中缅油气管道怒江悬索跨越设计

Nujiang River suspension cable crossing design of Myanmar-China Oil and Gas Pipeline

怒江油气双管同桥跨越是中缅油气管道的控制性工程,跨越处河面宽270 m,主跨长320 m,边跨长60 m。为了解决单跨跨度大、柔性结构、桥身重、跨越国际性河流、油气管道同桥跨越等设计难点,创新性地采用公路桥梁的设计理念和方法,运用三维模型离散处理技术,研究柔性结构的力学特征,得出优化的荷载组合、适合工程实际的边界条件及求解方法。在对模型进行分析时,将塔顶与主索连接处全自由度耦合作为约束条件,在跨越结构的静力模拟和动力模拟分析方面提出了较为合理的设计思路,并在油气管道行业率先采用预应力锚碇设计技术,提高了锚体结构的抗开裂能力和锚固强度。

It is the dominating engineering for Myanmar-China Oil and Gas Pipeline to make both oil and gas pipelines cross the Nujiang River on the same bridge. At the crossing section, the river is 270 m wide, the main span is 320 m and the end span is 60 m. The design concepts and methods of highway bridges are innovatively adopted in this project to address the difficulties like large single span, flexible structure, heavy bridge body, international river crossing and oil and gas pipelines crossing the river on the same bridge. The optimized load combination and the reasonable boundary conditions and resolution methods are obtained after analysis is performed on the mechanical characteristics of flexible structures by using three-dimensional model discrete processing technologies. When the model is analyzed, the full freedom coupling at the connecting position of the overhead and the main cable is taken as the constraint condition. In this paper, a reasonable design solution is proposed for static and dynamic simulation of crossing structures, and the prestressed anchorage design technology is, for the first time, applied in the industry of oil and gas pipelines, so that the anti-cracking and anchoring capacities of anchor structures are improved.