow fractures,ensuring stable grouting pressure.In contrast,the clay-cement grout featured a static yield stress 4.5 times higher and a static viscosity 4.0 times compared to the cement grout.Therefore,such grout was prone to block fractures,and the pressure rise rate was approximately 10 times greater than that of the cement grout.An alternating grouting technique using clay-cement grout and cement grout was proposed following the principle of step-wise and gradual pressure rise,consisting of low-pressure filling,medium-pressure diffusion,and high-pressure fracture reinforcement(also referred to as the"three-stage"alternating grouting technique).This technique can significantly en-hance the treatment efficiency,providing a valuable reference for grouting treatment of low-permeability limestones un-der similar conditions.关键词
煤矿水害/底板岩溶水害/区域治理技术/注浆材料/絮凝机理/起压差异机制/交替注浆/豫西孟津煤矿Key words
water hazard in coal mines/karst water hazard in coal seam floor/regional treatment technology/grouting material/flocculation mechanism/mechanism underlying pressure rise difference/alternating grouting/Mengjin Coal Mine in western Henan分类
矿业与冶金引用本文复制引用
樊振丽,曹路通,崔勇,张志巍,张风达..低渗灰岩注浆压力跃变机理与调控工艺研究[J].煤田地质与勘探,2025,53(7):141-153,13.基金项目
国家重点研发计划项目(2022YFB4102105) （2022YFB4102105）
国家自然科学基金项目(51704158) （51704158）
中煤科工开采研究院有限公司科技创新基金青年项目(KCYJY-2023-QN-03,KCYJY-2025-QN-03) （KCYJY-2023-QN-03,KCYJY-2025-QN-03）
