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鹧鸪山隧道全长4448m,是我国目前海拔最高的特长公路隧道,具有高海拔、高寒、地质复杂、运营通风困难等特点.文章主要介绍了设计和施工阶段对冻胀冻融、运营通风、复杂地质、变形及坍方等采用的主要工程技术措施. 相似文献
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高尔寺隧道位于国道318线康定县与雅江县交界处,为单洞双向行车特长高海拔越岭公路隧道,目前隧道工程风险评估处于起步阶段.文章遵循“公路桥梁和隧道工程设计安全风险评估指南”的要求,同时参照了国内外其它行业隧道工程风险管理规范或规程,针对高尔寺隧道特点,采用了隧道分段风险评估流程、基于工程类比的检查表法风险辨识和专家调查法风险估测进行了隧道设计阶段的安全风险评估,分析了潜在的风险事件和风险等级,以及有效的风险控制.在无现行规范可循的情况下,进行了设计阶段隧道工程安全风险评估工作的实践,具有一定的参考意义. 相似文献
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文章介绍了秦岭终南山特长公路隧道通风系统规模以及国内外竖井的主要施工方法及各自的适用条件和优缺点;同时结合秦岭终南山公路隧道通风竖井的设计,探讨了其适用的施工方法,为类似工程提供参考依据。 相似文献
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文章介绍了四人八垴隧道通风方案、通风井井位选择、斜井与竖井的方案比选,并确定在ZK20+030处设置通风斜井.叙述了斜井平纵面、净空断面、衬砌结构、防排水的设计原则、思路及方案比选;斜井井底借鉴了分岔式隧道设计,技术创新方面采用叉洞结构,由大拱段、连拱段、小净距段三部分组成,使斜井与送排风联络风道连接平顺、顺畅,减少通风阻力,降低运营费用.初步拟定了斜井的施工方法,提出了斜井设计与施工的一些经验,可望为类似工程的设计、施工提供参考. 相似文献
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《现代隧道技术》2017,(6)
冻胀力是寒区隧道病害的主要影响因素之一,研究冻胀力量值和分布对寒区隧道保温设计具有重要意义。文章分析总结了目前几种冻胀模型和冻胀机理,在风化层冻胀模型的基础上建立了破碎圈冻胀模型,根据位移连续条件推导了冻胀力计算公式,采用控制变量法分析了冻胀力与影响因素关系,并用偏相关分析方法分析了各因素对冻胀力影响大小。研究结果表明:冻胀力量值与冻结深度、冻融圈冻胀率、衬砌及原始围岩的抗力系数有关;冻融圈冻胀率与破碎程度、含水率及水源补给条件密切相关;各因素对冻胀力影响关系为:冻结深度冻融圈冻胀率衬砌弹性当量抗力系数。根据工程实例计算,当冻结深度为2~3 m时冻胀力量值为7.43~11.05 MPa之间,计算值偏大于实测值。最后依据冻胀力影响因素讨论了防治冻胀力的工程措施,可为寒区隧道保温设计与施工提供借鉴。 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