Dowel bar design and modified method considered airport pavement structure damage(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年05期
- Page:
- 28-38
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Dowel bar design and modified method considered airport pavement structure damage
- Author(s):
- ZHANG Runfeng; QI Chunxiang; ZHANG Xianmin; GAO Yuhuan
- (Airport College, Civil Aviation University of China, Tianjin 300300, China)
- Keywords:
- road engineering; airport engineering; dowel bar; 3D finite element; sensitivity analysis; load transfer performance
- PACS:
- -
- DOI:
- -
- Abstract:
- To reduce the impact of airport pavement structure damage on the load transfer performance of joints, model tests of load transfer performance with two kinds of damage, namely the looseness of the dowel bar and the slab void, were investigated based on the similarity theory. In addition, the threedimensional finite element model of the airport cement concrete pavement structure with a joint dowel bar was established using ABAQUS finite element software, and the damage model test of pavement structure was simulated. Furthermore, the load transfer performance of the pavement slab was analyzed under seven levels of length, diameter, and spacing of the dowel bar. The sensitivity of the dowel bar parameters to load transfer performance under two kinds of structural damage were also analyzed using the finite element method for different degrees of dowel bar looseness, slab void size, and slab corner void size. On this basis, considering the joint shear transfer coefficient, distribution coefficient of the key dowel bar, bending stress amplitude at the bottom of the slab, and interface stress as control indexes, the rule of the above index growth rate with the increase in size of the dowel bar parameter was analyzed when the looseness of the dowel bar and the slab void damage existed, compared with the nondamage condition. Furthermore, the design range of the parameters of the dowel bar considering the damage of the pavement structure was proposed and compared with the code of Specifications for airport cement concrete pavement design (MN/T 5004—2010). The results show that the displacement load transfer coefficient LTEδ decreases first and then increases with an increase of the void size, and it decreases gradually with the increase of the looseness. The experimental results of the two structural damage models are consistent with the finite element simulation law. The diameter of the dowel bars is the most sensitive to the loose damage, and the dowel bar spacing is the most sensitive to the slab void. With an increase in diameter and spacing of the dowel bar, the growth rate of the control index decreases first, then increases slightly and finally tends to be stable. It shows that when considering the damage of pavement structure, increasing the diameter of the dowel bar and reducing its spacing can only improve its load transfer performance within a certain range. According to different slab thicknesses, the recommended value of the dowel bar diameter, considering the loose damage, is 110% to 130% of the maximum value of the code, and considering the slab void damage, the recommended value of the dowel bar spacing is 70% to 98% of the maximum value of the code. 5 tabs, 16 figs, 24 refs.
Last Update: 2019-10-16