1、B itional“ AC1 533.1 R-02 Design Responsibility for Architect u ral Precast-Concrete Projects Reported by AC1 Committee 533 american concrete institute PO. BOX 9094 FARM INGTON HILLS, MICHIGAN 48333-9094 First Printing, September 2002 Design Responsibility for Architectural Precast-Concrete Projects
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11、he problem. The Institutes Engineering Staff will review and take appropriate action on all comments and suggestions received. Members as well as nonmembers of the Insti- tute are encouraged to assist in enhancing the accuracy and usefulness of AC1 documents. ISBN 0-87031-080-1 AC1 533.1 R-02 Design
12、 Responsibility for Architectural Precast-Concrete Projects Reported by AC1 Committee 533 Benjamin Lavon Donald F. Meinheit Chair Secretary Robert B. Austin Edward M. Frisbee Navin N. Pandya George F. Baty Harry A. Gleich James B. Quinn Harry A. Chambers Thomas J. Grisinger Ralph C. Robinson Joseph
13、R. Tucker Sidney Freedman Theodore W. Huntt Allan R. Kenney Primary author tDeceased. Architectural precast concrete is a unique subcategory of concrete construction that involves the same basic entities as other construction. This document outlines the responsibilities for various parties of the de
14、sigdcon struction team for architectural precast-concrete projects. Keywords: Architect; architectural concrete; construction; design; design responsibility; general contractor; precast concrete. CONTENTS Chapter 1-Introduction, p. 533.1 R-1 1.1-Background Chapter 2-General responsibilities, p. 533.
15、1 R-2 2.1-Architect 2.2-Engineer of record 2.3-General contractor 2.4-Precaster (manufacturer) 2.5-Erec tor 2.6-Inspection AC1 Committee Reports, Guides, Standard Practices, and Commentaries are intended for guidance in plan- ning, designing, executing, and inspecting construction. This document is
16、intended for the use of individuais who are competent to evaluate the significance and limita- tions of its content and recommendations and who will accept responsibility for the application of the material it contains. The American Concrete Institute disclaims any and all responsibility for the sta
17、ted principles. The Institute shall not be liable for any loss or damage arising therefrom. Reference to this document shall not be made in contract documents. If items found in this document are desired by the Architect/Engineer to be a part of the contract documents, they shall be restated in mand
18、atory language for incorporation by the ArchiteciEngineer. Chapter 3-Forms of contracts, p. 533.1 R-4 3.1-Negotiated versus competitive bid 3.2-Single-source responsibility 3.3-Mockups Chapter 4-Conclusion, p. 533.1 R-5 Chapter 5-References, p. 533.1 R-5 5.1-Referenced standards and reports Appendix
19、-Prebid process, p. 533.1 R-6 CHAPTER 1-INTRODUCTION Design and construction of structures is a complex process. Defining the scope of work and the responsibilities of the involved parties by means of the contract documents is necessary to achieve a high-quality structure. This is a guide document f
20、or all parties involved in a precast-concrete project and defines the responsibilities of each party. This document does not specifically address the inspection functions but provides direction on who should be conducting inspections. These responsibilities are subject to relationships between the p
21、arties defined in the contract documents. 1 .l-Background Practices regarding the assignment and acceptance of responsibility in design and construction vary throughout North America. In many cases, there has been confusion regarding the responsibility of the various parties. This situation has some
22、times led to protracted legal proceedings. The first consensus document to attempt to define essential AC1 533.1R-02 became effective June 26,2002. Copyright O 2002, American Concrete Institute. All rights reserved including rights of reproduction and use in any form or by any means, including the m
23、aking of copies by any photo process, or by electronic or mechanical device, printed, written, or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. 533.1 R-1 533.1 R-
24、2 AC1 COMMITTEE REPORT roles was Quality in the Constructed Project, published by the American Society of Civil Engineers (ASCE) in 1990 (ASCE 1990). In 1987, AC1 organized a standing board committee on Responsibility in Concrete Construction. The document, Guide- lines for Authorities and Responsib
25、ilities in Concrete Design and Construction, was published by the committee (AC1 Committee on Responsibility in Concrete Construction 1995). One of the basic principles of the construction industry is that responsibility and authority should go hand in hand. Another principle is that every entity sh
26、ould be responsible for its own work. These principles are frequently violated. For example, an architecdengineer (A/E) can require that certain tasks not be undertaken by the contractor without the ABs approval, but the A/E may not wish to accept respon- sibility for problems that develop resulting
27、 from requiring those tasks. This is a case of requiring compliance without accepting responsibility. There have also been cases where owners have sued architects and engineers for approving poor-quality construction but gave them no contract to monitor the work as it progressed. Safety enforcement
28、agencies and plaintiffs lawyers have often charged engineers or architects with the responsibility for construction accidents. These last two situations typically are cases of responsibility without authority, although there could be instances where a design professionals work can affect jobsite saf
29、ety. If the designers are involved with construction-management functions, they could be making decisions affecting worker safety as well as quality of construction. Construction has reached a level of complexity today where it is essential to have design input from the subcontractors. This input, w
30、hether submitted as value engineering proposals, in response to performance requirements, or simply offered as design alternatives, has a legitimate place in construction. Panels are designed for stripping, handling, and installation loads, usually by the panel manufacturer. Service loads are set by
