沥青路面内动空隙水压力的数值模拟

摘要

为了研究沥青路面内的动水压力,基于Biot固结方程,将沥青混合料看作多孔介质,并考虑了它和水体的惯性力及两者之间的耦合作用,对饱水沥青路面进行了快速Lagrange有限差分分析.结果表明,水压的产生和消散在轮载作用过程中同时存在,导致面层内正负水压力及渗透力随时间交替出现,这证实了水损坏过程中的水力反复泵吸作用.动孔隙水压力随车速的增大而增大,而且由于水压力的存在路面弯沉和面层内的有效应力减小,但水对沥青膜的乳化和置换作用加强.动水压力的最大值出现在面层底部,所以建议在面层底部设一排水层,将排水状态由单面排水变为双面排水,有效抑制水损坏的发生.%For studying the driving role of dynamic pressure in water-induced damage of asphalt pavement.based on the fast Lagrangian finite difference method and Biot dynamic consolidation theory,fluid-solid coupling analysis of the pavement is conducted considering asphalt mixtures as porous media.Results reveal that the development and dissipation of the dynamic pore pressure are coinstantaneous and this makes both the positive and negaUve dynamic pore pressure and seepage force alternate with time.Repetitive hydrodynamic pumping and sucking during moisture damage is proved.The dynamic pore pressure increases with vehicle velocity.Effective stress and detlection of pavement decrease due to the dynamic pore water pressure.However,the emulsification and replacement of the asphalt membrane by water are accelerated.The maximum dynanuc pore pressure occurs at the bottom of the surface Course.So it iS suggested that a drain course should be set up to change the draining condition from single-sided drain to a two-sided drain,and thus moisture damage can be effectively limited.