Naslov
GEOTECHNICAL RECONNAISSANCE OF COVER-COLLAPSE SINKHOLE AREA FOLLOWING PETRINJA 2020 EARTHQUAKE
(GEOTECHNICAL RECONNAISSANCE OF COVER-COLLAPSE SINKHOLE AREA FOLLOWING PETRINJA 2020 EARTHQUAKE)

Autori
Tomac, Ingrid ; Kovačević Zelić, Biljana ; Perić, Dunja ; Domitrović, Dubravko ; Štambuk Cvitanović, Nataša ; Vučenović, Helena ; Parlov, Jelena ; Stipčević, Josip ; Matešić, Darko ; Matoš, Bojan ; Vlahović, Igor

Kolaboracija
GEER

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the 2nd Croatian Conference on Earthquake Engineering - 2CroCEE / Atalić, Josip ; Šavor Novak, Marta ; Gidak, Petra ; Haladin, Ivo ; Frančić Smrkić, Marina ; Baniček, Maja ; Dasović, Iva ; Demšić, Marija ; Uroš, Mario ; Kišiček, Tomislav - Zagreb : Građevinski fakultet Sveučilišta u Zagrebu, 2023, 57-68

Skup
2nd Croatian Conference on Earthquake Engineering - 2CroCEE

Mjesto i datum
Zagreb, Hrvatska, 22.03.2023. - 24.03.2023

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
cover-collapse sinkholes, karstic aquifer, unsaturated soil dynamics, earthquake, progressive failure

Sažetak
This paper shows an overview of extensive geotechnical and geological investigation of soils around cover collapse sinkholes that appeared in a constrained area around Mečenčani and Borojevići villages following the 2020–2021 Petrinja earthquake sequence. A total of 122 new and 49 pre-existing historical sinkholes were recorded, mapped, and classified during the geological and geotechnical reconnaissance fieldwork. Many sinkholes collapsed within an area of only 1.13 km2, a relatively rare phenomenon associated with earthquakes, thus motivating soil investigations to better understand associated failure mechanisms and underlying conditions. This paper shows an overview of triaxial test data in synergy with soil water retention curves of unsaturated soils detected in the area, along with results of standard physical soil tests. The soil in the area consists of a 4–15 m thick clayey cover with sporadic gravel lenses. Clays are mostly over-consolidated, with varying degrees of saturation ranging from very small to fully saturated. Underneath are intensely karstified Miocene carbonate rocks. Seasonal and climate-change-induced variations in the groundwater table interact with the artesian/subartesian karst aquifer, thus affecting the suction and the shear strength. In addition, soil water retention curves indicate that desaturation is possible for deeper groundwater table levels and can further affect effective stress, shear strength, and interparticle tensile forces. Collapsed sinkholes have predominately vertical walls, indicating brittle failure of a cohesive cover with varying degrees of saturation. Based on the specific geomechanical properties of soils, this paper offers several hypotheses of failure mechanisms based on the synergy of earthquake-induced dynamic loading and hydro-mechanical interactions of unsaturated soil layers and pore pressure dynamics between two interconnected aquifers.

Izvorni jezik
Engleski

Znanstvena područja
Geologija, Građevinarstvo, Rudarstvo, nafta i geološko inženjerstvo, Interdisciplinarne tehničke znanosti

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