Abstract

Reinforced concrete (RC) pontoons have been widely used as floating foundations to support various structures. However, pontoons are under the threat of accidental collisions from passing ships and service vessels. To ensure the integrity of pontoons and the supported structures in a collision accident, special strengthening techniques may be required to increase the impact resistance of the pontoons. Carbon fibre reinforced polymer (CFRP) composites have been extensively used in strengthening RC structures under blast and impact loads. However, the effectiveness of CFRP strengthening of RC pontoons against ship collisions has not been investigated. In this study, CFRP composites are used to strengthen RC pontoon walls against ship bow collisions. It is observed that while CFRP-strengthened pontoon walls still experience punching shear failures as the normal RC pontoon walls, the wall damage is nonetheless significantly reduced. With the strengthening of 4 mm CFRP sheet, the impact resistance of the pontoon wall is increased by 5-10% depending on the pontoon wall thickness. An analytical method for calculating the punching shear capacity of CFRP-strengthened RC pontoon walls is also proposed based on the critical shear crack theory. The method significantly reduces the computational efforts and can be used in the preliminary design phase.

摘要

钢筋混凝土 (RC) 浮筒已广泛用作支撑各种结构的浮动基础。然而，浮桥受到过往船只和服务船意外碰撞的威胁。为了确保在碰撞事故中浮筒和支撑结构的完整性，可能需要特殊的加固技术来增加浮筒的抗冲击性。碳纤维增强聚合物 (CFRP) 复合材料已广泛用于在爆炸和冲击载荷下加固 RC 结构。然而，尚未研究 CFRP 加固 RC 浮筒对船舶碰撞的有效性。在这项研究中，CFRP 复合材料用于加强 RC 浮筒壁以防止船首碰撞。据观察，虽然 CFRP 加固的浮桥壁仍然像普通的 RC 浮桥壁一样经历冲剪破坏，但壁损坏显着减少。随着4的加强 mm CFRP板材，根据浮筒壁厚不同，浮筒壁的抗冲击能力提高5-10%。基于临界剪切裂纹理论，提出了一种计算CFRP加固RC浮筒墙体冲剪承载力的解析方法。该方法显着减少了计算工作量，可用于初步设计阶段。