Application of Miniature FBG-MEMS Pressure Sensor in Penetration Process of Jacked Pile

Abstract

In order to study the penetration mechanism of jacked piles in viscous soil foundation, the stress variation law of the pile–soil interface was obtained by installing silicon piezoresistive earth pressure and pore water pressure sensors, and fiber Bragg grating (FBG) sensors in a model pile body, and the penetration characteristics of jacked piles in homogeneous viscous soil were defined. The test results show that: Fiber Bragg grating and silicon piezoresistive sensing technology can better meet the requirements of testing the characteristics of jacked pile in viscous soil. The ratio of pile lateral resistance to pile end resistance varies when pile is jacked in homogeneous viscous soil. In the early stage of pile jacking, the ratio of pile lateral resistance is small, and in the later stage of pile jacking, the ratio of pile lateral resistance increases, but the ratio of pile end resistance is still higher than that of pile lateral resistance. The ratio of the effective stress to the total radial stress is high, and the variation law of the two is consistent with the depth. The total radial stress, pore water pressure, and effective radial stress all exhibit the degradation phenomenon, and the degradation degree decreases gradually with the increase in penetration depth at the same depth. The ratio of excess pore water pressure to overburden weight decreases with the increase in depth, and the maximum value is 87%. The research results can provide a reference for the engineering practice of jacked pile in viscous soil foundation.

MEMS technology and applications in geotechnical monitoring: a review

“…The tensiometer was able to measure both positive and negative pore water (soil suction) in the range 100-600 KPa. By MEMS earth pressure and pore water pressure sensor in combination with FBG developed by [22]. Reproduced from [22].…”

“…By MEMS earth pressure and pore water pressure sensor in combination with FBG developed by [22]. Reproduced from [22]. CC BY 4.0. installing this device in different location and depths (up to 3 m), it was possible to obtain precise and reliable information pore water pressure regime within slopes in response to rainfall.…”

“…CC BY 4.0. installing this device in different location and depths (up to 3 m), it was possible to obtain precise and reliable information pore water pressure regime within slopes in response to rainfall. Most recently, a combination of FBG and MEMS monitoring system was developed to investigate the mechanisms of penetration for jack piles (figure 16) [22]. In this application, two different types of MEMS silicon piezoresistive was developed with a pressure range of 500 kPa, a dynamic range of 2000 kHz, and a precision 0.1% to measure both earth and pore water pressure.…”

“…Combined with WSNs, the recent progress in MEMS technologies provides an opportunity for autonomous, real-time monitoring of in-situ geotechnical conditions. In geotechnical monitoring, MEMS technology has been introduced to provide advanced, low cost, real-time solutions for current in-situ operational challenges ranging from ground deformation [12,[15][16][17], geo-structural health monitoring [18][19][20][21] and pressure monitoring [22,23]. The success of these initial applications reveal that MEMS technology is capable of providing reliable in-situ monitoring data with decreased cost and complexity of installation when compared to traditional approaches.…”

Fiber Bragg Grating Pressure Sensor Integrated with Epoxy Diaphragm

“…Wang et al [ 22 ] integrated a diaphragm-assisted Fabry-Perot interferometer with a fiber Bragg grating for pressure measurement with temperature compensation. Liu et al [ 23 ] employed an FBG pressure sensor to study the penetration mechanism of jacked piles in viscous soil foundation. Cheng et al [ 24 ] developed a highly sensitive gas pressure sensor based on a Fabry–Perot interferometer with a silicone rubber diaphragm.…”