Technische Universitat Munchen

Faculty of Civil Engineering and Geodesy

Computational Modeling and Simulation Group

Calculation and representation of structural rein-forcement in Building Information Models using Re-vit Structure and SOFiSTiK

Jose Manuel Sols Lopez

Masters thesis

for the Master of Science program Computational Mechanics

Author: Jose Manuel Sols Lopez

Matriculation number: 3273568

Supervisor: Prof. Dr.-Ing. Andre Borrmann

Date of issue: 01. August 2011

Date of submission: 21. December 2011

Involved Organisations

Computational Modeling and Simulation GroupFaculty of Civil Engineering and GeodesyTechnische Universitat MunchenArcisstrae 21D-80333 Munchen

Declaration

With this statement I declare, that I have independently completed this Masters thesis. Thethoughts taken directly or indirectly from external sources are properly marked as such. Thisthesis was not previously submitted to another academic institution and has also not yetbeen published.

Munchen, December 15, 2011

Jose Manuel Sols Lopez

Jose Manuel Sols LopezHaymann Str. 6D-85764 Oberschleiheime-Mail: manuel.solis.lopez@googlemail.com

Abstract

The 3D visual objects are very useful to improve the understanding of technical documenta-tion and descriptive specifications. However, the representation of structural reinforcementin concrete structures has been relegated to bidimensional graphics, even if the structureitself is modeled in three dimensions. Nevertheless, creating a 3D reinforcement model is nota trivial task, since it has to be incorporated in the structural design phase of the buildingprocess.

In this context, the combination of Revit Structure and SOFiSTiK shows many advantagesto complete the structural design in a BIM environment. By means of Revit Structure, a 3Dreinforcement model can be generated; besides, the 3D visualization can be enriched signifi-cantly through the multidimensional data scheme established by the BIM concept.

In this way, the critical issue in the Revit-SOFiSTiK Workflow is the exchange of informationbetween both software packages, i.e. the interoperation capacity. Currently, the SOFiSTiKextensions for Revit Structure are able to export data from Revit to SOFiSTiK, however thelink is unidirectional and the data network cannot retrieve information from SOFiSTiK toRevit. Therefore, in order to improve the interoperability between the software in questionregarding the structural reinforcement, the Revit .NET API was implemented to develop anapplication i.e. 3DReinforcement with the capacity to read the SOFiSTiK database andto map this raw data to an equivalent 3D reinforcement model.

Likewise, the alternative of a 3D representation of reinforcement enriched with metadatain PDF format is explored in order to offer a variant to integrate the documentation of theproject. The PDF files are a convenient option to exchange information, since this data for-mat is commonly used almost everywhere and it allows a live interaction of the user with thereinforcement model in order to improve the understanding of the 3D objects description,i.e. the specifications of the reinforcing bars.

Summarizing, this work presents an approach to link SOFiSTiK and Revit in order to createa 3D reinforcement model, which can be also used to produce a 3D PDF document. Thesolution is synthesized in an application based on the Revit API, i.e. 3DR, which is integratedin the Revit-SOFiSTiK workflow.

IV

Contents

Abstract III

Contents IV

List of figures VII

List of tables XI

List of Code Regions XIII

Nomenclature XIV

1 Introduction 11.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Scope of the project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2.1 Project limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3 Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.4 Instructions for reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Fundamental concepts 62.1 Building Information Modeling - Basic Concept . . . . . . . . . . . . . . . . . 6

2.1.1 Historical overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.1.2 Structural Building Information Modeling . . . . . . . . . . . . . . . . 102.1.3 BIM interoperability . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.2 Autodesk Revit Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.2.1 Data structure in Revit . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.2.1.1 Families, types and elements . . . . . . . . . . . . . . . . . . 172.2.2 Structural modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.2.3 Structural analytical model . . . . . . . . . . . . . . . . . . . . . . . . 21

2.3 SOFiSTiK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232.3.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232.3.2 SOFiSTiK Extensions for Revit Structure . . . . . . . . . . . . . . . . 25

