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Research purposes: The large-span transition section tunnel of the Badaling Great Wall station on the Beijing-Zhangjiakou high-speed railway with the maximum excavation width of 32.7 m, and the largest excavation area of 494.4 m 2 , is the world's biggest traffic tunnel in the world with the largest excavation width and excavation area, which has difficult construction and high security risks. The initial support system of tunnel is mainly realized by prestressed bolt, prestressed cable and shotcrete. After test, anchor cable tension using the traditional anchor cable construction technology can't meet the design requirements, at the same time, it takes about 30 days to achieve prestressed tensioning. Therefore, we need to study the high-performance fast tensioning prestressed anchor cable technology, to effectively control surrounding rock deformation, to ensure the safety of construction, improve construction efficiency. Research conclusions:(1) The traditional anchor cable construction technology is adopted. The anchor cable tension value is mainly controlled by the grip force between the anchor rope and grouting body and the cohesive force between grouting body and surrounding rock. (2) The grip force between the anchor rope and the grouting body can be increased by about 2 times by increasing the "barb"; The cohesive force between the grouting body and the surrounding rock can be increased by 1.5 times by 6 ~ 7 MPa high-pressure grouting process. (3) The modified sulphoaluminate cement slurry can reach more than 30 MPa within 1 day of the slurry strength, so as to realize fast anchor cable tension within 1 day after grouting completion. (4)The research results can be used for reference in similar prestressed anchorage cable construction projects. © 2018, Editorial Department of Journal of Railway Engineering Society. All right reserved. 相似文献
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以格丑沟特大桥136m钢管混凝土拱桥为研究对象,采用MIDAS有限元分析程序,建立空间有限元计算模型,得出常见的失稳屈曲模态;分析横撑样式及布置位置对拱桥稳定性的影响,为该桥的设计、施工、监控及维护提供参考。 相似文献
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针对现有汽车检测线系统复杂的特点,在介绍现场总线技术和检测线结构的基础上。以CAN总线控制器SJA1000作为汽车检测线各单元的核心控制器,提出了基于CAN总线的汽车检测线网络系统设计改造方案。该方案简化了检测线网络系统结构,系统具有模块化、实时性和开放性等特点。实践表明,CAN总线技术在汽车检测线上的应用可以提高车辆的检测速度和质量,降低检测线改造和使用维护成本,具有较大的应用价值。 相似文献
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快速公交系统在大城市的应用研究 总被引:2,自引:0,他引:2
城市化进程导致城市规模和人口密度不断增加,大城市内部交通时常出现拥挤.修建道路的步伐总不能很好地满足出行需求,同时小汽车数量的日益增加,使得出行越来越困难.快速公交系统由于其客流运送能力大、运送速度快的特点得到了世界各地的重视,通过与常规公交和地铁的对比分析,得出我国大城市应建立快速公交系统的观点. 相似文献
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Xinjie Zhang Yi Yang Konghui Guo Jiming Lv Tao Peng 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(11):1748-1763
For vehicle rollover control systems, an accurate and predictive rollover index is necessary for a precise rollover threat detection and rollover prevention. In this paper, the contour line of load transfer ratio (CL-LTR) and the CL-LTR-based vehicle rollover index (CLRI) are proposed, describing LTR threshold and LTR change rate precisely, providing an accurate prediction of vehicle rollover threat. In detail, the CL-LTR is proposed via the roll dynamics phase plane analysis, and its analytical solution of one-degree-of-freedom vehicle roll model and extension for full vehicle are derived. Moreover, the predictive CLRI is proposed and evaluated via vehicle dynamics study. The results demonstrate that vehicle rollover threat is predicted accurately based on the CLRI, which shows benefits for the vehicle rollover prediction and stability control. 相似文献
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根据简奈特(Genette)超文本概念中要着重关注文化观点,探讨了汉语与英语由于源于各自不同的语境,在语言的结构、语意及其语言逻辑思维和推理等的理解翻译表达上,如何挖掘其文化意义.并通过理论和实例阐释了英汉两种语言互译的翻译策略. 相似文献
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标准化效益评估作为全面衡量标准化项目在军用装备研制、生产、验收等领域作用的有效途径,是现代军用装备标准化管理的重要组成部分。文章分析研究了军用装备标准化效益分析与评估的主体、目标、评估流程、评估指标体系的确定以及评估方法等内容,指出了今后工作的重点方向。通过开展军用装备标准化效益评估,可以获得可信的定量和定性分析评估结论,有效发挥标准化工作对军用装备发展的促进作用。 相似文献
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有效预测崩塌灾害致灾区域及其危险性,为合理规划土地资源、实施崩塌防灾减灾提供重要指导借鉴。遴选斜坡坡形、坡度、坡高、下垫面岩土性质、落石质量、落石形状和落石的岩性条件等7个因子作为崩塌区域致灾危险性评价指标;通过指标量化,采用广义集对分析法和层次分析法相结合,确定了崩塌区域致灾危险性评价指标权重;采用同、异、反联系测度提出了落石停积在各承灾区的可能性评价模型,并根据落石停积位置的预期概率将崩塌致灾危险性分为极高危险、高危险、中危险、低危险和极低危险等5个危险性等级。最后通过现场落石试验,验证了危岩崩塌区域危险性广义集对-层次耦合评价方法的合理性 相似文献