Building Geometry Research Articles

RECONCILING CITY MODELS WITH BIM IN KNOWLEDGE GRAPHS: A FEASIBILITY STUDY OF DATA INTEGRATION FOR SOLAR ENERGY SIMULATION

Abstract. Solar energy simulations are used to quantify the potential of the passive use (daylight, solar gains) and the active use (photovoltaics and solar thermal) of solar energy. The simulations can be performed at different scales e.g. buildings, neighbourhoods and cities, with different requirements on the data. For example, for the neighbourhood simulations we need simplified building geometries that can be retrieved from city models, and window information that can be extracted from BIM models (as in many cases window information is missing in city models). In this context, city models and BIM need to be integrated and reconciled. In this paper, we investigate two approaches to integrate and retrieve such information in a case study, where the BIM data is stored in IFC and the city model in CityGML (LOD2). The first approach is to perform a schema matching in an ETL tool, so as to convert and import window information from the IFC file into the CityGML model to create a LOD2-3 building model. We also investigate an alternative avenue, namely a semantic web approach, in which both the BIM and city models are transformed into knowledge graphs (linked data). City models and BIM utilize their respective but interlinked domain ontologies. Particularly, two ontologies are investigated for BIM data, i.e., the ifcOWL ontology and the building topology ontology (BOT). This paper compares different paths of such integrative data retrieval, as well as discloses the gaps mainly with the semantic web approach to further unlock its potential.

Investigating build geometry characteristics during laser directed energy deposition based additive manufacturing

Laser directed energy deposition (LDED) is one of the metal additive manufacturing processes for fabricating complex shaped metallic components directly from a digital model using high power lasers and metallic powder. To fabricate components with minimum inaccuracies in build geometry and maximum build economy, optimization of process parameters is significant. In the present work, an experimental investigation is carried out to optimize LDED parameters (laser power, scanning speed, powder feed rate, rastering pattern, and build orientation) using an L9 orthogonal array as per the Taguchi design, by building an effective portion of cube geometry. The influence of input process parameters on build geometry and build economy is investigated, and grey relational (GR) analysis is carried out for multiobjective analysis. ANOVA shows that the most significant parameter influencing inaccuracy along the length, inaccuracy along the height, surface unevenness, and edge deviation error is build-orientation, while inaccuracy along the width, build time, and build fraction are largely influenced by laser energy per unit length. GR analysis shows that the build orientation is the most significant parameter. This study is important for considering build geometry and build economy during LDED.

ENERGY EMBODIED IN, AND TRANSMITTED THROUGH, WALLS OF DIFFERENT TYPES WHEN ACCOUNTING FOR THE DYNAMIC EFFECTS OF THERMAL MASS

ABSTRACT Embodied energy is a measure of the energy used in producing, transporting and assembling the materials for a building. Operational energy is the energy used to moderate the indoor environment to make it functional or comfortable—primarily, to heat or cool the building. For many building geometries, the walls make the most significant contribution to the embodied energy of the building, and they are also the path of greatest heat loss or gain through the fabric, as they often have a greater surface area than the roof or floor. Adding insulation reduces the heat flow through the wall, reducing the energy used during operation, but this adds to the embodied energy. The operational energy is not only a function of the wall buildup, but also depends on the climate, occupancy pattern, and heating strategy, making an optimisation for minimum overall energy use non-trivial. This study presents a comparison of typical wall construction types and heating strategies in a temperate maritime climate. The transient energy ratio method is a means to abstract the heat flow through the walls (operational energy for heating), allowing assessment of the influence of walls in isolation (i.e. in a general sense, without being restricted to particular building geometries). Three retrofit scenarios for a solid wall are considered. At very low U-values, overall energy use can increase as the embodied energy can exceed the operational energy; current best practice walls coupled with low building lifetimes mean that this point may be reached in the near future. Substantial uncertainty is present in existing embodied energy data, and given its contribution to total energy use, this is a topic of urgent concern.

