The seismic response of primary structures (PS) can be significantly influenced by live loads, particularly when these loads consist of stacked bodies that are capable of sliding during seismic events. Conventional design methods often fail to account for the energy dissipation resulting from such sliding, leading to overly conservative structural estimates. This study examines the effects of sliding live loads on the seismic response of a PS, where two rigid bodies, referred to as secondary bodies (SBs), are stacked as live loads on a PS. The interaction between the lower SB and the PS, as well as between the SBs, is modelled using Coulomb's friction model. The governing equations are solved using the fourth-order Runge-Kutta method. Seismic Zones III and V from IS 1893:2016 are considered as hazard levels. A parametric investigation explores the impact of varying dynamic parameters of both the PS and SBs on the seismic response. The results demonstrate significant energy dissipation within the stack due to sliding, which, if not considered, results in conservative displacement estimates. The study also evaluates how friction coefficients, mass ratios, and excitation levels affect the stack's energy dissipation capacity. A novel method to compute the modified primary structural period (T-new) for design purposes is proposed, and an artificial neural network (ANN) model is developed, achieving a high prediction accuracy (R-2 = 99 %). Sensitivity analysis is performed to assess the influence of input parameters on the output. This research highlights the need to include sliding loads in seismic design.

Shear failures exhibit a brittle nature, often resulting in catastrophic collapse without sufficient advance warning or the capacity to redistribute internal stresses.Consequently, shear failures pose a greater risk and require more attention from structural engineers.It is crucial to incorporate preventive measures in structural design to avoid abrupt shear failures.The work presented in this article attempts to predict the shear strength of reinforced concrete beams as a complex structural engineering problem without the need for extra computational resources by employing the capabilities of Artificial Intelligence (AI) techniques.In recent decades, significant amounts of research have been done on the AI methods such as artificial neural networks (ANNs), fuzzy logic and genetic algorithms to predict the shear strength of RC beams.In this research, adaptive neuro-fuzzy inference system (ANFIS) and ANNs are developed to predict the shear capacity of RC beams.The required data in the form of major factors affecting the shear capacity of RC beams lacking stirrups are compressive strength of concrete, beam depth, effective width, shear span-to-depth ratio, proportion of longitudinal steel and the yield strength of the reinforced longitudinal steel have been considered in this study.Also, in the context of this investigation, a comparison was conducted between the techniques of ANNs and ANFIS.The outcomes demonstrated that both methods exhibited favourable predictive capabilities.Nevertheless, the ANFIS architecture proposed, which incorporates a hybrid learning algorithm, outperformed the multilayer feedforward ANN that utilizes the backpropagation algorithm.The findings indicated that ANFIS is a suitable technique for predicting intricate relationships between input and output parameters, thus making it a valuable tool in predicting the shear strength of RC beams.

Slabs are vital for supporting loads and forming the foundation for structures' floors and roofs, classified as one-way or two-way based on deflection characteristics. A recent innovation in construction, the Reinforced Bubble Deck Concrete (RBDC) slab, integrates spherical or elliptical hollow bubbles within the slab for reinforcement, reducing concrete usage without compromising structural integrity. This unconventional approach diverges from traditional methods. The manuscript thoroughly reviews existing literature on the design and testing of Reinforced Bubble Deck Concrete slabs, aiming to explore their diverse characteristics as observed in international research studies. Findings demonstrate that these slabs offer a sustainable and cost-effective alternative to traditional floor slabs. Their capacity to reduce weight while maintaining strength suggests they could revolutionize construction practices, potentially replacing conventional floor slabs in various projects.

