文章基本信息

标题：Monitoring and correction of the stress in an anchor bolt based on Pulse Pre‐Pumped Brillouin Optical Time Domain Analysis
本地全文：下载
作者：Qi Liu ; Jing Chai ; Shaojie Chen 等
期刊名称：Energy Science & Engineering
电子版ISSN：2050-0505
出版年度：2020
卷号：8
期号：6
页码：2011-2023
DOI：10.1002/ese3.644
出版社：John Wiley & Sons, Ltd.
摘要：Bolt is an important connection in underground construction and monitoring its stress characteristics is essential to evaluate the effectiveness of bolt. The strain information collected along a rock bolt reveals the long‐term movement characteristics of rock mass, which greatly helps toward disaster prevention and risk warning. Grooving on the surface of a bolt and embedding an optical fiber is one of the main methods for monitoring the anchorage performance and stress distribution around the bolt in underground engineering. In this study, Pulse Pre‐Pumped Brillouin Optical Time Domain Analysis (PPP‐BOTDA) technology is used to evaluate the stress, axial force, and shear stress distribution of the bolt under tensile load for different types (grooved and nongrooved) of bolts embedded in concrete with resin as anchoring agent. The results show that the PPP‐BOTDA sensor can be used to monitor the stress state of the bolt embedded in concrete with resin as anchoring agent when the bolt is subjected to a tensile force. However, the apparent stress value measured in this way is not the actual stress value of the bolt, but is an increased value caused due to the groove. The closer to the exposed end of the bolt, the greater is the deviation between the apparent stress value and the actual stress value of the bolt. Based on the monitoring results from this experimental study, a stress reduction calculation method is proposed, which can change the measured value into the actual stress of the bolt.
关键词：axial force;bolt;PPP‐BOTDA technology;pullout test;shear stress