Horizontal Elements Research Articles

In situ tests of building structures isolated by innovative three‐dimensional vibration isolation bearings

AbstractAn innovative three‐dimensional vibration isolation bearing (3D‐VIB) was proposed in past studies to mitigate rail‐induced vibration and improve the seismic performance of buildings. The 3D‐VIB was composed of a thick laminated rubber bearing as the vertical vibration isolation element and a friction pendulum system as the horizontal seismic isolation element. In this study, in situ tests were carried out on a subway over‐track structure with 3D‐VIBs. The in situ tests included the subway‐induced vibration excitation test and the horizontal loading test on the same structure. In the subway‐induced vibration excitation test, the vertical isolation performance of the test structure was changed by transforming the isolation layer from a normal vibration‐isolation‐state to a non‐isolation‐state. The comparison between the two states proved that the installation of 3D‐VIBs significantly changed the vertical vibration mode and reduced the subway‐induced vibration of the superstructure. The shear performances of the isolated structure were examined by the horizontal loading test, which subjected the superstructure to a large horizontal movement under external load. The shear performances of the structure with 3D‐VIBs were consistent with that of the 3D‐VIB specimens measured in the laboratory. The in situ tests confirmed the effectiveness and stability of the 3D‐VIBs when applied to practical engineering.

Influence of horizontal alignment elements on operating speed of vehicles on two-lane highways

Earlier studies acknowledged that the design speed does not principally assure consistency in the design of highway geometric elements. Methodologies for estimating operating speeds are limited to specific or local traffic conditions and design standards, as in various studies conducted on two-lane and multi-lane highways. The present study develops operating speed models of the vehicle types observed on horizontal curves and tangent sections on two-lane highways in southern parts of India. Geometric features of the curve section and adjacent tangent sections, such as the radius of the curve, curve length, deflection angle, degree of curvature, gradient, carriageway width, and shoulder width, are obtained from the field. The speed data collected at 24 locations on the highway, including curved and tangent gradient sections, are used to analyze and model operating speed. The results indicate that the inverse of the square root of the radius appears to be an influencing parameter for modeling the operating speed of vehicles. The operating speed is sensitive for a curve radius of up to 600 m; thereafter, the operating speed appears insignificant. On tangent sections, the gradient has a larger influence on the operating speeds of all vehicle types. The operating speed models are validated and compared with models available in the literature. The proposed models developed in the present study are helpful to traffic engineers for predicting the operating speed on two-lane highways.

Endophytic bacteria with allelopathic potential regulate gene expression and metabolite production in host Casuarina equisetifolia.

Casuarina equisetifolia is a common protective forest in coastal areas. However, artificial C. equisetifolia forests cannot self-renew, mainly due to the accumulation of allelochemicals. Endophytic bacteria may alleviate the root growth inhibition caused by allelochemicals in C. equisetifolia seedlings. B. amyloliquefaciens and B. aryabhattai were endophytic bacteria with strong allelopathy in C. equisetifolia root. The allelopathy mechanism of these two endophytes and their interaction with C. equisetifolia remains to be studied. Whole-genome sequencing of B. amyloliquefaciens and B. aryabhattai isolated from the roots of allelochemical-accumulating C. equisetifolia was performed using Illumina Hiseq and PacBio single-molecule sequencing platforms. Sterile seedlings of C. equisetifolia were treated with either individual or mixed bacterial cultures through root drenching. Transcriptional and metabolomics analyses were conducted after 3 days of infection. Whole-genome sequencing of Bacillus aryabhattai and Bacillus amyloliquefaciens showed that the two strains contained various horizontal gene transfer elements such as insertion sequence, prophage and transposon. In addition, these two strains also contain numerous genes related to the synthesis and catabolism of allelochemicals. After these two strains of bacteria were individually or mixed infected with C. equisetifolia, metabolomics and transcriptomic analysis of C. equisetifolia showed the 11 important secondary metabolite biosynthesis among them alkaloids biosynthesis, phenylpropanoid and terpenes biosynthesis and related genes were putatively regulated. Correlation analysis revealed that 48 differentially expressed genes had strong positive correlations with 42 differential metabolites, and 48 differentially expressed genes had strong negative correlations with 36 differential metabolites. For example, CMBL gene showed positive correlations with the allelochemical (-)-Catechin gallate, while Bp10 gene showed negative correlations with (-)-Catechin gallate. The intergenerational accumulation of allelochemicals may induce horizontal gene transfer in endogenic bacteria of Casuarina equisetifolia root. Endophytic Bacillus plays an allelopathic role by assisting the host in regulating gene expression and the production and/or variety of allelochemicals. This comprehensive study sheds light on the intricate genetic and metabolic interactions between Bacillus endophytes and C. equisetifolia. These findings provide insights into endophyte-mediated allelopathy and its potential uses in plant biology and forest sustainability.

