混凝土坝裂缝光纤监测复用能力及与灵敏性的关系

根据光纤微弯损耗原理,导出了混凝土裂缝引起的光纤微弯损耗方程.基于理论分析和混凝土模型试验研究结果,指出分布式光纤裂缝传感的复用能力与灵敏性之间存在约束关系,灵敏性高,则复用能力低,反之亦然.对两者关系的定量分析表明,光纤裂缝传感的工程应用,应结合具体的工程实际,对这2个基本参数进行均衡量化.

Relationship between sensitivity and multiplexing capability of optic fibre for crack monitoring in concrete dams

An equation for micro-bending loss of optic fibre caused by cracks in concrete was deduced.Based on theoretic analysis and model tests,it is pointed out that there is a constraint relationship between the sensitivity and multiplexing capability of distributed fibre optic sensors for crack monitoring,i.e.the higher the sensitivity,the lower the multiplexing capability,and vice verse.The quantitative analysis of the relationship shows that the balanced quantification of the two parameters should be performed for specific engineering conditions when fibre optic sensors are applied to practical projects.