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目前虽然国内外地下工程已有许多隧道工程穿越公路、铁路、既有建(构)筑物等相关施工经验和教训,但穿越机场在路网规划中尚不多见,因此依托下穿机场跑道暗挖隧道工程,针对飞机动荷载作用下的围岩压力展开研究。首先根据地质条件和工程支护特点,给出监测方案;然后根据理论知识计算土压力;最后,对动、静荷载作用下暗挖隧道围岩压力的现场试验进行对比分析。研究结果表明:动、静荷载作用下试验断面的围岩压力均在允许值范围内,动载作用下断面围岩压力整体增大45%~88%。从分布形态看,动、静荷载作用下围岩压力分布都不均匀,相对而言动荷载作用下围岩压力分布更为不均,但二者均表现出:隧道拱顶、底部处围岩压力较大,拱腰处相对较小。 相似文献
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美国“福特”级航母“一站式保障”技术特征和关键技术分析 总被引:4,自引:0,他引:4
“一站式保障”是美军“福特”级航母为提高舰载机出动架次率所采用的舰载机出动保障方式。通过对“福特”级航母“一站式保障”方式的深入分析解读,定义“一站式保障”的概念、作业流程、技术特征和优势,并在此基础上,提炼出实现“一站式保障”所需要突破的一系列关键技术,以及“福特”级航母实现“一站式保障”的设计经验对其他国家航母设计的启示。 相似文献
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Abstract Airport slot misuse disturbs the efficient and continuous operation of capacity-constrained airports, leading to congestion and delay problems. Deviations from the coordinated schedule in regional airport systems that feature seasonal demand and delays in certain peak periods are studied in this article. The Greek airport system is considered as a case study. Deviations are quantified by computing the difference between scheduled and actual aircraft arrival times as well as the hourly slot capacity utilization ratio. Two collective indicators for airport benchmarking are proposed. An in-depth analysis of slot allocation deviations and the delays they cause is carried out for a representative sample of airports that are classified according to the proposed indicators. A brief discussion on potential measures to mitigate slot misuse is also presented. 相似文献