Design Of Building Structures Research Articles

Dynamic mechanical response and failure characteristics of coal and rock under saltwater immersion conditions

The stability of coal and rock masses in water-rich mines is affected by both mine water erosion and dynamic disturbances. Thus, it is necessary to study the dynamic mechanical response and failure characteristics of coal and rock under the combination of saltwater and a high strain rate. To this end, a split Hopkinson pressure bar device was employed to investigate the effects of impact velocity, water content, and immersion liquid on the dynamic mechanical behaviours of coal and rock. The results revealed that the weakening effect of saltwater on the dynamic mechanical properties of coal and rock is much greater than that of distilled water. With increasing moisture content, the dynamic compressive strength of the coal specimens decreases monotonically, while that of the rock shows a trend of first increasing and then decreasing. The failure process and destruction of coal and rock are comprehensively affected by both the external impact load and the physical and mechanical properties of the material. The degree of damage of the coal and rock specimens increases with increasing impact velocity and water content. Moreover, the influence of various factors on the impact fracture mechanism of coal and rock under saltwater immersion conditions was revealed. These findings are highly important for the design and maintenance of underground coal and rock building structures.

The effect of the pitch of the boards in the transverse layer on the deformability and stress distribution in a threelayer CLT panel rigidly clamped on both sides

CLT panels are made by gluing several layers of boards crosswise, which provides them with high load-bearing capacity and bending resistance. In addition to the number of layers in the panel, the deformability and bearing capacity are influenced by the geometric parameters of the plate, the way the layers are attached to each other, the way the structure is supported, etc. Due to the fact that the material has recently been used in construction, many issues remain poorly understood, and therefore there is an opportunity and need to optimize some aspects both in the CLT panels themselves and in the way they interact with other building structures.In this article, the influence of the pitch of boards in the transverse layer on the deformability and stress distribution in a three-layer CLT panel rigidly pinched on both sides was studied. Numerical studies of the finite element method (FEM) were carried out using the computing complex SCAD+. The computational model of the plate in this study is a composite orthotropic plate with rigid connections between the layers. The result of the study is numerical data reflecting the dependence of the distribution of normal stresses OX and OY and the transverse deformation of the plate on the pitch of the lamellae (boards) in the bottom layer. Projections of the computational model with normal stress isofields on the stretched and compressed plate layer are also obtained. This makes it possible to identify general patterns of stress distribution and deformation changes with variations in geometric parameters for this type of support for their use in the design of building structures using CLT panels as well as in the optimization of the structure in order to increase the cost efficiency of resources.

Risk-based life cycle cost–benefit analysis for progressive collapse design of RC frame structures

Progressive structural collapse is a typical low-probability high-consequence event. Progressive collapse design can effectively improve the robustness of structures against accidental local damage and reduce the probability of collapse. However, progressive collapse design also increases the construction cost of buildings. Hence, it is necessary to conduct cost-benefit analyses for the progressive collapse design of building structures. This study first designs a reinforced concrete (RC) frame based on a progressive collapse design program that simultaneously optimizes material consumption and structural resistance. Then, the structural failure probability is quantified using an alternative path (AP) method-based fragility analysis that considers the structural uncertainties. Based on this, the life cycle costs and benefits of the structure designed with different design load factors are investigated. A four-story RC frame is used as an example. By considering the time value of money and threat probability, the break-even points and optimized design load factors for the progressive collapse design of the RC frame are analyzed. These research outcomes can help promote progressive collapse design in engineering practice and provide references for proposing scientific and reasonable design load factors.

Assessment of safety of masonry buildings near deep excavations: impact of excavations on structures

The knowledge of impacts and the load-bearing capacity of unstrengthened/strengthened structures is a crucial source of information about the safety of masonry buildings near deep excavations, especially in dense urban areas. Incorrect calculations made for such designs can seriously affect not only an analyzed object, but also the adjacent buildings. The safety of masonry buildings can be determined by many factors that are closely related to the hazards presented during the performance of deep excavations. These factors are at first identified and then prioritized. The AHP process in the multi-criteria analysis was used to support the decision-making process related to the verification of factors affecting the safety assessment of masonry buildings in the area of deep excavations. The proper design of building structures, including the verification of the structure strengthening near deep excavations, was found to be the most significant factor determining the safety of such buildings. The methodology for proceeding with the verification of ultimate (ULS) and serviceability (SLS) limit states in accordance with the literature data, current regulations, such as Eurocode 6 and other design standards, and know-how of the authors, described in this paper was the next stage of the discussed analysis.

