山区峡谷桥位风场现场实测与数值分析研究

发布时间：2018-10-17 21:40

【摘要】：随着我国西部大开发,促进川、滇两省跨区域联动发展的进程,越来越多的大跨度桥梁被建设于西部复杂的山区峡谷之中;虽然大跨度桥梁对西部山区峡谷地区的大力发展具有重要促进作用,但是很多桥梁建设地山高而谷深,特殊而又复杂的地理环境给大跨度桥梁抗风研究带来了诸多难题;即便桥梁结构抗风设计规范具有相应的规定,但也只是对平原和沿海地区具有较高的参考价值,对我国西部这种复杂的峡谷地形参考意义不大,故而对山区峡谷地形的风场特征深入研究就显得尤为重要。本文以拟建的西香高速中一座位于四川省,西昌盐源县境内的某大桥为研究背景,在桥位处,峡谷两侧分别架设一个美国YOUNG-81000型三维超声风速仪,对桥位处风环境进行持续的现场实测。通过实测数据,对桥位处风攻角、风向角、湍流强度、积分尺度、功率谱进行了系统分析。结果表明:桥位处风速的整体分布情况为上午小而下午大,每天的大风记录都在10m/s以上,出现时间段为下午14时到17时之间。风攻角主要集中在±5°之间,受桥位处复杂的地形影响风攻角有部分突变。风向来流集中在东南偏南向,与拟建桥轴线夹角接近90°。另一方面,根据计算流体力学(CFD)知识,采用SST k-ω湍流模型,对峡谷区整体风环境进行数值模拟,根据风向来流每隔30°划分了十二个工况进行分析。研究结果表明:风速放大系数平均值为0.78;风攻角主要分布在-2°到5.5°之间;受地形影响,部分工况下风向角大于40°,桥位处可能存在斜风作用。
[Abstract]:With the development of western China and the promotion of cross-regional linkage development between Sichuan and Yunnan provinces, more and more long-span bridges have been built in the complex mountain canyons in the western part of China. Although long-span bridges play an important role in promoting the development of mountain canyons in the western part of China, many bridges are constructed in high mountains and deep valleys, and the special and complex geographical environment brings many difficulties to the study of wind-resistance of long-span bridges. Even though the wind-resistant design code for bridge structures has corresponding regulations, it is of high reference value to the plain and coastal areas, and is of little significance to the complex canyon topography in the western part of China. Therefore, it is very important to study the wind field characteristics of mountain canyons. In this paper, a bridge located in Yanyuan County, Xichang County, Sichuan Province, is proposed to be built. In this paper, an American YOUNG-81000 type three-dimensional ultrasonic anemometer is set up on both sides of the bridge. Continuous field measurement of wind environment at bridge site is carried out. The wind attack angle, wind direction angle, turbulence intensity, integral scale and power spectrum at the bridge are systematically analyzed by the measured data. The results show that the overall distribution of wind speed at the bridge is small in the morning and large in the afternoon, the daily wind records are above 10m/s, and the time between 14:00 and 17:00. The angle of attack of wind is mainly between 卤5 掳, and the angle of attack of wind has some abrupt changes due to the complex terrain at the bridge. The wind current is concentrated in the south-southeast direction, and the angle between the wind flow and the proposed bridge axis is close to 90 掳. On the other hand, according to the (CFD) knowledge of computational fluid dynamics and SST k- 蠅 turbulence model, the overall wind environment in the canyon is numerically simulated. Twelve conditions are analyzed according to the wind flow at 30 掳intervals. The results show that the average wind speed magnification factor is 0.78, the wind attack angle is mainly between -2 掳and 5.5 掳, and the wind direction angle is more than 40 掳under the influence of topography.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442

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