Liquefaction-induced settlement, site effects and damage in the vicinity of Yalova City during the 1999 Izmit earthquake, Turkey

Abstract

Yalova City (Turkey) is in a tectonically active location that is particularly affected by the northern branch of the North Anatolian Fault Zone. Magnitudes 7.4 and 7.2 earthquakes in 1999 caused great destruction in Yalova. The heavy damage to buildings and other civil engineering structures was mainly due to liquefaction-induced settlement and site effects such as resonance and amplification. In the first phase of this study, the soil liquefaction potential index (PL) and the induced soil settlement were estimated. In the second phase, the effects on sites in Yalova soil were investigated using microtremor and earthquake data. The fundamental periods and amplification in soft soil were compared with microtremor data and strong ground motion records obtained by a local array of eight accelerograph stations deployed in Yalova. Thirty-seven 'single site' ambient noise measurements were taken in a dense grid of points covering the centre of the city. A comparison between fundamental periods obtained from strong ground motion records and from microtremor measurements showed similarities, in the 0.1-5 Hz range. Finally, soil liquefaction and amplification (or resonance) were divided into regions according to the extent of damage and the geotechnical/geophysical results.

A comparative soil liquefaction analysis with a Matlab® based algorithm: soiLique

“…To test the robustness of soiLique, Soil Engineering, which was introduced by Ozcep (2010), was used for comparison. A real data set from Ozcep et al (2014) is utilized in the present study for settlement and SPT-based analyses. Ozcep et al (2014) have investigated to understand what role the soil properties play as one of the main factors causing earthquake damage in Yalova, and to compare the influence of two soil problems -amplification and liquefaction -on earthquake damage (Ozcep et al 2014).…”

“…A real data set from Ozcep et al (2014) is utilized in the present study for settlement and SPT-based analyses. Ozcep et al (2014) have investigated to understand what role the soil properties play as one of the main factors causing earthquake damage in Yalova, and to compare the influence of two soil problems -amplification and liquefaction -on earthquake damage (Ozcep et al 2014). All of the analysis sections, except settlement and SF analyses based on SPT data, were tested with synthetic data and presented under this heading.…”

“…The main drainage system is dominated by the Samanli, Safran, Balaban, and Kazimiye rivers. Borehole records throughout the study area show that the groundwater table is generally very shallow (Yılmaz and Yavuzer, 2005;Ozcep et al 2014).…”