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。     

建筑施工IFC数据描述标准的研究

IFC标准是国际协同工作联盟IAI发布的建筑产品数据描述标准, IFC标准提供了建筑产品大部分信息模型的定义和描述。但是, 在建筑施工领域IFC标准的模型体系尚不完善, 无法完全满足建筑施工IFC数据描述的需求。本文通过对IFC标准的体系结构、数据描述方法、扩展机制和应用流程的系统研究, 建立面向建筑施工的IFC数据扩展模型, 编制了建筑施工IFC数据描述标准, 并通过工程实际应用验证了模型和标准的可行性和适用性, 提出了对IFC标准进一步研究和应用的建议。     

IFC深入解析及三维可视化

随着建筑信息模型的应用越来越深入,不同专业领域通过多种软件之间简单模型转换导致语义信息部分缺失而难以全面共享,无法实现BIM技术真正的含义。一种软件对于数据标准的支持实际上就是支持对数据的读写,IFC标准作为BIM领域的主要数据模型标准,具有多种几何表达方式,可面向设计应用,含有丰富的建筑语义信息,因而需要通过构建标准化的数据接口来实现BIM的价值。本文基于IFC标准,深入研究IFC构件信息的几何形状表达方法以及构件信息的分解,通过局部坐标转换得到世界坐标系下构件的点坐标信息,最终在三维图像引擎Direct X 11中通过Delaunay三角剖分生成表面模型,为后续室内导航奠定基础。实验证明,本文深入研究的解析方法和可视化技术路线切实可行,期望为从事相关工作的建筑信息化科研人员提供有效参考。     

基于IFC标准的BIM模型编程语言解析方法研究

IFC标准定义了建筑信息模型交换的数据格式,为面向建筑全生命周期的信息交换和共享提供了标准的数据定义和数据模型,是目前对建筑信息描述最全面、最详细的标准,是解决建筑行业BIM软件之间数据交换性和互操作性问题的重要标准。但是IFC基于EXPRESS语言来定义建筑信息交换与共享,EXPRESS语言本身不是编程语言且不可被计算机编译执行,因此使用计算机编程语言解析和处理基于IFC标准的BIM模型,是BIM软件开发的基础和关键技术。本研究利用开源的Java插件,解析基于IFC的BIM模型,生成相对应的IFC实体类,在此基础上,利用Java语言来具体编程实现不同的应用功能,为下一步的基于IFC标准的土木建筑工程BIM软件开发奠定了基础。     

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的桥梁病害信息可视化表达

基于建筑信息模型(BIM)技术的桥梁设计、施工和管养一体化,是未来桥梁工程发展的必然趋势。正确表达和不断更新运营中的桥梁病害,直观展示和基于动态病害信息的桥梁技术状况智能评价,是桥梁智能化管养追求的目标,亟待深入研究。本文提出一种依附构件几何特征的桥梁病害信息表达技术。该技术基于工业基础类(IFC)模式,遵循IFC语法和文件结构,描述构件几何特征信息的IFC表达。在此基础上,将桥梁病害信息几何化,进一步推演病害信息的IFC描述,最终得到普遍适用的桥梁病害信息IFC语句,实现对桥梁病害信息的可视化表达。该算法基于构件的几何特征,可确保病害的准确、直观表达,且可以实现病害信息的动态更新和展示发展历程。对于任意桥梁表观病害,只需依据具体病害信息生成IFC语句,并更新桥梁BIM模型的IFC文件,生成新的带病害信息IFC文件,即可实现病害信息在桥梁三维模型中的可视化表达。     

基于IFC标准的建筑施工信息模型

为了解决当前建筑施工中信息共享问题,基于IFC标准对建筑施工信息组织与表达方式进行研究。通过对建筑施工过程信息需求分析,建立起以B IM为载体的施工统一信息模型;按照IFC标准对建筑信息的定义,把施工统一信息模型分为过程信息模型、资源信息模型和成本信息模型;通过建立与IFC数据实体一致的类和结构体,对IFC标准对所需信息的表达方法进行研究,进而建立起各自的模型。提出的施工信息统一模型基于B IM技术,采用IFC标准为数据表示和交换规范,不依赖于具体的施工流程和信息管理系统,为促进建筑施工过程中不同专业和部门的信息共享和协作提供了支持。     

基于IFC标准的建筑构件入库信息管理方法

目前IFC格式构件的储存和运用不广泛,建立构件库仍依靠手工搜集与检查入库,效率与质量较低,因此需利用信息化技术快速且低成本地搜集BIM构件.提出一种基于IFC标准的构件入库信息管理方法,通过信息提取算法从已有模型的IFC文件中提取建筑构件所需信息,根据建筑信息分类原则将构件自动分类储存,实现构件信息的高效入库储存管理.     

基于IFC标准的建筑电气系统方案设计模型构建

高效的信息互用是BIM的核心价值所在。IFC标准的提出,推动了建筑生命期不同阶段信息交换和共享的研究。本文根据建筑业以及工程信息的特点,提出基于IFC的建筑电气系统方案设计方案。通过分析建筑工程初期阶段不同参与方需求的信息及项目总体流程,并依据IFC标准,规划电气系统方案设计模型。同时,对过程模型中信息结构做初步探讨。方案设计使得项目参与方对工程信息有明确的认识。     

基于IFC的建筑协同设计标准研究初探

本文介绍了基于工业基础类IFC (Industry Foundation Class)的协同设计标准研究。初步研究指出:作为建筑行业中协同设计数据标准应该是开放的标准,IFC是满足该要求的建筑行业数据标准。进一步的研究实践表明,IFC数据格式标准只是协同设计的必要条件,但不是充要条件。设计中各专业之间信息交互的流程也必须要明确定义,否则作为建筑信息模型的通用数据结构IFC格式无法保证专业之间信息交互的正确性和高效性。本文介绍了基于“用例”(use case)分析的方法——信息提交手册IDM(Information Delivery Manual),来定义设计工作流程的信息交互标准,以及在IDM基础上的计算机软件实现的模型视图定义MVD (Model View Definition)。本文指出,基于IFC的协同设计标准框架应该包括三个层次,即IFC数据结构、信息提交手册,以及模型视图定义。     

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.     

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.     

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.     

Utilizing IFC for shield segment assembly in underground tunneling

The shield method is a common approach used for subway tunnel excavation. A critical function of the shield method is the segment assembly process. It is, therefore, imperative to have access to information to be able to manage and control the performance of segment assembly during the construction process. However, an issue that hinders the capacity to undertake these tasks during construction is the inability of existing Building Information Modeling (BIM)-related software used to design tunnels to support information exchanges during a project's execution. The Industry Foundation Class (IFC) has evolved as an open and neutral data format to support information exchanges, but they are yet to be able to accommodate the segment assembly process. Considering the absence of such a data format, this research contributes to the extant literature through extending the IFC standard by treating the segment assembly shield used in construction as an ‘object’. It also proposes a new typesetting (i.e. positioning of segments) algorithm that can be used to automatically determine constraints. Moreover, the algorithm can define the design information that is required to enact data exchanges during construction. The newly developed IFC extensions are validated by demonstrating the successful transfer from a tunnel's parametric design models to the segment assembly system.     

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.     

基于识图语言的同步协同建模技术研究

论述以识图语言替代IFC数据模型作为网络传输对象在同步协同建模过程中的优势,并进一步以协同模型重建为例,论述同步协同建模中的冲突管理技术。     

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.     

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.     

建筑物理模型与结构分析模型的数据映射研究

本文围绕AEC/FM领域应用软件的信息共享与互用,探讨了建筑建模软件与结构分析软件间的数据映射方案。基于IFC(Industry Foundation Classes)标准,分析了建筑物理模型与结构分析模型的异同,提出了从IFC建筑物理模型文件中提取结构构件以及结构构件连接节点拓扑信息的方法,并基于这些映射算法,利用C++编程语言实现了本文提出的通用结构分析模型(SGF)与IFC建筑物理模型的双向数据接口。最后,提出了以SGF为中心的多种建筑物理模型与多种结构分析模型的数据集成基本框架。     

IFC标准在中国的应用前景分析

信息交换与共享是对建筑行业信息化提出的基本要求，而要达到信息交换与共享的目标，必须实现规范化和标准化。在国外建筑业广泛应用的IFC标准是建筑业事实上的数据交换与共享标准，在众多的工程项目中得到应用。在本文中，将简要介绍IFC标准，并分析其在中国的应用前景，供业内人士参考。