Niavaran Complex features a mix of architectural styles with the elements from modernism and traditional Iranian architecture and is situated in the northern part of Tehran. The Sahebqaraniyeh Heritage Palace from the time of Naser al-Din Shah of the Qajar dynasty is located in this complex (1846-1896). Based on the initial investigation done by Iran's Cultural Heritage Handicrafts and Tourism Organization (ICHHTO), significant damages and cracking were observed in structural elements of the palace (walls and roofs). To this end, since early 2014, the monument is closed to the public and in-depth assessment has been carried out. The study includes seismicity of the Niavaran fault, soil liquefaction, landslides, land subsidence, and historical aspects, such as the removal of stabilizing walls about half a century ago and the reduction in underground water level. The detailed field investigation and experimental testing were performed by the Building and Housing Research Center (BHRC) of Iran. One of the main investigations has been the influence of deep excavations downstream in the south part of the palace. The outcome of structural, geotechnical, geophysical, and other related investigations indicated that the Niavaran Cultural/Historic Complex has been damaged significantly in the last decades and is in urgent need of retrofitting/strengthening.

The Niavaran Complex features a mix of architectural styles with elements from modernism and traditional Iranian architecture and is situated in the northern part of Tehran. The Sahebqaraniyeh Heritage Palace from the time of Naser al-Din Shah of the Qajar dynasty is located in this complex (1846–1896). Based on the initial investigation done by Iran’s Cultural Heritage Handicrafts and Tourism Organization, significant damages and cracking were observed in structural elements of the palace (walls and roofs). Since early 2014, the monument has been closed to the public, and in-depth assessment has been carried out. The study includes the seismicity of the Niavaran fault, soil liquefaction, landslides, land subsidence and historical aspects, such as the removal of stabilising walls about half a century ago and the reduction in underground water level. Detailed field investigation and experimental testing were performed by the Building and Housing Research Center of Iran. One of the main investigations was on the influence of deep excavations downstream in the south part of the palace. The outcomes of structural, geotechnical, geophysical and other related investigations indicated that the Niavaran Cultural/Historic Complex has been damaged significantly in the past decades and is in urgent need of retrofitting/strengthening.

Increased exploitation of underground resources is one of the main reasons of subsidence occurrence. Subsidence causes infrastructure damage and ultimately leads to increased risk to society and the economy. In some areas of Iran recently, buildings, runways, bridges, tunnels, streets, railways and roads have been severely damaged. In this study, the amount of land subsidence was analysed in the western region of Kerman City using interferometry of radar images of Sentinel-1 satellite data from 2014 to 2020 in the Sentinel Application Platform software. The results show that the subsidence rate in the area changed between 3.3 and 13.2 cm, confirming a significant increase. Field studies indicate that increased exploitation of groundwater resources, compaction due to ground drainage and imposition of heavy loads can all cause subsidence, which leads huge damage to the infrastructure.

This study is aimed at evaluating the durability of buildings in Batu Pahat area against seismic activity. To carry out this assessment, data about the building structure is collected, including architect plans, site investigations, and photos. This data is then processed and analysed using manual methods. To determine the Peak Ground Acceleration (PGA) value, the coordinates of Batu Pahat area are needed. This value can be calculated using Mathematica software, which gives a PGA value of 0.0553 g for Batu Pahat area. Based on this value, the Low Map Area form is used for the evaluation, using the ATC-21 form. The evaluation results indicate that 70% of the buildings in the area are in good condition, 25% are in a satisfactory condition, and only 5% are in a weak condition. However, it is important to note that even though only a small percentage of buildings are classified as weak, it does not mean that seismic hazards can be ignored. The study also suggests that the durability of building structures depends on various factors, such as the columns' strength, the building's bottom situation (e.g., empty space or unit), the building's shape (e.g., plan or upright), and the surrounding area's situation. Overall, this study offers valuable insights into the durability of buildings in the Batu Pahat area against seismic activity. It provides crucial information for stakeholders to make informed decisions regarding building safety in the region. The study's findings will guide decision-making processes, helping determine necessary precautions, retrofitting measures, or potential relocation of high-risk buildings. By enhancing the resilience of buildings, this evaluation contributes to the safety and well-being of occupants in the face of seismic hazards. Ultimately, the study's comprehensive assessment and subsequent insights lay the groundwork for informed decision-making and proactive measures to mitigate seismic risks, benefiting the overall resilience of buildings in the Batu Pahat District.

