超大跨度公路隧道衬砌的变形规律及裂缝处理

Deformation Law and Crack Treatment of Lining of Super-long Span Highway Tunnel

为研究超大跨度公路隧道二次衬砌裂缝的变形规律及产生原因,以滨莱高速姚家峪隧道为依托,对超大跨度公路隧道二次衬砌开裂段进行监控与量测。监测内容包括拱顶沉降、净空收敛及裂缝宽度,并对监测结果进行分析。结果表明:二次衬砌变形规律与洞内气温变化相关,随着气温上升,变形表现出先增大后逐渐平缓的规律;混凝土材料的收缩及温度应力作用是隧道二次衬砌开裂的主要原因,因此冬季施工时应加强混凝土的养护,防止裂缝持续发育;衬砌裂缝主要位于隧道洞口段,并沿起拱线上下纵向曲折延伸,施工时应采用低压速灌法、环氧树脂等协同处理。

In order to study the deformation law and the causes of the cracks in the super-long span highway tunnel,the cracking section of the secondary lining of the super-long span highway tunnel was monitored and measured based on the Yaojiayu Tunnel of Binlai Expressway.The vault settlement,clearance convergence and crack width were monitored and analyzed.The results show that the deformation law of the secondary lining is related to the temperature change in the tunnel.As the temperature rises,the deformation shows the law of increasing first and then gradually smoothing.The shrinkage of concrete materials and the effect of temperature stress are the main reasons for the cracking of the secondary lining of the tunnel,so the maintenance of concrete should be strengthened during construction in winter to prevent the continuous development of cracks.Cracks on the lining mainly locate in the tunnel entrance section and extend longitudinally and zigzag along the arching line.During the construction,low-pressure rapid irrigation method,epoxy resin and other treatments should be used in collaboration.