A robustness-oriented procedure for the design of tying reinforcement in precast concrete hollow-core floors

Buildings may be subjected during their service life to extreme events which can trigger progressive collapse. On this front, the role played by tying reinforcement in structural members is crucial for an adequate load redistribution and the avoidance of disproportionate collapse. This work proposes a robustness-oriented procedure for the design of tying reinforcement placed in the hollow-core units and beams of precast concrete buildings, where limited studies are available in scientific literature. In particular, the aim is to provide a simple yet reliable approach for the design of concentrated and distributed ties in precast floors by adopting fundamental input parameters such as the system’s chord rotation capacity and dynamic amplification factor, which are not considered in current design codes. Firstly, a flow-chart of the design procedure is proposed and discussed. Secondly, the input parameters are calculated based on recent analytical approaches - proposed by some of the authors - to optimize the tying reinforcement design. Finally, the efficiency of the design procedure is demonstrated with an application example, and a novel detailing scheme is proposed which is aimed at a significant enhancement of structural robustness. Due to its simplicity, the proposed design procedure is contended to be applicable in robustness assessment and design of building structures with precast concrete hollow-core floors.

Seismic Performance Evaluation of a Chilean RC Building Damaged during the Mw8.8 Chile Earthquake

Chile, recognized as one of the world’s most earthquake-prone nations, has gained valuable insights from significant earthquakes, such as those in 1985 and 2010, which have influenced updates to the nation’s design codes. Although Chile’s seismic design approach has been largely effective in recent earthquakes and demonstrated an “operational” performance level in most structures, performance-based design (PBD) methods have not yet been officially incorporated as valid approaches in the Chilean seismic design codes for buildings. However, in 2017, the Chilean Association on Seismology and Earthquake Engineering (ACHISINA) introduced a PBD approach, primarily for verification purposes, based on the Los Angeles Tall Buildings Structural Design Council (LATBSDC) framework. In this work, firstly, we provide an overview of Chile’s PBD methodology, focusing on the thresholds for various performance levels. These levels are established through experimental and numerical analysis, correlating performance with permissible damage levels. The second part of the paper examines the seismic performance of a residential building, designed before the 2010 Maule earthquake and subsequently damaged, using Chile’s PBD guidelines. This case study highlights the implementation and effectiveness of PBD for assessing seismic resilience in Chilean structures.

GNN-LSTM-based fusion model for structural dynamic responses prediction

With the rapid growth of deep learning technology, the potential for its use in structural engineering has substantially increased in recent years. This study proposes an innovative deep-learning fusion network architecture based on the graph neural network (GNN) and long short-term memory (LSTM) network. The proposed fusion model can accurately predict nonlinear floor acceleration, velocity, and displacement responses of typical steel moment-resisting frames (SMRF) with 4 through 7 stories subjected to strong ground motions. The fusion model framework overcomes a major drawback in existing deep learning models as it can predict the dynamic responses of various structures. This has widened the range of potential applications of structural surrogate models generated through deep learning technology on the design and analysis of building structures with different geometries. Additionally, this paper presents two LSTM-optimized learning strategies, namely packing padded sequences and sequences compression strategies. These strategies improve the model’s performance significantly without modifying its architecture. Finally, this study reveals that the model’s internal graph embedding is highly correlated with certain critical structural parameters, such as the first natural period and the height of a building. This shows that the proposed fusion model is interpretable and has the ability to extract vital information that influences structural dynamic responses.

The engineering legacy of the FIFA World Cup Qatar 2022TM: the gahfiya-shaped Al Thumama Stadium

The structures of the Al Thumama Stadium could be categorised into four main building components: The permanent bowl structure with the lower and middle tiers are mainly cast-in-place reinforced concrete with precast seating units. Structural steel is utilised for the upper tier stands which is to be dismantled for legacy conversion after FIFA World Cup Qatar 2022™. The roof and façade system utilises steel and cable systems with a unique membrane cladding design derived from the cultural gahfiya symbol. The roof is a self-anchored tension-compression ring system based on the principle of a horizontal spoked wheel with one compression ring along the outer perimeter and two tension rings along the oculus. The façade consists of lightweight double-layered and pre-stressed cable nets spanning between curved vertical beams. A translucent PTFE coated fibreglass membrane with highly transparent mesh inserts form the cladding of the stadium and provide its unique architectural design. This article gives an overview of the entire building structure design and construction methodology.

