沥青路面条状修复基层的自膨胀和温度应力

Self-expansion and Thermal Stress in Notch-shaped Rehabilitated Semi-rigid Base under Asphalt Pavement

推导了沥青路面半刚性基层条状修复结构在修复材料自膨胀和降温共同作用下,半刚性基层结构的自膨胀和温度应力的解析解,提出了考虑材料徐变影响的自膨胀和温度应力计算方法,并给出了自膨胀效应、温度年变化和日变化的等效徐变系数,讨论了基层平均温度的年较差和日较差与路表温度的年较差和日较差的之间关系。以上海地区为例,计算了不同修复结构下新旧基层界面和修复基层最大的自膨胀和温度应力,由计算结果看出,修复材料的自膨胀率宜大于800με,它可使新旧基层界面基本上始终处于受压状态,从而避免界面脱离而出现结构裂缝及修复区下沉的危险。

The analytical solution of the self-expansion and temperature stresses in notch-shaped rehabilitated semi -rigid base arising from self-expansion and temperature drop were worked out, and a computing approach for self- expansion and thermal stresses considering creep effect of rehabihtation materials was initiated, therefore, corresponding equivalent creep coefficients for self-expansion effect, annual temperature variation and daily temperature variation were provided. At the same time, the relationship between annual temperature variation and daily temperature variation in base （average in thickness） and that in pavement surface were discussed. Taking Shanghai for example, the maximum self-expansion and thermal stress in interface between fresh/original base and rehabilitated base of a number of pavement structures were computed accordingly. The results indicate that the selfexpansion ratio of the rehabilitation materials shall not be less than 800 uε, which can make the interface between existing base and brand-new base normally under compression, therefore the risks of cracking and settlement in rehabilitation areas due to interface failure can be avoided.