This study investigates the underlying causes of pier displacement and cracking in a highway link bridge. The initial geological assessment ruled out slope instability as a contributing factor to pier movement. Subsequently, a comprehensive analysis, integrating in situ soil investigation and finite element modeling, was conducted to evaluate the influence of additional fill loads on the piers. The findings reveal that the additional filled soil loads were the primary driver of pier tilting and lateral displacement, leading to a significant risk of cracking, particularly in the mid- of the piers. Following the removal of the filled soil, visual inspection of the piers confirmed the development of circumferential cracks on the columns of Pier 7, with the crack distribution closely aligning with the high-risk zones predicted by the finite element analysis. To address the observed damage and residual displacement, a reinforcement strategy combining column strengthening and alignment correction was proposed and validated through load-bearing capacity calculations. This study not only provides a scientific basis for analyzing the causes of accidents and bridge reinforcement but, more importantly, it provides a systematic method for analyzing the impact of additional filled soil loads on bridge piers, offering guidance for accident analysis and risk assessment in similar engineering projects.

Two disastrous earthquakes, named Pazarc & imath;k (Mw7.8) and Ekin & ouml;z & uuml; (Mw7.6), occurred on February 6, 2023 in the southeast part of T & uuml;rkiye and were collectively named Kahramanmara & scedil; earthquakes. These seismic events were caused by a left lateral strike-slip faults, and resulted in significant loss of life, severe damage to infrastructures and buildings, and geotechnical damages such as mainly large-scale slope failures, rockfalls, and ground liquefaction. The main goal of this study is to assess the extend and impact of widespread ground liquefaction, particularly on built environment. Additionally, the ranges of amount of settlement and tilting of buildings due to ground liquefaction were briefly discussed and liquefaction caused by Kahramanmara & scedil; earthquakes were compared with those others occurred in T & uuml;rkiye. The site observations indicated that except a village, a short of a highway, a few bridges and two settlements, widespread liquefaction was mainly observed in agricultural non-urbanized fields. The maximum amount of settlement at some liquefaction locations reached up to 2 m and high-raise buildings tilted 7-8 degrees from the vertical reaching up about 20 degrees. Observations indicated that single-storey and two-storeys buildings with a basement to a certain depth, a lower center of gravity and raft foundation should be considered suitable on soils susceptible to liquefaction in earthquake-prone regions without taking any counter-measures against ground liquefaction. Mass movements along the shoreline of the G & ouml;lba & scedil;& imath; Lake were unlikely to be caused by lateral spreading resulting from ground liquefaction and they were rather due to planar sliding along a weak layer dipping towards the lake with progressive failure.

In recent years, many housing retaining walls have been damaged or even collapsed by earthquakes in Japan. Among them, the damage to dry masonry retaining walls was prominent. Although there are reinforcement methods for retaining walls such as the earth nailing or the ground anchors, which are not suitable for housing retaining walls due to inadequate construction space. Other reinforcement method such as the root piles, on the other hand, straight piles and tilting piles are installed into sloping ground from the top of slope bank vertically so as easier to construct in narrow residential areas, hence widely applicable for housing retaining walls. But the problem of root piles is that the construction cost tends to be high for individual houses since many straight piles and tilting piles are used. From this background, we propose a reinforcement method in which only use tilting piles and connect the top of them to the top of the existing retaining wall to reduce construction cost by decreasing the number of reinforcing materials. This report aims to confirm how a distance between a retaining wall and a reinforcing material affects on the earthquake resistance by conducting centrifugal tilting tests using dry masonry retaining walls. The results show that connecting the top of the retaining wall to the top of the reinforcement allows the retaining wall retain higher soil pressure and the influence of reinforcement becomes increasing.