This study aims to assess the effectiveness of inter-storey isolation structures in reducing seismic responses in super high-rise buildings, with a focus on analyzing the impact of soil-structure interaction (SSI) on the dynamic performance of the buildings. Utilizing the lumped parameter SR (Sway-Rocking) model, which separately simulates the overall displacement of the super high-rise structure and the rotational motion of the foundation, the dynamic characteristic parameters of the simplified model are derived. The natural frequencies of the system are calculated by solving the equations of motion. The study examines the influence of parameters such as soil shear wave velocity and structural damping ratio on the dynamic response of the structure, with particular emphasis on displacement transfer rates. The findings indicate that inter-storey isolation structures are highly effective in reducing displacement responses in super high-rise buildings, especially when considering SSI effects. Specifically, for high-damping inter-storey isolation structures, modal frequencies decrease as soil shear wave velocity decreases. In non-isolated structures, the damping ratio increases with decreasing soil shear wave velocity, whereas for isolated structures, the damping ratio decreases, with a more pronounced reduction at higher damping ratios. Increasing damping significantly reduces inter-storey displacement and damage indices. However, under low shear wave velocity conditions, inter-storey isolation structures may experience increased displacement and damage.

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.

All Nuclear power plants consist of several structures of varying importance that have to be designed for dynamic loading like earthquakes and impacts that they might be exposed to. Research on the influence of dynamic loading from blast events is still crucial to address to guarantee the general safety and integrity of nuclear plants. Conventional structural design approaches typically ignore the Soil-Structure Interaction (SSI) effect. However, studies show that the SSI effect is significant in structures exposed to dynamic loads such as wind and seismic loads. The present study is focused on evaluating the Soil-Structure Interaction effects on G + 11 storied reinforced concrete framed structure exposed to unconfined surface blast loads. The SSI effect for three flexible soil bases (i.e., Loose, Medium, and Dense) is evaluated by performing a Fast Non-linear (Time History) Analysis on a Two-Dimensional Finite Element Model developed in (Extended Three-Dimensional Analysis of Building System) ETABS software. Unconfined surface blast load of three different charge weights (i.e., 500 kg TNT, 1500 kg TNT, and 2500 kg TNT) at a standoff distance of 10 m are applied on the structure. Blast wave parameters are evaluated based on technical manual TM-5-1300. The blast response of the structure with and without the SSI effect is studied. It is concluded from this study that, there is a significant variation in dynamic response parameters of the structure with flexible soil bases compared to rigid or fixed base. For all magnitudes of surface blasts and soil base conditions, the ground floor is the most vulnerable floor against collapse. The study recommends measures to mitigate the damage due to unconfined surface blasts on multi-storey reinforced concrete structures.

The semi-underground double-storey squat silo (SUDSSS) is a new type of silo with the advantages of preserving grain quality. In this paper, a numerical model of SUDSSS was constructed using solid elements. The proposed numerical model was validated by test results of an experimental underground silo, and the results demonstrated that: (1) Before and after backfilling, the radial and circumferential stress of the underground storey reached their maximum at 2/3 from the bottom and 2/3 from the ground surface, respectively; (2) As the height of grain storage increases, the silo wall stress in the overground storey increases. From the top of the underground storey up to 1/4 height of the overground storey, the stress of silo wall increases. (3) For the underground storey, the maximum stress occurs at 1/3 of the way from the apex of bottom cone.Practical applicationsThe semi-underground double-storey squat silo is a new grain storage device proposed by this paper, which consists of two layers. The lower layer is located in the ground and can utilize the shallow ground temperature to realize the green and low-temperature storage of grain, the upper layer is conducive to the turnover of grain, which can ensure the quality of grain storage. The new silo has the advantages of saving land, energy saving and carbon reduction. Based on the silo, this paper investigates the stress-strain properties of the silo before and after soil backfilling during the construction stage, and obtains the change pattern of the static mechanical properties of the silo. This paper analyses the mechanical properties of semi-underground double-storey squat silo under different storage conditions at the grain storage stage, and studies the change patterns of the mechanical properties of the silo body under different storage heights. Based on SUDSSS, a new type of silo, the mechanical properties of the silo in the construction and grain storage stages were investigated, and the changing patterns of the mechanical properties in these two stages were obtained, which can provide a reference for the engineering design and construction of SUDSSS. image

Earthquake-induced liquefaction is a geological disaster that caused extensive damage to buildings, railways, dams. Due to the construction techniques and economic conditions, the subsurface layers of some buildings must be reinforced to resist seismic loads. Microbial-induced desaturation is a development technique which can be used for existing buildings to mitigate liquefaction. Shaking table tests were conducted to survey the effect of microbial induced desaturation on liquefaction-prone foundations beneath buildings. The test results showed that, lower saturation degree delays the generation of excess pore pressure and reduces its magnitude. It appears that the resistance to excess pressure increases as saturation degree is reduced from 100% to 93.4% or 85.6%. Desaturation prevents the decay of the amplitude of acceleration oscillations, but increases the accelerations of the structure. The settlement of the sandy soil decreases as the saturation degree decreases. Resistance to liquefaction increased by more than twice than that in the saturated sample after induced desaturation to 93.4%. The weight of the building structure contributes to the anti-liquefaction capacity.

Earthquake is one of the most critical hazard that damage buildings all over the world. Earthquake can result in ground shaking, soil liquefaction, damages, or even leads to complete collapse of buildings. So, buildings must be built to withstand the effect of earthquake so as to secure living conditions. Isolation method emerged as one of the efficient techniques for reducing the severe effects of earthquake. This project proposes a promising seismic isolation method by analysing different isolation method. A variety of isolation materials are available in order to reduce the seismic impact on buildings. This study investigated the efficiency of isolation materials such as polyurethane (PU) foam, coir fibre polyester composite, and geomembrane on seismic effect. In order to study the effectiveness of different isolation materials, seismic responses such as maximum roof acceleration, storey displacement, drift, and base shear of G+4 building was analysed using linear analysis by ANSYS software. Thus, this work aimed to propose the best suitable position of the most effective isolation material that reduces the seismic energy transferred. On other hand the use of this isolation method can provide an economic way to reduce the seismic energy transferred.