Computational derivation of irradiance on building surfaces: An empirically-based model comparison

Performance simulation applications require reliable information regarding the intensity of solar irradiance on arbitrarily oriented building surfaces in order to properly predict buildings' energy use or to configure building-integrated solar energy systems. Since measured irradiance databases typically include only horizontal irradiance values, solar radiation intensity on inclined surfaces must be computationally derived. In this context, the present paper compares six options to derive, from horizontal irradiance data, solar radiation intensity levels on inclined surfaces. To evaluate these options, simulated downward vertical irradiance on four orientations were compared with measurements obtained in Austria. Two options that use both global and diffuse horizontal irradiance values for sky radiance generation delivered slightly better results than the others, which require only global horizontal irradiance. However, the range of errors was rather high for all options. Even for the best-ranked option, no more than 64% of the results had a relative error of less than ±20%.     

Dynamic structure response excited by technical seismicity effects

The subject of the solution consists in the design and evaluation of vibro-isolation of the multifunctional reinforced concrete frame structure of a building over the tunnel metro structure, based on analysing its 3D calculation model. Measured vibrations in accelerations from passing metro trains were used as non-periodic excitation of the object on the level of its foundation slab. Results of the dynamic calculation are used to document the nature of the building structure response, and of the reduction/amplification of the vibrations at selected points of individual storeys during the pass of metro trains, including the frequency characteristics of the response. The comparison of the building response without and with vibro-isolation is used to demonstrate the efficiency of using a rubber layer in the footing bottom for reducing the transfer of vibrations from the metro to the building. Measurement of the vibrations when the construction had been finished allowed to compare the vibration prognosis to vibrations actually measured in the finished structure.     

Response of framed buildings to excavation-induced movements

This paper presents a study of the influence of frame action on the response of buildings to deformations induced by deep excavations in soft clay. Using the finite element method, a building was modelled as a framed structure adjacent to a multi-propped excavation, firstly as a frame with continuous footings and then as a frame with individual footings. The geometry, location, and structural elements forming the frame models were varied to investigate the response of various frames. Using a structural analysis, parameters representing the stiffness of the frames in reducing deflection ratios and horizontal strains were derived. The influence of the frame action on the building stiffness can be quantified using the results from the finite element models. This makes it possible to estimate building modification factors from the relevant design charts so that induced deflection ratios and horizontal strains, caused by adjacent excavation and tunnelling activities, can be calculated. The approach gives a more realistic estimate of the tensile strains for assessing the potential damage caused to buildings.     

A Quantitative Study of the Relationship between Project Performance and BIM Use on Commercial Construction Projects in the USA

This article reports the findings of a quantitative study on the relationship between various project performance outcomes and the use of Building Information Modeling (BIM), within the commercial construction industry. The literature review identified inconsistent results among prior qualitative and quantitative work concerning the relationships of key project performance measures and BIM use. Data on 13 variables from 93 completed construction projects were collected and examined through a causal comparative research design. Projects that used BIM (in design or construction) were not found to experience significant performance outcomes when controlling for the contribution of other independent variables and covariates at the 95% confidence level (CL). At the lower 90% CL, however, projects using BIM in construction experienced significantly higher levels of schedule growth than projects that did not use BIM in construction. Recommendations are made for training of construction management staff as a step to avoid unwanted schedule growth associated with BIM use during construction. This study is one of a very small group of rigorous quantitative analyses of BIM project performance outcomes conducted to date; additionally, it is the only study that has analyzed BIM in a multivariate context that controlled for the contribution of other project variables not directly related to BIM use.     

Extended Process to Product Modeling (xPPM) for integrated and seamless IDM and MVD development

This paper proposes a new extended Process to Product Modeling (xPPM) method for integrated and seamless information delivery manual (IDM) and model view definition (MVD) development. Current IDM development typically uses Business Process Modeling Notation (BPMN) to represent a process map (PM). Exchange requirements (ERs) and functional parts (FPs) specify the information required when information is exchanged between different activities. A set of information requirements, specifically defined as a subset of Industry Foundation Classes (IFC), is called an MVD. Currently however, PMs, ERs, FPs, and MVDs are developed as separate documents through independent development steps. Moreover, even though ERs and FPs are designed to be reused, tracking and reusing the ERs and FPs developed by others is practically impossible. The xPPM method is proposed to provide a tight connection between PMs, ERs, FPs, and MVDs and to improve the reusability of predefined ERs and FPs. The theoretical framework is based on the approach of the Georgia Tech Process to Product Modeling (GTPPM) to suit the IDM development process. An xPPM tool is developed, and the validity of xPPM is analyzed through the reproduction of existing IDMs and MVDs. The benefits and limitations of xPPM and lessons from the applicability tests are discussed.     

Performance based earthquake evaluation of reinforced concrete buildings using design of experiments

Seismic resiliency of new buildings has improved over the years due to enhancements in seismic codes and design practices. However, existing buildings designed and built under earlier codes are vulnerable and require a performance-based screening and retrofit prioritization. The performance modifiers considered are soft story, weak story, and the quality of construction, which are collated through a walk down survey. The building evaluation is performed through a pushover analysis, and performance objective are obtained through initial stiffness of the pushover curve. Using a design of experiments technique, a reliable system input-output relation has been identified and used to evaluate the performance criteria at untried design points (i.e., buildings with different modifier values). The proposed method of performance based evaluation is illustrated through consideration of the different structural deficiencies on a typical six-storey reinforced concrete building in Vancouver. Through the designed experiments, the main and interaction effects of the performance modifiers have also been studied.     

State of research in automatic as-built modelling

Building Information Models (BIMs) are becoming the official standard in the construction industry for encoding, reusing, and exchanging information about structural assets. Automatically generating such representations for existing assets stirs up the interest of various industrial, academic, and governmental parties, as it is expected to have a high economic impact. The purpose of this paper is to provide a general overview of the as-built modelling process, with focus on the geometric modelling side. Relevant works from the Computer Vision, Geometry Processing, and Civil Engineering communities are presented and compared in terms of their potential to lead to automatic as-built modelling.     

A strategy for reducing CO2 emissions from buildings with the Kaya identity – A Swiss energy system analysis and a case study

Within the general context of Greenhouse Gas (GHG) emissions reduction, decomposition analysis allows the quantification of the contribution of different factors to changes in emissions as well as the assessment of the effectiveness of policy and technology measures. The Kaya identity has been widely used for that purpose in order to disaggregate carbon emissions into various driving forces. In this paper, it is applied for the analysis of emissions resulting from energy use at three different scales. First, a decomposition analysis of the carbon emissions for the complete Swiss energy system is presented using the future projections from the Swiss Energy Strategy 2050. The Kaya identity is then applied to the Swiss building sector after it is adapted with factors that are more relatable to building parameters, such as floor area instead of Gross Domestic Product (GDP). Finally, the last level of analysis is a small scale community energy system for a unique Swiss village that aims to significantly reduce its emissions. An energy strategy is developed and its effectiveness is assessed with the adapted Kaya identity and benchmarked against the Swiss average values. The presented method demonstrates how the performance of buildings under various retrofitting scenarios can be benchmarked against future emission targets.     

视域融合下的建筑改扩建探析

理解是一种视域融合。在伽达默尔看来,作为理解条件之一的视域融合,就是不同的视域相互结合的状态。该文试图通过现代解释学的视域融合理论来探讨建筑的改扩建,希望从中为我们提供一个新的思考问题的方法,也为我们更好地开展建筑改扩建实践提供新的理论基础。