机场水泥混凝土道面脱空判定及影响

Identification of Void Beneath Airport Cement Concrete Pavement and Its Influence

根据现场实测弯沉数据和理论计算结果,提出了适用于机场水泥混凝土道面的基于HWD(High WeightDeflector)弯沉测试的脱空判定标准.采用三维有限元软件ABAQUS,分析了不同脱空状态对道面荷载应力的影响,并给出了不同脱空程度对道面使用寿命影响的算例.研究表明,水泥混凝土道面板边脱空判定标准为"板边弯沉/板中弯沉>1.8";板角脱空判定标准为"板角弯沉/板中弯沉>3.0";道面脱空严重时,道面板的荷载应力增幅超过250%,道面使用寿命下降迅速;在脱空发展初期时,脱空面积的影响并不显著,随着脱空区域基层反应模量下降,脱空面积影响的显著性迅速增大.

According to the field test data and theoretical calculation result, a standard based on high weight deflector （HWD） testing was established to identify void beneath airport cement concrete pavement. An analysis was made of the influence of all kinds of voids on loading stresses of airport cement concrete pavement with ABAQUS 3D-FEM model, and an example was given to show the influence of void on pavement＇s service life. The result shows that identification standard for void beneath slab edge is ＂slab edge deflection/ slab center defection 1.8＂, and void identification standard for void beneath slab corner is ＂slab corner deflection/slab center defection 3.0＂. When the void beneath slab becomes prominent loading stresses of airport cement concrete pavement will increase by over 250%, and the pavement~ s service life is shortened distinctly. The influence of the void area is not obvious on the early stage of void development, but it increases while the base response modulus of void region decreases.