Bending characteristics of Prestressed High Strength Concrete (PHC) spun pile measured using distributed optical fibre strain sensor

다국어 초록 (Multilingual Abstract)

Pre-stressed concrete circular spun piles are widely used in various infrastructure projects around the world and offer an economical deep foundation system with consistent and superior quality compared to cast in-situ and other concrete piles. Conventional methods for measuring the lateral response of piles have been limited to conventional instrumentation, such as electrical based gauges and pressure transducers. The problem with existing technology is that the sensors are not able to assist in recording the lateral stiffness changes of the pile which varies along the length depending on the distribution of the flexural moments and appearance of tensile cracks. This paper describes a full-scale bending test of a 1-m diameter spun pile of 30 m long and instrumented using advanced fibre optic distributed sensor, known as Brillouin Optical Time Domain Analysis (BOTDA). Optical fibre sensors were embedded inside the concrete during the manufacturing stage and attached on the concrete surface in order to measure the pile's full-length flexural behaviour under the prescribed serviceability and ultimate limit state. The relationship between moments-deflections and bending moments-curvatures are examined with respect to the lateral forces. Tensile cracks were measured and compared with the peak strains observed from BOTDA data which corroborated very well. By analysing the moment-curvature response of the pile, the structure can be represented by two bending stiffness parameters, namely the pre-yield (<i>EI</i>) and post-yield (<i>EI_cr</i>), where the cracks reduce the stiffness property by 89%. The pile deflection profile can be attained from optical fibre data through closed-form solutions, which generally matched with the displacements recorded by Linear Voltage Displacement Transducers (LVDTs).

참고문헌 (Reference)

1 H. Mohamad, "Thermal Strain Sensing of Concrete Piles Using Brillouin Optical Time Domain Reflectometry" ASTM International 37 (37): 20120176-, 2014

2 Hong-biao Liu ; Qiang Zhang ; Bao-hua Zhang, "Structural health monitoring of a newly built high-piled wharf in a harbor with fiber Bragg grating sensor technology: design and deployment" 국제구조공학회 20 (20): 163-173, 2017

3 Won Pyo Hong, "Role of piles in mitigating the movement of pipes in soft grounds during embankment loading" Informa UK Limited 37 (37): 1019-1031, 2018

4 Whiting, W. A., "Reinforced concrete pipe"

5 Vitharana, N., "Rational prediction of lateral behaviour of concrete piles incorporating pile(concrete)non-linearity" 915-920, 1997

6 Chow, C. C., "Performance of jack-in pile foundation in weathered granite" 1-4, 2010

7 Aso, T., "Nonlinear bending characteristics of PHC piles under varying axial load" 1-9, 2004

8 "MS1314: Part 2, Precast Concrete Piles: Part 2: Method for Determination of Bending Strength of Precast Concrete Piles (Bend Test)"

9 "Joint ACI-ASCE Committee 423, ACI PRC-423.10-16 Guide to Estimating Prestress Losses"

10 Mohamad, H., "Investigation of shaft friction mechanisms of bored piles through distributed optical fibre strain sensing" ISMGE 2829-2832, 2017

11 Avent, R. R., "Investigation of Cracks in Cylindrical Spun-Cast Concrete Piles in a Marine Environment" Louisiana Transportation Research Center 1998

12 Mohamad, H., "Instrumented laterally loaded pile test using distributed fibre optic sensor" 50 (50): 36-42, 2019

13 Liew, S. S., "Failure Investigation of Piled Reinforcement Soil Wall & Excessive Movements of Piled Embankment at Soft Ground, Malaysia" 3-191, 2010

14 Jing Zhou ; Xin Feng ; Wenjing Wu ; Xingyu Li ; Xiaowei Zhang, "Experimental investigations on detecting lateral buckling for subsea pipelines with distributed fiber optic sensors" 국제구조공학회 15 (15): 245-258, 2015

15 Lufan Zou, "Effect of Brillouin slow light on distributed Brillouin fiber sensors" The Optical Society 31 (31): 2698-, 2006

16 Loizos Pelecanos, "Distributed Fiber Optic Sensing of Axially Loaded Bored Piles" American Society of Civil Engineers (ASCE) 144 (144): 04017122-, 2018

17 Yiska Goldfeld, "Damage Identification in Reinforced Concrete Beams Using Spatially Distributed Strain Measurements" American Society of Civil Engineers (ASCE) 139 (139): 2013

18 Xiaofei Huang ; Meng Yang ; Longlong Feng ; Hao Gu ; Huaizhi Su ; Xinbo Cui ; Wenhan Cao, "Crack detection study for hydraulic concrete using PPP-BOTDA" 국제구조공학회 20 (20): 75-83, 2017

19 Rausche, F., "Contemporary Issues in Deep Foundations" American Society of Civil Engineers 2007

20 Hartman, J. J., "Contemporary Issues in Deep Foundations" American Society of Civil Engineers 2007

21 István Völgyi, "Concrete strength tendency in the wall of cylindrical spun-cast concrete elements" Periodica Polytechnica Budapest University of Technology and Economics 54 (54): 23-, 2010

22 Genda Chen ; Yi Bao ; Fujian Tang ; Yizheng Chen ; Weina Meng ; Ying Huang, "Concrete pavement monitoring with PPP-BOTDA distributed strain and crack sensors" 국제구조공학회 18 (18): 405-423, 2016

23 Pengpeng Ni, "Compressive and flexural behaviour of reinforced concrete permeable piles" Elsevier BV 147 : 316-327, 2017

24 Hisham Mohamad, "CHARACTERIZING ANOMALIES IN DISTRIBUTED STRAIN MEASUREMENTS OF CAST-IN-SITU BORED PILES" Penerbit UTM Press 78 (78): 75-82, 2016

25 K. Kesavan ; K. Ravisankar ; S. Parivallal ; P. Sreeshylam, "Applications of fiber optic sensors for structural health monitoring" 국제구조공학회 1 (1): 355-368, 2005

26 Y Lu, "Application of a distributed optical fiber sensing technique in monitoring the stress of precast piles" IOP Publishing 21 (21): 115011-, 2012

27 Pam Hoat Joen, "Analysis of Spirally Reinforced Prestressed Concrete Piles" Precast/Prestressed Concrete Institute 35 (35): 54-83, 1990

28 Abendroth, R. E., "An Integral Abutment Bridge with Precast Concrete Piles" Iowa Highway Research Board & Iowa Department of Transportation 2007

29 Murad Y. Abu-Farsakh, "A full-scale field study for performance evaluation of axially loaded large-diameter cylinder piles with pipe piles and PSC piles" Springer Science and Business Media LLC 12 (12): 753-772, 2016

30 Sung Kim, "A Sensor-Type PC Strand with an Embedded FBG Sensor for Monitoring Prestress Forces" MDPI AG 15 (15): 1060-1070, 2015