纤维编织网增强混凝土加固隧道衬砌数值研究

Numerical study on tunnel lining strengthened by textile-reinforced concrete

为了克服隧道衬砌内表面常用补强方法的不足,探索纤维编织网增强混凝土(Textile-reinforced concrete,TRC)加固隧道衬砌的适用性。开展界面黏结试验,分析TRC加固隧道衬砌的界面应力分布规律,在此基础上建立TRC加固隧道衬砌的合理数值模型并开展加固参数优化分析。结果表明:TRC加固隧道衬砌的最大界面应力出现在加固层端部,并沿着加固层迅速降低;TRC适合加固处于大偏心受压的衬砌截面,偏心距越大,增强效果越明显;采用提高纤维编织网用量的方法在一定程度上可以增强加固效果,但是增强趋势呈现出减弱趋势;隧道衬砌前期受力对加固效果存在负面影响,前期受力越大,加固效果越弱;采用TRC抑制衬砌张拉裂缝扩展的效果优异。

In order to overcome the shortcomings of strengthening methods commonly used in tunnel lining on internal interface,the applicability of textile-reinforced concrete in strengthening lining is explored. Interface bond tests were conducted and interface stress distribution law of tunnel lining strengthened by TRC was analyzed. Further, the numerical model of TRC in strengthening tunnel lining was proposed and strengthening parameters optimization analysis was conducted. The results show that the TRC is suitable to strengthen lining with big eccentricity and the strengthening effect increases with the eccentricity. The strengthening effect can be increased by adding textile ratio to some extent,but it shows decreasing trend. Load history is harmful to strengthening effect,and the strengthening effect decreases with the load history. It is of good effects to limit tensile cracks by using TRC.