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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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节点半刚性特性对钢管脚手架的使用性能影响显著。为此,文章针对不同的半刚性脚手架开展了节点性能研究,通过ABAQUS软件分别建立盘扣式脚手架节点模型及插销式脚手架节点模型,并针对节点的主要力学性能进行研究。结果表明:半刚性脚手架在荷载作用下,存在明显的非线性变化特性;在节点抗拉承载能力方面,插销式脚手架要略优于盘扣式脚手架,而在节点抗弯承载能力方面,盘扣式脚手架则要优于插销式脚手架。 相似文献
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为提高支架法在现浇桥梁中的施工效率和适用性,文章提出一种抱箍与钢管组合支架体系作为十万山大桥现浇箱梁的施工方法:结合施工特点对支架体系的整体布置进行设计,使用大型桥梁有限元分析软件Midas Civil对该支架体系建立模型,对钢管、贝雷梁和抱箍等结构进行结构计算和受力分析,优化支架体系,确保支架施工的安全。抱箍与钢管组合支架体系利用圆柱墩的结构形式将抱箍和钢管有效结合,可周转反复使用且安全系数高,对现浇箱梁的施工环境的适用性更强,整体经济性好,为现浇桥梁的支架法施工提供了经验借鉴。 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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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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Considering the influence of many factors (soil loss, frontal additional thrust, the friction force of the shield shell and the additional grouting force), a method for improving the uniform soil body movement model is pro-posed, and a mechanical calculation model is established to study the calculation method for soil body deformation caused by double-line parallel shield driving. Based on the Mindlin solutions of elastic mechanics, the theoretical solutions for soil body deformations caused by the last three factors are calculated; considering the uniform soil body movement model, the theoretical solutions for soil body deformations caused by soil loss are calculated, then the to-tal theoretical solutions for soil body deformations under multiple factors are obtained by means of superposition. The vertical surface settlement, vertical horizontal displacement, and vertical displacements of the soil body at different depths of Hangzhou Metro Line 1 are calculated to analyze the variation laws. Meanwhile the influential factors for horizontal displacement variation are studied. The research shows that with a change of depth, the settlement of the soil body changes within the scope of 10 to 13 m in the horizontal direction near where the maximum settlement occurs;the direction of the horizontal displacement of the soil body changes with a change of the positional relationship be-tween the calculation points and the tunnel; and with an increase of interval J for the two tunnels, the horizontal dis-placement of the soil body of a deep double-line tunnel decreases while the displacement near the surface changes slightly. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 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