动荷载作用下高温冻土路基的动力响应分析

Analysis of Dynamic Response of High Temperature Frozen Subgrade to Dynamic Loading

采用有限元计算和模拟试验相结合的方法,研究了高温冻土路基在列车动荷载作用下的动力响应。首先,通过数值计算分析了路基的地表变形、内部土压力的变化规律。根据相似理论确定并没计了冻土路基模拟试验装置,通过在路基周围地表及其内部布设压力和变形传感器,并用自行设计的列车动荷载加载装置对路基施加模拟荷载,进行了冻土路基的模拟试验。模拟试验和数值计算的结果分析表明:采用的数值计算模型和模拟试验方法基本可行,研究结果可为青藏铁路的安全运营以及维护提供参考。

The dynamic response of high temperature frozen subgrade to dynamic loads was studied by combining the finite element simulation with simulated experiment.The variation characteristics of deformation of the surface of the surrounding ground and inner soil pressure were analyzed through numerical calculation. The simulation test equipment was set up by the analysis of the main factors which influence the inner soil pressure,the displacement and the temperature field of the subgrade.Using the self-made experimental load device,pressure and deformation sensors were placed inside the subgrade and on the surface of the surrounding ground.The dynamic response of the subgrade under the train loads was investigated.The results obtained from numerical calculation and simulated experiment indicate that the proposed model is practicable,and can provide reference for maintenance of Qinghai-Tibet railway and its safety operation.