Finite element simulation of the UHPC reinforced negative moment zone of continuous concrete box girder after simple support (CCBGSS)

In order to explore the improvement effect of UHPC on the mechanical property and crack resistance in the negative moment zone of the continuous concrete box girder after simple support (CCBGSS), based on the experimental research, the finite element software was used to simulate and analyze the parameters of the reinforced beam. The variation trend of the load-deflection curve obtained from numerical simulation and experimental measurements was basically consistent. The minimum error value of the cracking load was 2.0%, and the maximum was 8.4%. The minimum error value of the ultimate load was 2.0%, and the maximum was only 4.4%. This showed that the finite element model can well simulate the stress behavior of the test beam in the whole process. The parameter analysis showed that the cracking load and ultimate load of the box girder increased with the increase of the thickness and length of UHPC in the negative bending moment zone. When the pouring thickness of UHPC increased from 60 mm to 100 mm, the cracking load and ultimate load increased by 10.3% and 5.6% respectively. When the pouring length of UHPC increased from 1.6 m to 2.0 m, the cracking load and ultimate load increased by 18.3% and 6.5% respectively.