Bridge construction is one of the cores of traffic infrastructure construction. To better develop relevant bridge science, this paper introduces the main research progress in China and abroad in 2020 from 16 aspects. The content consists of four major categories in 16 aspects. The first part is about the bridge structure, including concrete bridge and high-performance materials, steel bridges, composite girders. The second part is about the bridge disaster prevention and mitigation, including bridge seismic resistance, wind resistance of bridge, train-bridge coupling vibration research, bridge hydrodynamics, the durability of the concrete bridges, fatigue of steel bridge, temperature field and temperature effect of bridge; The third part is about the bridge analyses, including numerical simulation of bridge structure, box girder and cable-stayed bridge analysis theories. The last part is concerning the bridge emerging technologies, including bridge informatization and intelligent bridge, the technology in bridge structure test, bridge assessment and reinforcement, prefabricated concrete bridge structure.

The cracking problem of a precast beam of a highway in North China was investigated, and the field tests were carried out to test the stress in the cracking area during the prestress tensioning process. The distribution state of the main stress of the web and the influence of prestress tensioning on the stress concentration were obtained. A three-dimensional finite element model is also built to simulate the precast box girder, and the variation character of concrete stress with the tensioning procedure is simulated, which is compared with the test results. The results of both test and numerical analysis show that the principal tensile stress in the prestressed anchorage area and the web area near the diaphragm plate exceeds the tensile strength of the concrete. The test and numerical results predicted the correct direction of the observed crack preciously. Suggestions for reduce the principal tensile stress in the anchorage area are proposed.

Compared with circular, square and diamond piers, the N60 pier proposed in our previous study has been numerically proven to be effective in reducing tsunami force. The relatively stronger vortices behind the N60 pier are responsible for the not-small-enough tsunami force on the N60 pier. The asymmetry in shape makes the N60 pier fail to reduce flood force because flood propagates in the opposite direction of tsunami bore. A series of new type piers named [Formula: see text] are proposed to further improve the anti-tsunami ability of the N60 by computational fluid dynamics (CFD) method among which the N60-60 pier is proven to be most effective in reducing tsunami force, and its tsunami force mitigation mechanism is analyzed numerically. Further, the physical experiments were conducted to validate the N60 pier and the new type pier N60-60. Results show that compared with circular, square and diamond piers, the N60 pier is indeed capable of reducing tsunami force, and compared with the N60 pier, the new type N60-60 pier is capable of further reducing tsunami force. The order of magnitudes of tsunami forces on piers is: N60-60 [Formula: see text] N60 [Formula: see text] circular [Formula: see text] diamond [Formula: see text] square.

The performance of composite girder double element model and composite cross-section model in the finite element analysis of composite beam were introduced, and three simulation method of the interface in the composite beam was studied, and then the three finite element modeling method of were adopt to analysis a composite beam under different load, and two simulation models including shrinking and the creep effect were computed. It is concluded from the computational results, when the mesh of dual element model is refined, the difference between the calculation results of the dual element model and the transformed section model remains very small, which means that dual element model can meet the requirements of calculation accuracy in case of the fine mesh size.

Bearing capacity of the composite beam is analysis with three nonlinear finite element methods in the thesis, in which Hognostand’s uniaxial compression equation and BKIN model was applied to represent the constitutive relationship of concrete and steel in consideration of nonlinearity of concrete and the yield and strengthening characteristics of steel respectively. The interface slip between steel and concrete in composite beam is reasonably taken into account in the analysis with two methods. Those methods are compared according to the finite element analysis result, and the character of those methods are discussed and verified with the experimental result.