运营越江隧道服役现状调查与检测评估

Investigation and evaluation of present state and serviceability of existing river-crossing tunnel

既有打浦路隧道在运营36年后,隧道结构目前正处于严重的老化阶段,由于隧道衬砌结构的混凝土劣化,接缝材料老化,钢筋和螺栓锈蚀,渗漏水以及隧道纵横向差异变形等已非常严重,对隧道的安全运营造成了严重隐患.基于此需要对隧道结构进行一次全面地检测与评估.从隧道结构服役性能出发,对既有打浦路隧道的历史资料及现状进行了较为详细的调查,给出了隧道结构的主要损伤因素,并制定了详细的隧道结构检测方案,包括检测的内容、数量、具体要求、检测方法等.通过对既有隧道渗漏状况以及隧道纵向的长期沉降情况的初步检测,发现对于直径10m左右的软土盾构隧道,纵向变形曲率半径小于35～40 km时产生的差异变形,易导致衬砌环向接头的张开度增大,引起渗漏,同时渗漏又导致隧道继续产生纵向不均匀变形,二者相互影响.最后给出了用于既有隧道结构损伤评估的宏观安全性模型和微观耐久性模型.

After having been operated for 36 years, the structure of Dapu road tunnel is in serious aging state now. Because of the concrete deterioration, joint material aging, the corrosion of the steel bar and the bolt, leakage and the differential deformation of the tunnel lining, the existing Dapu river-crossing road tunnel is facing severe dangers and risks. So investigation and evaluation for the tunnel are urgent. Analysis of the service life, investigation of the history materials and the present state of the tunnel are carried out and the main damage reasons of the tunnel lining are obtained. Based on the investigation results, the inspection schemes are made including investigation contents, quantity, requirements and investigation methods. Through the preliminary investigation of the leakage and longitudinal long-term settlements for tunnel lining, it is shown that when radius of curvature of tunnel's longitudinal deformation is less than 35 to 40 km, the crack of the tunnel lateral joint will lead to leakage and at the same time the leakage will lead to longitudinal difference deformation. Finally, the macroscopic safety model and microscopic durability model are presented for the damage evaluation of the existing tunnel linings structure.