【摘要】 爆破施工振动对邻近已有洞室的影响及其控制是隧洞工程中的关键技术问题。新建隧洞在与已有隧洞间距比较小的情况下进行爆破开挖,爆破开挖产生的爆破波会危及已有隧洞围岩和衬砌结构的安全与稳定性。结合锦屏一级水电站左岸洞群工程施工爆破的相互影响分析课题,应用动力有限元数值模拟,研究不同的围岩类别、洞室间距、岩体阻尼比、单响药量情况下爆破振动对邻近已有洞室围岩和衬砌结构的影响问题。根据洞壁振动速度允许值与隧洞衬砌在邻近爆破振动波作用下的动拉应力值,得出施工爆破洞室的最小间距及单响药量控制:III类围岩、洞间距为(1.5～2.0)D时,单响药量应控制在15 kg以内;IV类围岩、洞间距为(1.5～2.0)D时,单响药量应控制在12 kg以内;V类围岩、洞间距为(1.0～1.5)D时,单响药量应控制在10 kg以内。研究结果为实际工程的施工和设计提供了参考和依据。更多还原

【Abstract】 The effect of blasting vibration on a new tunnel adjacent to existing tunnel and its control technology are the key issues of tunnel project.Since the new tunnel is close to existing tunnel,the seismic wave-induced by blasting endangers the safety and stabilization of surrounding rock and lining of existing tunnel.For different tunnel spacing distances,different types of surrounding rocks and safety explosive charge adopted in project are in need of determination.On the basis of the simulation with the dynamic FEM,the effects of blasting vibration on the surrounding rock and lining structure of adjacent existing tunnel with different types of surrounding rocks,tunnel spacing distances,rock mass damping ratios,explosive quantity circumstances are studied combining with mutual influences of blasting on left bank tunnels project construction of Jinping I Hydropower Station.According to the velocity of tunnel lining vibration and lining dynamic tensile stress caused by adjacent tunnel blasting vibration,the minimum spacing distance and explosive charge of blasting construction tunnels with surrounding rock grade III are obtained.When tunnel spacing distance varies from 1.5D to 2.0D,the explosive charge should be controlled less than 15 kg;for surrounding rock grade IV with the tunnel spacing distance 1.5D–2.0D,the explosive charge should be less than 12 kg;for surrounding rock grade V with tunnel spacing distance 1.0D– 1.5D,the explosive charge should be less than 10 kg.The achieved results can provide the references and analytical analysis to the construction and design of practical project.更多还原