MODELING OF EMERGENCY EVACUATION IN BUILDING FIRE

Abstract. One of the main problems of rescue workers in confrontation of fired complex buildings is the lack of sufficient information about the building indoor environment and their emergency exit ways. Building information modeling (BIM) is a database for building a 3D model of building information to create a 3D building geometry network model. This paper has implemented some GIS and BIM integration analyses to determine the shortest and safest paths to people under fire risk and simulate their movement in the building. Plasco building was a multi-story shop in Tehran which has been fired in 2017 and destroyed. This paper attempts to simulate the firefighting and rescue operations in Plasco Building using an integration of BIM and GIS. There is no detailed information about the building and the fire incident, therefore the developed BIM and corresponding geometric network might differ slightly. The shortest and safest paths to the exit door or windows where the fire ladders are located are computed and analyzed. As a result of 15 scenarios developed in this paper, it was found that at 87% of the cases, the safest paths for the emergency exit of the people at risk were longer than the shortest paths. This study has evaluated different scenarios for the shortest and safest paths using Dijkstra algorithm considering different origins and destination points in the 3D indoor environment to assist the rescue operations.

Visualized Co-Simulation of Adaptive Human Behavior and Dynamic Building Performance: An Agent-Based Model (ABM) and Artificial Intelligence (AI) Approach for Smart Architectural Design

Human (occupant) behavior has been a topic of active research in the study of architecture and energy. To integrate the work of architectural design with techniques of building performance simulation in the presence of responsive human behavior, this study proposes a computational framework that can visualize and evaluate space occupancy, energy use, and generative envelope design given a space outline. A design simulation platform based on the visual programming language (VPL) of Rhino Grasshopper (GH) and Python is presented so that users (architects) can monitor real-time occupant response to space morphology, environmental building operation, and the formal optimization of three-dimensional (3D) building space. For dynamic co-simulation, the Building Controls Virtual Test Bed, Energy Plus, and Radiance were interfaced, and the agent-based model (ABM) approach and Gaussian process (GP) were applied to represent agents’ self-learning adaptation, feedback, and impact on room temperature and illuminance. Hypothetical behavior scenarios of virtual agents with experimental building geometry were produced to validate the framework and its effectiveness in supporting dynamic simulation. The study’s findings show that building energy and temperature largely depend on ABMs and geometry configuration, which demonstrates the importance of coupled simulation in design decision-making.

LONG-SHORT SKIP CONNECTIONS IN DEEP NEURAL NETWORKS FOR DSM REFINEMENT

Abstract. Detailed digital surface models (DSMs) from space-borne sensors are the key to successful solutions for many remote sensing problems, like environmental disaster simulations, change detection in rural and urban areas, 3D urban modeling for city planning and management, etc. Traditional methodologies, e.g., stereo matching, used to generate photogrammetric DSMs from stereo imagery, usually deliver low-quality results due to the matching errors in homogeneous areas or the lack of information when observing the scene under different viewing angles. This makes the tasks related to building reconstruction very challenging since in most cases it is difficult to recognize the type of roofs, especially if overlaid with trees. This work represents a continuation of research regarding the automatic optimization of building geometries in photogrammetric DSMs with half-meter resolution and introduces an improved generative adversarial network (GAN) architecture which allows to reconstruct complete and detailed building structures without neglecting even low-rise urban constructions. The generative part of the network is constructed in a way that it simultaneously processes height and intensity information, and combines short and long skip connections within one architecture. To improve different aspects of the surface, several loss terms are used, the contributions of which are automatically balanced during training. The obtained results demonstrate that the proposed methodology can achieve two goals without any manual intervention: improve the roof surfaces by making them more planar and also recognize and optimize even small residential buildings which are hard to detect.

Building Geometry Simplification for Improving Mesh Quality of Numerical Analysis Model

Numerical analysis, especially the finite volume method (FVM), is one of the primary approaches employed when evaluating a building environment. A complicated geometry can degrade the mesh quality, leading to numerical diffusions and errors. Thus, this study develops and evaluates an automatic building geometry simplification method based on integrating similar surfaces for the geometry of an indoor space. A regression model showed that the complexity of the simplified geometry and its similarity to the original geometry decreased linearly with the threshold of the method. The mesh quality was significantly improved by the simplification. In particular, the maximum skewness decreased exponentially with the threshold of the method. It is expected that the simplification method and regression model presented in this study can be used to quantitatively control the mesh quality.

