地下厂房无裂缝预应力岩壁吊车梁施工技术

大型地下厂房岩壁吊车梁的防裂技术一直是困扰地下洞室的施工难题,因为以往的岩壁吊车梁在结构衬砌后,表面普遍存在贯穿性裂缝。彭水水电站地下厂房预应力岩壁吊车梁布置在薄层、陡倾角、软弱岩层中,边墙自稳定性差、开挖卸荷、不均匀沉陷对岩壁梁的结构安全十分不利。在应用传统施工经验的基础上,对岩壁梁结构衬砌与预应力锚固时机、梁体下部薄层开挖随层支护等施工技术进行了系统研究,成功地解决了因开挖卸荷、不均匀变形导致岩壁梁混凝土产生裂缝的施工难题。彭水水电站地下厂房的岩壁吊车梁于2005年3月完工,2006年4月投入使用,经受住了荷载试验及施工期的机组安装等大件吊装的考验,通过近5a实践,梁体结构尚未发现有裂缝。成功地实践了无裂缝预应力岩壁吊车梁施工技术。

Study on construction technology of pre-stressed ledge crane beam without cracks in large underground powerhouse

Based on traditional construction experience,we systematically study the construction technologies concerning lining of ledge beam,timing of pre-stressed anchorage,layered support in the thin layer under the parts of beam body and the practice,which could successfully overcomes the difficulties in the construction such as cracks in the ledge beam formed by excavation unloading and inhomogeneous deformation.The ledge crane beam in the underground powerhouse of Pengshui Hydropower Station was completed in Mar...