2.3.2.1 SeRs description . . . . . . . . . . . . . . . . . . . . . . . . . 252.3.2.2 Results using SeRs . . . . . . . . . . . . . . . . . . . . . . . . 272.3.2.3 Limitations and Restrictions of SeRs . . . . . . . . . . . . . . 31

2.4 Reinforcement in Revit Structure . . . . . . . . . . . . . . . . . . . . . . . . . 312.4.1 Placing reinforcing bars . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2.4.1.1 Area reinforcement . . . . . . . . . . . . . . . . . . . . . . . 352.4.1.2 Path reinforcement . . . . . . . . . . . . . . . . . . . . . . . 36

2.4.2 Structural detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372.4.3 Revit Extensions for Reinforcement . . . . . . . . . . . . . . . . . . . 38

2.4.3.1 Revit extensions Description . . . . . . . . . . . . . . . . . . 392.4.3.2 Results using Revit Extensions . . . . . . . . . . . . . . . . . 402.4.3.3 Limitations and Restrictions of the Revit Extensions . . . . . 44

2.5 Revit .NET API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452.5.1 Basic technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462.5.2 Application structure . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

2.5.2.1 IExternalCommand . . . . . . . . . . . . . . . . . . . . . . . 472.5.2.2 IExternalApplication . . . . . . . . . . . . . . . . . . . . . . 482.5.2.3 Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

2.5.3 Database organization . . . . . . . . . . . . . . . . . . . . . . . . . . . 492.5.3.1 Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502.5.3.2 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512.5.3.3 Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522.5.3.4 Units in Revit Structure . . . . . . . . . . . . . . . . . . . . 53

2.5.4 Structural Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . 542.5.4.1 Rebar elements . . . . . . . . . . . . . . . . . . . . . . . . . . 542.5.4.2 Rebar types . . . . . . . . . . . . . . . . . . . . . . . . . . . 562.5.4.3 Hook types . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562.5.4.4 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

2.6 3D PDF documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 592.6.1 PDF internal structure . . . . . . . . . . . . . . . . . . . . . . . . . . . 592.6.2 3D models in PDF format . . . . . . . . . . . . . . . . . . . . . . . . . 60

2.6.2.1 Universal 3D file format . . . . . . . . . . . . . . . . . . . . . 622.6.2.2 Universal 3D Sample Software . . . . . . . . . . . . . . . . . 632.6.2.3 The movie15 LATEX package . . . . . . . . . . . . . . . . . . . 64

2.6.3 3D PDF from Revit Models . . . . . . . . . . . . . . . . . . . . . . . . 66

3 3DReinforcement: a Revit API implementation 683.1 The application 3DR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

3.1.1 Basic technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703.1.2 Workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703.1.3 3DR Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3.1.3.1 A 3D reinforcement model in Revit Structure . . . . . . . . . 723.1.3.2 The reinforcement model in PDF format . . . . . . . . . . . 74

3.1.4 Integration of 3DR with the Revit reinforcing tools . . . . . . . . . . . 763.2 3DR Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

3.2.1 3DR internal process . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783.2.2 Working sequences in 3DR . . . . . . . . . . . . . . . . . . . . . . . . 79

3.2.2.1 Set initial conditions . . . . . . . . . . . . . . . . . . . . . . . 803.2.2.2 Read the SOFiSTiK database . . . . . . . . . . . . . . . . . 803.2.2.3 Create the internal data structures . . . . . . . . . . . . . . . 833.2.2.4 Generate the Rebar . . . . . . . . . . . . . . . . . . . . . . . 843.2.2.5 Integrate the 3D PDF interface . . . . . . . . . . . . . . . . . 87

3.3 3DR in the context of interoperability . . . . . . . . . . . . . . . . . . . . . . 903.4 Limitations and restrictions of 3DR . . . . . . . . . . . . . . . . . . . . . . . . 93

3.4.1 Delimitation of the applicability of 3DR . . . . . . . . . . . . . . . . . 933.4.2 Compatibility with the new software releases . . . . . . . . . . . . . . 95

4 Use cases 984.1 3D reinforcement models and their applicability . . . . . . . . . . . . . . . . . 98

4.1.1 Isolated elements . . . . . . . . . .