地下水封石油储库硬岩大断面控制爆破

大型地下水封石油储库作为原油战略储备的一种重要手段,在世界范围内被普遍采用。地下水封储库不同于其他岩石地下工程,其跨度大、边墙高、开挖断面特大,同时要求爆破振动低、围岩损伤小、稳定性高,对开挖爆破有着更为严格的要求。本文以华南某地下水封石油储库硬岩特大断面爆破开挖为例,基于钻爆开挖的特殊要求,提出"大洞小打、分部开挖"的施工原则,划大断面为小断面,分层分次爆破。采用复式楔形掏槽、毫秒延迟起爆、周边孔光面爆破等技术,综合选取孔径、孔深、孔距、最小抵抗线、炸药单耗及炮孔数目等参数,精心设计炮孔布置、装药及起爆顺序,给出爆破方案。实践表明,爆破振动、炮孔利用率、壁面成型、开挖进尺等均达到了预期,较好地满足了洞库开挖要求,特大断面硬岩爆破设计能够取得良好的爆破效果,可为类似工程提供借鉴与参考。

Controlled blasting of underground water-sealed oil storage cavern with super large section in hard rock

As an important method for storing strategic oil, large-scale underground water-sealed oil storage caverns have been widely used worldwide. Underground water-sealed caverns are different from other underground rock engineering, with large span, high sidewalls, super large section, and the requirements of weak vibration, small damage of surrounding rock and high stability, so these caverns are stricter with excavation blasting. Based on the special requirements of drilling and blasting of underground water-sealed oil storage cavern, we propose a construction principle: large cavern divided into small sections, and cutting partial sections, which divides large section into small section and separates blasting a few times. The controlled blasting adopts duplex wedge cut, millisecond delay initiation and contour hole with smooth blasting, and selects blasting parameters comprehensively, such as diameter, depth, spacing, minimum burden, specific charge and amounts of borehole. The blasting design is given with layout of boreholes, charging and initiation sequence. Field tests show that blasting vibration, utilization rate of borehole, formation of excavation and advance per round achieve desired objectives. The blasting design of hard rock excavation with super large section gets good blasting results, and can provide reference for similar underground rock projects.