Search Results (57)

A steel modular building is a highly prefabricated form of steel construction. It offers rapid assembly, a high degree of industrialization, and an environmentally friendly construction site. To promote the application of multi-story steel modular buildings in earthquake fortification zones, it is imperative to conduct in-depth research on their seismic behavior. In this study, a seven-story modular steel building is investigated using shaking table tests. Three seismic waves (artificial ground motion, Tohoku wave, and Tianjin wave) are selected and scaled to four intensity levels (PGA = 0.035 g, 0.1 g, 0.22 g, 0.31 g). It is found that no residual deformation of the structure is observed after tests, and its stiffness degradation ratio is 7.65%. The largest strains observed during the tests are 540 × 10⁻⁶ in beams, 1538 × 10⁻⁶ in columns, and 669 × 10⁻⁶ in joint regions, all remaining below a threshold value of 1690 × 10⁻⁶. Amplitudes and frequency characteristics of the acceleration responses are significantly affected by the characteristics of the seismic waves. However, the acceleration responses at higher floors are predominantly governed by the structure’s low-order modes (first-mode and second-mode), with the corresponding spectra containing only a single peak. When the predominant frequency of the input ground motion is close to the fundamental natural frequency of the modular steel structure, the acceleration responses will be significantly amplified. Overall, the structure demonstrates favorable seismic resistance. Full article

With the development of autonomous driving technology, the application scenarios for mobile robots and unmanned vehicles are gradually expanding from simple structured environments to complex unstructured scenes. In unstructured three-dimensional spaces such as urban environments, traditional two-dimensional map construction and path planning techniques struggle to effectively plan accurate paths. To address this, this paper proposes a method of constructing a map and planning a route based on three-dimensional spatial representation. This method utilizes point cloud semantic segmentation to extract navigable space information from environmental point cloud data and employs voxelization techniques to generate a voxel map. Building on this, the paper combines a variable search neighborhood A* algorithm with a road-edge-detection-based path adjustment to generate optimal paths between two points on the map, ensuring that the paths are both short and capable of effectively avoiding obstacles. Our experimental results in multi-story parking garages show that the proposed method effectively avoids narrow areas that are difficult for vehicles to pass through, increasing the average edge distance of the path by 83.3% and significantly enhancing path safety and feasibility. Full article

Precast structures are widely used in many parts of the world. This construction technique is more commonly preferred for low-rise industrial buildings than multi-story structures. The most commonly used column–beam connection in precast buildings is the dowel connection (DC). Past earthquakes in various parts of the world have shown that these connections do not provide sufficient resistance. The main deficiencies of such connections are that they are sheared or stripped due to the shear force demand from the in-plane effects of large earthquakes, and that they do not provide sufficient resistance to the overturning moments from the out-of-plane effects of the earthquakes. Correspondingly, many prefabricated buildings have collapsed during earthquakes, causing loss of life and property. This study proposes using post-tensioning tendon (PT) systems and systems created by adding steel springs (PTS) to eliminate the weaknesses in column–beam connections in precast structures. To this end, real-sized column and beam specimens used in precast buildings were produced, and experiments were conducted under the cyclic loads defined by the American Concrete Institute (ACI) Committee, Report 374, simulating earthquake effects for three different connection types (DC, PT, and PTS). It was observed that the proposed PTS connection type dissipated approximately one-third of the energy transferred to the joint through elastic deformation in the springs, compared to the DC and PT connection types. This indicates that the PTS specimens transferred significantly less energy to the column–beam connection region. Consequently, the PTS system exhibited much less damage in the column foundation and especially the column–beam connection areas than other test specimens. In conclusion, it can be stated that the use of the PTS connection type in prefabricated structures has high potential to reduce damages due to dynamic loads such as earthquakes. Full article

Semi-Interlocking Masonry (SIM) represents an innovative building system developed at the Centre for Infrastructure Performance and Reliability at the University of Newcastle, Australia. This system employs a unique approach to interlocking mortar-less engineered masonry panels constructed from SIM units. These units are designed to offer substantial energy dissipation capacity, primarily attributed to the friction occurring on the sliding bed joints between the units within the panel during seismic events. The primary aim of this study is to evaluate the viability of incorporating semi-interlocking masonry as infill panels in the construction of multi-story buildings across diverse geographical locations with varying seismic conditions in Australia. To assess the feasibility of SIM panels in different conditions (according to Australian Standard AS1170) in Australia, a comprehensive analysis using Strand7 R3.1.4 is conducted on a three-story structure incorporating traditional masonry infill panels and SIM panels. Displacement and base shear capacities are compared in response to seismic events across various scenarios in different locations within Australia. The insights gained from this comparative analysis contribute valuable information regarding the viability of implementing SIM as a contemporary construction material. Full article

