AN INTEGRATED CAD AND SIMULATION MODEL FOR CONCRETE OPERATIONS Aly Abdel Fattah Janaka Y. Ruwanpura Project Management Specialization Schulish School of Engineering University of Calgary 2500 University Drive NW Calgary, AB T2N1N4, CANADA ABSTRACT Pouring a concrete raft slab is a classic problem in down- town projects because it requires special arrangements to be made with city authorities to close the area around the project during the operation. City authorities allow this only during the weekends that puts a lot of pressure on construction staff to finish pouring the concrete in a limited amount of time. In this paper, a simulation model for predicating the pouring time is introduced. This integrated model consists of: Special Purpose Simulation (Simphony), Microsoft Access, Visual Basic for Application (VBA) and AutoCAD software. Moreover, in this paper the sensitive parameters are analyzed and recommendations for choosing pouring concrete sub- contractors are provided. Additionally the proposed model is applied to a practical case for defining the required time for pouring a lower raft slab for “The Bow” project in downtown Calgary. 1 INTRODUCTION Concrete raft slab is a basic concrete foundation of any construction building. This paper addresses the problem of pouring concrete for raft slab in down town projects. Pouring concrete for raft slab in downtown projects is always a critical issue because of the necessity to close the area around the project site which is only possible on weekends. The duration of such a concrete pouring operation depends upon the following factors: • Number of concrete trucks; • concrete truck’s capacity; • truck’s speed (emptying and loading); • number of batch plants available; • batch plant production rate; • distance between the construction site and the concrete batch plant; • number of concrete pumps; • concrete pump‘s production rate. The objective of this study is to develop a computer model for determining the required time for pouring concrete of raft slab by integrating the Computer Aided Design (CAD) software and simulation. Generally the main purpose for using computer simulation software is to support decision making which improved efficiency and reduce cost (Klingstam and Gullander 1999). Special purpose simulation software “Simphony” is used to model the pouring time and examine the different scenarios to determine the sensitive parameters (Hajjar and AbouRizk 1999). The required amount of concrete is calculated automatically through “AutoCAD” software. Furthermore, Simphony software is applied to define the relevant sensitive parameters that need to be taken into consideration for this operation. Defining sensitive parameters help the project staff to focus on the important parameters that influence the concrete pouring time. The model proposed in this paper connects Simphony with AutoCAD software by using Visual Basics for Applications (VBA) and Microsoft Access software, both of VBA and Microsoft Access are transparent to the users. VBA exports the object (2D or 3D) properties to Microsoft Access which is accessed by Simphony .This arrangement requires no special interface as the connection establishes by issuing the command of running the VBA on AutoCAD command line and choose the right module from a pop up box. 2 BACKGROUND The Connection between CAD and simulation software has been investigated in industrial and construction fields. AutoCAD is often used to document proposed factory arrangement, including the placement of tools, material handling systems, and physical arrangement, as well as testing for clearances (McGinnis et al 2006). The cost effective way to integrate CAD and simulation is involved 2462 978-1-4244-2708-6/08/$25.00 ©2008 IEEE Proceedings of the 2008 Winter Simulation Conference S. J. Mason, R. R. Hill, L. Mönch, O. Rose, T. Jefferson, J. W. Fowler eds.