The Unique Morphofunctional Structure of the Reptilian Heart

The paper analyzes the evolution of the thermoenergetic statuses of vertebrates and the associated evolutionary development of their heart. The analysis shows that in most modern lepidosaurs and turtles, the heart is not completely, conditionally five-chambered: it has two atria and one ventricle, in which two incomplete septas divide it into three functional chambers. In some of them, these two septas were modified in evolution so that they turned into one with vertical and horizontal elements, as a result of which the heart became functionally four-chambered, with improved separation of arterial and venous blood flows. Crocodiles have a fully morphologically four-chambered heart. But the hearts of all reptiles, both recent and extinct, perform two opposite functions in parallel – the separation of arterial and venous blood flows and at the same time their regulated mixing. To do this, there are special morphological and physiological mechanisms in their hearts. Such a strange functional duality in the work of the reptilian heart aims to regulate the metabolism level by controlling the amount of carbon dioxide entering the blood flow: increasing the amount of CO2 in the blood flow reduces the metabolic rate, reducing its amount increase metabolism. Mixed blood in reptiles’ blood flow is not an immature, primitive state, but a physiological necessity. Moreover, this method of regulating of metabolic rate is most adequate to the initial, ancestral thermoenergetic state in reptiles, because basal terrestrial tetrapods and most ancient reptiles were meso- and even tachymetabolic, i.e. almost or completely warm-blooded, endothermic animals. It was just these endothermic animals that needed such type of metabolism regulation. As a result, all recent reptiles have a complex morphophysiological organization of the heart, which was functionally more suitable for their almost warm-blooded ancestors. Recent reptiles use part of their ancestral properties as an adaptation to new environmental conditions, new environmental requirements, and their new morphophysiological state. This unique organization of the heart is characteristic of all modern and extinct reptiles, and, importantly, it is characteristic exclusively for reptiles due to their original endothermic state.

Cypriot Fabrics? White Slip Pottery and Élite Linen Clothes of the Late Bronze Age

Abstract In this article we will point to the similarity between the decoration on Cypriot White Slip (WS) I and II pottery and contemporary 15th–14th-century BCE “Syrian” elite garments shown in 18th Dynasty Egyptian tombs. Depiction of men and women in the tombs of Rekhmire (TT100), Sobekhotep (TT63), Menkheperraseneb (TT86), and Anen (TT120) show white clothes decorated with both vertical and horizontal elements, with dotted and wavy additions. Such elements find direct parallels in the WS I decorative “vocabulary.” We will examine the possibility that the Cypriot WS pottery imitates elite linen clothing produced during the international Late Bronze Age, some even on Cyprus, as indicated by the mention of “linen of Alashiya” (gad uru Alašiya) in Hittite inventory texts.