The construction industry is embracing digital technologies, particularly generative or algorithm-aided design principles. However, integrating these digital tools into design processes while ensuring compliance with rules and regulations remains a significant challenge. This study aims to address this challenge by identifying the essential design parameters and constraints required for semi-automated building model design in the early design stages, with a specific focus on a use case of modular multi-story housing in Vienna. To achieve this, we investigate which parameters are fundamental, how constraints must be formulated, and how these aspects can be covered effectively in the design process. Our research provides a parameter catalog in natural language format to be used for scripting algorithms to generate parametric models. We delineate crucial housing-specific design parameters and identify constraints derived from legal, technical, evaluative, and expert knowledge sources. These constraints ensure that the designs comply with regulations and standards. The findings are organized into eight thematic clusters, each detailing specific conditions, and their interdependencies, thus offering a guideline for scripting algorithm-aided design processes. In conclusion, we propose a conceptual model for translating natural language design parameters into visual programming language. Full article

Unlike in Western countries, land ownership in China is overwhelmingly vested in the state, and individuals cannot directly own private lands and build houses. Therefore, developers will contract the land to the government and build it into collective apartments. Against this backdrop, a different kind of multi-story, high-density self-built residential buildings is widespread in small towns along the southeast coast of China. These buildings were built between 1980 and 2000 by residents who acquired land-use rights from the government for compensation. The uniqueness of these buildings is what makes them incompatible with the most mainstream, government-led urban renewal model in China, resulting in a large area of dilapidated and aging areas. Zherong County, Ningde, Fujian Province, is a typical example town, with a large number of such self-built houses, known locally as Liu Houses. In this study, these residential areas were selected as typical research objects of “characteristics of residential small towns”. Combined with the property rights of the sample cases, the methods of diagram and quantitative analysis are used to summarize the causes of the three types of residential areas from the aspects of regional planning, land division, building construction, and renovation. In the early days, the planning of the Liu House was greatly influenced by the residents, and the construction and renovation of the building was led by the residents, which strengthened the diversity of the style. In the middle period, the government had relatively dominant control over the planning of Liu Houses, and supervision was conducted during the construction and renovation process, resulting in a relatively balanced power between residents and the government. In the later period, the houses were built and operated by the developer, and the residents no longer directly participated in the construction and renovation, so the unity of style was strengthened. At the same time, the study finds that, in the process of the formation of the style of the residential area, on the one hand, the property rights directly affect the style through its own physical land attributes, and on the other hand, it becomes the basis of the game between the government, residents, and the county environment through its own property rights, thus indirectly affecting the style. In conclusion, this paper may provide theoretical support and design reference for the renewal of the characteristic features of residential small towns. Full article

As the largest contributor of carbon emissions in China, the building sector currently relies mostly on enterprises’ own efforts to report carbon emissions, which usually results in challenges related to information transparency and workload for regulatory bodies, who play an otherwise vital role in controlling the building sector’s carbon footprint. In this study, we established a novel regulatory model known as QCEPM (Quantitative Carbon Emission Prediction Model) by conducting multiple linear regression analysis using the quantities of concrete, rebar, and masonry structures as independent variables and the embodied carbon emissions of a building as the dependent variable. We processed the data in the detailed quantity list of 20 multi-story frame structure buildings and fed them to the QCEPM for the solution. Comparison of the QCEPM-calculated results against the time-consuming and error-prone manual calculation results suggested a mean absolute percentage error (MAPE) of 2.36%. Using this simplified model, regulatory bodies can efficiently supervise the embodied carbon emissions in multi-story frame structures by setting up a carbon quota for a project in its approval stage, allowing the construction enterprise to carry out dynamic control over the three most important audited building materials throughout a project’s planning and implementation phase. Full article

