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.     

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.     

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.     

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。     

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.     

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。     

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。     

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IFC标准的BIM技术在大型公共建筑消防的应用探讨

本文总结了建筑消防信息难以在多平台有效互用的原因,探讨了基于IFC标准的BIM技术在大型公共建筑消防设计和管理领域的应用。该技术促进了消防信息在不同机构、不同专业间的交换与互用,对实现大型公共建筑动态化、交互化、扁平化的消防管理模式具有推动作用。     

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.     

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.     

基于Revit的BIM技术结构设计中的数据交换问题分析

BIM技术在结构设计中应用的难点在于结构分析软件与BIM建模d软件之间的数据转换。本文主要从IFC标准、Revit API以及基于Excel的数据交换等方面进行了数据交换测试,并对测试结果进行了理论分析,测试结果为:IFC标准仅适合结构物理模型的数据交换,后续的结构分析设计或实体配筋难以进行;基于Revit API二次开发的接口在进行结构分析设计上的数据交换上是可行的,但是存在诸如接口不稳定等问题;基于Excel的转换依赖于软件是否支持Excel数据文件的导入导出,但转换过程稳定。实际运用上,应当针对结构体系和模型复杂程度的不同,采用不同的转换策略。     

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。     

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。     

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。