采空区不均匀沉降引起的沥青路面附加应力分析

Analysis of Additional Stresses in Asphalt Pavement due to Asymmetrical Subsidence of Mined-out Region

采用随机介质理论计算采空区地表沉降,根据所得采空区沉降盆地函数采用经验计算方法预计地表剩余沉降,再采用弹性力学方法分析不均匀地表剩余沉降对半刚性基层沥青路面结构层的影响,得到了结构层附加应力的解析表达式,并以某通过采空区的高速公路为例,分析采空区地表剩余沉降引起的路面结构附加应力。计算结果表明:采空区地表剩余沉降对路面结构层附加应力的影响十分显著,所生产的水平和竖向拉应力以及剪切应力易导致路面结构层产生裂缝和脱空,影响路面的使用功能,因而在路面结构设计时应考虑附加应力的影响。

The surface subsidence of mined-out region is calculated by using stochastic medium theory,and the surface residual subsidence is predicted by using empirical calculation method according to the obtained subsidence basin function of mined-out region. Then,the effects of asymmetrical surface residual subsidence on the semi-rigid base asphalt pavement structure layers are analyzed by using elasticity method,and the analytical solutions of additional stresses of the structure layers are obtained. Finally,taking an expressway which crosses the mined-out region as an example,the corresponding additional stresses in the pavement structure layers resulted from mined-out region surface residual subsidence are analyzed. The result indicates that the surface residual subsidence of mined-out region has remarkable impact on additional stresses of pavement structure layers,of which the lateral and horizontal tensile stresses and shear stress will lead to cracks and voids in structure layers,thus influencing the service function of pavement. Therefore,the additional stresses should be taken into account when designing pavement structure in mine-out region.