大跨度桥梁钢箱梁外表面风压实测与研究

发布时间：2018-01-16 10:13

本文关键词：大跨度桥梁钢箱梁外表面风压实测与研究　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：为了获得风对流线型扁平钢箱梁表面的压力大小和分布规律的第一手资料，沿厦漳跨海大桥跨中的主梁横截面的检修道、风嘴和梁底布设若干风压传感器，现场实测记录风压数据。本文首先总结了桥梁抗风理论在国内外的发展历程和研究现状，以及各国学者对结构物外表面的风压实测与研究，详细描述了钢箱梁外表面风压现场测量成果。总结整理了自然风的特性，风对桥梁的静力作用和动力作用，测压法原理，现场实测所依托厦漳跨海大桥的基本概况。介绍了风压测量系统的设计方案，对初期拟定的多个实测方案进行了反复比较、实验与修正，确定最佳方案。实验采用风压传感器和数据采集器的各种参数、数量并对测量系统进行了室内校验及系统的现场布设方案、安装方法和采集工况等。现场记录良态条件下的风压值。研究分析了在不同风向、风速、风攻角和风偏角情况下，风压沿箱梁表面的大小和分布规律，并对产生这种分布规律的原因进行了初步分析与推断。发现风速与箱梁表面的压力大小成正相关关系，风攻角是影响风压分布规律的主要因素，风偏角对风压大小和分布规律影响不大。对比不同时距下风压沿箱梁分布，，发现风压值大小与时距长短成反相关关系。分析箱梁在静止和振动状态下的风压分布的异同，发现不同时距同一测点下风压值大小没有明确的几何关系，处于静止或振动状态下的箱梁表面的风压分布趋势一致。运用伯努利方程和边界层理论能够对风压沿箱梁截面的分布规律与特点进行很好的解释。与CFD和风洞试验风压值对比，发现其与现场实测结果略有差别，但能够较真实地反映风对桥梁表面的作用。通过对风压值积分，计算静力三分力系数，用实测值计算阻力系数和风洞结果相近，但升力系数和扭矩系数两者有很大不同，原因在于现场实测未考虑桥面行车道部位风压值。
[Abstract]:In order to obtain the firsthand information of wind pressure on the surface of streamlined flat steel box girder, a number of wind pressure sensors are arranged along the overhaul track of the cross section of the main girder in the middle span of Xiazhang cross sea bridge, the wind nozzles and the bottom of the beam. Field measured wind pressure data recorded. Firstly, this paper summarizes the development and research status of bridge wind resistance theory at home and abroad, as well as the measurement and research of wind pressure on the outer surface of structure by scholars from all over the world. The field measurement results of wind pressure on the external surface of steel box girder are described in detail. The characteristics of natural wind, the static and dynamic effects of wind on the bridge, and the principle of pressure measurement method are summarized. This paper introduces the design scheme of the wind pressure measurement system, and makes repeated comparison, experiment and correction of several measured schemes in the initial stage. The best scheme is determined. The parameters and quantity of wind pressure sensor and data collector are used in the experiment, and the indoor calibration of the measurement system and the field layout scheme, installation method and acquisition condition of the system are also carried out. The value of wind pressure in good condition was recorded. The size and distribution of wind pressure along the surface of box girder were studied and analyzed under different wind direction, wind speed, wind attack angle and wind deflection angle. It is found that the wind speed has a positive correlation with the pressure on the surface of the box girder, and the angle of attack is the main factor affecting the distribution of wind pressure. The wind deflection angle has little effect on the wind pressure size and distribution, and the wind pressure is distributed along the box girder at different time intervals. It is found that the wind pressure value is inversely correlated with the time distance. By analyzing the difference of wind pressure distribution between static and vibration states, it is found that there is no clear geometric relationship between the wind pressure value and the wind pressure value at the same measuring point at the same time. The distribution trend of wind pressure on the surface of box girder in static or vibration state is consistent. The distribution law and characteristics of wind pressure along the section of box girder can be well explained by using Bernoulli equation and boundary layer theory, which is similar to that of CFD and wind. Comparison of wind pressure in tunnel test. It is found that it is slightly different from the measured results, but it can truly reflect the effect of wind on the bridge surface. The static three-point force coefficient is calculated by integrating the wind pressure value. The calculated resistance coefficient is similar to the wind tunnel result, but the lift coefficient and the torque coefficient are very different, the reason is that the wind pressure value of the bridge deck carriageway is not taken into account in the field measurement.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U446

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