The Behavior Subject To Force Of Multiple-Span Simply Surported-Continuous Skew Small Box Girder Bridge

With the continuous development of China’s transportation industry, bridge construction has reached it’s heyday. Due to the continuous progress of the bridge construction technology, the available selections of bridge types become more and more diverse. In order to adapt to the condition of terrain, geology etc., and taking into account the advantages of driving comfort, short construction period, small human consumption, saving building material and high economic benefits etc., the application of simply supported-continuous skew small box girder bridge becomes more and more frequent in medium and small span bridges when route selection of highway. In this paper, by consulting a large number of domestic and foreign literature, author elaborates the development process and research of simply supported-continuous skew small box girder bridge. And taking Changsha to Xiangtan expressway (Double Track) Jinzhou separate interchange bridge in Hunan Province as the engineering background, discusses the spatial structure response of multiple-span simply supported-continuous skew small box girder bridge to the changing skew angle. The main research contents and conclusions are as follows.1. For multiple-span simply supported-continuous skew small box girder bridge, using finite element software Midas/Civil to establish multiple beam grillage models. By changing skew angle (9< 60°), research the structure effect of main girder under vehicle load, the main conclusions are as follows:With the increase of skew angle, the moment, stress of main girder at mid-span and abutment increses continuously; With the increase of skew angle, the mid-span torque of main girder increses continuously, but the displacement decreases continuously.2. For four-span simply supported-continuous skew small box girder bridge, using finite element software Midas/Civil to establish multiple beam grillage models. By changing skew angle(9<60°), research the mechanical properties of main girder under temperature load, the main conclusions are as follows:With the increase of skew angle, the moment, stress, displacement of main girder at mid-span of side span decreased first and then increased, the moment, stress, displacement of main girder at mid-span of middle span and abutment of side-mid span increased first and then decreased. With the increase of skew angle, the moment, stress of main girder at abutment of mid-mid span and the mid-span torque of main girder increses continuously.3. For four-span simply supported-continuous skew small box girder bridge, using finite element software ANSYS to establish multiple solid models. By changing skew angle (θ< 60°), research the variation of the transverse load-distributing of the main girder at each span under the action of concentrated force, and compared with the results of load test of the real bridge to verify each other, the main conclusions are as follows:the transverse distribution coefficient of the main girder can be calculated as a orthogonal girder bridge when skew angle changes from 0° to 10°; When the skew angle is greater than 10°, due to crankle coupling effect, the transverse distribution coefficient of the main girder decreases obviously. load test at the same time shows, the measured values compare with the theoretical values of the mid-span transverse distribution coefficient are similar, and both of their change trends are basically the same, the transverse connection of main girder is tight, the load distribution has achieved the desired effect.