公路隧道洞口段衬砌裂缝的性状特征及成因

Characteristics and Cause Analysis of Lining Crack in Entrance Section of Highway Tunnel

以豫西某高速公路隧道群洞口段衬砌结构裂缝为实例,针对不同结构形式的裂缝性状特征,从地质条件、设计理念、施工方法、养护制度等不同方面对裂缝成因进行系统研究。结果表明,隧道洞口段裂缝数量、长度均远高于洞身段;洞口段裂缝主要成因是地质条件不良、基础沉降不均匀、衬砌施作时间不当、衬砌厚度不足或背后脱空、防排水不当等;并提出了"针对病因、辨证施治,防治结合、综合处理,早期发现、及时维护"的治理原则。

Taking the lining structure cracks of the entrance section of highway tunnel group in Western Henan as an example,the causes of cracks were systematically studied from different aspects,such as geological conditions,design ideas,construction methods and curing systems,according to the properties and characteristics of cracks with different structural forms.The results show that the number and length of cracks in the entrance section of tunnel are much higher than those in the body section of tunnel and the cracks in the entrance section of tunnel are mainly due to poor geological conditions,foundation uneven subsidence,improper lining construction time,insufficient lining thickness or cavity behind lining,improper waterproof and drainage and so on.Besides,the treatment principle of syndrome differentiation,prevention and treatment integrated,comprehensive prevention,early detection and timely maintenance are put forward based on different causes of the cracks.