高土石坝地震工况坝坡稳定安全系数研究

Research on Slope Stability Safety Factors of a High Earth rock Dam under Seismic Conditions

摘要:

现行碾压土石坝设计规范（DL/T5395-2007）明确规定只适用于低于200 m土石坝，随着设计施工技术的发展对于超过200 m的高土石坝坝坡设计安全标准问题亟待解决。相对安全率理论把可靠指标和安全系数置于同一平台进行关联和映射。现行碾压土石坝设计规范规定的低于200 m的土石坝坝坡稳定允许可靠指标4.2。基于风险控制原则提出200~250 m高土石坝坝坡允许可靠指标取4.45，250~300 m高土石坝坝坡允许可靠指标取4.7，相应的地震工况高土石坝坝坡稳定安全系数1.35和1.4，高土石坝工程实例地震工况下坝坡稳定安全系数均满足所提安全系数标准值。

Abstract:

The current design code for earth-rock dams （DL/T5395-2007）specifies that it applies only to earth-rock dams up to 200 m in height. With new developments in dam design and construction technology，design safety standards must be established for slopes of earth-rock dams more than 200 m high. Based on the theory of relative safety, the reliability index and safety factors associated with mapping should have the same platform.The permissible slope stability reliability indicator for a rolled earth-rock dam less than 200 m high, as specified by the current design code，is 4.2.Based on risk management principles，an allowable slope stability reliability indicator for a 200~250 m high earth-rock dam is 4.45，and that for a 250~300 m high earth-rock dam is 4.7.The corresponding slope stability safety factors for high earth-rock dams under seismic condition are 1.35 and 1.4，respectively.Slope stability safety factors for high earth rock dams under various seismic conditions were shown to meet safety standards.