考虑滑移的多梁式组合小箱梁桥荷载横向分布

摘要

To obtain calculation formula of lateral load distribution for multi-box steel-concrete composite girder bridges,the traditional rigid transverse beam method,modified rigid transverse beam method and rigid connected beam method are modified for the multi-box composite girder bridges by considering the interface slippage’s effect.The results obtained by the modified theoretical algorithms are compared with the values gained by finite element method which has been validated by experiments.The results show that the modified rigid connected beam method considering slippage effect is applicable to calculate the lateral load distribution of mid-span cross section in multi-box composite girder bridge.When the bridges meet the narrow bridge conditions,i.e.the bridges with span-width ratio is not less than 2,the modified and simplified rigid transverse beam method considering slippage effect is also suitable to calculate the lateral load distribution of the mid-span in the bridges.Finally,it is suggested that the partial load effect of the bridge could be reduced by using incomplete shear connection form or properly strengthening the transverse connection rigidity among steel box girders when the multi-box composite girder bridges are designed.%为获得多梁式钢-混凝土组合小箱梁桥荷载横向分布系数计算公式,本文考虑其界面滑移效应,分别对传统的偏心压力法、修正偏心压力法、刚接梁法计算公式进行修正,并用所提出的各修正方法对一座典型的多梁式钢-混组合小箱梁桥的荷载横向分布进行计算.将修正理论算法计算所得结果与经试验验证有限元方法计算结果进行比较.结果表明,考虑滑移修正的刚接梁法适用于计算多梁式钢-混组合小箱梁桥的跨中荷载横向分布系数,当满足窄桥条件时,则可采用更为简洁的考虑滑移修正的偏心压力法进行计算.同时,在进行多梁式钢-混组合小箱梁桥设计时,为减少桥梁的偏载效应,建议适当加强横向连接的钢横梁刚度,采用不完全剪力连接形式.