Load Transfer Law of Anti-Floating Anchor With GFRP Bars Based on Fiber Bragg Grating Sensing Technology

Yamei Zhang,Xiaoyu Bai,Mingyi Zhang,Songkui Sang,Nan Yan,Desheng Jing,Xiaoyu Chen

doi:10.3389/fmats.2022.849114

Yamei Zhang, Xiaoyu Bai + Show 5 more

Open Access

https://doi.org/10.3389/fmats.2022.849114

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Abstract

The glass fiber-reinforced polymer (GFRP) anchor, a new type of composite material anchor, has been widely used in foundation engineering of coastal areas. This study investigated the feasibility of applying the fiber Bragg grating (FBG) sensing technology to monitor the strain of the GFRP anchor during the pull test. Based on an advanced method, the FBG strain sensors were installed in GFRP anchors during the anchor manufacturing process. Then, GFRP anchors were installed into the pre-created borehole with an M30 cement mortar. Meanwhile, the FBG temperature sensors were installed next to the GFRP anchors to monitor the temperature change during the test. The axial force and average shear stress of GFRP anchors along depth during the pull test were analyzed, and the influence of temperature change on strain measurement was studied. The test results showed that the FBG sensing technology and the installation method of FBG strain sensors used in the test were feasible to monitor the mechanical properties of the GFRP anchor during the pull test. Moreover, the effect of temperature change on strain monitoring of FBG strain sensors was negligible.

Highlights

In coastal areas, the traditional steel anti-floating anchors are prone to corrosion due to the high chlorine content within the underground water
The axial strain εi of the glass fiber-reinforced polymer (GFRP) anchors under different pulling forces can be measured by fiber Bragg grating (FBG) strain sensors, and the axial force Fi can be calculated by using the following equation (Zhu et al, 2011): Fi E · A · εi, (4)
The objective of this study is to validate the feasibility of installing the FBG strain sensors in the GFRP anchor during the anchor manufacturing process

Summary

Introduction

The traditional steel anti-floating anchors are prone to corrosion due to the high chlorine content within the underground water. The glass fiber-reinforced polymer (GFRP) anti-floating anchor is a new type of anchor made of resin and glass fiber (Toutanji and Saafi, 2000; Won et al, 2008). Compared with the reinforced anchor, the GFRP anchor has the advantages of high strength, strong corrosion resistance, and low electromagnetic properties (Ahmed et al, 2008; Robert and Benmokrane, 2010). The GFRP anchor has been widely used in foundation engineering of coastal areas (Larralde and Silva–Rodriguez, 1993; Pecce et al, 2001; Lee et al, 2009; Sebastian et al, 2013). Tensile strength is one of the most important mechanical properties of the anti-floating anchor. In the pullout test of the GFRP anchor, the stress and strain of anchors were generally measured by electrical sensors, such as wire strain gauge and dial gauge

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