大型港工系船柱结构安全监测方法与实验

Structure monitoring mothod and experiment of large-scale wharf bollards

现有的结构安全监测方法尚无法完全满足复杂系泊条件下系船柱结构安全监测的需要。针对系船柱结构及系缆特点,提出了标准条件系缆力的概念与指标。以此为基础,依据弹性力学原理推导了标准条件系缆力反演模型,并根据缆力方向的范围与反演模型的应变监测点要求,研究了系船柱表面多点应变布置方案,提出了基于多点应变融合的系船柱结构受力安全监测方法。针对系船柱应变分布特点与长期监测要求,研究提出了应变均化的布拉格光纤光栅传感器表面焊接传感方案,并在1 500 kN系船柱上成功部署了5支应变传感器与1支温度传感器,开展了长时间连续监测。通过分析标准条件反演缆力与船舶实际缆力值,标准条件系缆力反演误差最大为8.1%。证明该方法具有较强的可行性与操作性,能有效实现港工既有系船柱结构的安全状态监测与预警。

Existing structural safety monitoring methods cannot fully meet the requirements of bollard structure safety monitoring under complex mooring conditions. Herein,the concept and index of the standard state mooring force are proposed according to the structure and mooring characteristics of bollards.The standard state mooring force inversion model is derived according to the elastic principle. According to the range of the mooring force direction and requirements of the strain monitoring points of the inversion model,the multi-point strain arrangement scheme on the surface of the bollard is studied,and a structural safety monitoring method for bollards is proposed based on multi-point strain fusion. Additionally,a strainequalized fiber Bragg grating sensor-based surface welding sensing solution is proposed based on the strain distribution characteristics and long-term monitoring requirements of the bollards. Furthermore,five strain sensors and one temperature sensor were successfully deployed on the 1500 kN bollard at Ningbo Daxie International Merchants Container Terminal,and long-term continuous monitoring was carried out. By analyzing the inversed cable force under the standard conditions and actual values,the maximum error of the inversion of the standard conditions was found to be 8. 1%. It is proved that this method has high feasibility and operability and can effectively perform monitoring and provide early warnings regarding the safety of large mooring column structures in harbors.