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从刚度、强度、稳定性等方面对现浇桥梁施工中搭设的碗扣式钢管脚手架进行结构计算,并介绍支架搭设中应注意的问题. 相似文献
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以福州绕城高速公路(西北段)RAll合同段洋门互通c匝道桥工程为例,介绍了现浇箱梁施工中扣件式钢管支架的设置方案,并对满堂支架各部分进行受力荷载验算.分别阐述了预压及拆除,并提出施工时注意事项,以保证工程的质量、安全、进度. 相似文献
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本文介绍了成都珠峰宾馆主楼加层工程中,采用扣件式钢管井架作为垂直运输机械装置的设计、施工要点以及实施效果。 相似文献
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根据西宁火车站综合改造片区路网工程设计,为保证施工安全并考虑降低成本等因素,对互通立交A匝道现浇箱梁采取了WJΦ48mm×3.5mm碗扣式钢管满堂支架。本文详细介绍了现浇混凝土箱梁碗口支架体系的设计方案和验算步骤,可供工程技术人员借鉴。 相似文献
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钢管拱肋安装是钢管混凝土拱桥施工的关键技术。本文论述了鸿福路跨河钢管拱桥钢管拱肋采用墩式支架法安装的施工方法,施工工艺,以及机具设备等施工技术。 相似文献
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文章介绍了公路项目平面交叉口工程安全评价的目的,分析了影响公路项目平面交叉口工程安全的因素,并以广西来马高速马山南互通出口与G210公路平交口项目为工程实例,从平纵线形、视距、交叉口间距、交通工程、施工方案等方面对公路项目平交式工程进行安全评价。 相似文献
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《Transportation Research Part A: Policy and Practice》2000,34(6):481-496
Introducing spiral curves before and after horizontal circular curves has been widely accepted to enhance traffic safety, highway esthetics, sight distance, and driver comfort. Though, vertical curves are still designed as parabolic curves that are connected directly to the tangent (without transitions). In this paper, a cubic polynomial is used to develop a vertical transition curve before and after the parabolic vertical curve. The resulting curve, called transitioned vertical curve, consists of transition-parabolic-transition segments. Detailed mathematical formulation and derivation of the instantaneous elevation, grade, rate of curvature, and offset from the first tangent at any point are presented. The highest (or lowest) point on a transitioned crest (or sag) vertical curve, where the instantaneous grade equals 0, is determined as it is of particular importance in highway drainage design. The minimum length of a transition curve is derived based on the criterion of driver comfort. In addition, guidelines are provided to identify the conditions where the drainage of surface water on transitioned curves can be a concern. Finally, the layout of the transitioned vertical curve is described and illustrated using two numerical examples. The new transitioned vertical curve, which exhibits striking similarities to the spiraled horizontal curve, should enhance the design of highway vertical alignments. 相似文献
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《Transportation Research Part A: Policy and Practice》2000,34(7):565-584
The mathematical properties of a new vertical curve that consists of a transition curve (cubic polynomial), a parabolic curve, and another transition curve have been presented in a companion paper. The present paper addresses the sight distance characteristics of this new curve, called transitioned vertical curve. The minimum sight distance and the required curve length are analytically derived for both crest and sag curves, considering various cases related to the minimum sight distance and the lengths of transition and parabolic curves. Using the developed analytical models, example design graphs are established for the length requirements of the transitioned vertical curve based on the upper range of stopping sight distance presented by the American Association of State Highway and Transportation Officials. The transitioned vertical curve, which resembles the spiraled horizontal curve commonly used in practice, represents an alternative to the simple vertical curve especially for sharp vertical alignments. 相似文献
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传统真空预压技术机理通过垂直排水通道排水板与水平排水通道砂垫层排水。文章介绍的采用直排式真空预压技术,不仅能节省水平排水通道砂垫层,而且能将排水板直接与滤管缠绕连接,提高了真空度的传递效率。试验证明,直排式真空预压技术相对传统工艺,不仅加固效果理想,而且既缩短了工期,又节省了工程造价。 相似文献