基于路面破坏响应的差异沉降控制标准

Control criterion of subgrade differential settlement based on pavement damage response

针对高速公路路基差异沉降引起的路面破坏问题,经过路面结构力学响应分析,建立差异沉降控制标准,对路基施工质量进行控制,防止路面开裂。通过对路面结构有限元模型施加初始位移边界条件,模拟差异沉降对路面结构的影响;对不同差异沉降作用下路面结构附加应力进行分析,综合考虑路面材料抗弯拉强度与结构层抗疲劳破坏性能,提出了基于路面破坏响应的差异沉降控制标准。结果表明:只考虑路面材料抗弯拉强度时,以变坡率0.23%作为沉降控制标准;考虑结构层抗疲劳破坏性能时,以变坡率0.58%作为差异控制标准,综合考虑二者共同影响时,以变坡率0.37%作为差异控制标准,相应的路基横向与纵向沉降控制值分别为4.5 cm和7.5 cm。

Aimed at expressway pavement damage caused by differential settlements,a differential settlement control standard is established according to the mechanical response of pavement structure,so that the subgrade construction quality can be controlled and pavement cracking can be prevented.A boundary condition is imposed to the finite element model of pavement structure in order to simulate differential settlement on the pavement structure.A differential settlement control standard was proposed considering flexural strength of pavement materials and fatigue damage performance of pavement structure.The results show that： the variable slope rate of 0.23% can be taken as settlement control standards when only considering the flexural strength of pavement materials;considering the fatigue performance of pavement,the rate of 0.58% as the control standard,considering the combined effects,the rate of 0.37% as the control standard,the corresponding horizontal and vertical subgrade settlement control values are 4.5 cm and 7.5 cm respectively.4 tabs,2 figs,8 refs.