SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

Abstract

Abstract. SiSeRHMap is a computerized methodology capable of drawing up prediction maps of seismic response. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code-architecture composed of five interdependent modules. A GIS (Geographic Information System) Cubic Model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A metamodeling process confers a hybrid nature to the methodology. In this process, the one-dimensional linear equivalent analysis produces acceleration response spectra of shear wave velocity-thickness profiles, defined as trainers, which are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Spectra) is optimized on the above trainer acceleration response spectra by means of a dedicated Evolutionary Algorithm (EA) and the Levenberg–Marquardt Algorithm (LMA) as the final optimizer. In the final step, the GCM Maps Executor module produces a serial map-set of a stratigraphic seismic response at different periods, grid-solving the calibrated Spectra model. In addition, the spectra topographic amplification is also computed by means of a numerical prediction model. This latter is built to match the results of the numerical simulations related to isolate reliefs using GIS topographic attributes. In this way, different sets of seismic response maps are developed, on which, also maps of seismic design response spectra are defined by means of an enveloping technique.

Seismic site effects in the Red Zone of Amatrice hill detected via the mutual sustainment of experimental and computational approaches

“…Although it is extremely difficult to decouple stratigraphic effects from topographic effects (Kovacs et al 1971;Sitar and Clough 1983;Assimaki et al 2005;Assimaki and Jeong 2013), recent studies have tried to estimate topographic effects via an amplified/deamplified spectral function that can also be defined by using GIS morphometric elements (Molina et al 2019;Grelle et al 2016;Maufroy et al 2012;Rai et al 2016). The main advantage of this approach is that it allows to estimate the seismic response on large areas based on a limited number of significant parameters, even though its performances have been evaluated only in a few real cases (e.g.…”

“…The main advantage of this approach is that it allows to estimate the seismic response on large areas based on a limited number of significant parameters, even though its performances have been evaluated only in a few real cases (e.g. Maufroy et al 2015;Grelle et al 2016;Wang et al 2018).…”

“…In recent times, some GIS simplified software packages have been developed to implement the seismic site effects results for the purpose of seismic risk management and prevention studies carried out for urban planning. These codes provide computational maps of topographic seismic effects using empirical solutions (Maufroy et al 2012;Rai et al 2016;Wang et al 2018) or partially physical-based models such as the hybrid-model-SiSeRHMap (Grelle et al 2016), that takes into account both stratigraphic 1 3 and topographic effects. This latter is a modular computational methodology based on selflearning models (metamodels) trained on the results of local recurrent cases.…”

Seismic Response of a Mountain Ridge Prone to Landsliding

“…However, it seems suited to a general correction of the predicted ground motion for topographic site effects. A morpho-lithologic model such as that of Grelle et al, (2018) may provide better results for topographies covered by thick regolith.…”

“…This model predicted larger topographic site effects at ridge locations where damage was observed after the Amatrice earthquake in Italy (Maufroy et al, 2018). Grelle et al, (2018) presented a litho-morphometric model that considers stratigraphic and topographic effects of ridges, allowing a more realistic assessment of the response of a complex topography to seismic excitation.…”