高速铁路32m简支槽形梁桥结构噪声分析

Analysis on Structure-Borne Noise of 32m Simply-Supported Trough Girder Bridge for High Speed Railway

运用车桥耦合动力理论并结合基于间接边界元法的噪声分析方法，对高速铁路32m简支槽形梁桥结构噪声的声辐射特性进行研究。结果表明：简支槽形梁的抗扭刚度小，抗扭性能弱；6．3Hz以下频率的振动噪声主要由梁体的整体振动产生，6．3Hz以上频率的振动噪声主要由梁体构件的局部振动产生，振动噪声受构件的局部振动影响显著，声压级峰值频率为25Hz；横桥向，随着距桥梁中线距离的增大，场点声压级逐渐变小，距离每增大5m声压级平均降低1．2～2．5dB；梁下区域距桥梁中线15m范围内，行车侧声场声压级大于非行车侧，10m处行车侧场点声压级平均大1．87dB，距桥梁中线25m范围以外，行车侧声场声压级小于非行车侧，30m处行车侧场点声压级平均小1．46dB；底板的声压贡献系数要比腹板和翼板大的多，远场声压主要受底板的影响；地面附近的噪声基本由底板产生；应当有针对性的采取措施改善结构的振动噪声性能。

The vehicle-bridge coupling dynamic theory and the noise analysis method based on indirect boundary element method were applied to study the sound radiation characteristics of structure-borne noise radiated by a 32 m simply-supported trough girder bridge for high speed railway. Results show that the torsional stiffness of trough girder is small and the anti-torsion property is weak. The vibration noise below 6.3 Hz is mainly induced by the vibration of above 6.3 Hz is mainly caused by the local vibration the entire beam structure, while the vibration noise of the beam members. The vibration noise is signifi- cantly influenced by the local vibration of members, and the frequency of the maximum Sound Pressure Level （SPL） is 25 Hz. In the transverse direction of the bridge, the SPL of field points decreases gradually with the increase of the distance between the points and bridge center line. The average value of SPL decreases 1.2~2. 5 dB per increased 5 m distance. In the range under the beam where the distance to bridge center line is no larger than 15 m, the SPL of the sound field on train running side is larger than that on non-train running side. When the distance reaches 10 m, the SPL of field point on train running side is 1.87 dB larger in average. In the range where the distance to bridge center line is larger than 25 m, the SPL of the sound field on train running side is less than that on non-train running side. The SPL of field point on train running side with the distance of 30 m is 1.46 dB smaller than that of non-train running side in average. The sound pressure contribution coefficient of bottom plate is far larger than that of web and flange plate, and the sound pressure of far field is mainly influenced by bottom plate. The noise around the ground is basically induced by bottom plate as well. Therefore, targeted measures need to be taken to reduce structure-borne noise.