Synergising the thermal behaviour of water bodies within thermal environment of wetland settlements

The thermal characteristics of an area are influenced by the surrounding physical environment including land cover, land use, and urban geometry. The environment of wetland settlements is primarily influenced by the presence of water bodies. This study utilised land cover and urban geometry to characterise the thermal behaviour of the Ogan Permata Indah Jakabaring Palembang wetland settlement area. Data collected hourly during 72 h of field measurements included air temperature, relative humidity, globe temperature, and wind velocity. The cloud cover was qualitatively recorded. The land cover, urban geometry, and solar and wind orientations of the settlement were also investigated. Results showed that compared to the natural environment, the increase of air temperature during the day in built-up areas is about 2.5–7.4 °C which depends on the weather condition. Besides that, the openness of the area facilitated airflow, while roughness increased airflow turbulence, rendering more effective cooling. The role of the water body in delaying heat re-emission into the environment was more effective if the building geometry did not inhibit airflow. In this case, the role of the water body is to increase the surrounding air temperature by 1.2–1.6 °C at night, as stabilization of daily temperature. This study demonstrates that wetland settlement development policies should consider their unique thermal environment. Settlement development policies should be guided by form aspects, considering the role of the wind cooling effect, and by material aspects, considering the role of water thermal mass for delaying the re-emission of heat energy.

Assessment of surface parameters of VDW foundation piles using geodetic measurement techniques

Abstract This article presents in situ research on the side surface of Vor der Wand (VDW) foundation piles using 3D laser scanning and close-range photogrammetry to assess the morphology of pile concrete surface. Contemporary analytical methods for estimation of the bearing capacity of the foundation pile surface require determination of the parameters of the concrete roughness and the model of the surface being formed, which corresponds to the pile technology used. Acquiring these data is difficult due to the formation of piles in the ground and their subsequent work as a structure buried in the ground. The VDW pile technology is one of the widespread technologies of foundation pile used in practice. These piles exhibit a specific configuration of the lateral surface, which is related to the simultaneous use of auger drilling and casing that rotates in opposite directions. Two geodetic techniques most often used to measure the geometry of buildings are terrestrial laser scanning and close-range photogrammetry. To empirically verify the suitability of these two techniques for describing the VDW pile surface parameters, a two-stage field study was performed. In the first stage, the measurements of concrete test surfaces were conducted. This surface was formed in a smooth formwork and its roughness parameters (in accordance with ISO 25178-2: 2012) were calculated and compared with the reference surface. In the second stage, measurements of the secant VDW sheet pile wall protecting the deep excavation were carried out. The roughness parameters of the pile surface were calculated for the selected areas in diverse geotechnical conditions. The original procedure for processing data (obtained using the above techniques) for assessment of roughness parameters of unique concrete surfaces was presented. The conducted research demonstrates that a pulse scanner has very limited usefulness for determination of roughness parameters for very smooth concrete surface; however, the photogrammetry techniques give acceptable results. In regard to the VDW pile surface, the results obtained from both measurement techniques give satisfactory consistency of the roughness parameters. The relative errors of calculated roughness parameters do not exceed 29% (average 12%). The proposed procedure may improve the accuracy of the assumed friction factor between pile surface and soil for assessment of the pile shaft bearing capacity for various pile technologies and soil conditions.

Country-scale InSAR monitoring for settlement and uplift damage calculation in architectural heritage structures

The article proposes a methodology for assessing the development of damage in building structures, subjected to differential settlement and uplift, using the analysis of Interferometry Synthetic Aperture Radar (InSAR) data. The proposed methodology is targeted towards general applicability, capable of providing assessment results for measurements over wide geographic areas and for varying structural typologies. The methodology is not limited to ground movement measurements linked to tunnelling, as is the common case. Instead it extends to the monitoring of arbitrary movement in buildings, for example, due to ground consolidation, water table changes or excavation. The methodology is designed for use alongside patrimonial building databases, from which data on individual building geometry and typology are extracted on a region or country scale. Ground movement monitoring data are used for the calculation of the building deformation, expressed in different types of deformation parameters. The combined use of this data with analytical models for settlement damage classification in building structures enables the assessment in patrimonial building structures, at a country scale. The methodology is elaborated and applied on the patrimonial inventory of Belgium for the evaluation of potential settlement and uplift damage on buildings over a period of nearly three decades. The analysis results are compared to on-site observations.