31、 the governing building code and are multiplied by the appropriate load factor. Minimum load factors are set by the governing building code. Panel design should consider dead, live, and environ- mental loads including wind, earthquake (if applicable), temperature, and moisture effects. Service loads
32、 set by the governing building code should be considered only as minimum requirements. Frequently, a precaster wants to change some items in the design to make a fabrication or erection operation easier or more economical. In approving the changes, the A/E still has responsibility for proper interfa
33、cing with other materials in contact with precast concrete. This notion of responsibility is presented in the ASCE document (ASCE 1990) and in the PrecastPrestressed Concrete Institutes guidelines (PCI Ad-Hoc Committee for Responsibility for Design of Precast-Concrete Structures 1998). The engineer
34、of record (EOR) always has to take overall responsibility for the structurai design of the complete structure. Often, certain aspects of the design are delegated to specialty engineers working for the material suppliers or subcontractors. When any of this structural design work for that portion of t
35、he structure involves engineering (as opposed to simply detailing), then the design work should be under the control of a professional engineer licensed in the same state as the project who takes responsibility for the work done. One state, Florida, has formal legal procedures for this process. Loca
36、l regulatory authorities should be consulted for their specific requirements. Contract documents often require that structural design be the responsibility of a professional engineer, regardless of government mandate. CHAPTER 2-GENERAL RESPONSIBILITIES 2.1-Architect The architect develops the design
37、 concept, overall structure geometry, selects the cladding material for appearance, provides details for weatherproofing, selects tolerances for proper interfacing with other materials, and specifies perfor- mance and quality characteristics and inspection and testing requirements in the project spe
38、cifications. The architect and EOR should have responsibility for all aspects of the precast-concrete design. The architect can specify in the contract documents that design services for portions of the work are to be provided by the precaster. Such design services should be performed for the precas
39、ter by a licensed precast engineer who can be an employee of the precaster or an independent structural engineer. The architect and EOR should review these designs, including structural calculations. This review does not relieve the precaster and the specialty engineer of their design responsibility
40、. The contract and the design documents should state clearly the scope of both the precast design and review responsibilities, and the responsi- bilities of others providing design services. The contract drawings prepared by the architeclengineer should provide the overall geometry of the structure
41、and typical connection concepts to permit design, estimating, and bidding. Frequently, the architects drawings will only show joints, reveals, or panel articulation. This lets the precaster determine panel sizes. In the prebid process, the precaster and erector should discuss their approach to panel
42、ize and subsequently connect the units to the building frame within the architectural and structural concepts of the project. In addition, the contract documents (design drawings and specifications) also should provide the general performance criteria, including concrete strength requirements for lo
43、ading, deflection requirements, temperature considerations, and any tolerance or clearance requirements for proper interfacing with other parts of the structure. Precast-concrete components that are the design responsibility of the precaster (who takes responsibility for elements at interfaces with
44、other parts of the structure, such as the secondary steel bracing to prevent rotation of beams or panels); Details or concepts of supports, connections, and clearances that are part of the structure designed by the architect and that will interface with the precast- concrete components; and Permissi
45、ble load transfer points and indicate connection types to avoid having the precaster make assumptions on connection types and piece counts during bidding. The architect and EOR should review designs, calculations, and shop drawings submitted for conformance with design criteria, loading requirements
46、, and design concepts as specified in the design documents. This review, however, does not relieve the precaster and the precast engineer of their design responsibilities. Key design issues for the architect-Buildings using architectural precast panels are becoming increasingly The contract document
47、s should clearly define: DESIGN RESPONSIBILITY FOR ARCHITECTURAL PRECAST-CONCRETE PROJECTS 533.1 R-3 complex. The architect should understand the issues that affect a precaster?s bid and make sure the contract documents address these items clearly. For preparation of shop drawings, all items interfa
48、cing with other materials should be defined. Contract documents that lack detail generally require numerous requests for information. While such documents are easier and less expensive to produce, they may ultimately result in disputes, delays, and additional costs. The contract drawings developed b
49、y the architect should provide a clear interpretation of the configurations and dimensions of individual units and their relationship to the structure as a whole. To do this, the contract documents should supply the following data: Elevations, wall sections, and dimensions necessary to define the sizes and shapes of each different type of wall panel; Locations and sizes of all joints, both real (functional) and false (aesthetic). Joints between units should be completely detailed; Required materials and finishes for all surfaces, with a clear indication of which surfaces are to be expo
