Research Of Safety Control Standard For Rock Excavation Blasting In XiLuoDu Waterpower Station

According to the definition of safety control standard for blasting in certain rules and classifications, the safety control standards for slope excavation blasting in several similar projects, such as SanXia, GeZhouBa, GeHeYan, XiaoWan and so on, are completely investigated and compared. Considering the specific spandrel groove slope (EL. 610m and up) in XiLuoDu WaterPower station, the on site blasting tests are performed, including blasting parameter test, blasting vibration effect test, and detecting the depth of the blasting influence on the remain rock. The particle vibration velocity of the slope and the variation of the sonic wave speed in the rock are measured under different topographic and geological conditions with different blasting program and blasting parameters. Combined these measurements with the macro-investigation and the field inspection, the blasting safety control standard for spandrel groove slope excavation in XiLuoDu is proposed after comprehensive analysis and engineering analogy.A horse-way slope foot is used as the control point for the safety control standard for rock excavation blasting in XiLuoDu WaterPower Station. For the typeâ…¡rock with good integrity and strength, the allowed vibration velocity is controlled as 15 cm/s; For all other type rocks, the allowed vibration velocity is better to be controlled below 10 cm/s. For typeâ…¢rock, the allowed vibration velocity is controlled as 7.5~10 cm/s; For the heavy weathering typeâ…£rock and weak geological structure, the allowed vibration velocity is rigidly controlled as 5~7.5 cm/s. Aforementioned standards are obtained based on the blasting test results on slope over EL. 610m. By applying these standards to the rock excavation on slope EL.610~520m, notable achievements are obtained: the blasting size is under control, the blasting vibration effect is reduced, and the safety of protected constructions nearby is guaranteed. The remaining ratio of presplitting holes on abutment slot reaches 90% and above; theunsmoothness reaches the standard; the total quality is in good level; the expected quality and safety control target is obtained. Hence, the proposed standard is feasible and reasonable.The feasibility of aforementioned standard will still be investigated in the rock excavation blasting of abutment slot below EL.610m. Through the investigation of the safety control standard on slope excavation blasting of XiLuoDu WaterPower Station and the valuable materials obtained from on-site tests, the present work will contribute to the new blasting safety control standard for 300m double-curvature arch dam.