Baureka.online - Research Repository, Catalogue and Archive for Architectural History and Building Archaeology

Building archaeology (Historische Bauforschung) is an internationally renowned methodology for investigating historic buildings in research, heritage preservation and planning. It is a hands-on process which documents the geometry, construction, materiality, usage, form, and meaning of buildings and makes it possible to trace the processes of their creation throughout the various layers of time embodied in their fabric. Despite the extensive use of digital tools within its workflows building archeology has not yet embraced the digital age as firmly as other disciplines. While the research community has long been interconnected via societies and conferences, there still is no digital platform for the overarching valorisation of scientific building documentations. Baureka.online , a research data repository, catalogue and archive for building archeology in the German speaking area, seeks to provide an innovative answer to this urgent desideratum .

Relative brightness of facades in the L-shaped urban buildings

Day lighting of premises under conditions of compacted urban development is depended of brightness of the finishing material of the facades of buildings of the surrounding buildings. Measure of influence of opposing buildings on the light regime of the premises is determined by relative brightness coefficient of facade, which is the ratio of the brightness of the facade to the average brightness of the sky. Derivation of the formula for coefficient of relative brightness of the facade in L-shaped urban buildings is presented. The derivation of the formula is based on the some components. The first component is the light transmission rate component on the facade of the designed building, which takes into account the reflection of daylight from an area of the earth’s surface. The second component is a coefficient, which takes into account the increase in the light transmission rate component on the facade of the projected building. This is due to the exchange of reflected light fluxes between the facades of the buildings and the land surface, which is adjoined to the buildings. Relative brightness coefficient values are calculated depending on the building geometry and the reflective properties of the facade finishing material.

Numerical simulations for laser clad beads with a variable side-to-side overlap condition

Metal additive manufacturing (AM) processes have unique challenges that need to be addressed before metal-based AM can become a reality, and in particular, an understanding of the thermal cycling and heat transfer characteristics. In this research, variable bead overlap conditions are simulated and compared to a set of experimental data configurations. Variable bead overlap conditions occur at boundary-fill interfaces and may be a tool path solution for regions that have voids. A comprehensive understanding of the consequences related to this scenario needs to be determined as the heat transfer influences the resultant build geometry, and the mechanical and physical characteristics. A three-dimensional (3D) transient uncoupled thermo-elastic–plastic model is generated using ANSYS to simulate the thermal process, hardness, and distortion for selected single- and multi-track laser cladding models. The melt pool geometry, distortion, and hardness results are presented, including a detailed time temperature and hardness analysis. Simulation models provide insight into regions that cannot be readily measured, but the processing time is long. It is recommended to explore scaling and trend analysis approaches or combine simulation and machine learning strategies to reduce the processing time.

Scan-to-graph: Semantic enrichment of existing building geometry

Building Information Modelling (BIM) has changed the way in which buildings are conceived, planned and executed. Apart from their frequent use for as-planned buildings, BIM authoring tools have now been adopted for a number of years for digitising existing buildings as well, mostly by performing a ‘scan-to-BIM’ process: the creation of a BIM model, primarily based on point clouds. However, some inherent characteristics of existing buildings are complicating such a process: uncertainties, geometric irregularities, classification of heritage building components, linking sources about the real-world asset and an interdisciplinarity that may go beyond traditional Architecture, Engineering and Construction (AEC) topics (e.g. heritage, Facility Management, sensor data and damage assessment). In this paper, a framework called ‘scan-to-graph’ (STG) is proposed to integrate the concepts of scan-to-BIM with Semantic Web technologies, as these could provide answers to the above-mentioned challenges, most notably on documentation of uncertainties, sources and modelling decisions, element classification and cross-discipline information linking. In order to test the STG concept, a use case was developed where the Audience Room of the Gravensteen castle in Ghent was reconstructed from point clouds, semantically enriched and stored as an RDF graph. The resulting graph contains multiple interlinked geometry types, metadata about the reconstruction process and the sources and allows to unambiguously refer to other contextual data on the Web.

