Research On The Anti-overturning Stability Of Box Girder Bridges With Single-column Piers

Since the founding of the People's Republic of China,China's transportation industry has developed by leaps and bounds.At present,the number of bridges in China ranks first in the world.Single pier box girder bridge is also widely used in urban elevated bridge and ramp bridge because of its simple appearance and reasonable spatial layout.However,with the promotion of such bridge and the increase of service time,coupled with the defects of related bridge design theory,there have been many overturned accidents of single pier bridge.Therefore,in order to minimize design errors,this paper,based on an engineering example,takes single-column pier box girder bridge as the research object,and carries out the following research on its transverse anti-overturning stability characteristics:1.The current commonly used bridge stability theory,bending bridge stress analysis theory and related codes and standards on bridge anti-overturning stability at home and abroad are expounded.2.Relying on the existing engineering examples,using Midas / Civil large-scale finite element program software,a three-dimensional single beam structure model is constructed,and then the Civil Designer is used for post-processing of the model to check the anti-overturning results of the bridge.3.The most unfavorable lateral two-lane offset load specified in the code is applied to the single-column pier bridge,and the reaction force and void of the support and the anti-overturning stability of the bridge are studied under the influence factors such as the distance between the two supports at the joint end,the length ratio of the side-to-middle span,the radius of curvature and the eccentricity of the single support on the pier.4.The influence law of the above factors on the anti-overturning stability of single-column pier box girder bridge is summarized.It is found that the single-column pier bridge with large end-to-end bearing spacing is more stable than the bridge with small end-to-end bearing spacing.For a curved bridge,the anti-overturning effect is better if the single support on the middle pier is moved to the outside by a proper distance than to the inside.The larger the radius of curvature the single-column pier bridge is more likely to overturn.The single-column pier bridge with equal span arrangement is more stable than the bridge with non-equal span arrangement.5.At last,according to the theoretical research basis and model analysis results of this paper,some suggestions on improving the anti-overturning characteristics of the new bridge in the design process are put forward,as well as some matters for attention in the construction and operation.The above suggestions also provide a reference for the similar new bridge design and the reinforcement of the old bridge in the future.