高陡边坡混凝土T构桥通长悬浇施工方案研究

Research on the Full Length Cantilever Casting Construction Scheme of Concrete T-type Rigid Bridge with High-steep Rock Slopes

研究目的:采用悬臂浇筑法施工的桥梁,一般在梁端边支点处都会设置一定长度的支架现浇段。当桥梁位于高陡边坡时,梁端搭设支架难度大、费用高,现浇段临时支架的地基处理对环境影响大。为此,本文以某客运专线铁路具体工点为分析对象,对T构通长悬浇施工进行深入研究,希望能够解决此类问题,指导类似桥梁设计。研究结论:(1)随着梁端现浇段长度的减小,T构桥钢束用量呈增加趋势,但对梁体残余徐变变形及支反力影响较小;(2)T构桥整体费用随着现浇段长度的减小而降低,且边坡越陡,费用降低速率也随之加快;(3)采用通长悬浇施工方案,可有效避免梁体施工对环境造成的影响;(4)该研究成果对高陡边坡及跨河、跨线等不便于搭设支架的T构桥设计具有一定的指导意义。

Research purposes： The cast - in - site section is commonly set at the end of the bridge, which constructed by cantilever casting method. It is far more difficult and costly to install the scaffold on the high - steep rock slopes, and the foundation treatment makes great impact on the environment. In order to solve those problems and continue to guide scheme design of similar bridge, a specific engineering of passenger dedicated railway is taken as the analysis object to make a deep research on the full length cantilever casting construction scheme. Research conclusions： （ 1 ） With the length decrease of the cast - in - place segments of the bridge end, the amount of the prestressed steels of the T - type rigid bridge tends to be larger, however, it has little influence on the creep deformation and the reaction force. （2） For prestressed concrete T - type rigid bridges, the cost decreases when the length of the cast - in - place segments decreases, and the rate of cost reduction will be accelerated if the slope is steeper. （3） Using the full length cantilever construction scheme can effectively avoid the impact of construction on the environment. （4） The research results can provide a valuable reference for the design of T - type rigid bridge with high- steep rock slopes or other conditions, which are difficult to erect the support, such as flyover and cross river bridge.