Fiber Bragg Grating Sensors for Pile Jacking Monitoring in Clay Soil

The small deformation of the model pile in a pile jacking test makes its accurate measurement very difficult. Based on the installation method of clamping at both ends, a sensitized miniature fiber Bragg grating (FBG) strain sensor was developed to measure the pile strain of small-size model piles. This study investigated the working principle of the sensitized miniature FBG sensor and analyzed the strain transfer characteristics of the sensor by calibration test. The lateral resistance and the earth plug resistance of the model pile were measured accurately by the grooves embedded in the outer tube of the double-wall opening model pile and the sensors directly pasted on the surface of the inner tube. The results of this study show that the sensitized miniature FBG strain sensor has the advantages of high sensitivity, strong interference resistance, and high test accuracy. The FBG strain sensor was completely fixed on the pile by clamping supports at both ends, and the strain measured using the FBG strain sensor was found to be consistent with the pile deformation.

[1]  Seung-Rae Lee,et al.  Behavior of Soil Plug in Open-Ended Model Piles Driven into Sands , 1993 .

[2]  Yunjie Zhao,et al.  Application of Fiber Bragg Grating Strain Sensors to a Centrifuge Model of a Jacked Pile in Collapsible Loess , 2016 .

[3]  Matthew Richard Coop,et al.  An investigation of the effect of soil state on the capacity of driven piles in sands , 2001 .

[4]  Lizhong Jiang,et al.  Improving the durability of the optical fiber sensor based on strain transfer analysis , 2018 .

[5]  Ginu Rajan,et al.  In situ process monitoring for automated fibre placement using fibre Bragg grating sensors , 2016 .

[6]  H. Unwin,et al.  Long-term pile testing in London Clay: a case study , 2004 .

[7]  Zitao Zhang,et al.  Examining Setup Mechanisms of Driven Piles in Sand Using Laboratory Model Pile Tests , 2015 .

[8]  R. Jardine,et al.  Effective stress regime around a jacked steel pile during installation ageing and load testing in chalk , 2018, Canadian Geotechnical Journal.

[9]  Hongnan Li,et al.  Pipeline corrosion and leakage monitoring based on the distributed optical fiber sensing technology , 2018, Measurement.

[10]  Mark Randolph,et al.  Centrifuge modelling of pipe piles in sand under axial loads , 1999 .

[11]  Yonghong Wang,et al.  A Model Test for the Influence of Lateral Pressure on Vertical Bearing Characteristics in Pile Jacking Process Based on Optical Sensors , 2020, Sensors.

[12]  Lei Gao,et al.  Study on the Deformation Measurement of the Cast-In-Place Large-Diameter Pile Using Fiber Bragg Grating Sensors , 2017, Sensors.

[13]  Chien-Ching Ma,et al.  Free‐edge sensor placement for identifying vibration modes of structures subjected to impact loadings using fiber Bragg gratings , 2016 .

[14]  Yiqiang Sun,et al.  Fiber Bragg grating sensors for subgrade deformation monitoring in seasonally frozen regions , 2019, Structural Control and Health Monitoring.

[15]  Jianhua Yin,et al.  Influences of Initial Water Content and Roughness on Skin Friction of Piles Using FBG Technique , 2016 .

[16]  Yonghong Wang,et al.  Test and Study of Pipe Pile Penetration in Cohesive Soil Using FBG Sensing Technology , 2020, Sensors.

[17]  Oreste S. Bursi,et al.  Structural monitoring for the cyclic behaviour of concrete tunnel lining sections using FBG sensors , 2016 .

[18]  Liang Ren,et al.  Investigation of fiber Bragg grating strain sensor in dynamic tests of small‐scale dam model , 2015 .

[19]  Luca Schenato,et al.  Distributed strain measurements in a CFA pile using high spatial resolution fibre optic sensors , 2018 .

[20]  R. Jardine,et al.  Design and Performance of the Imperial College Instrumented Pile , 1991 .

[21]  Xiao-cen Lu,et al.  Experimental Investigations on Load Transfer of PHC Piles in Highway Foundation Using FBG Sensing Technology , 2017 .

[22]  Tao Liu,et al.  Strain Monitoring on PHC Pipe Piles Based on Fiber Bragg Grating Sensors , 2019, Journal of Performance of Constructed Facilities.

[23]  S. Buontempo,et al.  Radiation hard humidity sensors for high energy physics applications using polymide-coated Fiber Bragg Gratings sensors , 2011, 2011 IEEE SENSORS Proceedings.

[24]  David White,et al.  Friction fatigue on displacement piles in sand , 2004 .

[25]  Ying Huang,et al.  Glass fiber–reinforced polymer–packaged fiber Bragg grating sensors for ultra-thin unbonded concrete overlay monitoring , 2015 .

[26]  Malcolm D. Bolton,et al.  Displacement and strain paths during plane-strain model pile installation in sand , 2001 .