西北地区哈密抽水蓄能电站隧洞洞口段边坡支护效果及抗震分析

Analysis of Slope Support Effect and Seismic Resistance of Tunnel Opening Section of Hami Pumped Storage Power Station in Northwest China

为分析强震作用下洞口段岩土质边坡与支护和洞室结构的动力响应规律,以西北地区哈密抽水蓄能电站洞口段工程为例,先提出综合治理方案;后采用现场监测和FLAC^(3D)数值模拟相结合的方法分析治理效果;最后在强震荷载下,分析了支护结构及洞室对岩土质边坡动力响应的影响,并探讨给出一些洞口段工程抗震设防建议。结果表明,治理后稳定系数从1.140增大至1.473,增幅达29.2%;支护结构的施加有效降低了坡面和洞顶轴线的加速度和位移;洞室的存在相较于坡面动力放大效应的影响,对洞轴线影响更大;通过分析坡面和隧洞轴线拱顶衬砌加速度,马道对边坡抗震十分重要,建议该工程抗震设防长度取3.4~4.8倍洞径之间。

In order to analyze the dynamic response law of geotechnical slope, support and cavity structure under strong earthquake, taking a cavity section project in northwest China as an example, this paper firstly proposed a comprehensive management plan and then analyzed the management effect by combining field monitoring and FLAC^(3D) numerical simulation. Finally, the effect of support structure and cavern chamber on the dynamic response of rocky soil slope was analyzed under strong seismic load, and some suggestions for seismic protection of cavern section were discussed. The results show that after the treatment, the stability coefficient increases from 1.140 to 1.473, an increase of 29.2%;The imposition of the support structure effectively reduces the acceleration and displacement of the slope and cave roof axis;The presence of the cave chamber has a greater impact on the cave axis compared with the impact of the slope dynamic amplification effect;By analyzing the acceleration of the slope and the tunnel axis vault lining, the maddle is very important for the slope seismic resistance. It is suggested that the seismic protection length of the project should take the range of 3.4 and 4.8 times the diameter of the cave.