拱肋施工偏差对斜靠式拱桥力学性能的影响

采用MIDAS/Civil软件建立某斜靠式拱桥空间有限元计算模型,通过改变内外拱肋的倾角来考虑拱肋施工可能出现的偏差,分10种工况计算该桥在恒载和恒载 活载作用下的桥梁稳定系数和拱肋位移。计算结果表明,改变内外拱肋间的倾角对该桥稳定性系数影响较小,但对拱肋位移的影响较大。随着内拱肋的倾角由外向内改变,拱肋顶部横向位移逐渐加大,特别是当内拱肋偏过竖直位置向内倾时,拱肋顶部横向位移增幅显著。

Effect of Arch Rib Construction Errors on Mechanical Properties of Double X-Shape Arch Bridge

The software MIDAS/Civil is used to establish a 3dimensional finite element calculating model for a double X-shape arch bridge.By changing the sloping angles of the inner and outer arch ribs of the bridge,the possible construction errors of the arch ribs are considered,and the stability factors and arch rib displacement of the bridge under dead load and dead plus live loads are calculated respectively for 10 load cases.The results of the calculation reveal that changing of the sloping angles between the inner and outer arch ribs has little effect on the stability factors,on the contrary,the displacement of the arch ribs will be fairly greatly affected under similar conditions.As the sloping angles of the inner arch ribs change from the outer side towards inner side,the lateral displacement at the top of the arch ribs gradually increases.Especially when the inner arch ribs pass beyond the vertical position towards the inner side,the lateral displacement at the top of the arch ribs will significantly increase.