Zeng Cong, Gong Chenkun, Wang Fuzhi, Zhu Zihao, Zhao Yahong, Ariaratnam Samuel T
Faculty of Engineering, China University of Geosciences (Wuhan), Wuhan 430074, China.
School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85259, USA.
Polymers (Basel). 2022 Jul 7;14(14):2781. doi: 10.3390/polym14142781.
A large number of drainage pipes and canals in China have been in disrepair for a long time and there have been problems such as leakage and corrosion. In response to these problems, this paper studies a non-excavation technology for repairing the arched canal structure-the in-situ spraying method. To study the influence of the original canal structure on the mechanical characteristics of the lining structure by in-situ spraying and the restraint effect on the lining structure, a field model test with a similar ratio of 1:2 was conducted in the field test pit. By conducting four stages of three-point concentrated load loading tests, the mechanical characteristics of the lining structure were investigated to reveal the influence of the canal structure on the force of the lining structure. The test results show that: the maximum crack width of the newly added lining structure is 0.27 mm and the normal service ultimate bearing capacity of the arched structure repaired by H-70 reaches 150 kN; comparing the loading test and the numerical simulation results, the difference between the two vault displacement results is 4.65% and the results are relatively consistent. The displacement of the bottom of the lining structure is small and the participation of the bottom plate is small, while the displacement of the upper arch structure of the lining is significantly larger than the lateral displacement, indicating that the canal structure can effectively limit the lateral displacement of the newly added lining and that the canal structure is greatly reduced. The bending moment of the lining structure is improved and the restraint effect on the arch foot is more obvious. This paper proposes the use of H-70 to repair arched canal structures by the in-situ spraying method and seeks to prove the feasibility of this method and fill the gap of research in this area. This paper provides the structural design basis and experimental knowledge for the construction of the repair method, which has important practical significance for the pipeline repair project in the future.
我国大量排水管道及渠道长期失修，存在渗漏、腐蚀等问题。针对这些问题，本文研究了一种修复拱形渠道结构的非开挖技术——原位喷射法。为研究原位喷射时原有渠道结构对衬砌结构力学特性的影响以及对衬砌结构的约束作用，在现场试验坑内进行了相似比为1:2的现场模型试验。通过进行四个阶段的三分点集中荷载加载试验，研究衬砌结构的力学特性，以揭示渠道结构对衬砌结构受力的影响。试验结果表明：新增衬砌结构的最大裂缝宽度为0.27mm，采用H-70修复后的拱形结构正常使用极限承载力达到150kN；对比加载试验与数值模拟结果，两者拱顶位移结果相差4.65%，结果较为一致。衬砌结构底部位移较小，底板参与度小，而衬砌上部拱形结构的位移明显大于侧向位移，表明渠道结构能有效限制新增衬砌的侧向位移，且渠道结构作用大大减小。衬砌结构的弯矩得到改善，对拱脚的约束作用更明显。本文提出采用H-70通过原位喷射法修复拱形渠道结构，旨在证明该方法的可行性并填补该领域的研究空白。本文为该修复方法的施工提供了结构设计依据和试验认识，对今后的管道修复工程具有重要的现实意义。
