向家坝水电站岩锚梁爆破开挖的试验研究

岩锚梁的开挖是向家坝地下厂房开挖施工过程中最困难也是最重要的一部分.夹层、层面和节理裂隙的存在对岩锚梁岩台的开挖爆破质量提出很高的要求.根据向家坝地下洞室围岩的特点,进行爆破试验设计时,将围岩按Ⅱ、Ⅲ类和Ⅳ、Ⅴ类选取两段,每段再分别细分为3组,每组的钻孔参数相同,装药参数赋予不同值,分别进行爆破试验.试验结果显示,在Ⅳ...

Experimental Study on Rock Anchor Beam Blasting Excavation at Xiangjiaba Hydropower Station

The excavation of rock anchor beam is the most difficult and important part of underground powerhouse excavation at Xiangjiaba Hydropower Station.High requirement is put on rock bench with rock anchor beam for there are interlayer,bedding plane and joint fissure.In order to carry out blasting test,two areas of surrounding rock in Class II & III as well as Class IV & V respectively are selected.Each area is furthered divided into three groups.Each group has the same drilling parameters and different charge parameters.Test results find that the test on the second group of Class IV & V surrounding rock and on the first and the second groups of Class II & III surrounding rock gets the best effect.Sound wave detection finds that the surrounding rock of the two test areas is hardly or not damaged in blast and meets standards.Blasting test at the two areas gets satisfactory results and provides important design parameters for the following rock anchor beam excavation.