Environmental noise beside an elevated box girder bridge for urban rail transit

来源 :浙江大学学报(英文版)(A辑:应用物理和工程) | 被引量 : 0次 | 上传用户:xiao137wu
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Noise generated by trains running on elevated lines creates many disturbances to the normal lives of surrounding residents. Investigations have shown that people living along elevated lines complain that the noise is sometimes unbearable. To better control the noise and optimize the acoustic environment, noise spectrum characteristics were analyzed and compared with a field test and a numerical simulation. Through an energy analysis of the noise on the bridge side, the energy distribution charac-teristics of the noise at specific measuring points in different frequency bands were obtained. The influence of the Doppler effect on frequency shift was analyzed. Based on the partial coherence theory, a multi-input and single-output program was compiled to calculate the correlation and contribution degree of the bridge structure-borne noise and wheel/rail noise at the one-third octave center frequency. The results show that the peak noises of the bridge and the wheel/rail are concentrated at 31.5–63 Hz and 400–800 Hz, respectively. For environmental noise on the bridge side, the frequency band above 250 Hz is mainly affected by the wheel/rail noise. In areas of noise source strength, the relative ratio of noise energy above 250 Hz can reach 83.4%. Noise in the near ground and far bridge area is mainly low-frequency, and the relative energy ratio is about 8.9%. The Doppler effect has an influence of less than 6% on the frequency shift with a speed of 67.9 km/h. In the low-frequency band below 250 Hz, the noise in the acoustic shadow area near the bridge and the ground is mainly contributed to by the vibration-radiated noise of the bridge, of which the contribution of the bottom panel is the most prominent. The noise in the comprehensive noise area of the far bridge is mainly caused by the structure-borne noise of the bridge, and the contribution of each bridge panel is different. This study can provide a reference for finding the source of elevated rail noise in some challenging frequency ranges and for then determining optimal designs and measures for noise reduction.
其他文献
北京中轴线辐射区主要指二环路以内的老城区.针对旧城区土地资源极为紧张,传统景观特色逐渐弱化,仿古建筑的建设带有明显的盲目性,街区商业气息过浓,胡同环境较差等问题,提出
汾河是中华文明发源地之一,独特的地理环境为汾河文化的诞生、发展和繁荣创造了良好的条件.历史时期,汾河文化逐步形成了晋中文化、临汾文化和运城文化等三大文化区域,其重心
本文从生态课堂的概念和地理学科的具体特征入手,探讨地理生态课堂建设的各个方面,对教学准备、教学设计、教学实施、教学评价和教学反思等各个方面进行思考.在这些环节中,与
近年来,随着景观生态学的发展,景观格局及其动态研究已成为景观生态学的研究热点之一.而对流域景观格局的研究,是揭示流域生态状况、空间变异性特征、以及与生态过程相关的区
会议
小时候常常被小狗们欺负,经常要藏进屋中躲避;长大后,当再次面对小狗们的挑战,竟然奋起反抗.合作小区北区门口小卖部内,有这样一只敢于向狗挑战的大公鸡,只要它发现有狗经过
增强信贷资金营销观念 ,主动选择和培养客户 ,积极开拓信贷市场 ,扩大贷款营销 ,这是提高商业银行经营水平的重要途径。转变观念 ,增强信贷营销意识  变坐门等客为上门服务
冬、春塑料大棚蔬菜栽培,在棚内地面均匀地撒施一层草木灰,可以有效地降低棚内湿度,提高地温,补充钾肥,是冬、春大棚蔬菜栽培有效防病防虫、提高增产的措施。其具体的好处是
文章采用2015~2019年吉林省国控站点发布的城市日均空气质量指数AQI和首要污染物监测数据,讨论不同季节、区域及月份变化规律方面存在的不同.为进一步掌握吉林省空气质量分布
契丹族是一个游牧为主兼营狩猎的中国古代北方草原民族.自四世纪中叶起,契丹族集中生活在以今内蒙古赤峰市为中心的松漠地带.过着以畜牧田猎为主的游牧生活,狩猎是他们经济活
会议
随着课程改革的深入,培养的科学素养己成为新世纪人才培养目标.地理科学素养是公民构成其科学素养的重要组成部分.在新课程标准下,提出了培养人才的核心是培养学生的科学素养