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高速公路中钢筋混凝土圆管涵的内力计算探讨 总被引:1,自引:0,他引:1
针对目前高速公路中钢筋混凝土圆管涵普遍开裂这一现象,本文对国内现行有关规范中关于钢筋混凝土圆管涵内力计算方法进行了分析、比较和评述,提出了比较符合实际情况的高速公路中钢筋混凝土圆管涵的内力计算方法。 相似文献
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张文 《内蒙古公路与运输》2021,(2):34-36
结合110国道圆管涵加固工程实例,介绍了粘贴钢板条加固钢筋混凝土圆管涵技术原理,阐述了粘贴钢板条加固钢筋混凝土圆管涵施工工艺,指出粘贴钢板条加固圆管涵具有施工周期短、不中断交通等优点,对今后类似工程具有参考意义. 相似文献
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圆管涵承载能力的研究 总被引:2,自引:1,他引:1
采用有限元方法和结构力学方法对圆管涵进行力学分析,通过对2种方法之结果的比较,定量分析了早几年圆管涵普遍开裂的原因。在此基础上提出一种圆管涵的合理结构形式,并介绍了这种结构形式在实际应用中的良好效果。理论和实践证明,提出的这种结构形式具有优良的结构承载性能。 相似文献
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钢筋混凝土圆管涵是公路排水设计中常用的构造物,其管节接头处理是否恰当,直接到工程进度及质量,就钢筋混凝土圆管涵的管节接头处理方法作一粗浅探讨。 相似文献
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张志耕 《内蒙古公路与运输》2006,(1):67-70
在高速公路建设过程中,出现了已完工的圆管涵工程在道路通车之前就开裂的情况。本文以内蒙古老集高速公路部分开裂圆管涵为工程背景,通过理论分析并运用大型通用有限元计算软件AN SY S8.0,对可能导致圆管涵开裂的各种原因进行了分析,结果表明,施工方法不当和混凝土收缩是引起圆管涵开裂的主要原因。 相似文献
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钢筋混凝土圆管涵破裂原因分析 总被引:2,自引:0,他引:2
在高速公路建设过程中,出现了已完工的圆管涵工程在道路未通车之前就开裂、受挤压变形等现象,文中分析了引起圆管涵破裂的原因-涵顶填土压力超过设计值、施工荷载过大及填筑方法不当等,并给出了正确的填筑方法。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):573-596
An existing driver–vehicle model with neuromuscular dynamics is improved in the areas of cognitive delay, intrinsic muscle dynamics and alpha–gamma co-activation. The model is used to investigate the influence of steering torque feedback and neuromuscular dynamics on the vehicle response to lateral force disturbances. When steering torque feedback is present, it is found that the longitudinal position of the lateral disturbance has a significant influence on whether the driver’s reflex response reinforces or attenuates the effect of the disturbance. The response to angle and torque overlay inputs to the steering system is also investigated. The presence of the steering torque feedback reduced the disturbing effect of torque overlay and angle overlay inputs. Reflex action reduced the disturbing effect of a torque overlay input, but increased the disturbing effect of an angle overlay input. Experiments on a driving simulator showed that measured handwheel angle response to an angle overlay input was consistent with the response predicted by the model with reflex action. However, there was significant intra- and inter-subject variability. The results highlight the significance of a driver’s neuromuscular dynamics in determining the vehicle response to disturbances. 相似文献
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预应力曲线箱梁和异形箱梁的研究 总被引:7,自引:0,他引:7
近年来 ,国内外学者对曲线箱梁和异形箱梁的静力分析理论和计算方法作过大量的研究 ,但这些理论和方法在某种程度上都存在着一定的局限性 ,特别是在实际设计工作中 ,运用起来不能得心应手。为此本文在综合前人已取得经验下 ,针对桥梁结构设计中分析曲线箱梁、异形箱梁 ,经常遇到的难题进行了研究 ,建立一个较为完善的理论和方法 ,编制了等参元空间分析程序。在实际工程中进行实桥试验 ,验证了本文理论和方法的正确性。本文的研究工作更准确描述了箱梁的荷载响应 ,为设计人员提供直观的设计依据。对曲线箱梁和异形箱梁受力特性有了更一步的理解 ,并提出了新的见解 相似文献
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If a vehicle that meets emission regulations operates sufficiently for a long time under low speed and low load conditions,
soot contained in the exhaust gas is accumulated on the inner surface of the exhaust system. This soot deposition problem
occurs frequently in all diesel cars. However, when a vehicle is placed under the conditions of sudden start and sudden acceleration
after city mode driving for a long time, the deposited soot is abruptly blown up with the soot produced during fuel combustion.
In the present study, the main cause of the abrupt outburst of deposited soot is investigated to overcome this adverse phenomenon.
First, we developed a method to quantify the amount of the exhausted soot particles (or the accumulated soot particles) by
measuring the opacity that represents the contamination level of the exhaust gas due to soot particles. Using this measuring
scheme for deposited soot, we found the critical conditions for engine speeds and load conditions at which soot particles
are emitted into the air without accumulation in the exhaust system using main muffler composed of three chambers. In order
to meet these critical conditions and thus to drastically reduce soot accumulation, the exhaust system using the main muffler
applied in this study must be designed to ensure that the flow velocity of the exhaust gas is higher than 62 m/s when the
back pressure at the exit of the turbocharger is under 0.08 bars. 相似文献
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该文从研究超薄磨耗层的级配的选择入手,简单分析了超薄磨耗层的结构特点和强度形成机理,给出了几种国内外常用的超薄磨耗层级配范围,并提出了将SAC-10做为其研究的设计级配。在研究超薄磨耗层沥青混合料配合比设计的基础上,通过对SAC-10沥青混合料的马歇尔试验,确定了该沥青混合料的矿料级配和最佳沥青含量。最后采用车辙试验、浸水马歇尔和冻融劈裂试验及小梁弯曲试验等一系列试验,检测超薄磨耗层沥青混合料的各项路用性能,为在实际工程中的应用提供理论依据。 相似文献
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农村公路在建设中和投入使用后,要承受车辆荷载、自然因素的影响。为了充分保证使用性能,必须在建设中和建成后确保其自身的质量,以更好地服务于广大群众。该文对农村公路建养的管理措施及有关注意事项进行了阐述,可供专业人员参考。 相似文献
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The sub-chamber type gasoline engine was suggested to be a type of clean engine, but the presence of residual gas in the sub-chamber
was a serious fault. In this experimental study, the CNG direct injection method was applied to scavenge residual gas from
the sub-chamber. The CVC (constant volume chamber) is divided into the sub-chamber and main-chamber and used as the main experimental
apparatus. Because each combustion chamber of the CVC has an injector, the injector can be used freely, at the same time or
individually. Therefore, the scavenging efficiency can be improved by changing injection times for the sub-chamber. The experimental
results demonstrated that when all the fuel was injected into the sub-chamber, the combustion duration was shortened by 30%
compared to that of injection into the main-chamber. Although residual gas was observed in the CVC, when the frequency of
injections into the sub-chamber increased, good combustion characteristics were obtained. 相似文献