改良型锚喷技术在敦化电站长斜井中的应用

斜井开挖采用新奥法施工,钻爆法开挖需要锚喷混凝土支护紧跟掌子面。目前市面上成品混凝土喷射机额定喷射距离较短,无法适应长斜井长距离工况。通过采取改造供风供料系统、混凝土喷射机、输料管路优化、喷射机前移等施工技术,实现了远距离喷射混凝土施工,有效地解决了长斜井井下喷射混凝土堵管、回弹率高或锚喷工作滞后影响开挖进度的难题。该技术的应用保证了斜井的安全和施工质量,加快了施工进度,对同类工程长斜井喷射混凝土支护具有借鉴意义。

The new Austrian method is used in the excavation of inclined shaft,and the excavation of drilling and blasting method requires anchor and shotcrete support to follow the face of the face.At present,the rated injection distance of the finished concrete injector on the market is short,which can not adapt to the long-distance working condition of long inclined shaft.The construction of long-distance shotcrete is realized by reforming the air supply system,concrete injector,optimization of conveying pipeline,forward movement of sprayer and other construction technology.The difficult problems of pipe plugging of shotcrete in long inclined shaft,high rebound rate or lag of anchor and shotcreting work affecting the excavation progress are effectively solved.The application of this technology ensures the safety and construction quality of inclined shaft,speeds up the construction progress,and can be used as a reference for shotcrete support of long inclined shaft in similar projects.