摘要
煤炭地下气化引发的高温环境对浆-岩界面黏结性能及裂隙扩展特征具有显著影响。采用自主研发的耐高温复合水泥材料,结合保压注浆技术,研究了高温作用下浆-岩界面剪切性能与损伤机制。通过室内剪切试验与数字散斑相关法(DIC)分析发现,随着温度升高,浆-岩界面剪切强度显著下降,400℃为临界温度,超过此阈值后,界面黏聚力下降42.11%,内摩擦角下降23.43%;显微观测分析发现,在600~800℃高温区间,裂隙开度增加是界面损伤的主要原因;通过引入峰值摩擦系数和稳定摩擦系数,系统评价了法向应力与高温对浆-岩界面剪切性能的影响;同时,分析了高温下砂岩与浆液结石体热膨胀系数差异对界面黏结性能的影响,随着温度升高,热膨胀差异引发的热应力增加导致界面裂纹形成,进一步加剧了界面损伤。研究结果可为煤炭地下气化环境下裂隙岩体加固提供理论支持。
The high-temperature environment induced by underground coal gasification considerably affects the bonding performance of the slurry-rock interface and the propagation characteristics of fractures.In this study,a self-developed high-temperature-resistant composite cement material combined with pressure-maintaining grouting technology was used to investigate the shear performance and damage mechanism of the slurry-rock interface under high temperatures.Through indoor shear tests and digital image correlation(DIC)analysis,it was found that with the rise of temperature,the shear strength of the slurry-rock interface falls noticeably,with 400℃ identified as the critical temperature.Beyond this threshold,the interface cohesion drops by 43.34%,and the internal friction angle declines by 23.34%.Microscopic observation and analysis revealed that,in the high-temperature range from 600℃ to 800℃,the increase in fracture aperture is the primary factor contributing to interface damage.By introducing the peak friction coefficient and the stable friction coefficient,the effects of normal stress and high temperature on the shear performance of the slurry-rock interface were systematically evaluated.Additionally,the impact of the thermal expansion coefficient difference between sandstone and cement paste on the bonding performance of the interface was analyzed.As the temperature rises,the thermal stress caused by the thermal expansion coefficient difference leads to the formation of cracks at the interface,further exacerbating the interface damage.The findings of this study provide theoretical support for the reinforcement of fractured rock masses in underground coal gasification environments.
作者
王帅
浦海
王红红
王连国
王清
胡李华
苏海霆
WANG Shuai;PU Hai;WANG Honghong;WANG Lianguo;WANG Qing;HU Lihua;SU Haiting(School of Civil and Architectural Engineering,Taishan University,Tai'an,Shandong 271000,China;Shandong Engineering Research Center of High Durability and Corrosion Resistant New Building Materials,Taishan University,Tai'an,Shandong 271000,China;State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Logistics Management Office,Taishan University,Tai'an,Shandong 271000,China)
出处
《采矿与安全工程学报》
北大核心
2026年第1期208-220,共13页
Journal of Mining & Safety Engineering
基金
国家自然科学基金面上项目(52374147)。
关键词
煤炭地下气化
注浆裂隙岩体
浆-岩界面
高温损伤
剪切强度
underground coal gasification
grouting fractured rock mass
slurry-rock interface
high temperature damage
shear strength