Sensitivity and Optimization Analysis of Torsional Behavior in Multicellular Thin-Walled Tubes

Multicellular thin-walled tubes are widely used due to their lightweight, economical design, and superior shear and torsional performance. Their design is sometimes governed by the available materials and the required dimensions. The current study uses advanced sensitivity analysis with meta-modeling tools to understand how different geometric and mechanical factors affect the torsional performance of multicellular thin-walled tubes. The geometric factors include the length, thickness, and width of the beams, while the mechanical properties involve the shear modulus. Variance-based sensitivity analysis is used to assess how variations in these factors impact the rate of twist, torsional stiffness, and shear stress. The interconnected relations between input parameters are exploited for optimal design and superior performance. The results revealed that for a three-celled tube, thick horizontal interior elements with thin deep vertical elements and thin exterior elements provide an optimal design when the cross-sectional area is constrained. This finding, combined with varying the geometrical and material properties, results in an optimal design using CFRP composites when constrained by minimizing the total weight and superior torsional performance. The analysis can be extended to include other constraint(s), but changing the design constraints might change the optimal design. Doi: 10.28991/CEJ-2024-010-09-09 Full Text: PDF

Об элементных фундаментах опор высоковольтных линий

Purpose: to substantiate the possibility of using the foundations of supports of high-voltage lines in the form of dispersed horizontal elements combined into a single structure for the perception of alternating loads. To determine by experimental and computational methods the effect of the mutual displacement of elements in the form of an increase in the bearing capacity of foundations and a decrease in their deformations under the influence of pressing and pulling loads. To show the possibility of replacing slab foundations of supports of high-voltage lines with structures made of prefabricated elements to reduce the volume and weight of products transported from the factory. Methods: application of the moire photogrammetric method to assess the development of soil compaction zones and angular deformations of the soil base in a tray with a glass wall under models of slab and elemental foundations. Using the method of boundary integral equations to obtain the dependence of precipitation on the step of elements for flexible and rigid foundations. Results: the effect of mutual influence of foundation elements during their convergence and dispersal in the form of a change in the stress-strain state in their base is illustrated. Differences in the depths of the distribution of compaction zones and areas of development of angular deformations are revealed. Quantitative data on the precipitation of slab and elemental foundations and the influence of the depth of the roof of the solid underlying layer on them have been obtained. Graphical dependences of the relationship of sediment elements with the distance (step) between them are presented. The effect of the division of the foundation on the rate of extinction of marginal tangential stresses in the base is shown. An illustration is made of an increase in the volume and surface area of the bulging body of the elemental foundation, which leads to an increase in its bearing capacity compared to the slab one when calculating for pulling out. Practical importance: the effectiveness of the use of an element foundation in comparison with the paid option in reducing the parameters of the stress-strain state of the base and facilitating logistical tasks during construction is shown. The experimental and computational methods used can be recommended for further refinement of the parameters of the elemental foundations.

Cost-Effective Data Acquisition Systems for Advanced Structural Health Monitoring.

With the growing demand for infrastructure and transportation facilities, the need for advanced structural health monitoring (SHM) systems is critical. This study introduces two innovative, cost-effective, standalone, and open-source data acquisition devices designed to enhance SHM through the latest sensing technologies. The first device, termed CEDAS_acc, integrates the ADXL355 MEMS accelerometer with a RaspberryPi mini-computer, ideal for measuring strong ground motions and assessing structural modal properties during forced vibration tests and structural monitoring of mid-rise buildings. The second device, CEDAS_geo, incorporates the SM24 geophone sensor with a Raspberry Pi, designed for weak ground motion measurements, making it suitable for seismograph networks, seismological research, and early warning systems. Both devices function as acceleration/velocity Data Acquisition Systems (DAS) and standalone data loggers, featuring hardware components such as a single-board mini-computer, sensors, Analog-to-Digital Converters (ADCs), and micro-SD cards housed in protective casings. The CEDAS_acc includes a triaxial MEMS accelerometer with three ADCs, while the CEDAS_geo uses horizontal and vertical geophone elements with an ADC board. To validate these devices, rigorous tests were conducted. Offset Test, conducted by placing the sensor on a leveled flat surface in six orientations, demonstrating the accelerometer's ability to provide accurate measurements using gravity as a reference; Frequency Response Test, performed at the Gebze Technical University Earthquake and Structure Laboratory (GTU-ESL), comparing the devices' responses to the GURALP-5TDE reference sensor, with CEDAS_acc evaluated on a shaking table and CEDAS_geo's performance assessed using ambient vibration records; and Noise Test, executed in a low-noise rural area to determine the intrinsic noise of CEDAS_geo, showing its capability to capture vibrations lower than ambient noise levels. Further field tests were conducted on a 10-story reinforced concrete building in Gaziantep, Turkey, instrumented with 8 CEDAS_acc and 1 CEDAS_geo devices. The building's response to a magnitude 3.2 earthquake and ambient vibrations was analyzed, comparing results to the GURALP-5TDE reference sensors and demonstrating the devices' accuracy in capturing peak accelerations and modal frequencies with minimal deviations. The study also introduced the Record Analyzer (RECANA) web application for managing data analysis on CEDAS devices, supporting various data formats, and providing tools for filtering, calibrating, and exporting data. This comprehensive study presents valuable, practical solutions for SHM, enhancing accessibility, reliability, and efficiency in structural and seismic monitoring applications and offering robust alternatives to traditional, costlier systems.