Today, the subjectof a building's resistance to lateral loads is one of the most important concerns of structural engineers. The partitions and infilled walls are non-structural elements that are important due to their effects on the lateral resistance of the building frame. Recently, it has been observed that great damage is occurring to infilled walls, partitions, and buildings in an earthquake-prone area. Infilled walls are effective at increasing the hardness and resistance of building frames, which changes the seismic properties of structures. Therefore, the study of interactions between the structural frame and the infilled walls is essential for a better understanding of structural behaviors. In this paper, the effect of infilled walls is investigated on the behaviour of steel frames using ABAQUS software. Modeling is carried out for different types of infilled materials, including brick and panel, as well as different thicknesses of the infills. It was observed that with an increase in the thickness of infills from 7 to 20 cm, the final capacity and energy absorption increased by 78%. Also, the panel-infilled frames have 18% more capacity and 3.8% more energy absorption than the brick-infilled frame in the same full state. As a result, panel-infilled frames outperform brick infilled frames in terms of performance.

By considering the adverse environmental impacts of the cement manufacturing process, there have been many efforts for cement replacement by supplementary cementitious materials (SCMs), which can enhance the produced concrete performance while reducing cement consumption. This study evaluated the effects of various proportions of silica fume (SF), waste glass powder (WGP), and ground granulated blast furnace slag (GGBFS) on the mechanical and durability properties of concrete. The properties evaluated in this study include compressive, tensile, and flexural strength, magnesium sulfate and sulfuric acid attack, surface resistivity, rapid chloride penetrability test (RCPT), water absorption, depth of penetration of water, and microstructure analysis by scanning electron microscopy (SEM). The results of compressive, tensile, and flexural strength, chloride ion penetrability, and water absorption tests showed that adding 5% of SF to mixtures containing 10% WGP or 10% GGBFS improved concrete performance significantly due to packing density and synergistic effect; however, adding 5% of SF to concrete mixtures decreased the resistance against the magnesium sulfate and sulfuric acid attack. The binary mixture of 15% of WGP showed appropriate performance against the magnesium sulfate and sulfuric acid attack, which may be due to the sacrificial nature of WGP. In addition, the binary mixtures of 15% of WGP and 15% of GGBFS reduced the depth of penetration of water by 45%. Microstructure analysis by SEM showed that the presence of SF, along with WGP and GGBFS, improves the packing density. Finally, adding 5% of SF is suggested to improve the properties of concrete mixtures containing WGP and GGBFS.

The optimum raising conditions to synthesis the high crystallinity carbon nanotubes (CNTs) for improvement of their physical properties are presented in this study, thus, ANFIS has been used to optimise the most effectual characteristics for predicting the crystal growing of oriented vertically aligned carbon nanotubes (OVACNT) by discovering the subset of input characteristics' whole set. ANFIS has also been applied to delineate four characteristics as: 1) vaporising time (min); 2) annealing time (AT) (min); 3) precursor's concentration (mL); 4) deposition temperature (degrees C) have influenced the predicting of crystallinity of highly OVACNTs. The outcomes have shown that precursor's concentration has the highest influence to the crystallinity of OVACNTs predicting with higher accuracy.

