基于风险评估理论,针对姚河坝小净距隧道雅安端小净距、大偏压、差地质情况,研究了暗挖进洞的位置,通过分析了各方案的风险等级,确定了错开进洞方案,并对比分析了可选择的子方案,探讨关键点及注意事项,对类似工程设计具有参考价值。 Based on the risk assessment theory, according to the small clear distance, large bias and poor geological conditions of Yahe dam with small clear distance, this paper studies the position of undercutting tunnels. By analyzing the risk level of each plan, Hole program, and comparative analysis of alternative sub-programs to explore the key points and precautions, for similar projects with reference value.