基于黏聚区域模型的石拱圈承载力分析方法研究

石拱桥拱圈石之间的拼接界面往往是拱圈结构的薄弱处，决定着拱桥的安全性和承载力。该连接界面往往因其强度低而沿法向起裂并张开扩展，或沿切向发生相对滑移，此复杂的界面行为特性成为石拱桥承载力分析及安全性评估的难点。针对拱圈石连接缝处的起裂及裂缝扩展后结构非连续变形的复杂力学行为的模拟问题，采用多折线型黏聚区域模型描述拱圈石间界面滑动和拉裂破坏变形，并构造无厚度界面单元，形成考虑非连续变形效应的石拱桥极限承载力分析的方法。采用该方法对一石拱圈的破坏全过程进行模拟分析，实现拱圈石块之间非连续变形的数值模拟，得到拱圈结构的极限承载力及相应的破坏形态，验证了本文方法的可行性。本文方法可以模拟石拱桥结构破坏的全过程，可用于石拱桥的承载能力分析及石拱桥结构脆性破坏的安全性评估。

Cohesive zone model based analysis of load-carrying capacity of stone arch ring

Interface between the stone of arch ring tends to be weak position of the structure,which determines the safety and load-bearing capacity of the arch bridge.Because of the low strength,the interface between the stone and the mortar will be cracked and extended in the normal direction.Along the tangential direction of the interface relative slip between arch stone may occur.The complex interface behavior becomes the difficulty of load-carrying capacity analysis and safety assessment of stone arch bridge.In order to simulate the crack of the interface and the discontinuous deformation with the crack extended,multiple broken lines mode cohesive zone model is used to describe the tangential sliding and normal crack,and interface element of zero thickness is established.Thus,ultimate load-bearing capacity analysis method considering the discontinuous deformation effect for the stone arc bridge is formed.Then the whole destruction process analysis of stone arc ring is carried out with this method.Numerical simulation of the discontinuous deformation between the arch stone is realized,and the ultimate load-bearing capacity and the corresponding failure mode are obtained.And the feasibility of the analysis method proposed in this paper is verified.The method proposed in this paper can simulate the whole destruction process of the stone arc structure,and can be used for the load-carrying capacity analysis and the safety assessment of the brittle failure of the structure.