Study on the Excavation Treatment Measures and Anchor Grouting Timing for the Crane Beam Rock Bench at the Underground Powerhouse of the Dadu River Jinchuan Hydropower Station in Sichuan Province
In order to solve the problems of the development of cracks in the surrounding rock of the underground powerhouse cavern of Jinchuan Hydropower Station and the serious over-excavation of the rock bolted beam rock platform,with consideration of factors such as on-site geological conditions,excavation status,construction conditions and subsequent excavation may further aggravate the deterioration of the surrounding rock,the over-excavated part of the rock platform is back-filled with concrete and constructed at the same time as the rock bolted beam.By establis-hing a three-dimensional finite element numerical model of the rock bolted beam,backfill concrete and surrounding rock,the influence of the stress release of the cavern wall during the excavation of the lower part of the cavern,the bridge crane wheel pressure and grouting timing of ten-sile bolt on the stress of tensile bolt and rock bolted beam is calculated and analyzed.The results show that the stress of the tensile bolt of the rock bolted beam is mainly affected by the stress release of the cavern wall.The maximum value of the axial tensile stress is in the rock mass.The influence range of the bridge crane wheel pressure is only 0.32～3.15 MPa;the tensile bolt of the rock bolted beam should not be grouted simultaneously with system rock bolts.The rock bolted beam is in good operating condition and meets the stability requirements.
万方数据
维普
