Premium
Imaging near‐surface defects using step‐frequency ground‐penetrating radar
Author(s) -
Balasubramaniam V.R.,
Jha P.C.,
Chandrasekhar E.
Publication year - 2013
Publication title -
near surface geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.639
H-Index - 39
eISSN - 1873-0604
pISSN - 1569-4445
DOI - 10.3997/1873-0604.2012044
Subject(s) - ground penetrating radar , geology , ground subsidence , foundation (evidence) , oil tank , oil storage , hydrogeology , subsidence , geotechnical engineering , petroleum , petroleum engineering , cracking , mining engineering , radar , engineering , geomorphology , materials science , paleontology , archaeology , structural basin , composite material , history , telecommunications
Step‐Frequency GPR (SFGPR) investigations were carried out at the location of a crude oil storage tank at a petroleum refinery. The storage tank was founded on an elevated platform (tank‐pad). Subsidence of a portion of the tank‐pad led to cracking of its bottom steel plates and subsequent leakage of crude oil. SFGPR imaging was done within and outside the tank, in the frequency range of 10‐260 MHz, to understand the cause of the subsidence. Complex signal analysis was useful in identifying a series of cavities in the subsurface, in the depth range of 2–15 m, close to the location of subsidence of the tank‐pad. In order to stabilize the foundation of the tank, the subsurface area infested with cavities was grouted systematically. SFGPR imaging was done again after grouting, in the same area in the same manner to evaluate the efficacy of grouting and check for presence of remnant cavities. Results of the SFGPR investigations, before and after grouting, which aided restoration of the foundation of the oil tank, are discussed.