金鸡关隧道渗水变形特征研究及其治理

The Research on the Characteristics of Jinjiguan Tunnel′s Water Penetration and Deformation with Defects Control Measures

川藏公路雅安金鸡关隧道于1995年元月开始双洞全线通车运行,但是从2001年左右开始左、右隧道均出现了不同程度的渗水变形,并有裂缝以及局部隆起鼓出现象。通过实地勘查和采样分析,结合前人的研究,认为金鸡关隧道的病害主要是地质原因,即灌口组地层中的膨胀性粘土遇水膨胀造成顶拱和路面鼓出隆起变形;溶解了地层中石膏的地下水沿施工造成的环向裂缝渗水重结晶,其诱发因素为地下水。在研究了金鸡关遂道渗水变形特征的基础上,围绕治理表部和隧道周边的地下水提出了相关的治理方案。

Jinjiguan tunnel on Chuan-Zang highway at Ya-an was entirely open to traffic on January of 1995, however,about in 2001 the two tunnels of it appeared water penetration and deformation to a different degree with crevices and upheaval. Based on the author′s investigation and analysis at field and antecedent studies, it was three factors which resulted in the Jinjiguan tunnel′s all kinds of defects: the first factor was geological factor that was expansive soils in Guan-kou (lithostratigraphical unit) expanded to cause arch and road surface upheaval on encountering water; the second was that the groundwater dissolving the gypsum in Guan-kou seeped and recrystallized along toroidal crevices caused by the third factor construction reason. All the defects are mainly caused by the inducing factor groundwater, and on the base of these studies, the author offered some measures to control the defects,of which main measures are to cure surface water and groundwater surrounding the tunnel.