为有效解决和控制仰拱厚度不够、强度不足、施工缝翻浆冒泥及上拱等施工质量问题,保障隧道工程建设和运营安全,依托渝昆高铁昭通隧道工程,采用隧道扫描系统检测仰拱开挖断面,确保仰拱厚度满足设计要求;采用液压自行式整体仰拱栈桥,优化仰拱弧形模板,实现分段分层浇筑和振捣工艺,提高混凝土施工质量;采用分离式仰拱端头钢模板,预铺仰拱端头弧形带并安装橡胶背贴和中埋止水带,提高了施工缝质量,减少了施工缝翻浆冒泥现象;设置隧底纵向排水管及逆向导水管等优化隧底排水设计措施,解决了水害造成的仰拱上拱问题;制定并落实隧道仰拱施工质量管理措施。通过在渝昆高铁昭通隧道施工中采取以上措施,实现了仰拱零欠厚,仰拱混凝土强度满足设计要求,施工缝质量零缺陷。
In order to effectively solve the construction quality
problems such as insufficient thickness and strength of inverted arch, grouting
and mud gushing from construction joints and upward arch, and ensure the safety
of tunnel construction and operation, the tunnel scanning system is used to
detect the excavation section of inverted arch of Zhaotong Tunnel project of
ChongqingKunming Highspeed Railway, so as to ensure
that the thickness of inverted arch meets the design requirements. And then the
hydraulic selfpropelled integral inverted arch trestle
is adopted to optimize the inverted arch arc template, realize sectioned and
layered grouting and vibration, and improve the quality of concrete
construction. The separate type steel formwork at the inverted arch end is
used, the arcshaped belt at the inverted arch end is
prelaid, and rubber back paste and medium steel plate
embedded water stop belt are installed, which improves the quality of
construction joint and reduces the occurrence of mud gushing in construction
joint. The longitudinal drainage pipe and reverse water diversion pipe at the
tunnel bottom are set to optimize the drainage design measures, which help to
solve the problem of upward arch caused by water damage. Finally, the
construction quality management measures for tunnel inverted arch are
formulated and implemented. By adopting the abovementioned
measures in the construction of Zhaotong Tunnel of ChongqingKunming Highspeed Railway, the thickness
and the concrete strength of the inverted arch and the construction joint
quality meet relevant design requirements.