城市道路路基拓宽处治中土工格栅数值分析

Numerical Analysis of Geotechnical Grid in Widening Treatment of Urban Road Roadbed

公路改扩建城市道路工程中通常采用土工格栅处治路基拓宽搭接处新旧路基差异沉降。相关设计规范明确了新旧路基差异沉降的控制技术和控制标准,但对于土工格栅在路基拓宽处治段中最佳布设层数和竖向间距、位置等目前多为经验性的缺乏相应的设计方法和规范指导,存在经济上的浪费或效果不佳。以荆门南高速出入口综合整治工程拓宽搭接段为研究对象,建立路基拓宽有限元计算模型,通过有限元数值分析研究铺设不同方式土工格栅拓宽路基对路面竖向位移及路面横坡比的影响。根据计算结果确定了合理的格栅竖向间距与铺设方案,该研究结果可以为公路改城市道路路基拓宽处治提供方案参考。

The geotechnical grids are often used to treat the difference settlements of old and new roadbeds at the widening and overlapped sections in urban road reconstruction extension projects. The relevant design specification defines the control technology and control standard of difference settlements of old and new roadbeds. But there are no corresponding design methods and guidelines empirically for the optimum layout layer, vertical spacing and position of geotechnical grids in the roadbed widening treatment section with the economic waste or poor result now. By the study object of the widening overlap section of Jingmen South High Speed Entrance and Exit Comprehensive Treatment Project, the finite element calculation model of roadbed widening is established. The finite element numerical analysis is used to study the effect of the different geotechnical grid widened roadbeds on pavement vertical displacement and pavement cross slope ratio.According to the calculation results, the reasonable vertical spacing and laying scheme of grids are determined. This study result can provide a reference for the widening treatment scheme of urban road roadbed.