沥青加铺层结构中格栅夹层合理位置的确定

Determination of grid interlayer rational position in asphalt overlay structure

分析了沥青加铺层常见剪切损坏形式及其产生机理,建立有限元模型,对比研究了基于加铺层结构抗剪性能的不同夹层层位的加筋效果,同时计算了加铺层结构各最大剪应力所在点竖向位置随轴载、旧路竖向开裂深度、旧路横向开裂宽度、水平荷载、加铺层厚度及加铺层模量与旧路当量回弹模量比值的变化规律。结果表明:格栅的加入改变了加铺层结构最大剪应力的分布,而且在加铺层结构剪应力最大值发生部位以及周围较小范围内加筋才会取得明显效果;加铺层结构各最大剪应力所在点竖向位置仅随模量比及沥青加铺层厚度的变化而改变;最后给出了基于沥青加铺层结构抗剪性能的夹层合理位置。

The common shear damage pattern and generation mechanism of asphalt overlay are firstly analyzed, and then the finite element model is established, the reinforcement effect of different interlayer positions based on shear behavior of asphalt overlay is comparatively studied. Meanwhile, the change law of shear stress vertical position of asphalt overlay, along with axle load, vertical cracking depth of old road, transverse cracking width of old road, horizontal load, thickness of overlay, and the ratio between modulus of overlay and equivalent resilient modulus of old road, is calculated. The results show that the distribution of maximum shear stress about the overlay structure is changed by adding the grid, and the significant effect is only obtained at the location where the maximum shear stress of overlay structure and the minimum range of its surrounding are reinforced, and also the vertical position of maximum shear stress of asphalt overlay is only changed along with the modulus ratio and thickness of overlay. Finally, the rational position of interlayer based on shear behavior of asphalt overlay structure is proposed.6 tabs, 4 figs, 10 refs.