Effect of build thickness and geometry on quasi-static and fatigue behavior of Ti-6Al-4V produced by Electron Beam Melting

The geometry and material properties of additively manufactured (AM) parts are closely related in a way that any alteration in geometry of the part will change the underlying manufacturing strategy. This in turn, affects the microstructure and consequently, the mechanical behavior of material. This paper aims to evaluate the effect of the AM part’s thickness and geometry on microstructure, surface roughness, and mechanical properties under quasi-static and fatigue loading conditions by performing experimental tests. A series of Ti-6Al-4V specimens with three different thicknesses and two different geometries were fabricated using electron beam melting (EBM). The results of microstructural analyses revealed that specimens with lower build thickness experience finer grain size, higher microhardness, and lower elongation at failure. Although the microstructure of the produced parts was strongly affected by the build thickness, different surface to volume ratios eliminated the effect of microstructural differences and governed the fatigue properties of the parts. The size effect on the microstructural features, geometrical appearance, mechanical properties of the AM parts should be considered for the design and failure analysis of complex structures.

A Linear Programming Method for Finding a Minimal Set of Axial Lines Representing an Entire Geometry of Building and Urban Layout

This paper devises an algorithm for finding the minimal set of axial lines that can represent a geometry of building and urban layout in two dimensions. Although axial lines are useful to analyze spatial configuration in the Space Syntax, existing methods for selecting axial lines seldom address the optimality of their solutions. The proposed algorithm uses linear programming to obtain a minimal set of axial lines. To minimize the number of axial lines that represent the entire geometry of building and urban layout, a linear programming problem is established in which a set of axial lines represents the entire geometry. The axial lines must have at least one intersection with every extension line of the wall edges to the sides of the reflex angles. If a solution to this linear programming problem exists, it will be guaranteed to be an optimum. However, some solutions of this general linear programming problem may include isolated lines, which are undesirable for an axial line analysis. To avoid isolated axial lines, this paper states a new formulation by adding a group of constraints to the original formulation. By examining the modified linear programming problem in various two-dimensional building maps and spatial layouts, this paper demonstrates that the proposed algorithm can guarantee a minimum set of axial lines to represent a two-dimensional geometry. This modified linear programming problem prevents isolated axial lines in the process of axial line reduction.

Water-energy nexus: A thermoeconomic analysis of polygeneration systems for small Mediterranean islands

This paper focuses on the energy-water nexus, aiming at developing novel systems producing simultaneously energy and water. This work investigates two solar polygeneration plants for the production of thermal and cooling energy, electricity, and desalinated water for two small Mediterranean islands. In this case, seawater and solar energy are largely available, whereas freshwater is scarce and extremely expensive. The work also aims to compare different technologies included in the polygeneration systems. In particular, the first plant is based on concentrating photovoltaic/thermal solar collectors, producing electric and thermal energy. The thermal energy is used to produce space heating, domestic hot water and space cooling by means a single-stage Lithium Bromide/Water absorption chiller. An electric auxiliary chiller is also included. A multi-effect distillation unit is included for freshwater production supplied by the concentrating photovoltaic/thermal collectors solar energy and an auxiliary biomass-fired heater. In the second plant, a photovoltaic field is coupled with electric driven technologies, such as heat pumps for space heating, cooling and domestic hot water production and a reverse osmosis unit. The solar electrical energy excess is delivered to the grid. The third polygeneration plant includes the same components as the first layout but it is equipped with a reverse osmosis unit. Two main case studies, Favignana and Salina islands (South Italy) are selected. The heating, cooling and electric hourly loads of some buildings located in both investigated weather zones are calculated in detail. In particular, space heating and cooling loads are calculated by means of the Type 56 of TRNSYS (version 17), coupled to the Google SketchUp TRNSYS3d plug-in. The buildings geometry, envelope, windows, lighting, machineries heat gains schedule, as well as the buildings users’ occupation and activity are simulated by means of the Type 56. TRNSYS is also used to accurately model all of the plant components. The work also includes comprehensive energy, environmental and economic analyses to maximize the plants profitability, evaluated by considering both operating and capital costs. Sensitivity analyses aiming at establishing the optimal values of the most important design parameters are also performed. The developed plants achieve important savings in terms of carbon dioxide emissions due to the use of renewable energy sources and the high efficiency of the included technologies. The best economic indexes are obtained for the layout using electricity-driven technologies, resulting in very profitable operation with a payback period of about 6.2 years.

