超载车辆作用下箱梁顶板受力分析

发布时间：2018-01-09 06:27

本文关键词：超载车辆作用下箱梁顶板受力分析　出处：《长沙理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：箱形梁以其独特的结构特点和良好的受力性能,在近些年得到了广泛的应用,许多大跨径预应力混凝土箱形梁桥如雨后春笋般出现在祖国的大地上。我国经济的快速发展促进着交通运输业的飞速发展,各地区之间的经济贸易越来越频繁,公路桥梁的压力也与日俱增。由于超载车辆的轴重一般都较大,有可能会超过设计轴重标准,对桥梁的破坏作用是不容忽视的。箱梁顶板结构是承受负弯矩的主要部位,箱梁顶板受到过大车辆荷载作用时,顶板中轴线位置会产生较大的横向正应力,当横向正应力超过混凝土的设计抗拉强度时,顶板就会有开裂的危险。本文的主要内容及结论如下：(1)本文首先介绍了国内外连续梁桥的发展史,详细论述了国内外关于车辆超载的规定、治理措施以及对公路桥梁的破坏作用。(2)然后介绍了箱形梁的结构特点和受力特点以及对顶板进行分析时所用到的有限元理论方法。对比新旧规范关于车辆荷载的超载评价标准。通过查阅相关文献资料和交通调查报告确定了计算分析的三轴(1+22)型、四轴(1+1+22)型车辆的模型。(3)以某省某高速公路上的一座桥梁为工程研究背景,采用ANSYS建立局部模型。首先,分析了五轴、三轴、四轴车辆沿顶板中轴线偏载布置时,顶板中轴线上的应力分布特点,得出了轴数少,轴距小的车辆在同样总重的前提下,对顶板的影响比较大；超载车辆作用下,箱梁顶板应力较大的范围集中在车轮作用位置前后1米的区域。然后,计算两种不同工况中两辆三轴、两辆四轴车辆在几种不同超载程度下顶板的拉应力大小,发现在工况一中,三轴、四轴车辆分别在超载3.0倍、3.5倍；在工况二中,三轴、四轴车辆分别在超载2.5倍、3.0倍时,顶板中轴线上出现的拉应力已经超过了混凝土设计抗拉强度值,工况二比工况一对顶板的影响更大。最后,采用迈达斯Civil建立板单元模型,计算出轮压荷载作用面积的弯矩值和轴力值大小,对单位宽度正截面配筋要求进行验算,由计算可知满足要求。
[Abstract]:The box girder with its unique structure and good mechanical properties, has been widely used in recent years, many long-span prestressed concrete box girder bridges such as bamboo shoots after a spring rain like appearance in the motherland. The rapid development of China's economy to promote the rapid development of the transportation industry, regional economic and trade more and more frequently, the highway bridge pressure. Due to the overloading of vehicle axle load grow with each passing day are generally larger, there may be more than the design load standard, damage to the bridge can not be ignored. The roof structure of box girder is the main parts to withstand the negative bending moment, the roof box girder by effect of vehicle load, large transverse it will stress the axis position in the roof, when the design tensile strength of transverse stress is more than the concrete roof, there will be danger of cracking. The main contents and conclusions of this paper are as follows: (1) the This paper first introduces the development history of domestic and international bridge, detailed provisions on the overloading of vehicles at home and abroad, control measures and damage of highway bridges. (2) and then introduces the structure characteristics of box girder and stress characteristic and finite element analysis on the roof when used to the theory. Comparison of new and old standard evaluation criteria for overloading the vehicle load. By referring to the relevant literature and traffic survey report identified three axis analysis (1+22), four axis (1+1+22) vehicle model. (3) to a bridge on a expressway as the engineering background, using ANSYS to establish the local model first, analysis of the five axis, three axis, four axis along the axis of the vehicle roof deflection arrangement, the stress distribution on the axis of the roof, the axis of a few small wheelbase vehicles in the same weight under the premise, on the roof. Sound is relatively large; effect of overloading of vehicles under the roof box girder stress range more concentrated in the area 1 meters around the wheel position. Then, the calculation of two different conditions in two axis three, two vehicles for four axle vehicle roof under different overload degree under tensile stress, a condition found in, three axis, four axis vehicle overload respectively in 3 times, 3.5 times; in the second condition, three axis, four axis vehicle overload respectively in 2.5 times, 3 times, appeared on the roof in the axial tensile stress has exceeded the design tensile strength of concrete, the effect of operating conditions on a condition more than two top plate more. Finally, using the Midas Civil plate element model, calculate the moment wheel loading area value and the value of axial force on the size of the unit width of reinforcements is checked by calculation requirements, meet the requirements.

【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441

【共引文献】