Devastating earthquakes around the world highlight the crucial need to understand the seismic performance of structures. Local soil conditions are among the most significant factors influencing a structure's seismic behavior. Earthquake-soil-structure interactions directly affect seismic damage levels. In performance-based earthquake engineering, accurate target displacements enable a more realistic estimation of the expected performance levels for structures. This depends on obtaining realistic local soil conditions. This study conducted structural analyses on seven different variables, considering four different local soil conditions specified in Eurocode 8. The variables selected were importance class, peak ground acceleration (PGA), damping ratio, ground storey height, frame openings, number of storeys, and storey height, applied to a symmetrical and regular reinforced concrete structure. Period, base shear, stiffness, and target displacements were obtained for each variable through pushover analyses for the four various local soil conditions. All structural results were compared with one another and with other variables. This paper also aimed to reveal the effect of local soil conditions in the context of the 6 February 2023 Kahramanmara & scedil; (T & uuml;rkiye) earthquakes. The study confirms that variations in soil types, as classified in Eurocode 8, have a major impact on the seismic behavior of reinforced-concrete structures. Weaker soils amplify seismic effects, increasing target displacements and structural vulnerability.

Purpose - The purpose of this paper is the dynamic analysis and seismic damage assessment of steel sheet pile quay wall with inelastic behavior underground motions using several accelerograms. Design/methodology/approach - Finite element analysis is conducted using the Plaxis 2D software to generate the numerical model of quay wall. The extension of berth 25 at the port of Bejaia, located in northeastern Algeria, represents a case study. Incremental dynamic analyses are carried out to examine variation of the main response parameters under seismic excitations with increasing Peak ground acceleration (PGA) levels. Two global damage indices based on the safety factor and bending moment are introduced to assess the relationship between PGA and the damage levels. Findings - The results obtained indicate that the sheet pile quay wall can safely withstand seismic loads up to PGAs of 0.35 g and that above 0.45 g, care should be taken with the risk of reaching the ultimate moment capacity of the steel sheet pile. However, for PGAs greater than 0.5 g, it was clearly demonstrated that the excessive deformations with material are likely to occur in the soil layers and in the structural elements. Originality/value - The main contribution of the present work is a new double seismic damage index for a steel sheet pile supported quay wharf. The numerical modeling is first validated in the static case. Then, the results obtained by performing several incremental dynamic analyses are exploited to evaluate the degradation of the soil safety factor and the seismic capacity of the pile sheet wall. Computed values of the proposed damage indices of the considered quay wharf are a practical helping tool for decision-making regarding the seismic safety of the structure.

The Nilufer district experienced the most recent urbanization among the central districts of Bursa in South Marmara region with the completion of rapid construction. Since 358 BCE, many destructive earthquakes were reported on the branches of the North Anatolian Fault (NAF) which caused extensive damage to buildings and loss of life near Bursa city. Besides some studies conducted to define the soil behavior in the vicinity of Bursa, a seismic hazard study in Nilufer is still lacking. We, therefore, carried out a microzonation study including the following steps. First, an earthquake hazard analysis was conducted and the peak ground acceleration (PGA) values were determined for an expected earthquake. In the next step, MASW (Multi-Channel Analysis of Surface Wave) measurements conducted at 54 points in 28 neighbourhoods of Nilufer district were evaluated. Soil mechanical parameters were determined at 11 boreholes to assess the liquefaction potential. It was found that almost half of the study area suffers from low damage considering only the vulnerability index (Kg) index, which depends on the site effect. Therefore, in addition to the Kg values, we created a microzonation map using the results of soil liquefaction, settlement, changes in groundwater level, and the average values of spectral acceleration. The study area is classified by four damage levels changing from low to high. Using only the Kg index could not quantify the potential damage level in the study area, thus we showed that the districts of Altinsehir, Hippodrome, Urunlu and Alaaddinbey, Ertugrul, 29 Ekim, 23 Nisan, Ahmetyesevi and Minarelicavus were identified at potentially high-risk damage zones. The results of this study clearly showed that considering the Kg index, which depends only on the local site effect, may lead to inadequate damage values.

Polyglycolic acid (PGA) and poly (butylene adipate-co-terephthalate) (PBAT), as widely applied biodegradable polymers, the degradation behavior of their blends in marine environments has not been proven. This study investigated the changes of macroscopic and microscopic morphology, thermal properties, crystalline and chemical structure, degradation rate of PGA/PBAT blends with different ratios in the simulation marine environment containing sediments and marine organisms. The results showed that degradation primarily occurred due to ester bond breakage, and PGA exhibited a faster degradation rate than PBAT films. The amorphous region degraded more rapidly than the crystalline region, and the thermal stability of the materials decreased. The degradation of PGA and PBAT blends followed their respective single degradation laws and the compatibility of blend samples decreased after degradation. The degradation rate of the samples was obtained by measuring the biochemical oxygen demand, which indicated that a higher PGA content could result in a faster degradation rate for PGA/PBAT films. This study provides an efficient method for constructing materials with controlled biodegradability.

Two large earthquakes (Mw = 7.7 and Mw = 7.6) that occurred in Turkey on February 6, 2023, affected a very extent region and caused a lot of loss of life and property. This paper presents preliminary results from geophysical measurements (Seismic Refraction Tomography-SRT, Multi-Channel Surface Wave Analysis-MASW and Microtremor-MT) on eight profiles in four provinces (Kahramanmaras, Hatay, Malatya, Gaziantep) to understand the relationship between subsurface properties and the destruction that occurs immediately after earthquakes. By analyzing the geophysical data, the dynamic-elastic properties of ground and the soil classification according to Vs30 were determined. It is generally understood that the near-surface (= similar to 15-20 m) have a very porous/fractured structure. Soil classes were defined as ZD (Malatya-1, Hatay-1 and Kahramanmaras-1) and ZC (Malatya-2, Hatay-2, Gaziantep-1,2 and Kahramanmaras-2). In addition, by evaluating the information of strong ground motion station closest to the measurement profiles, it is observed that the PGA values versus epicenter distances are higher at stations in the zone parallel to the direction of both faults than those in the perpendicular zones. This leads directivity effect in the propagation of earthquake waves. The results indicate that one of the basic reasons for the damages is that the earthquake-ground-structure relationship has not been fully and accurately reflected in building designs. Therefore, future researches involving more geophysical data and PGA values will provide more information about the structural, physical and geotechnical properties of subsurface and definitive results.