Groundwater seepage into built infrastructure is a recurrent operational problem in tropical basement complex terrains, causing unplanned facility downtime, structural degradation, and escalating lifecycle maintenance costs. This paper presents a dual-method investigation integrating Ground Penetrating Radar (GPR) geophysical surveys with comprehensive geotechnical laboratory testing to diagnose chronic basement flooding at the Spider Building, Obafemi Awolowo University (OAU), Ile-Ife, Nigeria. Ten GPR traverse lines delineated four subsurface strata to 12 m depth, identifying Fractures F1 (≥2 m wide) and F2 (~1.2 m wide), and eleven micro-fractures. PQWT-S150 deep mapping confirmed a separate 3 m-wide aquifer fracture starting at 125 m depth beneath the F1 trace. Geotechnical tests on five soil samples identified Silty Sand (SM), Clayey Sand (SC), and Clay with low plasticity (CL) soils with low permeability (8.03×10−6 – 1.05×10−5 cm/s). Exploratory regression (n = 5; R = 0.86–0.98) indicated that percentage fines has potential as a maintenance monitoring proxy, requiring validation with larger datasets. These findings are synthesised into a Failure Mode and Effects Analysis (FMEA) matrix and an Asset Integrity Management (AIM) decision framework grounded in ISO 55000 and Reliability-Centred Maintenance (RCM) principles. A key finding is ‘priority inversion’ with rebar corrosion (RPN = 384). It is the highest-risk failure mode yet the least managed, because it is far less visible than flooding (RPN = 243). The paper demonstrates a generalisable IE/OM framework for evidence-based infrastructure maintenance management.

Keywords

Ground Penetrating Radar; Asset Integrity Management; FMEA; Groundwater Seepage; Reliability-Centred Maintenance; Basement Complex Nigeria