The block-scale application of photovoltaic technology in cities is becoming a viable solution for renewable energy utilization. The rapid urbanization process has provided urban buildings with a colossal development potential for solar energy in China, especially in industrial areas that provide more space for the integration of PV equipment. In developing solar energy resources, the block layout and the PV materials are two critical factors affecting the distribution of solar radiation and generation. However, few studies have analyzed how to select the most suitable PV materials for different layouts of industrial blocks to obtain the best generation. This study considered the layout of industrial blocks and PV materials simultaneously, and the generation yield was calculated when combined. A total of 40 real industrial block cases were constructed, and radiation distribution data on building surfaces of different block cases were calculated. Data on both were combined to calculate the generation of different PV materials for each block type. The findings indicated that single-story industrial blocks possessed the highest potential for solar radiation, primarily due to the higher percentage of roof area. The influence of PV materials on the installation rate of different building facades varied, with the installation rate of the west facade being the most impacted by PV performance and the roof being the least impacted. Using different PV materials in industrial blocks could lead to a 59.2% difference in solar generation capacity. For single-layer industrial blocks, mono crystalline and poly crystalline silicon were preferable to achieve higher power generation. In contrast, multi-story and high-rise industrial blocks were best suited for a-Si and CIGS to attain higher cost performance. The methods and results of this study guided the selection and installation of PV equipment in various block typologies, thereby improving the refinement of solar resource development, maximizing solar resource utilization, and promoting the development of energy conservation and carbon reduction in cities. Full article

To date, the existing literature lacks any studies that compare timber and concrete apartment buildings in the Finnish context regarding their carbon footprint, handprint, and the cost of frame structures. This study rigorously analyzes and calculates the carbon footprint, carbon handprint, and costs associated with various structural solutions in a proposed multi-story building located in Laajasalo, Helsinki, Finland. While the primary focus is on wooden frame construction, exploring both its challenges and opportunities, this study also includes a comparative assessment with concrete frame construction. In Finland, regulations require a sprinkler fire extinguishing system to be installed inside. Also, weather protection is typically added to the top of building in connection with the construction of wooden apartment buildings. When the costs of a sprinkler system and weather protection are taken into account, the cost of achieving positive climate effects through a concrete frame is 290% higher than that of a solid wood frame. Our findings will provide a robust basis for assessing the sustainability and feasibility of construction methods, offering valuable insights into environmental and economic considerations for decision-makers in Finland and beyond as regulations evolve and awareness of climate impacts grows. Full article

In the Changxi River Basin in eastern Fujian, a few stone elements remain and Buddhist buildings with one bay in width and three bays in depth have been preserved dating from the timespan of the Tang to the Song dynasty. These features are characterized by a regional form of early Buddhist architecture seldom seen in Chinese history. The article focuses on the reconstruction of a Song dynasty Buddhist building at the Gonghoulou Temple site in Huotong Town, Jiaocheng District, Ningde City, and aims to analyze the potential characteristics and rules of single-bay Buddhist architecture. From the styles of the remaining stone columns, the direction of the lotus carving at the column base, and the mortises of the plinth stone, a spatial arrangement is indicated that includes an open front corridor and a closed rear section. A “reconstruction” of the ruler used in the original building reveals the possibility that a local Fujian ruler was used, shorter than the standard measurement device employed elsewhere. The analysis of the frame construction indicates that this hip-gable roof-covered Buddhist hall utilizes the horizontally layered logic of multi-storied palatial-style halls. Key elements include its gentle roof slope, restraint from the practice of shortening the roof ridge, use of the traditional chuji method, and the interior columns use of internal longitudinal architraves secured to beam supporting brackets. This research brings to light a unique architectural type that has disappeared in the course of history and was previously unknown to the academic community. It holds significant importance and value for deepening the understanding of the history of timber frame architecture technology in Fujian. Full article

In recent years, the use of timber as a building material in larger construction applications such as multi-story buildings and bridges has increased. This requires a better understanding of the material to realize such constructions and design them more economically. However, accurate computational simulations of timber structures are challenging due to the complexity and inhomogeneity of this naturally grown material. It exhibits growth inhomogeneities such as knots and fiber deviations, orthotropic material behavior and moisture dependence of almost all physical parameters. Describing the creep response of wood under real climate conditions is particularly difficult. Changes in moisture content, plasticity and viscoelasticity affect moisture-induced stresses and potentially lead to cracks and structural damage. In this paper, we apply a material model that combines time and moisture-dependent behavior with multisurface plasticity to simulate cross-sections of different dimensions over a 14-month climate period. Our findings indicate that considering this long-term behavior has a minor impact on moisture-induced stresses during the drying period. However, during the wetting period, neglecting the time- and moisture-dependent material behavior of wood leads to a significant overestimation of tensile stresses within the cross-section, resulting in unrealistic predictions of wetting-induced fracture. Therefore, simulations during wetting periods require a sophisticated rheological model to properly reproduce the stress field. Full article

