Logic for ensuring the data exchange integrity of building information models

Industry domains require distinct data and structures of building information models developed and tailored for their disciplines. To seamlessly exchange the building information models, Industry Foundation Classes (IFC), which is one of neutral formats, has been broadly used in the architecture, engineering and construction, and facility management industries. Model view definition (MVD), which is one of the IFC sub-schemas used by domain experts and BIM software vendors, consists of IFC-mapped data exchange requirements of each domain and helps software vendors develop IFC import and export features that allow project participants share and exchange BIM model information. Because of the heterogeneous translation processes and structures of IFC interfaces according to model views, their validation is imperative to ensure the integrity of BIM data and maintain a consistent data exchange environment. To accomplish this objective, this paper suggests the new approach to evaluating BIM data in accordance with diverse requirements of MVD. Since MVD entails various types of data exchange specifications, this research study examines their embedded checking rule types and categorizes corresponding implementation scenarios. In addition, this paper involves rule logic and IfcDoc-based BIM data validation developed based on the logical rule compositions of identified rules types and checking scenarios. This approach is expected to support sharing consistent BIM data sets and confirming the quality of received data pertaining to a syntax and semantics of a targeted model view.     

Logic for ensuring the data exchange integrity of building information models

Industry domains require distinct data and structures of building information models developed and tailored for their disciplines. To seamlessly exchange the building information models, Industry Foundation Classes (IFC), which is one of neutral formats, has been broadly used the architecture, engineering and construction, and facility management industries. Model views definitions (MVD), which is one of the IFC sub-schemas used by domain experts and BIM software vendors, consists of IFC-mapped data exchange requirements of each domain and helps software vendors develop IFC import and export features that allow project participants share and exchange BIM information. Because of the heterogeneous translation processes and structures of IFC interfaces according to model views, their validation is imperative to ensure the integrity of BIM data and maintain a consistent data exchange environment. To accomplish this objective, this paper suggests a new approach to evaluating BIM data in accordance with diverse requirements of MVD. Since MVD entails various types of data exchange specifications, this research examines their embedded checking rule types and categorizes corresponding implementation scenarios. In addition, this paper involves rule logic and IfcDoc-based BIM data validation developed based on the logical rule compositions of identified rules types and checking scenarios. This approach is expected to support sharing consistent BIM data sets and confirming the quality of received data pertaining to the syntax and semantics of a targeted model view.     

Mapping between BIM and 3D GIS in different levels of detail using schema mediation and instance comparison

The Building Information Modeling (BIM) domain and the Geographic Information System (GIS) domain share a mutual need for information from each other. Information from GIS can facilitate BIM applications such as site selection and onsite material layout, while BIM models could help generate detailed models in GIS and achieve better utility management. The mapping between the key schemas in the BIM domain and the GIS domain is the most critical step towards interoperability between the two domains. In this study, Industry Foundation Classes (IFC) and City Geography Markup Language (CityGML) were chosen as the key schemas due to their wide applications in the BIM domain and the GIS domain, respectively. We used an instance-based method to generate the mapping rules between IFC and CityGML based on the inspection of entities representing the same component in the same model. It ensures accurate mapping between the two schemas. The transformation of coordinate systems and geometry are two major issues addressed in the instance-based method. Considering the difference in schema structure and information richness between the two schemas, a reference ontology called Semantic City Model was developed and an instance-based method was adopted. The Semantic City Model captures all the relevant information from BIM models and GIS models during the mapping process. Since CityGML is defined in five levels of detail (LoD), the harmonization among LoDs in CityGML was also developed in order to complete the mapping. The test results show that the developed framework can achieve automatic data mapping between IFC and CityGML in different LoDs. Furthermore, the developed Semantic City Model is extensible and can be the basis for other schema mappings between the BIM domain and the GIS domain.     

从节能设计IFC数据生成IDF数据的机制及关键算法

为研制基于BIM技术的建筑节能设计软件,需要实现从IFC数据到能耗模拟软件所需数据的转换。目前国内外已经有一些相关研究,但其具体转换机制和算法并未公开,也没有实现商业化应用。本研究首先建立了建筑节能设计信息需求模型,然后通过分析IFC标准和主流能耗模拟内核EnergyPlus的IDF格式分别建立起了基于IFC标准和IDF格式的建筑节能设计信息模型,之后在该模型的基础上,通过解决一些关键算法建立并实现了由节能设计IFC数据生成ID F数据的转换机制。实际X-程的应用表明所建立的机制能大大提高建模效率。本研究为开发基于B IM技术的我国建筑节能设计软件奠定了基础。     