Concrete is one of the main structural materials used in the world; hence, improvement of the concrete mix design with respect to variable issues and requirements is of great importance. Moreover, environmental issues and waste materials have become major concerns these days. In this study, to move towards a more sustainable and ecofriendly construction industry, recycled waste glasses were used as partial replacement for sand and gravel aggregates in concrete. Simultaneously, the effects of silica fume as cement replacement and property enhancer in the eco-friendly concrete mix were investigated. The results of the conducted experiments indicated that utilisation of glass aggregates in general results in strength reduction. However, at proportions of 40% glass replacing aggregates and 5% microsilica replacing cement, no strength reduction was observed compared with normal concrete. An increase in the substitution of natural aggregates with glass reduced the total water absorption: at a proportion of 60% aggregate replaced by glass, the water absorption was reduced by 74%. On the other hand, with the replacement of 10% of cement with microsilica, water absorption decreased up to 17%. The results also indicated that an increase in the dosage of glass to 60% decreased the volume of permeable pore space by 70%.

This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/ rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature

High Strength Concrete (HSC) is a complex type of concrete, that meets the combination of performance and uniformity at the same time. This paper demonstrates the use of artificial neural networks (ANN) to predict the deflection of high strength reinforced concrete deep beams, which are one of the main elements in offshore structures. More than one thousand test data were collected from the experimental investigation of 6 deep beams for the case of study. The data was arranged in a format of 10 input parameters, 2 hidden layers, and 1 output as network architecture to cover the geometrical and material properties of the high strength self-compacting concrete (HSSCC) deep beam. The corresponding output value is the deflection prediction. It is found that the feed forward back-propagation neural network, 15 & 5 neurons in first and second, TRAINBR training function, could predict the load-deflection diagram with minimum error of less than 1% and maximum correlation coefficient close to 1.

Traditional base isolation systems focus on isolating the seismic response of a structure in the horizontal direction. However, in regions where the vertical earthquake excitation is significant (such as near-fault region), a traditional base-isolated building exhibits a significant vertical vibration. To eliminate this shortcoming, a rocking-isolated system named Telescopic Column (TC) is proposed in this paper. Detailed rocking and isolation mechanism of the TC system is presented. The seismic performance of the TC is compared with the traditional elastomeric bearing (EB) and friction pendulum (FP) base-isolated systems. A 4-storey reinforced concrete moment-resisting frame (RC-MRF) is selected as the reference superstructure. The seismic response of the reference superstructure in terms of column axial forces, base shears, floor accelerations, inter-storey drift ratios (IDR) and collapse margin ratios (CMRs) are evaluated using OpenSees. The results of the nonlinear dynamic analysis subjected to multi-directional earthquake excitations show that the superstructure equipped with the newly proposed TC is more resilient and exhibits a superior response with higher margin of safety against collapse when compared with the same superstructure with the traditional base-isolation (BI) system.

. Traditional base isolation systems focus on isolating the seismic response of a structure in the horizontal direction. However, in regions where the vertical earthquake excitation is significant (such as near-fault region), a traditional base-isolated building exhibits a significant vertical vibration. To eliminate this shortcoming, a rocking-isolated system named Telescopic Column (TC) is proposed in this paper. Detailed rocking and isolation mechanism of the TC system is presented. The seismic performance of the TC is compared with the traditional elastomeric bearing (EB) and friction pendulum (FP) base-isolated systems. A 4-storey reinforced concrete moment-resisting frame (RC-MRF) is selected as the reference superstructure. The seismic response of the reference superstructure in terms of column axial forces, base shears, floor accelerations, interstory drift ratios (IDR) and collapse margin ratios (CMRs) are evaluated using OpenSees. The results of the nonlinear dynamic analysis subjected to multidirectional earthquake excitations show that the superstructure equipped with the newly proposed TC exhibits a superior response with higher margin of safety against collapse when compared with the same superstructure with the traditional base-isolation (BI) system.

