移动荷载作用下沥青混凝土桥面铺装层动力响应分析

为了准确地分析铺装层的受力状态,将车辆荷载简化为移动均布荷载,采用有限元法分析了铺装层在移动荷载作用下的动力响应。分析结果表明,在移动荷载作用下,以较低的速度行驶对铺装各层应力影响较大,各应力分量与移动荷载速度基本呈线性关系;刹车情况下离表面较近区域不再经历正反两次剪应力作用,只是离表面较深处存在很小正反剪应力作用;最大水平剪应力发生在铺装表面,且随深度的增加迅速减小;水平荷载对水平剪应力影响很大,随着水平力系数δ增大,在同一铺装层深度处的最大水平剪应力增加比较明显;在相同δ的条件下,随着深度的增加水平剪应力越小。通过上述分析,提出桥面铺装层控制性设计指标,从而为桥面铺装设计提供理论依据。

Dynamic Response of Bridge Deck Pavement under Moving Load

Vehicle load is regarded as static load in calculating load stress or strain of bridge deck asphalt concrete pavement, but the load is actually moving in some velocity. To calculate mechanical states of the paving layers well and truly, vehicle load is simplified to moving equispaced load model, and FEM is used to analyze dynamic responses of the pavement under the moving load. Analytical results indicate that, the stresses are more strongly affected by the moving load while the velocity is low, and paving stresses and moving load show linear relation; positive and negative shear stress do not appear at near field from pavement surface under the brake, but it is small at deep position; the maximal horizontal shear stress appears at the surface, and shear stress rapidly decreases with the depth increasing; horizontal shear stress in the pavement is affected greatly by horizontal load, and the stress of the same depth in the pavement increases evidently with the horizontal load coefficient 3 increasing; horizontal shear stress decreases with depth increasing under the same 3.Accordingly, controlling indexes are put forward to provide academic basis for the design of bridge deck pavement, and to offer some helpful references for similar bridge deck pavement design.