Case studies are presented for two concrete lined channels shaken by strong ground motions during the 1994 Northridge earthquake, the high speed channel （HSC） and bypass channel （BC）, on the Los Angeles Department...Case studies are presented for two concrete lined channels shaken by strong ground motions during the 1994 Northridge earthquake, the high speed channel （HSC） and bypass channel （BC）, on the Los Angeles Department of Water and Power＇s Van Norman Complex. Performances of these two channels as they pass through different subsurface materials identify several important seismic aspects and the critical role of geotechnical earthquake engineering in assessing channel behaviors. Preliminary evaluations using detailed mapping of channel cracks, permanent ground movements, subsurface profiles, and nearby strong ground motion recordings from the 1994 earthquake show that the channel liners may have been damaged from both transient motions and permanent ground movements. Damage from permanent ground deformations is obvious by observation; therefore simplified analyses are presented only for transient movements. Site specific transient response analyses are performed to provide an initial assessment of the differing effects from transient and permanent ground movements on HSC and BC liner damage. These case studies are helpful for introducing the potential for lifeline damage from transient movements within zones of permanent ground movement, a concept not well understood in the earthquake engineering community展开更多
针对在越江海高水压水下超大直径盾构隧道联络通道施工过程中缺乏足够的工程技术标准和案例经验、设计与施工面临众多挑战问题,以广州海珠湾超大直径盾构隧道区间的6条联络通道工程为例,对工程地质补勘资料及现场施工情况进行分析,揭示...针对在越江海高水压水下超大直径盾构隧道联络通道施工过程中缺乏足够的工程技术标准和案例经验、设计与施工面临众多挑战问题,以广州海珠湾超大直径盾构隧道区间的6条联络通道工程为例,对工程地质补勘资料及现场施工情况进行分析,揭示原矿山法设计施工方案存在的不足,并基于此提出“矿山法结合地层冻结加固方案”和“机械顶管法施工方案”2种优化方案;随后在安全性、经济性、施工工期等方面对不同工法进行综合优选分析,同时引入碳排放指标进行绿色低碳评估。研究结果表明:1)机械顶管法在安全性和施工效率上优于其他方案,能够显著缩短施工周期;2)相比矿山法结合地层冻结加固方案,机械顶管法方案碳排放量减少了2 747.51 t CO_(2e)。展开更多
文摘Case studies are presented for two concrete lined channels shaken by strong ground motions during the 1994 Northridge earthquake, the high speed channel （HSC） and bypass channel （BC）, on the Los Angeles Department of Water and Power＇s Van Norman Complex. Performances of these two channels as they pass through different subsurface materials identify several important seismic aspects and the critical role of geotechnical earthquake engineering in assessing channel behaviors. Preliminary evaluations using detailed mapping of channel cracks, permanent ground movements, subsurface profiles, and nearby strong ground motion recordings from the 1994 earthquake show that the channel liners may have been damaged from both transient motions and permanent ground movements. Damage from permanent ground deformations is obvious by observation; therefore simplified analyses are presented only for transient movements. Site specific transient response analyses are performed to provide an initial assessment of the differing effects from transient and permanent ground movements on HSC and BC liner damage. These case studies are helpful for introducing the potential for lifeline damage from transient movements within zones of permanent ground movement, a concept not well understood in the earthquake engineering community
文摘针对在越江海高水压水下超大直径盾构隧道联络通道施工过程中缺乏足够的工程技术标准和案例经验、设计与施工面临众多挑战问题,以广州海珠湾超大直径盾构隧道区间的6条联络通道工程为例,对工程地质补勘资料及现场施工情况进行分析,揭示原矿山法设计施工方案存在的不足,并基于此提出“矿山法结合地层冻结加固方案”和“机械顶管法施工方案”2种优化方案;随后在安全性、经济性、施工工期等方面对不同工法进行综合优选分析,同时引入碳排放指标进行绿色低碳评估。研究结果表明:1)机械顶管法在安全性和施工效率上优于其他方案,能够显著缩短施工周期;2)相比矿山法结合地层冻结加固方案,机械顶管法方案碳排放量减少了2 747.51 t CO_(2e)。
