Deep-Seated Gravitational Slope Deformations (DSGSDs) are complex, slow-moving phenomena often controlled by inherited structures (Discenza & Esposito, 2021). In some cases, the presence of these structures or the progression of deformation (Agliardi et al., 2001) favours the development of a Basal Shear Zone (BSZ). Over the years, many numerical modelling were performed to study the time-dependent behaviour of DSGSDs and the role of faults, folds, and bedding planes (Discenza et al., 2011; Della Seta et al., 2017). This research focuses on development of the Luco dei Marsi DSGSD, in which the first evidence of a BSZ in the central Apennines was found. The DSGSD affects an anticline formed in a carbonate sequence, whose eastern limb is dismembered by Quaternary normal faults featuring the western edge of the Fucino Basin. The slope deformation was revealed by several orders of graben, scarps, and trenches, as well as bulging and landslides. The short-term activity of the process is on the order of a few mm/yr and was revealed by DInSAR time series. In this work a numerical modelling was performed to investigate the characteristics of DSGSD. Physical and mechanical properties of intact rock were determined through laboratory tests, while geomechanical characteristics of rock mass were determined through field surveys. The model was built up considering the slope debuttressing due to the erosion and the Late Pleistocene faulting along the eastern margin of the slope. In the analyses, both faults and bedding planes were considered to examine the development of deformation and BSZ. The numerical simulation highlights the role played by the structural setting of the relief and the geometry of bedding planes on the onset and evolution of DSGSD.
Numerical modelling unravelling the development of a Basal Shear Zone in a tectonic-driven DSGSD (Luco Dei Marsi, Central Apennines)
Di Luzio E;
2022
Abstract
Deep-Seated Gravitational Slope Deformations (DSGSDs) are complex, slow-moving phenomena often controlled by inherited structures (Discenza & Esposito, 2021). In some cases, the presence of these structures or the progression of deformation (Agliardi et al., 2001) favours the development of a Basal Shear Zone (BSZ). Over the years, many numerical modelling were performed to study the time-dependent behaviour of DSGSDs and the role of faults, folds, and bedding planes (Discenza et al., 2011; Della Seta et al., 2017). This research focuses on development of the Luco dei Marsi DSGSD, in which the first evidence of a BSZ in the central Apennines was found. The DSGSD affects an anticline formed in a carbonate sequence, whose eastern limb is dismembered by Quaternary normal faults featuring the western edge of the Fucino Basin. The slope deformation was revealed by several orders of graben, scarps, and trenches, as well as bulging and landslides. The short-term activity of the process is on the order of a few mm/yr and was revealed by DInSAR time series. In this work a numerical modelling was performed to investigate the characteristics of DSGSD. Physical and mechanical properties of intact rock were determined through laboratory tests, while geomechanical characteristics of rock mass were determined through field surveys. The model was built up considering the slope debuttressing due to the erosion and the Late Pleistocene faulting along the eastern margin of the slope. In the analyses, both faults and bedding planes were considered to examine the development of deformation and BSZ. The numerical simulation highlights the role played by the structural setting of the relief and the geometry of bedding planes on the onset and evolution of DSGSD.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
