大直径盾构隧道箱涵喷淋养护方法及应用

Spray Maintenance Method and Application of Box Culvert in Large-diameter Shield Tunnel

大直径盾构隧道预制箱涵件体积较大,在存放过程中,其结构内外温差过大极易导致箱涵表面产生裂纹,严重的将影响结构的牢固性。本文针对大直径盾构隧道箱涵件批量养护需求,开发了一套半自动化喷淋系统,并提出了系统的养护工艺。通过使用喷淋系统替代传统人工作业,可以精确控制喷水量;根据温度的不同,可自动调整喷洒量,单个喷头可喷淋40块中箱涵或者48块边箱涵,喷水量为2 m3/h,实现一天12 h连续喷淋。该系统成功应用于新建深圳至江门铁路珠江口隧道段站前工程SJSG-1标段,减少了盾构施工过程中箱涵长期存放导致的混凝土开裂、起皮等问题,降低了养护的水费和人工费,预计节约人工成本25.4万元,实现了高效、高质量的箱涵养护和环保施工。

The prefabricated box culvert components of large-diameter shield tunnels have a large volume.During storage,the large temperature difference between the inside and outside of the structure can easily lead to cracks on the surface of the box culvert,which will seriously affect the stability of the structure.This apaper develops a semi-automatic sprinkler system for batch maintenance of large-diameter shield tunnel box culvert components,and proposes a maintenance process for the system.By using a sprinkler system instead of traditional manual operations,the amount of water sprayed can be accurately controlled;according to different temperatures,the spraying amount can be automatically adjusted.A single nozzle can spray 40 medium box culverts or 48 side box culverts,with a spraying amount of 2 m3/h,realize continuous spraying for 12 hours a day.The system has been successfully applied to the SJSG-1 bid section of the the Zhujiang River estuary tunnel section of the newly built Shenzhen Jiangmen Railway,which reduced the concrete cracking,peeling and other problems caused by longterm storage of box culverts during shield construction,reduced the water and labor costs for maintenance,and was expected to save labor costs of 254000 yuan,realizing efficient,high-quality and environmentally friendly construction of box culvert maintenance.