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随着基础设施建设的不断发展,半刚性基层材料在道路建设中得到不断推广使用,但早期裂缝的出现,严重影响了道路的使用寿命。针对半刚性基层路面,为了探明裂缝自身三维尺度的变化对路面结构疲劳寿命的影响,采用断裂力学理论并以应力强度因子为计算指标,利用Ansys有限元软件进行路面的数值模拟,得到了裂缝三维尺度对应力强度因子的影响规律,同时利用Matlab软件将得到的应力强度因子分别对裂缝三维尺度进行函数拟合并运用Paris公式计算裂缝扩展的疲劳寿命。结果表明:应力强度因子中对裂缝三维变化最为敏感的都是剪切型应力强度因子K2;按照裂缝的三维对应力强度因子的增长起的有效作用大小可以排列为宽度>长度>高度;随裂缝高度上限的增加,其疲劳寿命近似直线增长;为了保证带隐含裂缝的半刚性路面结构在设计年限内的正常工作,对长度>0.2 m、宽度>0.035 m、高度>0.003 m的裂缝进行修补,能有效阻止裂缝的进一步发展,而长度>0.3 m、宽度>0.045 m、高度>0.003 m的裂缝必须进行处理。因此,运用探地雷达等无损检测技术检测隐含裂缝时,要求其检测精度至少能够达到0.005 m左右。
With the continuous development of infrastructure construction, semi-rigid base materials have been continuously promoted and used in road construction. However, the appearance of early cracks has seriously affected the service life of roads. For semi-rigid pavement, to ascertain changes in fracture impact on their three dimensions pavement structure fatigue life, fracture mechanics theory and to calculate the index of the stress intensity factor, using Ansys finite element software to simulate the road surface, cracks were Dimensional scale to the stress intensity factor. At the same time, the stress intensity factor obtained by Matlab was used to functionally fit the crack three-dimensional scale respectively and the fatigue life of crack propagation was calculated by Paris formula. The results showed that: stress intensity factor in the most sensitive to dimensional variations are shear fracture stress intensity factor K2; effective role in accordance with the three-dimensional growth of cracks from the stress intensity factor may be arranged in the width size> length> height; with crack In order to ensure the normal operation of semi-rigid pavement structure with hidden cracks within the design life, the cracks with length> 0.2 m, width> 0.035 m and height> 0.003 m are repaired , Which can effectively prevent the further development of cracks. However, the cracks with length> 0.3 m, width> 0.045 m and height> 0.003 m must be treated. Therefore, the use of ground penetrating radar and other non-destructive testing techniques to detect hidden cracks require that the detection accuracy of at least about 0.005 m.