A novel subsurface slopes hazardous mapping with engineering geologic and geophysical characterizations

Abstract

Engineering geological characterizations, and geophysical mapping of subsurface structures to monitor some susceptible infrastructural facilities to hazardous slopes for effectiveness, safety to lives and properties, in addition to policy management for sustainable development. Novel integrated engineering geology, geoelectrical resistivity (ER), and borehole data analysis, to characterize subsurface for slope instability, determining critical zones prone to hazardous slopes in Peninsular Malaysian (PM), east coast areas was focused on. Engineering Laboratory soil investigations using disturbed and undisturbed samples collected to obtain firsthand information on the subsurface soils, and rocks physical properties, integrated with ER data to obtain subsurface geoelectric profiles. Regions delineated as loose and marked as water saturated residual soils prone to slopes corresponds to ER values < 100 Ω-m. ER values between 100 ≥ 500 Ω-m, were delineated as residual soils zones devoid of water contents. Subsurface geoelectric profiles related to hard materials were delineated as weathered and fractured bedrock zones corresponding to ER values between 500 ≥ 2000 Ω-m. Granitic bedrock units delineated as subsurface lithological zones with ER values > 4000 Ω-m. Slope Mass Ratings (SMR), was carried out to construct suitability, and slope assessment system (SAS) model ratings map for the four classes obtained.

Graphical abstract

Highlights

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  A novel subsurface mapping was performed using engineering geology and geoelectrical resistivity.

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  Characterization of the subsurface slope instability to determine critical zones prone to hazards.

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  Results showed clear visible proofs of the occurrences of all types of slope hazards.

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  Exceptionally varied high hazards ratings with >63° steep angles were delineated.

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  Lack of exposure to slope cover conditions <80 % originated the high hazards slope ratings.

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  The geological model obtained shows triggering factors as naturally induced slope hazards.