白鹤滩水电站左岸地下厂房岩壁吊车梁承载特性分析

岩壁吊车梁是地下厂房重要的支撑结构,其安全稳定性尤为关键。基于原型观测结果,分析了受到洞室开挖卸荷作用和吊车荷载作用下岩梁锚杆受力、岩梁与围岩结合面情况和围岩变形情况,对岩壁吊车梁进行承载特性分析和安全稳定评价。结果表明,围岩开挖卸荷引起岩体较大的深部变形和应力调整,岩梁锚杆应力水平较高,在开挖完成后,各监测数据趋于稳定;锚杆应力值、锚索荷载未超过设计强度;岩梁与岩壁最大开合度1.24mm;岩梁荷载试验期间,各观测数据增量均较小。总体上,岩壁吊车梁安全稳定,能够满足生产运行要求。

Bearing Behavior Analysis of Rock-Bolted Crane Beam in Underground Powerhouse on the Left Bank of Baihetan Hydropower Station

The rock-bolted crane beam is an important supporting structure in underground powerhouse,so the safety and stability is especially important.Based on the prototype observation,anchor bar stress,attachment of its two crane beams to the surrounding rock and the deformation status of surrounding rock were analyzed with safety monitoring at its excavation stage and the crane load.The stress characteristics and stability of the rock-bolted crane beam were evaluated.The results show that the large deformation and stress adjustment of rock mass caused by the excavation unloading of surrounding rock,the deformation of surrounding rock is large,the stress level of anchor bar is high.After the excavation is completed,the monitoring data tend to be stable.All the bolt stresses are below the yield strength of steel,and the maximum joint opening between the girders and their surrounding rock is 1.24 mm.During the load test,the increment of each observation data is not large.In general,the rock-bolted crane beam is safe and stable,and can meet the production and operation requirements.