Abstract: The present disclosure provides a thin-layer low-frequency underwater sound insulation metamaterial, including two cover plates and a sound insulation layer. The sound insulation layer is composed of sound insulation components arranged in an array periodically. The sound insulation components each include a sound insulation unit and four connecting units. The sound insulation unit is of a hollow rectangular column structure. The four connecting units are arranged at four corners of the sound insulation unit. Every two adjacent sound insulation units are connected through the connecting units. A long side wall of the sound insulation unit and the corresponding cover plate have an included angle of 0-90°. The metamaterial can obtain a smaller equivalent acoustic impedance in propagation direction of acoustic waves, and compared with a sound insulation material of a square honeycomb structure with the same thickness, the metamaterial has greatly improved sound insulation performance.

Abstract: Disclosed are a composite box girder structure and a construction method therefor. The composite box girder structure includes a box enclosure and an inner core, where the inner core includes a thin-walled steel shell, shear connectors, and diaphragms, and the thin-walled steel shell is attached and fixed to an interior of the box enclosure by means of the shear connectors. In the present disclosure, the inner core and the box enclosure of the composite box girder structure jointly load force, such that effectiveness of the structure in resisting a use load can be improved. The inner core is directly used as an internal template of UHPC, such that rapid bridge construction can be achieved. Further, not only defects of conventional pouring can be overcome, but problems of excessive lateral local stress, overall stability, cross-section distortion and shear bearing capacity of web plates can be solved.

Abstract: Disclosed are a composite deck structure for a bridge, and a bridge structure and a construction method thereof. The composite deck structure includes a top plate (1), longitudinal ribs (2), and transverse ribs (3), where the longitudinal ribs (2) are fixedly connected to the transverse ribs (3), and are connected to the diaphragms (4) by means of the transverse ribs (3), and the transverse ribs (3) are not provided with cutouts for accommodating the longitudinal ribs (2). According to the composite deck structure, no cutout is provided on the diaphragms (4), and stress generated by the cutouts is reduced; hot-rolled section steel is used for longitudinal ribs (2) and transverse ribs (3) instead of welded steel plates, such that welding seams are reduced and fatigue resistance of the composite deck structure is improved.