路桥过渡段容许差异沉降计算模型

Theoretical models of determining tolerable differential settlement at end of bridge

为确定路桥过渡段桥台与引道之间的差异沉降,考虑行车的舒适,性和安全性,以人的振动频率和加速度最大瞬态振动值作为控制指标,建立了台阶状和折线形不设搭板与设搭板的路桥过渡段模型,提出以容许台阶高度和搭板容许纵坡变化值作为不设搭板与设搭板的路桥过渡段容许差异沉降,以三自由度体系作为单轮平整度测定车模型,以五自由度体系作为双轴车辆模型,而且五自由度体系中不能忽略车架的转动惯量.容许最大瞬态振动值为1.0 m/s2时,搭板容许纵坡变化计算值为0.42%,位于行车调查得到的0.4%～0.5%范围内,表明本文建立的模型是合理的.

In order to determine the tolerable differential settlement between bridge abutment and approach embankment, taking into account the comfort and safety of riders, the paper put forward the riders' vibration frequency and maximum transient vibration value of acceleration as controlling indices, built-broken lines models and step models for bridge approaches with and without approach slabs respectively, suggested the tolerable differential movement of embankment/structure interface and the tolerable differential slope of approach slab as the tolerable differential settlements, selected three freedom degrees system and five freedom degrees system as the models for the roughness testing vehicle with only one wheel and the vehicle with two axles respectively, and emphasized that the inertia moment of vehicle body in five freedom degrees system couldn't be ignored. The allowable differential slope of approach slab [Δz] is 0. 4% to 0. 5%. When the tolerable maximum transient vibration value was 1. 0 m/s2, [Δi] is 0. 42%. The result indicates that the models are reasonable.