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为探讨动载与冻融循环耦合作用下低路堤路基的沉降规律,以季冻地区典型低路堤断面为研究对象,利用ADINA有限元数值分析软件,建立了冻融循环和行车动载耦合作用下的路基三维分析模型。根据冻融循环期,将模型划分为6个过程模拟分析了低路堤沉降的竖向、水平位移及最大剪应力随时间和交通量变化的一般规律。研究结果表明:低路堤路面竣工后前6年弯沉增加较快,随着时间的推移,累积沉降逐渐趋于稳定;随着车流量的增加,由行车荷载和冻融引起的累积沉降和剪应力增大速度增快,限制超载是减小累积沉降的关键;隔离层能有效控制路面弯沉、地表水平位移和剪应力;分析模型实现了路基冻土体力学特征值的动态控制,为季冻区的低路堤沉降变形计算提供依据。
In order to investigate the settlement law of low embankment subgrade under the coupling of dynamic loading and freeze-thaw cycles, taking the typical low embankment section in quasi-frozen area as the research object, the finite element numerical analysis software ADINA was used to establish the freeze-thaw cycle Subgrade 3D Analysis Model. According to the freeze-thaw cycles, the model is divided into six processes to simulate the general law of vertical and horizontal displacements and the maximum shear stress with time and traffic volume of low embankment settlement. The results show that the deflection of the low embankment pavement increases rapidly in the first 6 years after the completion of the embankment, and the cumulative settlement tends to be stable with the passage of time. With the increase of traffic flow, the cumulative settlement and shearing caused by the traffic load and freeze- The stress increase speed is faster and the limit overload is the key to reduce the cumulative settlement. The isolation layer can effectively control the deflection of the pavement, the horizontal displacement of the ground surface and the shear stress. The analysis model realizes the dynamic control of the mechanical characteristics of the subgrade frozen soil, Provide basis for calculation of settlement of low embankment in frozen area.