对龙滩碾压砼大坝断面设计的建议

对龙滩电站碾压砼坝的断面设计计算．提出：建基面的抗滑稳定与碾压砼层间稳定不同；龙滩碾压砼的胶凝材料用量按不同高程上、中、下三个层次进行碾压砼级配选择．上部水泥６０ｋｇ／ｍ３．粉煤灰９０ｋｇ／ｍ３；中部水泥用量６５ｋｇ／ｍ３．粉煤灰１００ｋｇ／ｍ３；底部水泥用量７５ｋｇ／ｍ３．粉煤灰１０５ｋｇ／ｍ３。碾压砼的层间抗剪强度指标上部ｆ＇为１．１．ｃ＇为０．８ＭＰａ；中部ｆ＇为１．１，ｃ＇为１．０ＭＰａ；底部ｆ＇为１．１．ｃ＇为１．３ＭＰａ。碾压砼的层间稳定计算．采用不同安全系数计算式，即基本组合；Ｋｆ＇采用２．０；Ｋｃ＇采用１０；坝的宽高比在０．７５～０．８之间较为理想。

Proposition for Section Design of Rolled Concrete Dam of Longtan Hydropower Project

By the calculation of design of rolled concrete dam of Longtan hydropower project, proposition is put forward as follows: Stability against sliding between rock foundation and dam interface are different from that of rolled concrete lifts interfaces. The proportion of cementitious material contents of the rolled concrete should be different on different levels of the dam. The contents of cement and fly ash in upper level are 60 kg/m3 and 90 kg/m3 respectively, 65 kg/m3 and 100 kg/m3 respectively in middle level, and 75 kg/m3 and 105 kg/m3 respectively in low level. Shear strength indexes of the rolled concrete lifts interfaces are adopted as follows:In upper level,f' is 1. 1 and of is 0. 8 MPa;in middle level, f' is 1. 1 and c' is 1. 0 MPa; In low level, f' is 1. 1 and c' is 1. 3 MPa. The calculation of stability of the rolled concrete lifts interfaces are conducted by A equation which contains different satety factors. The equation is where Kf' is 2. 0,Kc' is 10. The width/height ratio of the dam from 0. 75 to 0. 80 is quite ideal.