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从设计方面、施工方面及混凝土原材料的质量及配合比设计三方面分析了钢筋混凝土防撞护栏表面早期裂缝出现的成因,并提出了相应的预防措施,以有效防止护栏表面裂缝的产生。 相似文献
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基于1∶60节段模型风洞试验,研究了桥面附属构件对宽高比为12的宽体扁平箱梁涡激振动性能的影响。研究发现,成桥态主梁在正攻角(+5°,+3°)下发生了显著的竖弯和扭转涡振,而提高人行护栏透风率或内移检修车轨道均可同时降低两种涡振的振幅,且提高人行护栏透风率还可缩短两种涡振的风速锁定区范围。采用三维大涡模拟(3D LES)进行了施工态和成桥态的静态绕流计算,发现不合理附属构件将使箱梁上下表面均形成大范围流动分离,在迎风侧人行护栏、两道检修车轨道三处分离点产生的漩涡各自以不同频率向尾流脱落,从而诱发较强的涡振响应。 相似文献
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Tomasch E Sinz W Hoschopf H Gobald M Steffan H Nadler B Nadler F Strnad B Schneider F 《Accident; analysis and prevention》2011,43(6):2112-2120
One way to protect against impacts during run-off-road accidents with infrastructure is the use of guardrails. However, real-world accidents indicate that vehicles can leave the road and end up behind the guardrail. These vehicles have no possibility of returning to the lane. Vehicles often end up behind the guardrail because the length of the guardrails installed before hazards is too short; this can lead to a collision with a shielded hazard. To identify the basic speed for determining the necessary length of guardrails, we analyzed the speed at which vehicles leave the roadway from the ZEDATU (Zentrale Datenbank Tödlicher Unfälle) real-world accidents database.The required length of guardrail was considered the length that reduces vehicle speed at a maximum theoretically possible deceleration of 0.3 g behind the barrier based on real-world road departure speed. To determine the desired length of a guardrail ahead of a hazard, we developed a relationship between guardrail length and the speed at which vehicles depart the roadway. If the initial elements are flared away from the carriageway, the required length will be reduced by up to an additional 30% The ZEDATU database analysis showed that extending the current length of guardrails to the evaluated required length would reduce the number of fatalities among occupants of vehicles striking bridge abutments by approximately eight percent. 相似文献
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冲击荷载作用下混凝土梁中钢筋应变变化率研究 总被引:1,自引:0,他引:1
本文通过对高架道路中间隔离护栏的冲击试验研究和理论计算给出了交通工程中常遇车辆冲击作用下的混凝土梁中钢筋应变变化率的最大值估算,为深入研究结构件在冲击荷载作用下的动力响应特性提供了必要的依据。 相似文献
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跨海大桥钢结构防腐涂料设计方案 总被引:1,自引:0,他引:1
介绍了跨海大桥钢结构防护涂层(包括防锈底漆、中间漆和面漆)的选择标准、原则以及主桥钢箱梁热喷涂防腐蚀涂层体系和热喷涂锌、铝涂层钢铁防护标准.通过实例说明了跨海大桥钢箱梁防腐涂料体系设计方案及其涂装注意事项.论述了钢丝主缆涂装工艺及钢质护栏内、外表面防腐涂装方案. 相似文献
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简要介绍了GB/T25833-2010《公路护栏用镀锌钢丝绳》标准起草过程中的工作简况和制定原则,并重点介绍了该标准的主要技术内容及与相关标准的对比情况。 相似文献
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结合繁大高速公路桥梁施工实践,针对桥梁混凝土防撞护栏精细化施工技术进行了探讨,分别阐述了钢筋绑扎,模板拼装,混凝土拌和及浇筑等关键工序操作要点和施工要求,从而得出桥梁混凝土护栏精细化施工流程。 相似文献