松塔拱坝坝肩抗滑稳定分项系数研究

Research on Abutment Sliding Stability Partial Factors of Songta Arch Dam

松塔混凝土拱坝坝肩设计过程中分别采用了水利行业和电力行业混凝土拱坝设计规范对其抗滑稳定安全系数进行计算,而对于电力行业混凝土拱坝设计规范中规定的各分项系数取值合理性和正确性一直备受争议。为此,提出用相对安全率论证电力行业规范规定的各分项系数取值的合理性和正确性。结果表明,电力行业规范采用的岩石抗剪强度指标、各分项系数及其变异系数取值正确、合理,两规范计算得到的安全系数标准值属于同一风险水平,并提出在建筑物、安全级别均为1级时拱坝坝肩抗滑稳定允许可靠指标取值为4.2偏低。

The safety factor of abutment sliding stability of Songta Arch Dam is respectively calculated by using the specifications of SL 282-2003 and DL/T 5346-2006 in the design of Dam. Because the rationality and correctness of the determination of partial factor values in arch dam design specification of DL/T 5346-2006 has always been doubted, the relative safety rate is proposed to be used to demonstrate the rationality and correctness of the determination of partial factor values. The results show that： （a） the values of shear strength parameters, partial factors and variation coefficients of rock used in the specification of DL/T 5346-2006 are correct and reasonable; （b） the safety factors calculated by two specifications have same risk level; and （c） the safety level of abutment sliding stability of arch dam is slight lower when the allowed reliability indicator is valued as 4.2 for Class I structure with Class I security level.