Stress Monitoring on GFRP Anchors Based on Fiber Bragg Grating Sensors

Hai-Lei Kou; Wang Li; Wang-Chun Zhang; Yuan Zhou; Xiao-Long Zhou

doi:10.3390/s19071507

Stress Monitoring on GFRP Anchors Based on Fiber Bragg Grating Sensors

Sensors (Basel). 2019 Mar 28;19(7):1507. doi: 10.3390/s19071507.

Authors

Hai-Lei Kou^{1

2}, Wang Li³, Wang-Chun Zhang^{4

5}, Yuan Zhou⁶, Xiao-Long Zhou⁷

Affiliations

¹ College of Engineering, Ocean University of China, Qingdao 266100, China. hlkou@ouc.edu.cn.
² Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao University of Technology, Qingdao 266033, China. hlkou@ouc.edu.cn.
³ College of Engineering, Ocean University of China, Qingdao 266100, China. liwang@stu.ouc.edu.cn.
⁴ School of Architecture and Civil Engineering, Weifang University of Science and Technology, Weifang 262700, China. zhangwangchun@wfust.edu.cn.
⁵ Facility Horticulture Laboratory of Universities in Shandong, Weifang University of Science and Technology, Weifang 262700, China. zhangwangchun@wfust.edu.cn.
⁶ College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China. zy2057@stu.ouc.edu.cn.
⁷ Construction Engineering College, Qingdao Agriculture University, Qingdao 266109, China. b20130013@xs.ustb.edu.cn.

Abstract

Glass fiber-reinforced polymer (GFRP) bolts have been widely used in some applications of grouted anchors because of the advantages of better resistance to corrosion, high strength-to-weight ratio, low electromagnetic properties, and so on. This study presents a field test to assess the feasibility of fiber Bragg grating (FBG) sensors in monitoring the stress profile of GFRP anchors during pulling test. Two GFRP anchors were fully instrumented with FBG sensors and then installed into the ground using a drilling and grouting method. To measure the stress profile along test anchors, seven bare FBG sensors were arranged in a single optical fiber and then embedded in the middle of GFRP bolts in the process of extrusion molding. The procedure for embedding bare FBG sensors into GFRP bolts is introduced first. Then, the axial forces and shear stresses that were calculated from the measurements of the FBG sensors are discussed. The field test results indicate that the embedded FBG technology was feasible to monitor the stress state of GFRP anchors during pulling.

Keywords: axial force; fiber bragg grating (FBG) technology; field test; glass fiber-reinforced polymer (GFRP) anchor; shear stress.