ASCE/AWEA Recommended Practice for Compliance of Large-based Wind

Turbine Support Structures Nov 28, 2012

By: Rolando E. Vega, Ph.D., P.E.

Director of Research The University of Texas at San Antonio

Now

Ava

ilabl

e

Outline

1.  Introduction 2.  Past, present and future 3.  US Wind Energy Structures Working Group 4.  Memorandum of Understanding -AWEA and ASCE 5.  Industry statistics and the need for a Roadmap. 6.  The RP2011 Outline and Scope. 7.  Some unique elements of the RP2011 8.  Future Activities

Past, Present and Future

Large Wind Turbine Permitting Guideline Committee

Structural Wind Effects Committee

Wind Energy Structures Subcommittee

Committee name change to: “Large Wind Turbine Compliance Guideline”

AWEA/ASCE Recommended Practice is published

MOU between AWEA/ ASCE

2 groups joined forces

ASCE/ AWEA

Standard

2010

2009

2007 1996

4Q 2011

4Q 2011

2012-2015

AWEA/ASCE Working Group Leaders

Rolando Vega Working Group Chair

ABS

Nestor Agbayani Vice-Chair &

Tower Structure Agbayani Structural

Leonardo Dueñas-Osorio Group Secretary

Rice University

Jim Lockwood Inspection and

Structural Health Monitoring Aerosolutions

Xinguo Cai Referencing and

definitions Glenn Martin

Kevin Smith Survey, Outreach &

permitting DNV

Paul Sgambatti (ASCE) & John Dunlop (AWEA) Staff from umbrella orgs.

Rolando Vega External Load

Conditions ABS

Craig Moller Foundation Structure

GL GH

Paul Veers Committee Chairman

NREL

Memorandum of Understanding On December 9, 2011 ASCE and AWEA inked the agreement to continue cooperation for standardization of wind energy structures in the ANSI offices in Washington D.C.

Industry statistics I (we) am aware that wind turbines have a separate set of internationally recognized design and safety standards which equal or exceed building codes in our jurisdiction.

I (we) believe a guidance document that explains the inter-relationships of various codes that have been used to design and build a large wind turbine would be useful to all local jurisdictions

I (we) find it difficult to apply our codes and knowledge when needing to make approval decisions for large wind turbines, towers, and foundations.

Objective

•  Provide an appropriate minimum level of protection against damage from all hazards during the planned lifetime

•  Develop a document that clearly identifies typical and specific U.S. wind turbine design recommendations that are compatible with the International Electrotechnical Commission (IEC) requirements

•  Advance permit process consistency nationwide.

Table of Contents (Scope) 1.  Introduction 2.  Scope of Guideline 3.  Terms and definitions 4.  Principal Elements of Permitting, Design

and Quality Assurance 5.  External Conditions and Loads 6.  Materials 7.  Tower Support Structures 8.  Foundations 9.  Fabrication and Installation 10.  Inspection and Structural Health

Monitoring •  References •  Appendix A: Compliance Checklist for

Authorities Having Jurisdiction •  Appendix B: Sample Wind Turbine Loads

Document •  Appendix C: ASCE 7 vs IEC 61400-1

Wind Velocity Profile comparison

Some unique elements

Download ASCE/AWEA RP2011

Future Activities From 2012-2014, the following is expected:

1.  Industry’s wide use of the RP2011. 2.  Committees in ACI, AISC and ASCE (and others) consider the needed

research outlined in RP2011. 3.  Faculty and Researchers within the industry address the needed research

by publishing technical notes to address reliability of e.g. concrete fatigue, anchorage for high-cycle connections, fabrication tolerance for large steel cylinders, safety factor calibration, etc.

4.  ASCE/AWEA Wind Energy Structures committee should help direct national research with above associations.

5.  US should engage and help direct IEC efforts, as appropriate, for potential standardization efforts of wind energy support structures.

If development of an IEC standard for support structures is stagnated, the American Society of Civil Engineers (ASCE) and American Wind Energy Association (AWEA) may initiate standardization efforts.

Use ASCE 7 reference standard list EXAMPLES FROM

INDUSTRY:

Petroleum industry: API 650 standard is used for oil storage

tank design.

Waterworks Industry: AWWA D100 standard is used for water tank

design.

Logically, a specialty standard for wind turbine support

structures is the next step?

For further questions Please contact: Rolando E. Vega, Ph.D., P.E., M.ASCE Working Group Chair Director of Research The University of Texas at San Antonio Tel.: 210-458-8654 Cell: 210-848-6862 Rolando.Vega@utsa.edu Or Nestor Agbayani, S.E., M.ASCE Principal Engineer Agbayani Structural Engineering Tel.: 661-742-1327 nagbayani@sbcglobal.net

A S E

­

AGBAYANI