光纤光栅传感器在重力坝结构模型试验中的应用

在水工结构模型试验研究过程中,主要采用表面位移计、电阻应变片等仪器对坝体的位移和应变、坝基以及抗力体的位移进行测试,而传统的监测仪器难以准确测定模型的内部变形。以某重力坝段为基础,在坝体和坝基分别埋设光纤光栅传感器,对结构模型在超载过程中的内部位移进行监测,并采用位移计、电阻应变片对该物理模型进行了变形监测。通过光纤传感器和位移计对坝体和坝基位移的监测结果比较分析,表明两者在对应部位的监测结果较为一致,证明了光纤光栅传感器在重力坝结构模型试验应用中的可行性,同时试验结果揭示了坝基超载安全系数约为6.0,以及在超载作用条件下的坝基破坏机理。

Application of Optical Fiber Grating Sensor in Gravity Dam Structure Model Test

During the research of hydraulic structure model test,the displacement and strain of dam body and dam foundation are mainly measured by displacement transducers and foil resistance strain gauges on the model surface.For the internal deformation of model under overloading,it will be difficult to measure accurately with conventional monitoring instrument.For a structural model of gravity dam section,beside installing displacement transducers and foil resistance strain gauges on the surface,fiber grating sensors were installed in dam body and dam foundation so that the internal displacement of structural mode could be monitored during overloading.Comparison study shows that the displacements measured using the fiber grating sensor are in good agreement with those from displacement transducers.The test results reveal that the dam foundation overloading safety factor is 6.0,and the failure mechanism of dam foundation under overloading was obtained.The present study confirmed the feasibility of the application of fiber grating sensor in gravity dam structural model test.