基于BIM的建筑工程项目多利益方协同机制框架研究

“信息孤岛”现象制约着建筑行业全寿命周期协同管理效率, 各参与方都不愿意主动共享信息, 往往会导致建设后期出现大量的变更。基于统一的BIM标准, 各参与方在投资、设计、施工、竣工阶段的信息严格按照统一BIM标准进行创建、传输, 可以完全解决信息流在传输过程中的失真现象。首先, 打破传统BIM狭义认识, 从广义上将其定位为一种机制, 在此机制下在IFC标准基础上提出并建立BIM标准。其次, 引入熵值表示系统有序的程度, 基于熵和信息技术建立建筑全寿命周期信息传输模型。最后, 在BIM标准和信息传输模型的基础上提出建筑全寿命周期协同框架, 为减少建设后期的变更提供可能, 为解决建筑全过程中“信息孤岛”现象提供基础。     

基于IFC标准的结构耐久信息模型

结构耐久信息模型是用于建筑结构耐久性分析的信息模型,其包含设计, 施工, 维护等耐久性相关的信息。本文根据耐久性分析理论,提取耐久性影响因素,在已有的结构、施工信息模型的基础上通过扩充耐久信息建立了结构耐久信息模型,并从耐久信息模型方面扩展了现有的IFC标准,从而完善了IFC标准结构信息模型,也促进了结构耐久性评估软件系统的开发。     

建筑物BIM与实景三维模型融合方法研究

建筑物BIM和实景三维模型分别是建筑和地理信息领域两种三维模型,二者融合后的模型除了可展示建筑物自身内部细节,还可以分析建筑物与周边环境的相互作用,为智慧城市相关领域中的应用提供基础与支撑。二者融合的难点表现在建筑物几何信息融合、建筑物子组件语义信息的整合,以及空间位置的配准等方面。设计了二者融合的框架,选取IFC模型作为融合前的源模型,3DTitles作为融合后的目标模型,论述了融合流程和方法,包括：1） 重构BIM模型,根据建筑物构建类型,重构成子BIM模型; 2） 模型几何信息转换,采用中间交换格式法,选取obj和glTF格式实现交换; 3） 模型空间位置配准,先选取不同模型建筑物上的同名点,然后采用SVD算法计算配准参数完成配准; 4） 子组件语义信息映射,根据实景三维模型文件格式要求重新组织建筑物构建的语义信息。选取南京市某楼群开展了实验,验证了该融合方法,展示了此楼群BIM模型和实景三维模型的融合结果。总体上所论述的融合方法,除了可实现建筑物BIM与实景三维模型语义、几何和位置融合,在操作上除了需要手工选取同名点配准外,其他步骤均可通过程序自动实现,从而快速建立室内外一体化的建筑物模型。     

BIM与GIS数据集成:IFC与CityGML建筑几何语义信息互操作技术

近年来,建筑信息模型(BIM)与地理信息系统(GIS)的集成应用越来越广泛且深入,不同专业领域通过简单模型转换实现信息交互的方法由于只保留了少量的语义信息从而导致了应用的分散和独立,局限性十分明显。IFC和CityGML分别为BIM和GIS领域内通用的数据模型标准,两者之间的几何和语义信息共享将为BIM和GIS的集成奠定基础。本文基于IFC和CityGML标准,提出IFC几何要素过滤方法以及IFC到CityGML的语义映射规则,为IFC与CityGML建筑模型的几何、语义信息互操作提供一种通用手段,并通过实例进行了验证。     

基于IFC的建筑结构施工图设计信息模型描述

为解决建筑结构设计信息在工程的后续阶段信息重用和共享困难的问题,本文引入国际工业基础类IFC(Industry Foundation Classes)标准研究建筑结构施工图设计信息模型。通过分析钢筋混凝土结构施工图设计BIM (Building Information Model)数据需求,利用IFC的建筑结构信息模型描述方法和模型扩展机制,构建了建筑结构施工图设计的IFC扩展模型,并基于该模型开发了钢筋混凝土结构施工图设计原型系统。系统应用表明,施工图设计模型可自动转化为工程算量模型,进行工程算量统计和分析,实现设计信息的无损交换与充分共享,从而验证了建筑结构施工图IFC扩展模型的可行性。     

A conceptual framework to support solar PV simulation using an open-BIM data exchange standard