Comprehensive analysis of distribution characteristics and horizontal gene transfer elements of blaNDM-1-carrying bacteria

The worldwide dissemination of New Delhi metallo-β-lactamase-1 (NDM-1), which mediates resistance to almost all clinical β-lactam antibiotics, is a major public health problem. The global distribution, species, sources, and potential transfer risk of blaNDM-1-carrying bacteria are unclear. Results of a comprehensive analysis of literature in 2010–2022 showed that a total of 6002 blaNDM-1 carrying bacteria were widely distributed around 62 countries with a high trend in the coastal areas. Opportunistic pathogens or pathogens like Klebsiella sp., Escherichia sp., Acinetobacter sp. and Pseudomonas sp. were the four main species indicating the potential microbial risk. Source analysis showed that 86.45 % of target bacteria were isolated from the source of hospital (e.g., Hospital patients and wastewater) and little from surface water (5.07 %) and farms (3.98 %). A plasmid-encoded blaNDM-1Acinetobacter sp. with the resistance mechanisms of antibiotic efflux pump, antibiotic target change and antibiotic degradation was isolated from the wastewater of a typical tertiary hospital. Insertion sequences (IS3 and IS30) located in the adjacent 5 kbp of blaNDM-1-bleMBL gene cluster indicating the transposon-mediated horizontal gene transfer risk. These results showed that the worldwide spread of blaNDM-1-carrying bacteria and its potential horizontal gene transfer risk deserve good control.

Wall-frame interaction of steel plate shear wall strengthened by foam-infilled corrugated CFRP panel

In this study, a foam-infilled corrugated CFRP panel was proposed to improve the bearing capacity and energy dissipation of infill panels for steel plate shear wall (SPSW) as an effective lateral force resisting system in constructions. The horizontal corrugated CFRP panels were fixed to both sides of the inner steel plate, and polyethylene terephthalate (PET) foams were infilled between the steel plate and the corrugated panel. With the aim of fully exploiting the strength, the interaction between the infill panel and the boundary frame elements was investigated to guide the design of vertical boundary elements (VBEs) and horizontal boundary elements (HBEs). Equations for the shear buckling strength of the CFRP-steel sandwich shear wall (CFSSW) were analytically obtained to facilitate the design of the buckling restraining effect. Theoretical analyses of the force transfer mechanism between the wall panel and the boundary frame element were also presented. In addition, finite element models were developed to investigate the effect of the bending stiffness of the VBE on the load carrying capacity. Based on the theoretical and numerical analyses, the response of single-span two-story FE models for SPSW and CFSSW with steel frames (SF) were compared to further evaluate the hysteretic behavior of CFSSW. Finally, simplified models for CFSSW with tension-compression and tension-only trusses were proposed to facilitate practical design.

The thrust line in masonry arches: a new simplified algorithm

Masonry arches and vaults have been widely used in the past to construct horizontal structural elements using materials with low tensile strength. Initially, the design methods used were mostly based on empirical rules derived from the experience of builders. In more recent centuries, however, analytical theories and graphical methods have been developed to formalize the static behaviour of the masonry arch. Although computational methods for evaluating masonry arch structures have been widely developed in recent decades, graphical and analytical methods are still simple and clear tools for understanding the structural behaviour of these structures. Therefore, a simplified method for identifying the thrust line in masonry arches is presented in this paper. The proposed algorithm is then applied to several case studies, and the results obtained are compared with those derived from finite element models.

