混凝土高拱坝裂缝光纤监测网络构型的优化

提出基于瑞利散射的混凝土高拱坝裂缝分布式光纤监测网络优化的目标及技术路线;针对基于瑞利散射的光纤监测网络构型的优化,进行了正交失效混凝土模型试验,发现在光纤与裂缝面交角成60°时,在大坝安全监控缝宽控制范围内光纤最小裂缝分辨率仅达到我国水利技术标准规定的1/6;指出要满足大坝裂缝监测灵敏性的要求,对于基于瑞利散射的光纤裂缝传感,应将光纤布置在与预期的裂缝面成交角小于60°的范围内。基于此,结合小湾拱坝裂缝光纤监测研究,初步提出高拱坝裂缝光纤监测网络优化的构型。

Optimization of optical fiber monitoring network structure for crack detection of high concrete arch dams

The target and technical route of optimization of distributed optical fiber monitoring network for crack detection of high concrete arch dams based on Rayleigh scattering are presented,and orthogonal ineffectiveness concrete model tests are performed for optimization of the network structure.It is found that,at an angle less than 60?° between optical fiber and cracking surface and within the crack width range permissible in dam safety monitoring,the minimal resolution of cracks only reaches 1/6 of the corresponding water conservancy technical standard in China.It is pointed out that the optical fiber should be embedded within an angle 60?° to the predicted cracks in this method so that the monitoring results can meet the requirement of sensitivity of dam safety monitoring.Furthermore,an optimal structure for optical fiber monitoring network is proposed for crack detection of Xiaowan arch dam.