大跨度预应力混凝土连续梁桥拆除临时支撑的施工及稳定性浅析

Brief Analysis on Construction and Stability of Temporary Support for Demolition of Long-span Pre-stressed Concrete continuous Beam Bridge

随着社会经济的快速发展,越来越多的老桥已经不能适应当前交通量的迅速增长,通航净空的提升无法满足结构的安全性和耐久性要求,需要拆除重建。桥梁拆除是一项危险性较大的单位工程。拆除过程中的风险众多,包括:桥梁经过多年运营,自身结构预应力损失、开裂、下挠导致拆除过程中突然破坏、断裂、坍塌;临时支撑结构失稳导致T构倾覆等。一旦拆除过程中发生事故,后果往往极其严重。结合平申线大泖港桥拆除工程对大跨度预应力混凝土连续梁桥临时支撑施工及拆除过程中T构的稳定性进行浅析。

With the rapid development of social economy,more and more old bridges can no longer cope with the current rapid increase in traffic.The improvement of the navigable clearance is hard to meet the safety and durability of the structure.The bridges need to be demolished and reconstructed.The bridge demolition is a dangerous unit project.There are many risks in the demolition process including that the prestressing loss,cracking and down deflection of its structure because of the bridge in operation for many years lead to the sudden destroy,breakage and collapse in the demolition process of the bridge,and the instability of temporary support structure results in the T-frame to overturn.Once an accident happens in the demolition process,the consequences are often severe.Combined with the Pinghu-Shanghai Navigation Line Damao Port Bridge Demolition Project,the T-frame stability in the temporary support construction and the demolition process of a long-span pre-stressed concrete continuous beam bridge is briefly analyzed.