With the construction industry moving rapidly towards Building Information Modelling (BIM), it is essential that various analysis tools used in the Architecture, Engineering and Construction (AEC) domain are interoperable with a non-proprietary open BIM schema such as the Industry Foundation Classes (IFC). The UK government will be requiring fully-collaborative BIM in all public sector projects by 2016 and is also chasing the target of achieving zero-carbon buildings by 2019. This dual target will require the use of renewable energy analysis tools in the early stages of the building design process and establish the need for these tools to be IFC-compliant. This paper presents a conceptual framework for developing IFC-compliant renewable energy simulation tools using a multi-model concept in which the IFC data model provides partial input data required to run simulation models. A prototype has been developed as a ‘proof-of-concept’ for an IFC-compliant solar PV simulation tool. The prototype has been validated against other solar PV simulation tools such as PV*Sol, RETScreen® and HOMER to provide credibility to the simulation model. The developed conceptual framework is applicable not only to solar PV simulation but other renewable energy simulation models as well, thereby making an IFC-compliant renewable energy modelling tool capable of conducting, energy, carbon emissions and financial analysis.     

使用BIM方法发展三维规划管理系统势在必行

三维规划管理系统是当前城市规划管理信息化发展的热点之一,同时对三维建筑设计也提出了更高的要求。在对其发展现状及使用技术进行了简要概述和总结,认为在建筑全寿命周期的背景下,结合建筑信息模型(BIM)方法,对新建项目构建完善的建筑信息模型,使用IFC进行数据交换,可以促进信息共享交流,避免重复性劳动,提高建设项目管理的科学性和效率。     

IFC model viewer to support nD model application

Today, building information modelling (BIM) plays a crucial role in the research and development fields of construction information integration and interoperability. This paper, from an information technology point of view, outlines the definition and aims of the “3D to nD Modelling” project, a platform grant-funded project by UK’s British Engineering and Physics Sciences Research Council (EPSRC). It presents a scenario of widening BIM implementation into the overall aspects involved in the whole life cycle of a building project. Industry foundation classes (IFC) as a standard BIM specification has been adopted as a central information repository in order to deliver the integrated building information throughout the nD-driven assessments, evaluation and decision-making. This paper also focuses on the development of an IFC-viewer, which is defined as the holistic interface of the nD modelling tool. The techniques and methods including the auxiliary tools adopted in this development are detailed. This development presents a practical and economic way to reveal and retrieve the information of IFC models inclusively, structurally and visually.     

Automatic reconstruction of 3D building models from scanned 2D floor plans

The overall energy efficiency of existing buildings has to be significantly improved to comply with emerging regulations and to contribute to overcoming current environmental challenges. Many policies aim at accelerating the renovation rate. The effectiveness of renovation actions could be significantly improved through the systematic use of Information and Communication Technologies (ICT) tools and Building Information Modeling (BIM). But these solutions rely on full-fledged digital models, which, for most buildings, are not available. The present article introduces a research work aiming at the development of methods for the generation of 3D building models from 2D plans. The developed prototype is able to extract information from 2D plans and to generate IFC (Industry Foundation Classes)-compliant 3D models that include the main components of the building: walls, openings, and spaces. The article also presents the results of a quantitative assessment of the platform capabilities and performances, relying on a database of 90 real architectural floor plans. The results are very promising and show that such solutions could be key components of future digital toolkits for renovation design.     

PassivBIM: Enhancing interoperability between BIM and low energy design software

The process of building design is currently undergoing some major changes. In an attempt to mitigate climate change, the design of more sustainable buildings is advocated by the UK government. Furthermore, standalone design methods are being replaced with the concept of Building Information Modelling (BIM). The adoption of BIM has been documented to result in many benefits, which range from time to cost savings. During the initial planning stages, building performance simulation (BPS) can be used to inform design decisions. Data can be exchanged between BIM and BPS tools using data transfer schemas such as the Industry Foundation Classes (IFC). The IFC schema lacks an energy domain, and as a result, an extension is proposed in this paper. This contains energy concepts from a BPS tool called Passive House Planning Package (PHPP). The extended schema was developed by way of an externally coupled Java tool, which facilitates the transfer of data, and informs the building design decision-making process. The process of geometry extraction has been validated with several case studies, which are based on certified Passivhaus buildings in Hannover Kronsberg, Germany and Ebbw Vale, Wales. The amount of error is acceptable, and it is mostly due to differences in the initial BIM model setup, not due to the processing of IFC files.     