Emergence of Rarely Reported Extensively Drug-Resistant Salmonella Enterica Serovar Paratyphi B among Patients in East China.

In recent years, global concern over increasing multidrug resistance (MDR) among various Salmonella serotypes has grown significantly. However, reports on MDR Salmonella Paratyphi B remain scarce, let alone the extensively drug-resistant (XDR) strains. In this retrospective study, we investigated the isolates of Salmonella Paratyphi B in Jiangsu Province over the past decade and carried out antimicrobial susceptibility tests, then the strains were sequenced and bioinformatics analyses were performed. 27 Salmonella Paratyphi B strains were identified, of which the predominant STs were ST42 (11), ST86 (10), and ST2814 (5). Among these strains, we uncovered four concerning XDR Salmonella Paratyphi B ST2814 strains (4/5) which were previously unreported. These alarmingly resistant isolates showed resistance to all three major antibiotic classes for Salmonella treatment and even the last resort treatment tigecycline. Bioinformatics analysis revealed high similarity between the plasmids harbored by these XDR strains and diverse Salmonella serotypes and Escherichia coli from China and neighboring regions. Notably, these four plasmids carried the ramAp gene responsible for multiple antibiotic resistance by regulating the AcrAB-TolC pump, predominantly originating from China. Additionally, a distinct MDR ST42(1/11) strain with an ICE on chromosome was also identified. Furthermore, phylogenetic analysis of global ST42/ST2814 isolates highlighted the regional specificity of these strains, with Jiangsu isolates clustering together with domestic isolates and XDR ST2814 forming a distinct branch, suggesting adaptation to local antibiotic pressures. This research underscores the pressing need for closely monitoring the MDR/XDR Salmonella Paratyphi B, particularly the emerging ST2814 strains in Jiangsu Province, to effectively curb its spread and protect public health. Moreover, surveillance should be strengthened across different ecological niches and genera to track resistance genes and horizontal gene transfer elements under the concept of "ONE HEALTH".

Single layer dual hollow core antiresonant fiber based polarization beam splitters

To confront the growing challenges of integrated photonics, optical devices need to be compact in size to integrate them in communication networks where a polarization beam splitter device may play a crucial role. In this regard, hollow core antiresonant fibers have garnered significant attention as a versatile platform, for achieving efficient polarization splitting, owing to their promising characteristics. In this article, traditional and available multilayer complex cladding geometry, in dual hollow core antiresonant fiber, is simplified to single layer arrangement and created efficient polarization beam splitters device. First, we introduced a splitter with single layer cladding geometry that simultaneously presents a short device length of 2.24 cm and an ultra-wide bandwidth of 415 nm, with an extinction ratio exceeding 20 dB. This bandwidth also encompasses widely used communication wavelengths of 1.31μm and 1.55μm. Moreover, a careful investigation of geometrical dimensions, nesting, and conjoined tubes inclusion suggests that the device structure having two horizontal nested elements has an excellent splitting performance with a concise splitter length of 2.06 cm and an ultra-wide bandwidth of 465 nm, covering most telecom bands. Notably, the splitters have the highest extinction ratio of around 140 dB at 1.55μm, along with an effective single mode performance. Therefore, the claimed single layer polarization splitters might be an attractive candidate for the integration of optical devices in communication systems.

Shear performance and strength of reinforced concrete non-prismatic beams with basalt fiber reinforced polymer rebars

Tapered beams, which are horizontal structural elements, possess varying moments of inertia across their length. Among these, the pier cap mode is widely employed in engineering applications. This research explores the influence of incorporating basalt fiber reinforced polymer (BFRP) bars on the shear strength of eight concrete haunched beams. While two of these beams were straight beams, the others have different inclination angles. The study aimed to examine two main factors: the angles of tapered part in the compression chord and the effect of BFRP stirrups. Results from the experiment revealed a direct correlation between increasing tapered angles and the enhancement of shear capacity in haunched beams. Consequently, a comprehensive analysis was conducted using three different codes, leading to the formulation of proposed equations derived from semi-empirical methods. The analysis demonstrated a high level of accuracy in predicting shear strength with a satisfactory safety margin.

