单线铁路隧道衬砌环向施工缝质量控制技术

QUALITY CONTROL TECHNOLOGY OF LINING CIRCUMFERENTIAL CONSTRUCTION JOINT OF SINGLE TRACK RAILWAY TUNNEL

在隧道结构中,施工缝作为二次衬砌最薄弱的环节,导致在该处极易发生混凝土剥落掉块、渗漏水、耐久性降低及结构强度不足等严重病害,严重威胁到隧道质量及行车安全。基于上述背景,依托浦梅铁路工程,对沿线隧道衬砌环向施工缝缺陷问题进行统计分析,其主要病害可归纳为混凝土不密实剥落掉块、中埋式止水带外露或折叠空响、边缘开裂及闭环裂纹4大类,总结得出漏浆、振捣工艺不足、混凝土强度不足、中埋式止水带刚性不足及钢筋定位卡具定位点不足是造成环向施工缝缺陷的主要原因。针对不同类型的环向施工缝缺陷,提出相应的处治技术,并从新材料、新技术和新工艺的角度提出单线铁路隧道衬砌环向施工缝质量控制技术,研究成果在依托工程得到应用,效果良好,具有一定的工程价值和学术意义。

In the tunnel structure,as the weakest link of the secondary lining,the construction joint is prone to serious diseases such as concrete peeling off,water leakage,reduced durability and insufficient structural strength,which seriously threatens the tunnel quality and driving safety.Based on the above background,relying on the Pumei railway project,the paper makes a statistical analysis on the defects of tunnel lining circumferential construction joints along the line.The main diseases can be summarized into four categories:non dense concrete peeling off,exposed or folded hollow sound of embedded waterstop,edge crack and closed-loop crack.It is summarized that there are slurry leakage,insufficient vibration technology,insufficient concrete strength.The main reasons for the defects of circumferential construction joint are the insufficient rigidity of middle buried waterstop and the insufficient positioning points of reinforcement positioning fixture.Aiming at different types of circumferential construction joint defects,the paper puts forward the corresponding treatment technology,and puts forward the quality control technology of circumferential construction joint of single track railway tunnel lining from the perspective of new materials,new technology and new process.The research results have been applied in the project,with good effect and certain engineering value and academic significance.