摘要
以联合强化支护为主的控制技术是当前深部煤巷围岩控制的主要手段,复杂化的支护形式明显降低巷道掘进效率,采掘矛盾突出,已成为制约煤矿高效生产的普遍性难题。而不受巷道高度限制且能实现快速安装的柔性锚杆已在静态拉伸下表现出良好的力学性能,可有效解决巷道安全与掘进效率相制约的问题。为研究柔性锚杆在长期载荷作用下的力学特性和动态变化特征,通过自主研发的锚杆(索)耐久性实验系统对柔性锚杆进行长达5个月加载实验,分别设置无处理对照组、不同淋水环境和不同安装角度3种相似工程环境,并对长期加载后的柔性锚杆开展静态拉伸实验。结果表明,与未经长期载荷作用的柔性锚杆相比,长期加载对柔性锚杆力学性能影响较小,峰值力仅降低1.2%;淋水环境下柔性锚杆出现多处锈蚀,其峰值载荷和延伸性能较无处理对照组均出现降低,分别降低8.6%和21.4%,而经防锈处理的柔性锚杆能保持自身的力学性能;不同安装角度的柔性锚杆有差异性的力学行为,角度过大时对柔性锚杆的承载能力带来不利影响;现场应用时,要确保柔性锚杆经过防锈处理且安装角度不宜过大。最后,在大倾角强动压巷道、高应力大断面巷道和厚顶煤巷道等复杂条件巷道中进行柔性锚杆单一化支护技术的现场实践,锚杆支护效率和巷道掘进速度有明显提升,同时围岩变形得到有效控制。
The control technology based on combined strengthening support is the main means to control the surrounding rock of the deep coal roadway at present.The complicated supporting form obviously reduces the driving efficiency of roadway and the contradiction between coal mining and roadway driving is very serious,which has become a common problem restricting the high efficiency mining of coal mine.The flexible bolt,which is not limited by the height of roadway and can be installed quickly,has shown good mechanical properties under static tension,which can effectively solve the problem of mutual restriction between roadway safety and driving efficiency.In order to study the mechanical characteristics and dynamic change characteristics of the flexible bolt under long-term load,the flexible bolt was loaded for up to five months through the self-developed bolt(cable)durability test system,and three similar engineering environments were set up without treatment control group,different water pouring environment and different installation angle,and the tensile test of the long-term loaded flexible bolt was carried out.The test results show that the mechanical properties of untreated flexible bolts are less affected by long-term loading compared with those without long-term loading,and the peak value of the flexible bolt is only 1.2%lower.In the water pouring environment,the flexible bolts are rusted in many places,and its peak load and extension performance are reduced respectively by 8.6%and 21.4%,while the flexible bolts treated with antirust can maintain its own mechanical performance.The flexible bolts with different installation angles have different mechanical behavior,and when the angle is too large,the bearing capacity of the flexible bolt will be adversely affected.In the field application,it is necessary to ensure that the flexible bolts must be treated with antirust and its installation angle should not be too large.Finally,the field test of the flexible bolt single support technology is carried out in the roadways with complex condition such as large inclination strong dynamic pressure roadway,high stress large section roadway and thick top coal roadway.The efficiency of bolt support and the driving speed of roadway have been significantly improved,and the deformation of surrounding rock is effectively controlled.
作者
谢正正
张农
王朋
汪明坤
XIE Zhengzheng;ZHANG Nong;WANG Peng;WANG Mingkun(Key Laboratory of Deep Coal Resource Mining,Ministry of Education,China University of Mining and Technology,Xuzhou 221116,China;School of Mines,China University of Mining and Technology,Xuzhou 221116,China;Jiangsu Normal University,Xuzhou 221116,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2020年第9期3096-3106,共11页
Journal of China Coal Society
基金
国家重点研发计划资助项目(2017YFC0603001)
国家自然科学基金面上资助项目(51674244)。
关键词
柔性锚杆
长期载荷
力学特性
掘进效率
巷道安全
耐久性
flexible bolt
long-term load
mechanical properties
driving efficiency
roadway safety
durability