Integrative and conjugative elements of Pasteurella multocida: Prevalence and signatures in population evolution

ABSTRACT Pasteurella multocida (P. multocida) is a bacterial pathogen responsible for a range of infections in humans and various animal hosts, causing significant economic losses in farming. Integrative and conjugative elements (ICEs) are important horizontal gene transfer elements, potentially enabling host bacteria to enhance adaptability by acquiring multiple functional genes. However, the understanding of ICEs in P. multocida and their impact on the transmission of this pathogen remains limited. In this study, 42 poultry-sourced P. multocida genomes obtained by high-throughput sequencing together with 393 publicly available P. multocida genomes were used to analyse the horizontal transfer of ICEs. Eighty-two ICEs were identified in P. multocida, including SXT/R391 and Tn916 subtypes, as well as three subtypes of ICEHin1056 family, with the latter being widely prevalent in P. multocida and carrying multiple resistance genes. The correlations between insertion sequences and resistant genes in ICEs were also identified, and some ICEs introduced the carbapenem gene bla OXA-2 and the bleomycin gene bleO to P. multocida. Phylogenetic and collinearity analyses of these bioinformatics found that ICEs in P. multocida were transmitted vertically and horizontally and have evolved with host specialization. These findings provide insight into the transmission and evolution mode of ICEs in P. multocida and highlight the importance of understanding these elements for controlling the spread of antibiotic resistance.

Seismic Performance Analysis of Endo Indonesia Office Surabaya Building Structures Against Structural Irregularities

The structure of the building will be stable if the response of the structure is able to ignore the static and dynamic loads. The behavioral stability of the building structure is also influenced by geometry, configuration of horizontal and vertical elements, rigidity, lateral ability, and daktility of the structure. (Khanal Chaulagain, 2020). When the structure configuration of the building is irregular, there will be eccentricity which means that the center of the mass is incorrectly at the centre of rigidity (Faisal Darsono, 2019). If such conditions are not anticipated, the structure will be tortured until it eventually collapses. (Naveen dkk., 2019). In Surabaya there are office buildings that have irregular structures. This research will model the structure of the building into five variations. Each variation has a reduction in the value of structural irregularity. Next, we will examine the impact of structural irregularities on the reaction of structures of buildings. The results of the analysis showed that the irregularity of the inner angle had a significant impact on the shift of the roof, with the R-square of 0.9025 in the X axis and 0.9872 in the Y axis. Furthermore, based on the value of the soft level rigidity to the earthquake style at each level, R-quares of 0.8433 were found at the X-axis, and 0.825 at the Y-axe. Furthermore, changes in the inner angle of variations 2, 3, 4, and 5 resulted in successive increases in the mass of the structure by 0.18%, 4.09%, 7.86%, and 0.43%. These increases result in an increase in the basic sliding style in both directions. The variation 5 building designed without an inner angle showed an increase of 0.46% in the base sling style in either direction. Movement targets based on ASCE 41-13 NSP are 321.903 mm and 308.497 mm for the X and Y directions, respectively, which are in the Life Safety and Immediate Occupancy categories. While the total maximum drift values based on ATC-40 for the x and y directions are 0.0148 and 0.0150. The performance of the existing building structure is between B to C on the level of damage control (Immediate Occupancy to Life Safety), which means the building has suffered minor non-structural damage and may suffer structural damage but can still be repaired.

