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.     

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.     

Validations for ensuring the interoperability of data exchange of a building information model

During the design and construction phases of building projects, domain experts iteratively exchange building information models. One of their goals is to ensure that the requirements and objectives of a proposed project are satisfied. In addition, most building information modeling software currently implements heterogeneous mapping processes in their IFC interfaces that bind their native models to the IFC format. However, such exchanges frequently do not realize intended geometric transformations, project requirements, and required syntactic and semantic conditions in building model data, exacerbating the problem of model integrity and resulting in expensive changes during the construction and operation phases. These problematic issues have been addressed by the development of solid frameworks for validating a building design. This paper surveys six currently available applications for validating building design data and identifies their strengths and weaknesses: The Express Engine's EXPRESSO, the JDSAI™, the EXPRESS Data Manager™, the IFC server ActiveX Component, the IfcDoc, and the Solibri Model Checker^®. We also structured the validation processes into three types of tasks: 1) a syntax check of the assurance of compliance with the IFC schema defined by the EXPRESS language, 2) semantic and syntactic assessment in terms of conformity to model view definitions, which consist of concept modularizations, and 3) the validation of design programming requirements that evaluates regulations, project criteria, owner requirements, and functional performance. The purpose of this survey, based on available software that supports the validation of building model data for these three types of interoperability issues, is to integrate diverse checking approaches, as a basis for improving what are now widely distributed efforts.     

Design knowledge modeling and software implementation for building code compliance checking

Design knowledge formalization and design information modeling are critical issues in the development of building design support systems such as automated building code checking systems. This paper presents an object-based building modeling approach and its J2EE (Java 2 Platform, Enterprise Edition) implementation in a distributed system to facilitate the automated online code-checking process. It examines the issues of object-based representation of code provisions Industry Foundation Class (IFC)-compliant object model for building designs; Java-based rule inference and IFC-based geometric reasoning; and software prototype implementation on the J2EE platform. Application scenarios and online services of the prototype demonstrate the effectiveness of the approach and the system for building design conformance checking in a distributed environment.     

Benchmark tests for BIM data exchanges of precast concrete

Data exchanges between building information modeling (BIM) tools have been tested in a structured set of detailed benchmark tests using a small but complex building model. The tests have shown that despite progress in developing and implementing Industry Foundation Classes (IFC), much work is still needed to achieve fully effective interoperability. Imperfect exchanges arose from the lack of uniformity in the way the internal object schemas were mapped to IFC objects and properties. The benchmark tests showed clearly the need for a mutually agreed upon standard that defines how precast architectural facades should be modeled and mapped to the IFC schema and what information is required for each exchange in the workflow. Such definition is essential for coherent interoperability for this, and indeed any, domain.     

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.     

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。     

Interpretation of structural analytical models from the coordination view in building information models

Structural design/analysis is one of the most needed uses of Building Information Modeling (BIM). Transforming a building information model to an engineering analytical model is tedious and time-consuming. In addition to geometry transformation, extensive modifications and interpretations are required to make the complex transformed model ready for analysis. Despite such a recognized need, Industry Foundation Classes (IFC) has not been developed sufficiently in engineering analysis uses of BIM as much as it is in some other uses such as design coordination and facility management. As a contribution to addressing this void, development of a new mechanism is discussed in this paper for transformation of IFC building information models in the Coordination View to their equivalent structural models in IFC Structural Analysis View. Considering IFC as the input and output file formats of the mechanism significantly increases the level of interoperability in the proposed model interpretation process. This mechanism is designed to automate the required transformation, modification, and additions operations during such information exchanges. To illustrate feasibility of its implementation, a tool is introduced to automate the developed Interpreted Information Exchange (IIE) mechanism, and its application through a case study serves as validation of the mechanism. The designed IIE mechanism can be extended to automate additional structural modeling tasks. The IIE concept is also applicable to other uses of BIM, especially engineering analysis uses, in order to automate creation of analytical modeling from building information models.     

基于BIM 的建设领域文本信息管理研究

建设项目在其整个生命周期内产生大量的非结构化信息,其中大部分是文本信息,建筑信息模型（BIM）可以支持建设项目全生命周期的信息管理,因此基于BIM 的建设领域文本信息集成管理将大大提高项目管理的效率和质量。介绍了建筑信息模型的概念,实现平台,以及数据交换标准（IFC）,提出了一个系统化的建设领域非结构化文本信息的管理体系框架:以非结构化的文本信息为研究对象,采用文本挖掘的方法,将文本进行结构化处理,用于信息的检索、排序。在此基础上将文本信息按IFC 标准进行分类,并与建筑模型实体相关联,实现文本信息与建筑信息模型的集成。提出的方法可以为提高建设领域文本信息管理能力提供支持。     

The Rosewood experiment — Building information modeling and interoperability for architectural precast facades

The Rosewood experiment examined building information modeling (BIM) and product data exchange in the design and fabrication of architectural precast façades. The façade panels of a 16 story office building were designed and fabricated using traditional CAD, while a parallel workflow was performed independently using BIM tools. No limitations were encountered in designing and detailing of precast façade pieces with current software. Production of the same set of drawings showed a productivity gain of 57% over the CAD process. However, the data exchanges between architectural and precast engineering systems were incomplete and inconsistent, confirming the need for BIM exchange standards. The existing Industry Foundation Classes schema (IFC version 2x3) lacks precast-specific entities and property sets. The majority of the difficulties can be traced to a loss in translation of semantic meaning for the objects exchanged.     

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。     

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。     

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。     

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.     

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.     

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.     

BSPro COM-Server—interoperability between software tools using industrial foundation classes

The continuing development of the Industry Foundation Classes (IFC) standard by the International Alliance for Interoperability (IAI) creates new possibilities for achieving interoperability for design software through the use of a common object model of the building and its open data transfer standard. Several architectural CAD tools are already IFC-compliant. However, in-depth knowledge of the highly complex IFC object model is required to develop IFC-compliant software. It has proven quite difficult to read the huge amount of building data stored in an IFC file, extract the information needed by a particular application, and correctly update the IFC file with new data. To make this work easier for developers not familiar with the IFC, Olof Granlund Oy has developed a new development tool, BSPro COM-Server for IFC Files. Using this tool, a software developer of new or existing tools can achieve IFC compatibility with a quite reasonable amount of work.     

语义交换对象在交换模型中的使用

工业基础类库(IFC)标准的制定主要用来对建筑全生命周期过程中的建筑信息模型进行定义,它是达到建筑信息模型(BIM)工具之间协作的必要条件但不是充分条件。NBIM采用用例方法来精确的定义工程工作流规则之间信息交流的数据需求。工作流中的交换信息由交换模型(EM)定义,而交换对象(EO)是形成EM积木块。在为不同的BIM应用工具之间产品模型数据的交换编译模型视图定义(MVD)之前,我们必须确定工程、施工、产品的语义范围,并嵌入到EO中,形成语义交换对象(SEO),以达到更准确的效果。