Procjena amplifikacije gibanja tla uslijed Zagrebačkog ML5.5 potresa (2020.) ekvivalentno-linearnom metodom

master's thesis

• Title (english): Estimation of ground motion amplification of the Zagreb ML5.5 earthquake (2020) using equivalent-linear method
• Author: Jakov Stanislav Uglešić
• Mentor: Snježana Markušić (mentor)
• Mentor: Davor Stanko (mentor)
• Committee member: Snježana Markušić (predsjednik povjerenstva)
• Committee member: Davor Stanko (član povjerenstva)
• Committee member: Ivica Sović (član povjerenstva)
• Committee member: Maja Telišman-Prtenjak (član povjerenstva)
• Committee member: Giuliana Verbanac (član povjerenstva)
• Committee member: Antun Marki (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geophysics); Zagreb
• Defense date and country: 2021-10-01, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geophysics; Seismology and Physics of the Earth's Interior

Abstract

Zagrebački potres 2020. lokalne magnitude ML = 5.5 uzrokovao je veliku štetu u gradu Zagrebu i okolnom području. Najviše su bile pogođene stare zgrade (izgrađene prije 1963.) i zgrade kulturno povijesne baštine. U diplomskom radu napravljena je seizmička analiza odziva tla za scenarij zagrebačkog ML5.5 potresa 2020. na realnim profilima tla, koji su dobiveni pomoću podataka iz seizmičke i geološke mikrozonacije dijela grada Zagreba te uz pomoć dodatnih mjerenja dobivenih višekanalnom analizom površinskih valova na tri profila. 1D ekvivalentno-linearna analiza odziva tla napravljena je za dva slučaja, 1.) slučaj u kojem se svi profili tla nalaze u epicentru (tj. da su 1 km od epicentra) i 2.) slučaj u kojemu su uzete epicentralne udaljenosti svih profila (tj. ulazna gibanja stijene su atenuirana s udaljenošću). Izračunate vrijednosti korištene su za izradu interpoliranog 2D profila koji pokazuje promjenu vršne akceleracije tla po dubini, a samim time i amplikaciju seizmičkoga gibanja uslijed rasprostiranja kroz različite slojeve tla. Profil se proteže od epicentra zagrebačkog ML5.5 potresa do akcelerometarskih stanica QUHS i QARH. Rezultati diplomskog rada uspoređeni su s empirijskim podacima i rezultatima iz sličnih istraživanja. Procijenjeno je da amplikacijski faktor iznosi oko 2 za scenariji zagrebačkog ML5.5 potresa, a procijenjene vrijednosti vršne akceleracije tla su 0.35 g u epicentralnom području i 0.20 g na udaljenosti od 12 km od epicentra. Rad doprinosi boljem razumijevanju posljedica zagrebačkog ML5.5 potresa, ukazuje na važnost utjecaja lokalnih uvjeta tla na nastanak štete te značaj mikrozonacije i seizmičke analize odziva tla pri protupotresnoj gradnji.

Abstract (english)

The 22 March 2020 Zagreb earthquake of local magnitude ML = 5.5 has caused great damage in the city of Zagreb and in the local area. The most affected were old buildings (built before 1963) and cultural heritage buildings. Therefore, the thesis presents seismic site response analysis for the Zagreb ML5.5 earthquake scenario that was calculated on realistic soil profiles, which are based on data from seismic and geological microzonation of the part of the city of Zagreb area and from additional measurements with Multichannel analysis of surface waves on three soil profiles. 1D equivalent linear site response analysis was done for two cases, 1.) case in which all soil profiles are in epicenter area (1 km from epicenter) and 2.) case in which epicentral distance was taken into account (input rock motions are attenuated with distance).
These calculated values were used to construct an interpolated 2D profile showing the variation of peak ground acceleration with depth, and thus the amplification of seismic motion due to spreading through different soil layers. The profile extends from the epicenter of the Zagreb ML5.5 earthquake to the accelerometer stations QUHS and QARH. Furthermore, obtained results were compared with empirical values and with results from similar research. The amplification factor is estimated to be about 2 for the scenarios of the Zagreb ML5.5 earthquake, and the estimated values of peak ground acceleration are 0.35 g in the epicentral area and 0.20 g at a distance of 12 km from the epicenter. The paper contributes to a better understanding of the consequences of the Zagreb ML5.5 earthquake, it shows the importance of local soil conditions on the damage extent and the importance of microzonation and seismic soil response analysis for building earthquake-resistant structures.

• Keywords: zagrebački ML5.5 potres 2020.; analiza odziva tla; amplifikacija potresnog gibanja; ekvivalent-linearna analiza; seizmička mikrozonacija
• Keywords (english): Zagreb ML5.5 earthquake 2020; site response analysis; amplification of seismic motion; equivalent-linear analysis; seismic microzonation
• Language: croatian
• URN:NBN: urn:nbn:hr:217:934672
• Study programme: Title: Graduate university study pf Physics - Geophysics; specializations in: Seismology and Physics of the Earth's Interior, Meteorology and Physical Oceanography; Course: Seismology and Physics of the Earth's Interior; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra fizike – geofizike (magistar/magistra fizike – geofizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-10-08 08:10:14