Vertical spanning wall elastically restrained at the top: validation and parametric dynamic analysis

In unreinforced masonry structures, among the most dangerous events that can occur during earthquakes are the out-of-plane mechanisms. This type of response significantly changes if the wall is restrained by a horizontal element. The collapse, in this case, could take place for slipping/failure of the diaphragm connection or for overturning of the wall, following the formation of a crack at an intermediate height between the base and the top. A specific analytical model is used to capture the complex dynamic behavior of the wall, formed by two stacked rigid bodies (free to rock) with the top one connected to a flexible diaphragm. The model is calibrated using experimental data available in the literature and it is then used to carry out a dynamic parametric analysis. The variation range of relevant parameters refers to the building features surveyed in Emilia-Romagna region, Italy, and their effect on the global response of the system is investigated. Further, the influence of ground motion is considered, using different ground accelerations. The results of the analysis highlight that, for the considered area and return period, the maximum rotations of the system are significant only for large slenderness values. Further, the investigation shows that the diaphragm plays a crucial role in the dynamic response of the system. The stiffness of the diaphragm can significantly reduce the rotations and consequently the risk of overturning. Additionally, the study on the effect of the wall size pointed out how a top spring causes a reverse scale effect.

Ensuring Structural Integrity: An Evaluation of Vertical Shortening in Tall Concrete Buildings

Vertical shortening, a phenomenon inherent to concrete structures, plays a key role in the quality and safety of construction, particularly in tall reinforced concrete buildings. This behavior is intrinsically linked to the time-dependent properties of concrete, encompassing both creep and shrinkage. Neglecting these aspects, especially when non-uniformly distributed, can give rise to various structural issues, including partition distress, overloading, and potential cracking in horizontal elements. This paper delves into the principal factors influencing vertical shortening and presents a rigorous approach to their evaluation, treating creep and shrinkage as critical parameters. The investigation employs two illustrative case studies: the first revolves around a 15-story reinforced concrete building with single columns supporting tributary areas at various levels, acting as a calibration case; the second encompasses a 30-story reinforced concrete structure employing a dual system, providing a broader perspective applicable to three-dimensional structures. A diverse array of analyses is conducted, incorporating considerations for concrete’s linear and nonlinear behavior as well as the impact of construction stages. Our findings reveal that vertical shortening is directly proportional to the building’s height and inversely related to concrete strength, longitudinal reinforcement ratios, member dimensions, volume-to-surface ratios, age of the structure upon load application, and relative humidity. Consequently, precise assessments of differential shortening effects are paramount. The utilization of staged construction analysis and time-dependent effects is recommended as the most suitable approach for evaluating vertical shortening effects.

The effects of internal erosion on granular soils used in transport embankments

The flooding of embankments used for rail and other infrastructure has the potential to cause lasting weakening of slopes via the movement of fine particles induced by seepage. In laboratory experiments, internal erosion was induced in granular soil samples, with properties consistent with those used to construct transportation embankments, to assess how particle migration through, and out of, samples caused shear wave velocity, strength, stiffness and permeability changes. Shear wave velocity changes, measured using horizontal bender elements, of up to 19 % were observed following fine particle removal of up to 1 % of initial sample mass. Shear wave velocity change was found to be an indicator for identifying the development of permeability change during seepage-induced particle migration. Median measured permeability changes were +5 % and −34 % for samples containing 15 % and 30 % fines, respectively. The largest directly observed permeability and shear wave velocity changes occurred during the initial stages of seepage. Negative correlation was observed between mass of material removed from samples and peak friction angle. Following seepage, soils displayed a dual stiffness behaviour. Stiffness and strength changes were attributed to redistribution of fine particles and opening of pore spaces. Our results have implications for the monitoring of earthworks affected by flooding and seepage as the associated redistribution of fine particles may lead to large changes in slope properties.

The Effect of Using Horizontal Shading Elements on the Energy Efficiency of Multistory Residential Buildings

Shading elements have been considered to be an important element in controlling the amount of heat and sunlight entering the spaces, the most common kinds of horizontal shading devices include architectural components including balconies, louvres, and roof overhangs. Residential buildings consume high energy by household appliances from air conditioning, which makes it the most energy consuming building. Therefore, the aim of this research is determine the effect of using horizontal shading elements on the energy efficiency of multi-storey residential buildings. DesignBuilder is a tool used in this research to evaluate the energy efficiency by comparing the typical room without shading elements and with typical room with shading elements with different depths under two district climatic conditions cold semi-arid climate and hot arid climate. The research found that energy saving between 0.5% to 30.8% when using horizontal shading elements depending on the orientation and location of the case study beside the depth of shading elements.