Experimental study on the movement characteristics of adversarial people in the corridor

With the continuous development of pedestrian dynamics, the movement characteristics of multiple types of people (elderly, children, disabled people, etc.) under various scenarios (flood, fire, special building structure, etc.) have been extensively and deeply studied. The relevant conclusions and movement rules are of great significance for guiding the design of building structures and crowd evacuation instructions. However, there is a lack of research on the movement of adversarial crowds with different movement purposes and strong interactions. The analysis of its movement characteristics and the movement modelling of interaction rules need to be further explored through controlled experiments. Therefore, this paper focuses on the study of the movement characteristics of the adversarial crowd and carries out a realistic experiment in which pedestrians in the corridor escape from attackers to complete the evacuation. The purpose was to address the following questions: the impact of attackers and corridor width on pedestrian movement. It was found that the attacker's movement pause would increase the desired velocity of the crowd, and thus the velocity-density relationship was different from the traditional fundamental diagram. The width of the corridor has a great impact on the movement speed and the collision probability of the crowd. Based on the results of the experiment, a model was established and simulation experiments were carried out by changing the width of the corridor. It is hoped that the results of this paper can provide help for emergency evacuation guidance for pedestrians in the future.

Application of solar energy storage system in building structure design and its thermal process analysis

In order to understand the application and thermal process of solar energy storage system in building structure design, a research on the application and thermal process analysis of solar energy storage system in building structure design is put forward. This paper will take the outdoor climate conditions of residential buildings in a province as an example to conduct thermal analysis on the heat collection components and heat storage components of urban residential buildings. The building under test is a university teacher?s residence located in the university campus of Chengguan District of the city. It is a multi-storey building with a total of five floors, and the building is on the top floor. The experimental results show that the heat storage effect of the thick exterior wall can effectively reduce the temperature fluctuation of the exterior wall. The difference between the maximum and minimum values of the exterior wall surface temperature is 19?C, and the difference between the maximum and minimum values of the interior surface temperature is 5.4?C. The difference between the maximum and minimum temperature of the north exterior wall is 4.9?C, and the difference between the maximum and minimum temperature of the inner surface is 1.6?C. The work of this paper lays a foundation for the quantitative research on the temperature control of building heat collection and storage components, and provides a theoretical basis for solar heat storage.

A Comparison of the Effects of Different Slopes on Building Reaction in Wind Zones

Understanding and analysing wind-induced vibrations is a crucial part of the overall evaluation, design, and construction of high-rise building structures. Developers are exploring and using sloped or steep terrain for construction due to the ongoing trends of urbanisation, the ongoing demand for housing, and the constraints placed on available land resources. This change in the landscape underscores the necessity for considerable research endeavours by requiring a comprehensive grasp of the structural equilibrium of structures positioned on slopes. To investigate how wind speed affects the way building frames respond structurally when situated on sloping terrain is the principal objective of this research project. The study considers alternative frame geometries in combination with varying ground slopes. By highlighting the Taking into account wind loads—especially in different wind zones (like III and IV)—and different slopes— from 0° to 10°—the study seeks to clarify the complex dynamics at play in the relationship between wind forces and multi storey reinforced concrete building frames. As a consequence, it is essential to determine if a hillside can sustain building loads. In order to estimate the factor of safety against the slope’s sliding collapse, this study proposes a method that takes building loads transferred to the slope into account. Wind forces might also be included in the analysis. It is feasible to consider various slopes similar to the formulation provided in the research. Research on the stability of slopes with different building configurations has been conducted. This research has discussed the measures that must be implemented for stepped foundations on hill slopes.

REENGINEERING OF THE ACTIVITIES OF CONSTRUCTION PARTICIPANTS UNDER THE INFLUENCE OF DIGITALIZATION

The article researches the main trends in the digital transformation of the interaction of construction participants under the influence of digitalization. The peculiarity is that the directions and trends of digitalization are grouped in accordance with the stages of the life cycle of construction objects. The necessity of re-engineering the administrative-management interaction of construction participants has been identified, since the organizational structure of projects undergoes changes under the influence of digitalization, and accordingly the organizational and economic management mechanism of construction participants, in particular engineering companies, undergoes changes. 
 It was revealed that a great influence on the change of the principles and structure of administration of construction projects is carried out thanks to the use of systems of integrated management of construction projects, which are based on the use of VIM technologies. An overview of the modern software market was carried out. It was found that today the software market is filled with a large number of programs that are used to solve various problems of designing and transforming digital support in construction. The most common are software complexes for VIM design, automated general purpose design, design of building structures and geotechnical calculations, development of estimate documentation, development of calendar plans. Currently, all major developers of software complexes Autodesk, Trimble, SchneiderElectric, Graphisoft, etc. implement BIM technology in their products. 
 It is suggested that, when building the organizational and economic mechanism of modern engineering companies, take into account two main factors of the influence of digitalization in construction: the introduction of BIM technologies in the activities of design, construction and engineering companies, supported also at the state level, and digitalization of all processes related to the creation of a construction object - from obtaining technical conditions and urban planning restrictions to putting the facility into operation.

