研究了复合主拱圈加固石拱桥时极限承载力的受力特点。以一座在加固的等截面圆弧拱桥为例,考虑了加固结构二次受力的特点和新旧结构不同材料的力学性能,分析了其主要结构参数,如加固层高度、加固层宽度、加固层纵筋率和加固层箍筋率对加固后主拱圈承载力的影响。经过结构参数计算分析发现,当加固层高度为原拱圈0.25～0.50倍时,承载力增大值较明显;当加固层宽度超过原拱圈宽度的67%,承载力增大缓慢;加固层纵筋率超过1.162%,承载力增大值较小;增加加固层箍筋率对加固后拱桥的承载力影响较小。分析结果为复合主拱圈加固石拱桥设计提供了结构参数选取的建议,可为此类桥梁的设计提供有利的参考。

In order to study maximum bearing capacity of stone arch bridge reinforced by composite main arch, a circular arch bridge on reinforced equality section is analyzed. Characteristics of secondary loading on reinforcement structure and the mechanical properties of the two different materials of new and old structures are considered. The impact of the key structural parameters (height of reinforcing layer, width of reinforcing layer, longitudinal reinforcement ratio of reinforcing layer, and stirrup ratio of reinforcing layer) on the bearing capacity of reinforced main arch ring is analyzed. The results show that when the height of reinforcing layer is 0.25～0.50 times higher than original arch ring, the increment value of bearing capacity is quite obvious; when width of reinforcing layer is in excess of 67% over width of original arch ring, bearing capacity gradually increases; while longitudinal reinforcement ratio of reinforcing layer exceeds 1.162%, the increment value of bearing capacity is quite small; The effect of increasing stirrup ratio of reinforcing layer on bearing capacity of reinforcement arch bridge is relative low. In addition, the results recommend some structural parameters for the design of stone arch bridges reinforced by composite main arch circle method of this kind.