As the modular industry expands, the most widely used building materials are primarily concrete, steel, and wood. However, the use of wood and steel is severely limited compared to concrete for reasons such as durability and economy. To overcome these shortcomings, we aimed to apply ultra-high-performance fiber-reinforced concrete (UHPFRC), which has excellent compressive strength and tensile strength, high durability, and minimal reinforcement with steel fibers. In this study, research was conducted on the development of unit box-type architectural modules using UHPFRC with a compressive strength of 120 MPa and a tensile strength of greater than 7 MPa. Various amounts of steel fibers (Vf = 1.0, 1.5, and 2.0%) were evaluated to determine the optimal mixing ratio of UHPFRC, in which both the durability and mechanical performance were assessed. The compressive strength and tensile strength of UHPFRC were found to be 132 MPa and 10.1 MPa, respectively, while its resistance to chloride penetration averaged 14.47 coulombs, indicating superior durability compared to conventional concrete. To reduce the weight of the unit components of the architectural modular system, both normal concrete (NC) components and UHPFRC were applied. The main variables in the flexural tests were the cross-sectional thickness, steel fiber content, and presence of an insulation material, comprising a total of three variables for evaluating the flexural performance. The application of UHPFRC with a compressive strength of 120 MPa, a cross-sectional thickness of 120 mm, and a 10 mm diameter reinforcement provided a similar performance to that of NC components while reducing concrete usage by 60% compared to NC components. Additionally, structural analysis was performed to prototype the unit box-type modular structure using UHPFRC. The modular structural system developed in this study was found to reduce construction costs by 18.7% compared to traditional steel structural systems. Further research is necessary to address issues such as floor slab vibration and noise, connections, and expansion to multistory buildings for commercialization of modular structures using UHPFRC. Full article

Driven by climate change and the need for a more sustainable construction sector, policy is increasingly demanding and promoting timber hybrid construction methods. In the German state of Baden-Württemberg, every new public building has to be of timber or timber hybrid construction (Holzbauoffensive BW). The objective of multi-story buildings with large floor spans can only be achieved in a resource-efficient way by hybrid constructions combining timber and steel components. A research project recently completed at the Karlsruhe Institute of Technology was aimed at the development and systematic investigation of hybrid bending beams in which an advantageous combination of the materials steel and timber is used. For this purpose, steel profiles are integrated into timber cross-sections in a shear-resistant manner by adhesive bonding. As part of the experimental, numerical and analytical investigations, different cross-sections of steel and timber, as well as different construction materials, were considered (GL24h, LVL48p, LVL80p, S355 and S420). The results of large-scale four-point bending tests illustrate the potential of this new hybrid construction method. Depending on the geometry and material combinations tested, the bending stiffness could be increased by up to 250%, and the load-carrying capacity by up to 120%, compared to a glulam beam with identical dimensions. Full article

This study explores the potential use of new connections to shape precast building geometries, focusing on connection performance, robotic fabrication, and foldable structural elements. Three connection types, including coupled-bolts, hinges, and steel tubes, were initially proposed and assessed in beam and portal frame geometries. In contrast, the study introduces conceptual ideas; initial experimental and numerical studies were conducted to estimate connection capacities. Robotic fabrication for connecting elements to reused concrete and converting floor elements into beams was detailed, showcasing robotic technology’s performance and potential. These connections were employed in designing new precast element geometries, ranging from simple beams to multi-story buildings. Geometric properties and volume quantities of folded and opened geometries were studied using 37 CAD models. To properly discuss the joint performance reference, monolithic elements with exact dimensions were created for comparison. Despite varied connection capacity ($38\%$ to $100\%$), the steel tube exhibited the most desirable performance, resembling a monolithic element with an exact size. Some proposed foldable geometries showed a significant reduction (up to $7\%$) in element dimensions to facilitate transport and construction. Full article

The article presents ways of selecting effective designs and technological and organizational solutions for the bonded thermal insulation systems of complex-shaped facades based on thermal field and flow modeling using the SolidWorks Simulation Xpress 2021 software and experimental–statistical modeling using the Compex program. Determining optimal insulation parameters at the design stage will help eliminate the negative effects of thermal bridges at balcony junctions and reduce the cost of implementing bonded thermal insulation systems for facades with complex shapes. It has been established that the most effective approach is to insulate not the entire perimeter of the balcony slab, as required by normative documentation, but rather to insulate a sufficient portion of the exterior wall, which is equal to 750 mm, with a 30 mm insulation thickness on top of the slab and 50 mm beneath it. This insulation technology is economically feasible for modern multistory buildings with nonstandard volumetric and architectural solutions, constructed using frame–brick, frame–monolithic, or monolithic schemes without thermal breaks between the balcony slab and the monolithic floor slab, with open-type balconies, bays, or uncovered loggias. Full article