小湾地下厂房岩锚吊车梁施工技术

 简要介绍了小湾地下厂房岩锚梁开挖、受拉受压锚杆施工、混凝土浇筑等三个工序的施工方法及取得的工程经验。小湾地下厂房岩锚梁核心部位的开挖采用手风钻造孔，钢管脚手架搭设操作样架，施工精度控制在设计要求的范围内，孔距一般为32cm，线装药密度75.8g/m，地质条件不良段视实际情况适当折减，施工中获得了98%的半孔率，残孔无裂纹，平均超挖控制在了8.9cm之内，爆破振动控制各项指标均符合规范要求，施工质量达到优良标准；还对岩锚梁锚杆的施工方法及精度控制手段以及混凝土浇筑的方法分别做了详细介绍。

Case Study on Construction Technology for Rock Anchor Beam of Xiaowan Underground Powerhouse

The construction methods and engineering experience of the three construction steps of the rock anchor beam of Xiaowan underground powerhouse, i. e., rock anchor beam excavation, pulled/stressed rock anchor construction and concrete casting, are briefly presented. For the excavation of the critical part of the rock anchor beam of Xiaowan underground powerhouse, the shotholes are drilled by pneumatic drills, steel pipe scaffolds are erected so as to be used as working platforms, the construction accuracy is controlled within the designed limits, the spacing of the shotholes generally is 32cm, the linear charging density is 75.8k/m and is appropriately reduced in accordance with the actual conditions where the geology is poor. As a result, a semi hole ratio of 98% is achieved, the sockets have no cracks, the average overbreak is controlled below 8.9cm, the parameters of the blasting vibrations meet the requirements of the related standards and the construction quality reaches "excellent" standard. Furthermore, the construction methods and accuracy control methods for the rock anchors of the rock anchor beam and the concrete casting methods are described in detail.