Energy efficiency in small districts: Dynamic simulation and technoeconomic analysis

In European Union Countries, local authorities have developed their own Sustainable Energy Action Plan aiming at planning the urban strategies to achieve the European Union and national 2020 energy targets. This document is used for detecting and deploying the energy measures which each municipality should adopt in order to reduce the environmental impact of the municipality activities. Further efforts are expected to define the strategies for achieving 2050 goals. In this framework, this work deals with the dynamic estimation energy saving actions for small districts located in different Italian weather zones (Naples and Turin, located in South and North Italy, respectively). The data of the Sustainable Energy Action Plan were used to develop suitable dynamic models, implemented in TRNSYS environment, including different buildings of selected districts. In particular, all the buildings were modelled by means of the Type 56 of TRNSYS, coupled to the Google SketchUp TRNSYS3d plug-in. By means of Type 56, it is possible to take into account and simulate the buildings geometry, envelope, windows, lighting, machineries heat gains schedule as well as the buildings users’ occupation and activity. Given the loads, several energy efficient renovation alternatives based on the adoption of air-to-air conventional and carbon dioxide heat pumps, evacuated thermal collectors and photovoltaic panels, as well as the envelope renovation of all the public and private buildings of the district, are proposed and compared. Results, obtained by detailed dynamic energy and environmental analyses, can be used as guidelines for the local authorities to implement suitable energy efficiency actions of existing buildings in order to reduce both the thermal energy and carbon dioxide emissions due to the building space heating/cooling, domestic hot water and electricity. The proposed renewable layout for Naples case study achieves a primary energy savings of 58% with a payback period of 4 years. The renewable layout for Turin case study achieves a primary energy savings of 76% with a payback period of 10.6 years.

Registro y parametrización antropométrica del patrimonio arquitectónico: el Corral del Carbón de Granada

Se registra la geometría del edificio medieval del Corral del Carbón de Granada para posteriormente proceder al análisis metrológico y parametrización de sus dimensiones. El levantamiento se ha realizado mediante escáner láser 3D complementado con modelos fotogramétricos. Se adopta la premisa metrológica de que toda medida se compone con lados y diagonales de cuadrado antropométrico, lo que permite reconstruir las aparentes trazas del edificio. Se trata de una cuadrícula casi regular con el módulo de métrica Nazarí 2 de 182 cm como patrón cuadrado repetitivo, pero que adopta composiciones dinámicas en distintos elementos. Sorprende la curvatura de las galerías, y se detectan partes añadidas con distinta métrica. Los resultados animan a implantar los estudios antropométricos del patrimonio como fase de investigación histórica inmediatamente posterior al registro de su geometría, y previa a la modelización eBIM.

Developing Reference Building for Campus Type Buildings in Universitas Gadjah Mada

The building sector has been the highest consumer in the total energy consumption in Indonesia, in which the building sector shared 39% of the national energy consumption. A university is a campus that consists of the landscapes and buildings with many kinds of academic and social activities that creates a type of energy consumption profile. This paper aims to demonstrate the importance of having a complete and reliable audit data of a university to develop reference building for campuses. The reference building serves as a building benchmark model for energy consumption, for 20 faculties in Universitas Gadjah Mada (UGM) with more than 200 buildings. The energy consumption model of the buildings is developed using the CLTD/SCL/CLF calculation method. Data of the building geometry, building envelope, and building profile are using data collected from a green campus assessment tools (GreenmetricUI) by walkthrough audit. The research compared the energy profile obtained from the audit data and the model calculated. It is shown that the energy profile model from the CLTD/SCL/CLF method is generally higher than the reported energy consumptions from electricity bills. It can be concluded that the main success in developing a reference building is by having a reliable audit data and a complete record of the electricity bills to validate the model. Once the energy profile obtained from the CLTD/SCL/CLF modeling is available, the data can be used for modelling reference building using energy model software.