黄土公路隧道衬砌开裂分析

Analysis on lining cracks of highway tunnel in loess area

衬砌开裂是黄土公路隧道普遍存在的病害。为了预防和处治衬砌开裂,保证黄土隧道结构的长期稳定性,针对甘肃省榆中县新庄岭黄土公路隧道衬砌开裂的病害特征,运用数值仿真、实测等手段分析了病害产生的机理和原因。结果表明,黄土浸水导致土体强度降低、变形增大,从而增大了围岩塑性区范围和变形压力,恶化了衬砌结构受力状况,使衬砌结构拱顶内侧及拱脚外侧被拉裂,进而使拱脚内侧被压裂。根据隧道病害状况,提出了采用环氧树脂嵌补及凿槽嵌入钢拱架法处治衬砌开裂的建议,为分析和处治黄土公路隧道衬砌开裂提供了依据。

The lining cracks are widespread diseases of highway tunnel in the loess. In order to prevent the lining cracks and ensure the safety of highway tunnels, based on the disease characteristic of lining cracks on Xinzhuangling highway tunnel in loess, the developing mechanism and reason of lining cracks are analyzed through numerical simulation and field observation. The results demonstrate that water infiltration can lead to the decrease of soil strength and the increase of soil deformation, so the rock plastic area and deformation pressure are increased, the mechanical characteristic on lining is deteriorated, the cracks occure on inside of arch top and outside of arch foot by over tension, the cracks occure on inside of arch foot by over pressure. Considering the actual disease of the tunnel, the lining cracks should be maintained by resin and lattice girder implanting. The results provide a theory basis for treating these diseases in loess highway tunnel. 3 tabs, 10 figs, 10 refs.