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文章针对图山寺瓦斯隧道的特点及瓦斯的危害,介绍了图山寺高瓦斯隧道施工中采取的瓦斯防治措施,提出了隧道结构的瓦斯安全设防技术,并指出在高瓦斯隧道施工中瓦斯防治的关键是利用合理的通风方式,瓦斯堵排的主要措施是隧道结构设置瓦斯隔离层和排气管,为其他类似高瓦斯隧道工程施工提供了借鉴。 相似文献
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隧道作为地下工程,在勘察设计阶段将会遇到一些不可控和不可预见的因素,瓦斯就是其中之一。青海省祁连山2#隧道在掘进过程中发现了瓦斯等有害气体,成为青海省内第一座高瓦斯公路隧道。瓦斯出现后,对工程进度、施工安全都带来了较大的困扰。在保证安全、质量的前提下,依据《公路瓦斯隧道设计与施工技术规范》(JTG/T 3374-2020)并结合《铁路瓦斯隧道技术规范》(2019)从严提出针对性的处置方案。针对洞内相关段落高瓦斯及硫化氢等气体提出处置措施,明确设防段落和设防等级。在制定方案时,综合考虑洞内同时作业人数、最小风速、爆破时需要排除的炮烟量、机械设备总功率和瓦斯涌出量等因素,经过风量和瓦斯涌出量的计算,科学合理地配置通风设备、确定通风方案。在现场施工中以工程地质分析为基础,通过粗查、精查、物探、钻探等手段,结合最新取得的地质调查和勘察资料进行综合判定,使祁连山2#隧道的施工安全和质量处于可控状态。实践表明,隧道施工中出现高瓦斯并不可怕,只要及时制定科学合理的应对措施,坚持勤观测、早预判的原则,就能有惊无险地通过高瓦斯工区施工段。本文件拟通过总结祁连山2#隧道高瓦斯及硫化氢等气体的一些处置措施,... 相似文献
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结合图山寺隧道施工中瓦斯燃烧的必要条件,从“降低洞内瓦斯浓度,尽量减少热源,降低热源的温度”的角度出发,采取“禁绝火源、及时预报、排堵结合、及时封闭、强化通风,降低浓度”等配套施工技术,建立和健全了安全制度,制定并切实落实了相关安全措施,取得了高瓦斯隧道施工的完全成功,可为类似工程借鉴. 相似文献
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"超限超载"的产生与发展,蕴藏着深层的内在运作机理,包含着复杂的经济社会原因.其中道路货物运输价格体系的长期扭曲失衡与成本结构的有欠合理是一个不容忽视的根本原因.为此,公路所开展了货运市场运价与成本"治超"专项研究,先后历时一个多月,行程数千公里,深入7省市运输一线,对21家典型企业和个体业户的23辆货车、24条线路进行了跟踪调查,获取了大量的第一手资料与原始数据,并对此进行了解析. 相似文献
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Ngila Mwase† 《运输评论》2013,33(3):191-206
Zambia has attempted to reduce her excessive transport dependency on her traditional transport routes via South Africa and the former Portugese colonies. The costly construction of the Tanzania‐Zambia Railway (TAZARA) was part of this diversification strategy. This article examines the nature, extent and direction of Zambian traffic, including its historical evolution. It explores further the place of TAZARA among the various routes to Mozambican, Angolan and South African ports, and the ensuing actual and potential competition. Future traffic patterns will be influenced not only by the direct and service‐oriented costs of the different lines, but also by the region's volatile and uncertain political climate. 相似文献
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Robert E. Paaswell 《Transportation》1973,2(4):351-371
An examination of current population statistics shows that in the U.S. more than half of the population is without immediate access to a car, and in the U.K. more than three-fifths of the population is without access to a car. This phenomenon has been accentuated by national investment in both countries in major highway programs. The term carless refers to more than just households that own no cars. It extends, in households with cars to those without licenses (old and young), the handicapped, and even the licensed drivers who have no access to the family car when it is in use elsewhere (e.g. at work). The most severely effected are those in urban areas and especially the urban poor. Transportation expenses are limited for the poor when other family expenditures (food, shelter) take a high priority. Once the work trip has been satisfied, money for other trips, for the poor, is not always available. One solution to cost-free travel is pedestrianism (walking), but this too is difficult in urban areas where the pedestrian has been overlooked in favor of the car. Solutions to problems of the carless include dial-a-ride, better public transit, and better design of urban form. 相似文献
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针对海中箱梁现浇施工中的工程量大、工期紧迫、悬臂法施工不能满足工期要求和施工难度大等问题,文章结合青岛海湾大桥箱梁现浇施工实践,介绍以钢管桩支撑作为承载基础,采用贝雷梁与碗扣式支架相结合的支架,成功地解决现浇箱梁施工难题的方法。 相似文献
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章简略地分析了单线循环固定抱索器索道抱索器移位及索道频繁开停车对索道运载索、驱动机减速器、制动器等部件使用寿命的影响,并提出了相应的减轻这些影响的技术对策。 相似文献