This study investigates the wheelrail noise characteristics of urban rail trains passing through longspan bridges, focusing on the Dongshuimen Bridge of the Chongqing Rail Transit Line 6 and the Chaotianmen Bridge of the Chongqing Rail Transit Loop Line. Noise measurement data were collected for trains passing over the bridges. This study analyzed and compared the spectral characteristics of noise, summarizing the relevant patterns. The results indicate that the wheelrail noise generated by rail trains on largespan bridges exhibits a widefrequency characteristic, with the sound pressure level spectrum curve showing a “high in the middle, low on both sides" pattern. The noise peak of steel truss arch bridges is concentrated at approximately 800 Hz, and the structural noise generates a relative peak in the range of 6380 Hz. In contrast, the noise peak of the steel truss girder cablestayed bridges is in a higher frequency range. The threespan continuous steel truss suspension arch bridge exhibits a wide and highamplitude noise spectrum, with its noise being significantly greater than that of the steel truss girder cablestayed bridge, particularly in the midto highfrequency range of wheelrail noise.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |