桁式石拱桥病害分析及其加固改造

The disease analyze and reinforcement enhance of a truss stone arch bridge

钢筋砼及预应力砼桁式拱桥在国内建造较多,而桁式石拱桥很少见.文中分析桁式石拱桥-天池大桥振感明显的内在原因,根据拱桥一阶自振频率近似计算公式,采取加设三条钢筋砼拱肋加固改造方案,通过调整桥面系加载顺序确保新旧拱圈之间有良好结合,并将原设计标准由汽-10提高到汽-20,应用Nastran程序对加固前后进行静、动力分析.结果表明,加固后该桥的自振频率显著提高,满足承载力要求,达到了加固改造的目的,文中最后给出了施工要点.

The reinforced concrete and pre-stressed concrete truss arch bridges were largely built in China, otherwise truss stone arch bridge was rarely constructed. The inherent causes have been discussed for Tianchi Bridge which is a truss stone bridge. The method of adding to reinforced concrete arch with 3-ribs to reinforce and strength the original arch bridge was put forward aceording to approximate formula about oneorder self-vibration frequency. To ensure the excellent link with the two arch interfaces, the method with firstly remove pavement then reconstruct it was adopted. The capacity standard was improved from truck-10 to truck-20. The static and dynamic calculation for before and after reinforce have been performed by Nastran. The results show the self-vibration frequency was effectively improved and the capacity was achieved. At last, the construction key was given.