大悬臂盖梁桥梁成桥适用性研究

发布时间：2018-03-31 03:39

本文选题：大悬臂盖梁　切入点：有限元分析　出处：《长安大学》2014年硕士论文

【摘要】：在城市桥梁建设中，大悬臂盖梁的应用日益增多，大悬臂盖梁常与流线型桥墩搭配，线型优美，造型流畅。由于大悬臂结构体型庞大，内部体系受力复杂，在计算分析以及设计方法上仍然存在着尚未被完全理解和有效运用的问题，深入探讨和研究此类结构具有一定的现实和经济意义。同时，，随着社会经济的快速发展，我国公路运输中的车辆类型日益复杂，车辆大型、重型的发展的趋势明显。同时公路上行驶的密集大型、重型车辆所产生的效应，已远远超出了现行规范规定的荷载等级，由先前交通状况所得出的规范中的荷载标准已不能代表这些现行重载交通下的汽车荷载。本文针对大悬臂预应力盖梁这一新颖结构形式，对其在设计荷载和在重载荷载作用下的安全性进行研究。基于桥位附近宣平堡的调查数据，对车辆荷载数据中的各项参数进行了统计分析，得出了测点道路的分车型的荷载概率分布，计算分析了桥梁结构在现有调查荷载下的效应值。在公路-I级和调查重载汽车荷载下，计算了盖梁的承载力安全系数，并对盖梁的应力状态进行了分析，确定了各类型盖梁的最不利截面。在Midas Civil和MIDAS FEA实体分析的基础上，提出了承载能力安全系数和最不利截面压应力储备可作为各类型盖梁安全性评价的指标。 Midas Civil模型计算结果表明，Y外倾型桥墩盖梁安全系数大于直立式桥墩盖梁。各类型盖梁在公路-I级荷载下安全系数均较高；在重载荷载下，Y外倾型桥墩盖梁仍有较高的安全系数，直立式桥墩的安全系数仍大于1，但其量值相对较小。Y外倾型、直立式桥墩盖梁的最不利截面均位于墩梁固结区域，位置稍有不同。在两种运营荷载下，对应截面均有一定压应力储备，其中直立式桥墩盖梁重载荷载下最小压应力Midas Civil模型计算结果为-2.55MPa，MIDAS FEA计算为-4.01MPa。通过对典型盖梁的评价指标分析表明，文中各类型大悬臂盖梁均满足设计荷载和重载荷载下的适用性要求。
[Abstract]:In the urban bridge construction, the application of the large cantilever cover beam is increasing day by day. The large cantilever cover beam is often matched with the streamline piers, the shape is graceful and the shape is smooth. Because of the large cantilever structure, the internal system is complicated. There are still some problems in calculation analysis and design method which have not been fully understood and used effectively. It is of practical and economic significance to explore and study this kind of structure in depth. At the same time, with the rapid development of social economy, the types of vehicles in highway transportation in our country are increasingly complex, and the development trend of large and heavy vehicles is obvious. The load standard obtained from the previous traffic condition can no longer represent the vehicle load under the current heavy haul traffic. Based on the investigation data of Xuanping Fort near the bridge site, this paper studies the safety of large cantilever prestressed capping beam under the action of design load and heavy load. Based on the statistical analysis of the parameters in the vehicle load data, the load probability distribution of the sub-type of the measured road is obtained. The effect value of bridge structure under the existing investigation load is calculated and analyzed. Under the load of highway class I and investigation heavy duty vehicle, the safety factor of the cover beam's bearing capacity is calculated, and the stress state of the cover beam is analyzed. Based on the solid analysis of Midas Civil and MIDAS FEA, it is suggested that the safety factor of bearing capacity and the compressive stress reserve of the most unfavorable section can be used as indexes for evaluating the safety of each type of capping beam. The calculation results of Midas Civil model show that the safety factor of cover beam of overcast piers is higher than that of vertical piers, the safety factors of all types of cover beams are higher under highway class I load, and the safety factor of cover beams of Y type pier is still higher under heavy load. The safety factor of vertical pier is still greater than 1, but its value is relatively small. The most unfavorable section of cover beam of vertical pier is located in the consolidation area of pier beam, and the position is slightly different. The corresponding sections have a certain compressive stress reserve, in which the minimum compressive stress Midas Civil model under heavy load is -2.55 MPA MIDAS FEA and -4.01 MPa. Through the analysis of the evaluation index of the typical cover beam, it is shown that each type of large cantilever cover beam in this paper meets the requirements of applicability under the design load and the heavy load.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4;U446

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