In recent years, the deterioration of harbor structures has become a matter for concern, and the establishment of effective repair methods has become urgent. In this study, a repair method for installing permanent formwork panels and filling them with underwater inseparable mortar is proposed as an effective section-restoring method for deteriorated concrete caisson sidewalls. To investigate the integrity between existing concrete and repaired parts as well as the effect of thickness increase due to panel installation, static bending tests of a flat-reinforced concrete (RC)-beam-modeled side wall used in caisson structures are conducted. The results obtained from this study are as follows: (1) by attaching the permanent formwork panels to the flat RC beam, the bending crack occurring load was improved by a factor of three, and the rebar yielding load and maximum load were doubled. This tendency was the same even when the RC beam had a cross-sectional defect. (2) The RC beam with the permanent formwork panels finally failed with diagonal cracks opening after the maximum load was reached. The ductility ratio at this time was approximately 6. To improve the deformation performance, it is necessary to apply shear reinforcement. (3) The analysis results by the fiber model assuming the complete adhesion of the permanent formwork panels, underwater inseparable mortar, and RC beam were performed, and the results were compared with the experimental results. As a result, it was clarified that the adhesion of each constituent material was retained until the yield of the main reinforcing bar. After that, pulling out of the main reinforcing bar from the concrete and damage to the permanent formwork panel became apparent. (4) The curvature of the cross-section at the yield of the main reinforcing bar was φ_yc = 0.007 m⁻¹, and it was confirmed that the assumption of plane conservation was valid in the cross-section with a curvature less than that. This research is expected to promote the efficient maintenance of existing concrete caisson structures. As the amount of cement used and the construction period can be reduced, it is assumed that the environmental load can be reduced as well.

近年来，港口结构的恶化已成为人们关注的问题，建立有效的修复方法已成为当务之急。在这项研究中，提出了一种修复方法，该方法是安装永久模板面板并用水下不可分离的灰浆填充面板，作为对劣化的混凝土沉箱侧壁进行有效断面修复的方法。为了研究现有混凝土与维修零件之间的完整性以及由于面板安装而增加厚度的影响，对沉箱结构中使用的平面钢筋混凝土（RC）梁模型侧壁进行了静态弯曲测试。从这项研究中获得的结果如下：（1）通过将永久模板面板附加到平面RC梁上，弯曲裂纹的产生载荷提高了三倍，钢筋的屈服载荷和最大载荷增加了一倍。即使当RC梁具有横截面缺陷时，这种趋势也是相同的。（2）在达到最大载荷后，带有永久模板的RC梁最终因对角裂缝打开而失效。此时的延展性比约为6。为了改善变形性能，必须施加剪切增强。（3）进行了纤维模型的分析结果，假定永久性模板面板，水下密不可分的砂浆和RC梁完全粘合，并将结果与​​实验结果进行了比较。结果，澄清了直到主增强棒的屈服为止，每种构成材料的粘附力都得以保持。在那之后，从混凝土中拉出主钢筋，对永久模板的损坏变得显而易见。（4）主钢筋屈服时的截面曲率为φ _YC  =0.007米^-1，并确认了平面保护的假设是在横截面具有的曲率小于该有效。该研究有望促进对现有混凝土沉箱结构的有效维护。由于可以减少水泥的使用量和缩短工期，因此可以减少环境负荷。