基于BIM和GIS的数据集成在水利工程中的应用框架

为促进BIM技术在水利工程的应用,解决BIM和GIS集成的数据转换问题,基于对BIM的数据特征、IFC格式数据的结构层次、GIS系统的City GML数据格式以及City GML中语义信息和几何信息的细节层次结构进行详细分析的基础上,总结了BIM和GIS集成时IFC和City GML数据转换中存在的几个障碍。基于此,提出了可以实现BIM和GIS集成的IFC和City GML数据转换框架。并探讨了BIM和GIS集成系统在水利工程全生命周期中的应用和前景,为水利工程各个阶段应用BIM和GIS集成系统提供有利的参考建议。     

Semantic Enrichment for Building Information Modeling

Significant difficulties remain in exchanging information between building information modeling (BIM) tools. The industry foundation classes (IFC) exchange schema is too generic to capture the full semantic meaning needed for direct use by different construction project stakeholders’ BIM tools. Although BIM standards that prescribe model view definitions (MVD) for domain‐specific exchanges are under development, insufficient semantic definition of exchanges prevents achievement of the full potential of BIM through seamless interoperability. We propose an innovative approach for supplementing an IFC exchange file with semantically useful concepts inferred from the explicit and implicit information contained in the building model. A prototype software was implemented to test the applicability of the approach. It consists of a rule‐processing engine and allows composition of inference rule‐sets that can be tailored for different domains. The tests demonstrate semantic enrichment with precast concrete building models, adding inferred joint, slab aggregation and connection concepts.     

基于 BIM 的装配式建筑预制构件生产阶段能耗分析方法

BIM 技术在装配式建筑项目的能耗计算和优化过程具有降低建筑行业能源消耗水平的潜力。基于能耗分析的目标和系统范围,制定预制构件生产阶段的能耗清单和计算公式;对预制构件生产阶段的能耗清单进行基于 IFC 标准的扩展表达,将扩展后的能耗清单关联到装配式建筑项目的 BIM 模型中。并以南京某项目的预制柱为例,验证了 BIM 技术有利于计算工厂生产预制构件的能耗水平并实现能耗优化。     

A Natural‐Language‐Based Approach to Intelligent Data Retrieval and Representation for Cloud BIM

As the information from diverse disciplines continues to integrate during the whole life cycle of an Architecture, Engineering, and Construction (AEC) project, the BIM (Building Information Model/Modeling) becomes increasingly large. This condition will cause users difficulty in acquiring the information they truly desire on a mobile device with limited space for interaction. The situation will be even worse for personnel without extensive knowledge of Industry Foundation Classes (IFC) or for nonexperts of the BIM software. To improve the value of the big data of BIM, an approach to intelligent data retrieval and representation for cloud BIM applications based on natural language processing was proposed. First, strategies for data storage and query acceleration based on the popular cloud‐based database were explored to handle the large amount of BIM data. Then, the concepts “keyword” and “constraint” were proposed to capture the key objects and their specifications in a natural‐language‐based sentence that expresses the requirements of the user. Keywords and constraints can be mapped to IFC entities or properties through the International Framework for Dictionaries (IFD). The relationship between the user's requirement and the IFC‐based data model was established by path finding in a graph generated from the IFC schema, enabling data retrieval and analysis. Finally, the analyzed and summarized results of BIM data were represented based on the structure of the retrieved data. A prototype application was developed to validate the proposed approach on the data collected during the construction of the terminal of Kunming Airport, the largest single building in China. The case study illustrated the following: (1) relationships between the user requirements and the data users concerned are established, (2) user‐concerned data can be automatically retrieved and aggregated based on the cloud for BIM, and (3) the data are represented in a proper form for a visual view and a comprehensive report. With this approach, users can significantly benefit from requesting for information and the value of BIM will be enhanced.     

基于IFC标准的BIM数据共享与交换

BIM技术正在全球范围内推动传统建筑行业产生重大变革。对比过去建筑项目采用分散的图纸开展工作的习惯,BIM技术运用面向对象的方法,采用相互关联的建筑对象信息,能够实现建筑工程项目的协同设计、施工和运维管理。由于建筑项目具有多专业多部门的特点,各专业分工不可避免地使用不同的BIM软件。然而,目前不同的BIM软件主要采用自身的内部数据格式,不同的数据格式导致建筑项目BIM应用过程中普遍存在数据交互效率低的问题。鉴于此,该文提出基于IFC标准的BIM数据共享与交换技术路线,并自主研发基于IFC的结构模型服务器IFC-SMS与基于IFC的BIM协同平台SJTUBIM,为解决建筑项目过程中的不可避免的数据交互问题提供一条有效的途径。最后,以上海交大日上江村项目为分析案例,验证该技术路线的可行性。