青藏公路冻土路基最大设计高度研究

针对冻土路基斜坡稳定性受温度场影响的特殊性,采用自行开发的数字路基仿真平台对不同地温、不同坡度和不同路基高度条件下的大量工况进行了温度场数值模拟。采用冻土力学参数与地温的拟合公式将温度场与力学场关联起来,并考虑到冻融交界面作为软弱夹层对于冻土路基稳定性控制作用,采用自行编制的冻土斜坡稳定性评价程序对各工况进行了稳定性系数计算,并考虑了荷载作用对冻土路基斜坡稳定性的影响。参照《公路路基设计规范》中对于路堤软弱层滑动稳定性的设计规定,提出了不同坡比、不同荷载作用条件下的冻土路基最大设计高度。

Maximum design height of QinghaiTibetan highway embankment

The stability of the cold region slope is affected by its non-uniform temperature field.Temperature field of numerical examples with different soil temperature,slope and subgrade height have been simulated firstly by the self-developed numerical subgrade simulation software.Then the stability of different numerical examples is computed using the developed frozen subgrade stability computation program,in which the temperature linked frozen soil’s physical parameters are treated as the connection between temperature field and stress field,and the affection of freezing-thawing interface and loadings on the stability of frozen subgrade slope have also been considered.Based on the above computation analysis and specifications for design of highway subgrades including soft interlayer,the principles of maximum design height for frozen subgrade under different slopes and loadings,have been proposed.