Enhanced rational horizontal tying force method for practical robustness design of building structures

Under the backdrop of the rational horizontal tying force method recently developed at Imperial College London, which focuses on the tying resistance of floor systems based on constant tying forces and its planar interaction with the surrounding structure alone, this paper presents relevant enhancements to the original method. These enhancements involve simplified mechanics-based models quantifying i) the residual flexural resistance arising from the curtailed reinforcement in tying via beams, ii) the additional flexural resistance from transverse beam in one-way tying via floor systems and iii) the planar restraint stiffness from the surrounding structure, including the influence of the compressive ring mobilised within the affected floor system under tensile membrane action. Following a detailed exposition of the formulation of the models, the paper presents several studies which demonstrate the effectiveness of the enhanced tying force method. Importantly, the method addresses resistance and stiffness mechanisms not covered in the current prescriptive tying requirements within a practical application framework that is still comparable in simplicity to such requirements, thereby further promoting the rational horizontal tying force method as a potential replacement for the prescriptive tying requirements in the next generation of robustness design codes.

The Construction of Affordable Housing in Developing Countries: a Scientometric Review

The presence of affordable housing in developing countries is a crucial issue in order to fulfill the primary need for housing in a large market segment, especially people whose income is below the average household income. In contrast to developed countries, the development of studies on affordable housing construction (AHC) in developing countries has not been well mapped. This certainly creates many gaps in determining the direction of future developments, especially related to the studies that will be carried out. This study tries to map the development of scientific publications related to AHC in developing countries, from 1983 - 2021. Using scientometric techniques and VosViewers as a data processing tool, 116 publications that meet the given criteria have been identified. The findings of this study reveal a mapping of publications organized by country, organization, research outlet, author, document citation, and main research area. During the observation period, most research focused on developing nations, affordability, sustainable development, the construction industry, and the developing globe. In addition, the results of this study also successfully mapped opportunities for future research focuses related to building materials, affordable housing, low-income populations, decision-making, and structural design. In conclusion, this study highlights the need for further research on affordable housing development in developing countries to guide policy makers and researchers in developing affordable housing solutions that meet the housing needs of low-income households.

Media Pembangkit Gelombang Skala Laboratorium

In the design of offshore building structures, calculations are required by looking at the factors that occur in the ocean. A big factor that occurs is the disturbance force of waves which can disrupt the strength of the building structure to be created. For this reason, this research makes a wave generating media device on a laboratory scale. With this tool, efforts are also made to resemble the original wave, where the deeper it is, the smaller the strength of the wave formed. This effort is an implementation of the wave forms that occur in the open sea. The results of the design of a wave generating media device measuring 3690x830x940 mm. From wave observations and calculations, it was found that the wavelength was 0.5m and the amplitude was 0.01m. It was concluded that the type of wave characteristic produced by this tool was categorized as an airy wave.

Characteristics of aerodynamic interference and flow phenomenology around inclined square prisms

This study conducts large eddy simulations (LES) to investigate the aerodynamic interference effects and flow field characteristics of the flow around square cylinders, taking into account the inclination of the disturbed structure. The configurations of the structures involve tandem and side-by-side arrangements with the inclination angles of the disturbed structure including +15°, 0°, and −15°. The identification of flow field characteristics involves the examination of multiple components, particularly time-averaged velocity streamlines, axial flow patterns, instantaneous spanwise vortices, and time-averaged wake vortex structures. The results indicate that the vortex structure features of the flow field are significantly influenced by the arrangement type and the inclination angle of the disturbed structure. In contrast to the tandem arrangement, structures arranged in the side-by-side arrangement undergo a considerably reduced intensity of influence from aerodynamic interference effects. The blocking effect of the tandem arrangement and the channel effect of the side-by-side arrangement are undermined when the inclination angle is positive (α > 0). This study enhances the comprehension of aerodynamic interference in inclined prisms and simultaneously establishes a theoretical foundation for the wind resistance design of building structures.

