Construction Control Of Prestressed Concrete Cured Continuous Rigid Frame Bridge

The geometry linear and internal forces of the prestressed concrete cured continuous rigid frame bridge are both complicated. To make sure the quality and safety and the successful closure, and to ensure that the deformation and internal forces of the bridge are both under the bridge design standard scope, the construction control of the prestressed concrete cured continuous rigid frame bridge is very important during the bridge construction. Based on LiZiPing great bridge, the paper mainly studies the construction control of the prestressed concrete cured continuous rigid frame bridge. The main jobs and main conclusions as follow.1. Establish the whole construction process calculation models of LiZiPing great bridge by the finite element software "Midas/Civil". Analyze the mechanical behavior and deformation of LiZiPing great bridge during the construction stage and the finished bridge state. The results show that:during the whole process, the whole sections of the main pier and the girder are in compression, the stress of the bridge is under the bridge design standard scope, and the structure is safe. Because of the curvature of LiZiPing great bridge, the structure gravity and the prestressed force can cause the vertical displacement and the displacement to the inside of curve for the girder; to ensure the shape of the girder, we should set up vertical camber and horizontal deflection for LiZiPing great bridge. The curvature of the girder also can influence the distortion of the main pier; the main pier will cause the vertical displacement and horizontal deflection; to ensure the verticality of the main pier, we should set up pre-offsetting for the main pier during the construction process. The results provided the theory basis for the construction control of LiZiPing great bridge.2. According to the characteristic of LiZiPing great bridge, formulate the construction control scheme for LiZiPing great bridge, then guide the construction control of the bridge. Guide the bridge construction control with the adaptive method, and revise these parameters with the least squares method. The construction control of LiZiPing great bridge includes deformation monitoring, stress monitoring and temperature monitoring.3. According to the construction control scheme, guide the construction control of LiZiPing great bridge. Master the deformation of the girder by the measured date from the measuring point, comparative analysis the theoretical value, and then get the elevation of formwork erection, ensure the shape of the bridge and the closure deviation are both under the bridge standard scope. Master the actual stress of structure from the apparatus of the bridge control section; ensure the stress of the structure is reasonable, and ensure the structure is safe. Revise the model by the material properties until the theoretical results are identical to the measured data, then get the practical situation of the structure, and issue orders to guide the bridge construction.4. The actual closure temperature is different from the designed temperature. Amend the jacking force on the temperature by the relations between the structural distortion and the jacking force and the temperature, so we can ensure the effect of the designed jacking force.The construction control has ensured the construction safety and successful closure of LiZiPing great bridge. Finally, the deformation and internal forces of LiZiPing great bridge are both under the bridge design standard scope, and the bridge has achieved the purpose of the construction control.