ANALYSIS OF SURROUNDING ROCK DISPLACEMENT CHARACTERISTICS DURING CONSTRUCTION IN GUANDI UNDERGROUND POWERHOUSE CHAMBERS
GAO Chunyu1，2，DENG Jianhui1，2，WEI Jinbing1，2
(1. State Key Laboratory of Hydraulics and Mountain River Engineering，Sichuan University，Chengdu，Sichuan 610065，China；2. College of Water Resource and Hydropower，Sichuan University，Chengdu，Sichuan 610065，China)
Abstract：Based on the monitoring data of Guandi hydropower station underground powerhouse chambers during the construction period，displacement characteristics of surrounding rock are analyzed. Taking the generator chamber for example，research focuses on the structure face impact of the displacement and variation of the displacement-time curve. The research results show that the displacement of the rock mass is normally less than 20 mm. The larger displacement positions concentrate in the rock-anchored beam site and the middle and upper positions of generator chamber upstream side walls. Excavation exposed the larger displacement magnitude positions are controlled by the fault zone. The maximum displacement of construction period is 61.49 mm. The opening displacement of the structure face is the main displacement of the measuring point. Anchor bolts and anchor ropes restricted the rock displacement well. Displacement generate mainly during the excavation period，and display a typical characteristic step rise with the excavation process. When excavation completed，the surrounding rock mass deformation reduce quickly. The time characteristic of the surrounding rock displacement is not noticeable. The stability of the cavities is good.
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2012, Vol. 31 
