Short Piers’designing Analysis Of Long Span Continuous Rigid Bridge

According to the stress characteristics of the continuous rigid frame bridge, high pier can be used. to shorter pier situation, whether the continuous rigid frame bridge can be used need to study. Through the continuous rigid frame modeling analysis, this article takes measures and changes the bridge pier construction structure form to improve the force,and make short pier continuous rigid frame realize, the concrete work of this paper are as follows:1. The passengers in qinghai province in the Yellow River bridge93.5+170+93.5meters continuous rigid frame as the background, the MIDAS/Civil software based on the construction phase analysis model, and analysis in the process of construction bridge section stress and displacement change; Calculated the continuous rigid frame bridge later in different load combination of under stress, summarizes the long span continuous rigid mechanical characteristics.2. Keeping the upper beam structure, by changing the structure of the bridge pier form to comparatively analyse, we adopt the hollow and solid double thin-wall piers on the specific calculation method, and summarize different stress changing rules of the continuous rigid frame bridge pier, and the mechanical characteristics of changing high piers. In the most unfavorable load combination, when high piers equal, the top of solid double thin-wall piers has less tensile stress. In this situation, it is more reasonable for the short piers to be designed for solid section3. To improve dwarf piers force situation of continuous rigid frame,it can be considered from two aspects:one is to adjust the structure design to improve the structural physical and mechanical characteristics, such as the default eccentric, bridge pier foundation setting sewing, and adjust the edge of space across the ratio of pier; the other is to adjust the structure stress state, in the process of bridge structure in advance with the bridge after some reserves into the most unfavorable load combination the opposite effect. For example, gather together the cantilever folded counterweight and the cantilever, adjust fold order, etc. Through the corresponding construction measures of25m solid double thin-wall piers of continuous rigid-frame bridge calculation and analysis, it shows that it greatly improve the stress situation of long span continuous rigid frame Bridges.4. By changing the structure of the bridge pier, setting vertical joints on piers, and changing the original bilimbs thin wall pilla into four-limb thin wall pilla, it can greatly reduce the proof-stiffness of the continuous rigid frame bridge. So it comes ture to design short pier four-limb thin wall pilla continuous rigid bridge. Through calculation and analysis, the force is reasonable, which can be used to achieve short pier long span continuous rigid frame Bridge.in this thesis, I analyse a bridge of15-meter-high,170-meter-spanning and four limbs thin wall pilla, and compare it with the same pier high limbs thin wall pilla.5. Through linear stability analysis to thin wall pilla and limbs thin wall pilla continuous rigid frame, and compare the stability of different high piers two limbs thin wall pilla.