The behavior of shear connectors plays a significant role in maintaining the required strength of a composite beam in normal and hazardous conditions. Various types of shear connectors are available and being utilized in the construction industry according to their use. Channel connectors are a suitable replacement for conventional shear connectors. These connectors have been tested under different types of loading at ambient temperature; however, the behavior of these connectors at elevated temperatures has not been studied. This investigation proposes a numerical analysis approach to estimate the behavior of channel connectors under fire and compare it with the numerical analysis performed in headed stud and Perfobond shear connectors subjected to fire. This paper first reviews the mechanism of various types of shear connectors and then proposes a non-linear thermo-mechanical finite element (FE) model of channel shear connectors embedded in high-strength concrete (HSC) subjected to fire. Initially, an accurate nonlinear FE model of the specimens tested at ambient temperature was developed to investigate the strength of the channel-type connectors embedded in an HSC slab. The outcomes were verified with the experimental study performed on the testing of channel connectors at ambient temperature by Shariati et al. (2012). The FE model at ambient temperature was extended to identify the behavior of channel connectors subjected to fire. A comparative study is performed to evaluate the performance of channel connectors against headed stud and Perfobond shear connectors. The channel connectors were found to be a more economical and easy-to-apply alternative to conventional shear connectors.

This study discusses the use of Adaptive-Network-Based-Fuzzy-Inference-System (ANFIS) in predicting the shear strength of reinforced-concrete deep beams. 139 experimental data have been collected from renowned publications on simply supported high strength concrete deep beams. The results show that the ANFIS has strong potential as a feasible tool for predicting the shear strength of deep beams within the range of the considered input parameters. ANFIS's results are highly accurate, precise and therefore, more satisfactory. Based on the Sensitivity analysis, the shear span to depth ratio (a/d) and concrete cylinder strength (f(c)') have major influence on the shear strength prediction of deep beams. The parametric study confirms the increase in shear strength of deep beams with an equal increase in the concrete strength and decrease in the shear span to-depth-ratio.

A simple modification of the homotopy perturbation method is proposed for the solution of the Blasius equation with two different boundary conditions. Padé approximate is used to deal with the boundary condition at infinity. The results obtained from the analytical method are compared to Howarth’s numerical solution and fifth order Runge-Kutta Fehlberg method indicating a very good agreement. The proposed method is a simple and reliable modification of homotopy perturbation method, which does not require the existence of a small parameter, linearization of the equation, or computation of Adomian’s polynomials.

Jute rope is one of the most popular materials used for composites in various industries and in civil engineering. This experimental study investigated two types of jute rope with different diameters for jute rope composite plates to determine the best combination of jute rope and carbon fiber in terms of ratio and physical and mechanical properties. Eight combinations of carbon fiber and jute rope with different percentages of carbon fiber were analyzed. Tensile tests for the jute rope composite plate and hybrid jute rope composite were conducted, and the mechanical and physical properties of the specimens were compared. Thereafter, the ideal combinations of jute rope with an optimum percentage of carbon fiber were identified and recommended. These particular combinations had tensile strengths that were 2.23 times and 1.76 times higher than other varieties in each type.

For many years, high-strength concrete (HSC) has been used in high-rise buildings and bridges. The primary reasons for selecting HSC are to produce a more economical product, provide a feasible technical solution, or a combination of both. Despite a lot of advantages in the usage of HSC, it exhibits a brittle failure in comparison with normal strength concrete (NSC). For a comprehensive discussion on the failure of HSC beams, a total of six full scale reinforced HSC beams have been designed based on ACI code provisions and cast with compressive strength in the range of 65 MPa <= f(c)(1)<= 75 MPa and tested under two-point top loading. The general behaviour of tested beams has been investigated with observation on mid span deflection, failure mode and crack growth. Increase of the tensile reinforcement ratio results in more cracks but with lower height and width. The linear graphs between the applied load and corresponding deflection or curvature in reinforced HSC beams showed that the behaviour of these beams is elastic and any increase in the tensile reinforcement ratio results in an increase in the ultimate load too. The moment-curvature graph and load-deflection curve started with an initial elastic response followed by an inelastic behaviour that appears with a gradual decrease in stiffness till the ultimate moment is reached. (C) 2013 Elsevier Ltd. All rights reserved.