重载铁路路基基床结构强度控制设计方法研究

Study on Strength Control Design Method of Heavy-haul Railway Subgrade Bedding Structure

针对重载铁路路基基床结构建立了一套以动强度长期稳定性为准则的强度控制设计方法,该方法的主要设计步骤为:基于荷载分担Gauss函数法确定各轨枕承担的动轮载力;根据层状体系传递矩阵法计算最不利位置处轨枕下方的应力分布;以动强度长期稳定性为控制准则,确定基床厚度及基床表层厚度。进一步,采用建立的强度控制设计方法,对不同轴重下的重载铁路路基基床结构进行设计,结果表明:建议轴重25 t,基床表层厚度0.6 m,基床底层厚度1.9 m,基床厚度2.5 m;建议轴重30 t,基床表层厚度0.6 m或0.7 m,基床底层厚度2.4 m或2.3 m,基床厚度3.0 m。

A set of strength control design methods was established based on the principle of long-term stability and dynam-ic strength for heavy-haul railway subgrade bedding structure.The main design steps of the method are:determine the dy-namic wheel carrier force of the sleeper bear based on Gauss function method;calculate the stress distribution under the most disadvantageous position of sleeper based on transfer-matrix method;determine the thickness of subgrade and surface layer thickness based on the principle of long-term stability of dynamic strength.Further,heavy-haul railway subgrade bed-ding structure of different axle loads was designed by the strength control design method established,and the results show:for 25 t axle load the recommended surface layer thickness is 0.6 m,the bottom layer thickness is 1.9 m,the subgrade thickness is 2.5 m;for 30 t axle load the recommended surface layer thickness is 0.6 m or 0.7 m,the bottom layer thick-ness is 2.4 m or 2.3 m,the subgrade thickness is 3.0 m.