【摘要】 引入分布式光纤传感技术用于沥青路面荷载响应监测,提出一种浸入式的沥青路面荷载响应监测方案。为研究不同荷载和不同温度下沥青混凝土中光纤传感信号的变化规律,建立一套包含光源、传感元件、沥青混凝土结构、光电探测模块和数据采集模块的分布式光纤传感测试系统。将封装好的光纤传感器埋置于沥青混凝土车辙试件中,采用室内汉堡车辙试验的方法,分别在不同温度和不同大小荷载作用下,利用周期性运动的胶轮对车辙试件进行加载,模拟实际沥青路面受到交通荷载的作用。以光纤信号敏感度、信号强度为评价指标,对采集得到的光纤信号进行无载阶段和加载阶段的两阶段定义,研究两阶段内光纤信号特征与荷载大小、环境温度的定量关系。结果表明:汉堡车辙试验条件下,光纤信号稳定可读,从光纤信号曲线中可以获取加载特征、周期特征等信息;在30℃、45℃和60℃条件下,光纤信号敏感度与荷载大小均呈现线性正相关关系,且45℃和60℃条件下,光纤信号敏感度随荷载增大而增大的速度较30℃下大;相对于高温域(45～60℃)区间,低温域(30～45℃)区间光纤信号敏感度值增速较快,且温度越高,光纤信号敏感度值分布越分散。更多还原

【Abstract】 The distributed optical fiber sensing technology is introduced in response monitoring of asphalt pavement under loading, the corresponding immersion load response monitoring scheme for asphalt pavement is proposed. To study the change rule of optical fiber sensing signal in asphalt concrete under different loadings and temperatures, a distributed optical fiber sensing testing system is established. The system includes light source, sensing element, asphalt concrete structure, photoelectric detection module, and data acquisition module. Embedding the encapsulated optical fiber sensor in the asphalt concrete rutting specimen, under different temperatures and different size loads, the rutting specimens are loaded with periodically moving rubber wheels to simulate actual asphalt road traffic loads by indoor Hamburg rutting test method. Taking the optical fiber signal sensitivity and signal strength as evaluation indicators, the acquired optical fiber signal is defined in no-loading stage and loading stage. The quantitative relationship of fiber signal characteristics with load magnitude and ambient temperature in 2 stages are studied. The result shows that(1) in the Hamburg rutting test, the optical fiber signal is stable and readable, and the loading characteristics, periodic characteristics and other information can be obtained from the optical fiber signal curve;(2) there is a linear positive correlation between optical fiber signal sensitivity and load at 30, 45, 60 ℃, and the increasing speeds of the fiber signal sensitivity with the increasing of loading at 45 ℃ and 60 ℃ are larger than that at 30 ℃;(3) the fiber signal sensitivity value increases faster at low temperature(30-45 ℃) compared with the increases at high temperature(45-60 ℃), the higher the temperature, the more dispersed the optical fiber signal sensitivity value distribution.更多还原