摘要
斜井是介于平洞和竖井之间的一类地下洞室,在水电、水利等工程中,由于水道、电缆、通风、通行等需要,会大量用到此类地下洞室。反井法是斜井最高效的开挖方法,但当斜井倾角低于45°时,受散粒材料自然休止角的影响,二次正向扩挖爆渣可能无法通过导井自然溜送,从而发生堵井的安全风险;同时受反井钻机钻杆、钻头的自重作用,导孔难以准确贯通且导井反扩扭矩极大。上述两个因素使缓坡斜井施工难度和风险极大,对于小于45°的斜井,采用反井法施工至今还没有先例。针对上述问题,项目通过理论分析、模型试验,确定了缓坡斜井反导井正挖法开挖安全溜渣角度范围,为施工方法决策提供了依据;研制了定向钻进组合钻具装置,创造了1‰的贯通精度,为反井法施工奠定了基础;研发了水平抗滑机座,提出了保留导井光滑岩面和一次全断面扩挖成型的施工方案;有效控制了爆渣粒径级配和单次溜放量,规避了堵井风险,减少扒渣工程量,提高了施工效率。
An inclined shaft is a type of underground chamber situated between horizontal and vertical shafts.It is extensively used in hydropower and water conservancy projects due to the need for water conveyance,cabling,ventilation,and passage.The raise boring method is the most efficient excavation technique for inclined shafts.However,when the inclination is less than 45°,the natural repose angle of loose materials may hinder the downward flow of blasted rock during the second-stage forward enlargement,posing a safety risk of shaft blockage.Additionally,due to the self-weight of the raise boring machine's drill rods and drill bit,the pilot hole is difficult to align precisely,and the reverse reaming torque becomes extremely high.These two challenges significantly increase the difficulty and risk of constructing inclined shafts with gentle slopes.To date,there has been no precedent for using raise boring on shafts with inclinations less than 45°.To address these issues,the project conducted theoretical analyses and model experiments to determine the safe range of rock discharge angles for reverse pilot hole and forward enlargement excavation of gently sloping inclined shafts,thereby providing a basis for method selection.A directional drilling assembly was developed,achieving a penetration accuracy of 1‰,laying the foundation for raise boring application.A horizontal anti-slip machine base was also designed.Additionally,a construction plan was proposed that retains the smooth rock surface of the pilot hole and performs full-section enlargement in a single operation,effectively controlling the particle size distribution of the blasted rock and the volume discharged per cycle.This approach mitigates the risk of shaft blockage,reduces mucking workload,and improves construction efficiency.
作者
董树荣
DONG Shurong(The Second Branch of Sinohydro Bureau 7 Co.,Ltd.,Chengdu 611730,China)
出处
《四川建材》
2025年第12期120-127,共8页
Sichuan Building Materials
基金
国家自然科学基金青年科学基金项目(51909182)。
关键词
斜井
溜渣机制
定向钻进
控制爆破粒径
反导井正挖法
inclined shaft
slag slipping mechanism
directional drilling
control of blast particle size
anti-missile well digging method
