不同类型基层沥青路面设计指标的控制

Control of designing indices for asphalt pavement with different types of base

以西安—铜川高速公路改扩建工程为依托,分析半刚性基层沥青路面、复合式基层沥青路面及柔性基层沥青路面的破坏形式,并建立与之相对应的设计指标体系。采用壳牌计算软件Bisar3.0分析材料参数对路面力学响应的敏感性,从路面受力均衡角度验证各类沥青路面设计指标的合理性。结果表明:对柔性路面采取弯拉应变与面层剪应力指标进行双控,可实现基层模量的合理取值;半刚性路面与复合式路面采取基层拉应力与面层剪应力指标进行双控,可对半刚性基层模量起到牵制作用;沥青路面设计增加抗剪指标尤为必要,可对材料参数起到制约作用,实现结构设计与材料设计的双重优化。

Based on the reconstruction and extension project of Xitong expressway, the fatigue and breakage forms of semi rigid asphalt pavement, compound base asphalt pavement and flexible base asphalt pavement were analyzed and the corresponding design parameter system was estab- lished separately. The sensibility of the materials parameter as the mechanical responses was ana- lyzed using Shell designing software Bisar3. 0, which verified the rationality of pavement de- signing indices from the point of stress balance. The results show that taking flexible strain and surface shear stress as designing indices for flexible pavement could keep the modulus value of seml-rigid base in proper range. Taking flexible stress of base and shear stress of base as desig- ning indices for semi-rigid pavement and compound pavement could constraint the modulus value of semi-rigid base. The introduction of shearing stress is particularly necessary for asphalt pave- ment design because it can seriously affect material parameters and help optimize both the struc-ture and material design. 9 tabs, 6 figs, 10 refs.