开发了一套基于现代光纤光栅传感技术的测试系统和方法,用于测量振动台试验中模型土体内部的侧向变形的一维分布。将分布式光栅传感器黏贴在基底梁上,并植入土体,考虑土体与植入其中的柔性梁共同运动,利用光纤布拉格光栅(FBG)采集植入梁的变形信息,运用连续体力学的方法,计算得到植入梁周围土体的侧向扩展及剪应变沿深度的一维分布。将现代光学传感技术与传统土工试验技术相结合,应用FBG传感器支持单通道多测点,微型轻质及抗电磁干扰等特点,该系统对周围土体扰动小,导线数量也极少,并且信号不受其他传感器电磁信号的干扰。通过一次小型振动台试验,展示了该方法的可操作性,并与加速度记录信号进行对比,验证了方法的适用性。
In this work, a measurement system using the FBG sensing technology is designed to assess the one-dimensional distribution of lateral deformation of model soils in the shaking table tests. An optical fiber with multiplexed fiber Bragg grating (FBG) strain sensors is sticked to a thin and flexible strip, which is inserted vertically through the soils. The strip will be bended driven by the lateral movement of the soils due to horizontal ground motion. The strain information is obtained by the FBG sensors. The strain-to-displacement conversion is done via continuum mechanics models. The deflection of the strip is considered to be the lateral deformation of the soils in the front of the strip. This measurement system is tested and verified through the shaking table tests and compared with other measurements.