上覆硬壳层软土路基土层界面动力响应特征及工程应用  

Dynamic Response Characteristic of Interface of Layer of Soft Soil Subgrade with Dry Crust Covering and Its Engineering Application

作　　者：曹海莹[1] 刘云飞[1] 李慧剑[1] 吴吉贤[1] 

机构地区：[1]燕山大学建筑工程与力学学院,河北秦皇岛066004

出　　处：《公路交通科技》2015年第7期33-40,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51308486);河北省博士后择优资助科研项目(D2014003010);燕山大学博士基金项目(B712)

摘　　要：基于应力波理论,从硬壳层与下卧软土层波阻抗具有明显差异角度,利用透射系数揭示了硬、软土层界面处具有动应力突变现象,该现象是硬壳层壳体效应在动力学范畴的一种具体表现。借助数值模拟手段获取车辆荷载作用下路基土中竖向动应力峰值的衰减规律,依据衰减曲线符合负指数函数特征,推导得出一种能综合表征动应力突变规律的土层界面传递系数,并给出了相应的计算方法及应用范围。通过实测数据验证,该方法较已有方法具有过程简单、精度高等特点。经高速公路工程的实践检验,考虑上覆硬壳层软土路基土层界面处的动力响应特征,路基土的力学状态能够得到正确评估,其残余变形值也会被降低。Based on the stress wave theory, in respect of obvious wave impedance difference between dry crust and soft underlayer, the phenomenon of dynamical stress mutation at hard-soft soil interface, which is a simulation. On the basis of attenuation curve＇s negative exponential function characteristic, a transfer coefficient at soil layer interface, which can represent the law of dynamical stress mutation synthetically, is derived, and the corresponding calculation method and application range of the transfer coefficient is offered, which is of process simplicity and high precision compared with the existing methods via monitoring data verification. By practice validation of expressway engineering, the mechanical state of subgrade soil can be evaluated correctly and its residual deformation can be reduced considering the dynamic response characteristic of interface of layer of soft soil subgrade with dry crust.

关 键 词：道路工程 硬壳层 应力波理论 动应力突变 界面传递系数 

分 类 号：U416.1[交通运输工程—道路与铁道工程]