Quantification of differential axial shortening in reinforced concrete and concrete-filled steel-tube-based building structures

ABSTRACT This paper compares the axial shortening behaviors of reinforced concrete (RC) and concrete-filled tube (CFT) columns in high-rise building structures and proposes a relationship between the differential axial shortening and the dead load portion. This relationship can be used to determine the initial column sections in the preliminary design of building structures. Factors that can influence the differential axial shortening in columns were considered, and numerical analyses were conducted to compare the relative effectiveness of CFT columns. The time-dependent deformation of concrete was found to be the most significant influencing factor when compared with the flattening process of each floor level and construction sequence analysis. However, parametric studies demonstrate that axial shortening behavior can be ignored in buildings of fewer than 20 floors, and that it has a negligible effect even in taller buildings. Notably, the differential axial shortening effect can be excluded in the preliminary design stage when the dead load portion is less than 30% of the ultimate axial resistance. In the absence of design standards recommendations for reference values to minimize serviceability or damage problems in building structures, the proposed relation between the differential axial shortening and the dead load portion can be effectively used to determine initial column sections in the preliminary design of building structures.

Prediction of Failure Modes of Steel Tube-Reinforced Concrete Shear Walls Using Blending Fusion Model Based on Generative Adversarial Networks Data Augmentation

The steel tube-reinforced concrete (STRC) shear wall plays an important role in the seismic design of high-rise building structures. Due to the synergistic collaboration between steel tubes and concrete, they effectively enhance the ductility and energy dissipation capacity of conventional shear walls. To identify vulnerable areas prone to brittle failure and optimize the design, it is essential to develop a rapid method for identifying the failure mode of STRC shear walls. In this study, a fast identification method of STCR shear wall failure modes based on a Blending fusion model with Generative Adversarial Network (GAN) augmented data is proposed. The GAN is employed to address the issue of inadequate experimental data by generating new samples. This method combines classification boosting (Catboost), Random Forest (RF), K-Nearest Neighbors (KNN), and Least Absolute Shrinkage and Selection Operator (LASSO) to establish the Blending-CRKL fusion model to improve the prediction accuracy of the failure mode of STRC shear walls. The results reveal a significant improvement in the prediction performance of KNN, Backpropagation Neural Network (BPNN), RF, Light Gradient Boosting Machine (LightGBM), Catboost, and Blending-CRKL models after augmenting the training set with GAN. On average, the accuracy increased by 13%, precision increased by 81%, recall increased by 48%, and F1 score increased by 67%. The proposed Blending-CRKL fusion model outperforms the tested KNN, BPNN, RF, LightGBM, and Catboost models, achieving an accuracy rate of 97% in predicting the failure mode of STRC shear walls. Additionally, the stability and robustness of the Blending-CRKL model were validated, while the important features and value ranges of different failure modes were analyzed. This study provides a reference for the rapid identification of the failure mode of STRC shear walls.

Comparative study of seismic spectra of great magnitude occurred in Chile between 2012 to 2022 and the design spectra of seismic standard NCH433

In this document, a study of the spectra of large-magnitude seismic records that occurred in Chile between 2012 and 2022 is presented, comparing them with the design spectra of NCh433 and D. S 61. For this, seismic records greater than Mw = 6 have been used, with different depths to the hypocenter and with different types of soil. The catastrophes caused by earthquakes with magnitudes greater than Mw = 6 in the last decade in seismic zones (Turkey and Syria, 2023; Pakistan, 2013; Iran, 2014; Ecuador, 2016 or, Mexico, 2017; among others), have called into question the requirements structural aspects of earthquake-resistant standards in the world. That is why this work aims to demonstrate that highly seismic areas such as Chile, prone to having earthquakes with magnitudes greater than Mw = 6, have seismic-resistant regulations updated to the existing reality. The aim is to demonstrate whether the design spectra of the Standard have been sufficiently representative to determine the calculation accelerations used in the structural design of buildings. It is concluded that many of the spectral accelerations of the records that occurred in Chile exceed those of the design spectrum of the Standard, especially for short periods. Finally, in this research, new design spectra composed of 3 intervals (the 2nd interval is a plateau) are proposed that are more adjusted to the existing seismic reality in Chile during the last decade, considering the type of soil (A-D) existing in the Code (D.S 61).

Effects of displacement-pile construction and evaluations

The process of pilling construction (by hydraulic compression machines) causes lateral and vertical movement of surrounding soil. Adverse soil deformations can damage neighbor buildings and vicinity piles that have been constructed. The effects of pilling construction are usually omitted in structural design of buildings in practice. This paper presents a study of soil behavior around piles. Discussions on some methods of calculating soil movement during the pilling construction process are also provided.