Study on the structure-borne noise of U-shaped girder bridges with fully-enclosed sound barriers

•The noise reduction performance of the fully-enclosed sound barriers was investigated through field tests.•An analysis model of the U-shaped girder bridges (USGBs) with fully-enclosed sound barriers (FESBs) was established.•The structure-borne noise radiation characteristics of the USGB-FESB coupling system were studied.•The influences of sound barrier type and bridge type on the structure-borne noise radiation characteristics were analyzed. To investigate the structure-borne noise characteristics of U-shaped girder bridges (USGBs) with fully-enclosed sound barriers (FESBs), an analysis model of the USGB-FESB coupling system was established using the fast multipole boundary element method (FMBEM). The structure-borne noise analysis model was validated using a noise field test of a 27-m-long simply-supported concrete USGB under the loading of moving trains in an urban rail transit. The structure-borne noise radiation characteristics of the USGB-FESB coupling system were studied, and the influences of sound barrier type (vertical sound barrier and fully-enclosed sound barrier) and bridge type (U-shaped girder and box girder) on these characteristics were analyzed. The results show that the noise radiated from the USGB with FESBs was higher than the noise radiated from the USGB without FESBs by 0.28 to 2.53 dB (L) in the frequency band of 20 to 100 Hz. In comparison to vertical sound barriers, the structure-borne noise generated by the FESBs contributes more to the structure-borne noise. The structure-borne noise of a box-girder bridge with FESBs is more significant than that of the USGB-FESB.