基于重载作用下川藏公路柔性加固基层力学性能研究

Research on Mechanical Properties of Flexible Reinforcement Base under Heavy Load of the Sichuan-Tibet Highway

川藏公路路基易在重载和恶劣环境综合作用下产生不均匀变形,导致半刚性基层沥青路面发生破坏。为了减缓破坏,拟采用土工格室加固级配碎石组成柔性加固基层,提高道路力学性能。当前土工格室多应用于加固土体,而用于加固级配碎石形成复合整体直接应用于路面结构中的相关研究较少。因此,利用室内刚性承载板试验,基于0~1.3 MPa重载作用,对柔性加固基层开展竖向总变形量、塑性变形量、变形模量和回弹模量等力学性能研究。试验结果表明,较之未加固碎石基层,柔性加固基层的总变形量和塑性变形量可减少46.1%和61.4%,变形模量和回弹模量可提高33.4%和29.3%。研究成果不仅可用于减缓重载作用下路基不均匀变形对路面的危害,还可为该地区道路的设计和养护工作提供理论依据。

The subgrade of the Sichuan-Tibet highway is prone to uneven deformation under the combined action of heavy load and harsh environment, which leads to the destruction of semi-rigid base asphalt pavement. In order to slow down the damage, the geocell reinforcement graded gravel is used to form a flexible reinforcement base to improve the mechanical properties of the road. At present, geocells are mostly used to reinforce soil, and there are few related studies on the use of reinforced graded gravel to form a composite whole and directly applied to pavement structures. Therefore, in the paper, by means of the indoor rigid load-bearing plate test, based on the 0~1.3 MPa heavy load, the mechanical properties of the flexible reinforced base layer is studied in terms of the total vertical deformation, the plastic deformation, the deformation modulus and the resilience modulus. The results show that, compared with unreinforced gravel base, the total deformation and plastic deformation of the flexible reinforced base can be reduced by 46.1% and 61.4%, and the elastic modulus and deformation modulus can be increased by 33.4% and 29.3%. In the research, the geotechnical grid and graded broken stone are combined to form a flexible reinforcement base, and be directly applied to pavement structure. Its excellent mechanical properties are revealed through experimental research. The research results can be used to mitigate the road surface damage under heavy load and subgrade uneven deformation, which can also be the theoretical basis for road design and maintenance in this area.