An experimental study:Integration device of Fiber Bragg grating and reinforced concrete beam for measuring debris flow impact force

作     者：ZHANG Shao-jie CHEN Jiang 

作者机构：Key Laboratory of Mountain Hazards and Earth Surface ProcessInstitute of Mountain Hazards and EnvironmentChinese Academy of Sciences College of Architecture & EnvironmentSichuan University 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2017年第14卷第8期

页      面：1526-1536页

核心收录：

学科分类：08[工学] 0837[工学-安全科学与工程] 

基　　金：supported by the project of Science & Technology Department of Sichuan Province (Grand No: 2015JY0235) National Natural Science Foundation of China (Grand No: 51509174) the Science and Technology Service Network Initiative (No. KFJ-SW-STS-180) 

主　　题：Fiber Bragg grating Measurementdevice Debris flow Boulder Impact force 

摘      要：The impact effect of boulder within debris flow is the key factor contributing to peak impact as well as to the failure of debris flow control work. So accurate measuring and calculating the impact force of debris flow can ensure the engineering design strength. However, limited to the existing laboratory conditions and piezoelectric sensor performance, it is impossible, based on the conventional measurements, to devise a computing method for expressing a reliable boulder impact force. This paper has therefore designed a new measurement device according to the method of integrating Fiber Bragg grating(FBG) and reinforced concrete composite beam(RCB) for measuring the impact force of debris flows, i.e. mounting FBG on the axially stressed steel bar in the composite beam at regular intervals to monitor the steel strain. RCB plays the role of contacting debris flow and protecting FBG sensors. Taking this new device as the experimental object, drop testing is designed for simulating and reflecting the boulder impact force. In a series of impacting tests, the relationship between the peak dynamic strain value of the steel bar and the impact force is analyzed, and based on which, an inversion model that uses the steel bar strain as the independent variable is established for calculating the boulder impact *** experimental results show that this new inversion model can determine the impact force value and its acting position with a system error of 18.1%, which can provide an experimental foundation for measuring the impact force of boulders within the debris flow by the new FBG-based device.