Stress Analysis And Design Research On Continous Deck Structure Of Simply-supported Beam Bridge

To adapt to the deformation caused by temperature changing and vehicle load,it is usually need to set expansion joints at each pier(abutment)of simply supported beam bridges,but with the increasing of span number,the number of bridge expansion joint is also increasing,it will not only raise the construction and fix cost,but also greatly reduce the integrity and continuity of the bridge deck.Continuous bridge deck structures can reduce the number of expansion joint,enhance the integrity of the bridge deck and improve the continuity and comfort of driving.With the characteristics of its easy to design,rapid and convenient to construct,continuous bridge deck structure is widely applied in our country’s small and medium span simply-supported beam bridge,but the design and calculation method is not specified so far.Bridge design companies usually does not carries on calculation for its force and reinforcement design,and just simply use the existing standard drawing for design.Due to the complex stress state,designed at will,construction quality cannot be guaranteed,the damage of continuous deck of simply supported beam bridge often happens,the typical phenomenon such as cracking,holes,etc.,not only affects the beauty of bridge deck,but also disadvantage to the bridge structure and driving.This article models and analyzes a bridge with the help of a large general finite element software ABAQUS,researches the stress of the continuous deck structure under different load conditions and the influence factors,analyzes the main cause of the damage,and propose feasible method to improve its stress condition.The main work of this paper include:(1)The current research situation of simply supported beam bridge with continuous bridge deck,the structures commonly used at home and abroad and the destruction phenomena and the reasons has been introduced;(2)The stress calculation formulas of the continuous bridge deck under different load conditions is derived by using the linear elastic theory,the most unfavorable load combinations is obtained;(3)A simply supported PC hollow slab bridge with span of 2x20 m is used as the prototype.With the help of a large general finite element software ABAQUS,the model is established for analyzing the stress of the continuous bridge deck structure under different load conditions.The main loads that affect the stress of continuous bridge deck structure and the place where stress is concentrating are obtained.The tensile stress under the most unfavorable situation is obtained and it is greater than the tensile strength of concrete,that is root reason why it easy to crack;(4)The parameters including reinforcement ratio,thickness,debonded length and suface material of the continuous bridge deck are analyzed,the influence of these parameters on the stress of continuous bridge deck are determined,and the influence of construction sequence of deck system is analyszed;(5)The design method and advice and reasonable construction measure are proposed.