DST-0356_R01 Foundation Design Requirements ECO74 T80m

POWER WIND

Alstom Wind, s.l.u. Roc Boronat, 78. 08005 Barcelona, Spain Phone: +34 932 257 600 Fax: +34 932 210 939 www.power.alstom.com

TECHNICAL DESCRIPTION

DST-0356 Rev. 01

TITLE: ECO 74/80 – T80 FOUNDATION DESIGN REQUIREMENTS

Author: Checked by: Approved by:

A. Ortiz X. Bou / A. Andugar / J. A. Pagola / M. Basañez / N. García / A. González / M. Coelho

F. Schuon / M. Licata

REVISIONS

Rev. Date Description of changes Modifies pages Author

00 26/03/2010 Emission AO

01 30/11/2010 Template change (FRM-0966-EN_R04) AF

© ALSTOM 2010. All rights reserved. Information contained in this document is indicative only. No representation or warranty is given or should be relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express written authority, is strictly prohibited. Copyright © 2010 ALSTOM. All rights reserved. ALSTOM and the logo ALSTOM and its variations are trademarks and service trademarks of ALSTOM. Any other names mentioned are the property of their respective owners.

FRM-0966-EN_R04

2 / 14

DST-0356 Rev. 01

ECO 74/80 – T80 FOUNDATION DESIGN REQUIREMENTSCopyright © 2010 ALSTOM. All rights reserved.

TABLE OF CONTENTS

1. Aim.................................................................... 2 2. Scope................................................................. 2 3. Description ........................................................ 3 4. Documents to be delivered by ALSTOM WIND ... 3 5. Documents to be delivered by the CLIENT.......... 3 6. Design requirements .......................................... 4

6.1 Loads................................................................... 4 6.2 Geotechnical investigation report ......................... 4 6.3 Foundation design ............................................... 5

7. Deliverables and timing...................................... 7 8. Appendixes ........................................................ 8

1. AIM Quality and strength of foundations for the ALSTOM WIND’s Wind Turbines is a fundamental element in order to keep the correct operation and to fulfil the guarantees about quality, service or others from the Contract Agreement.

2. SCOPE

WT

50 H

z

60 H

z

Remarks

ECO74 For 80m tower ECO80 CII --

ECO80 CIII For 80m tower ECO80 2.0 -- ECO86 -- ECO100 -- ECO110 --

3 ECO 74/80 – T80 FOUNDATION DESIGN REQUIREMENTS

DST-0356 Rev. 01

Copyright © 2010 ALSTOM. All rights reserved.

3. DESCRIPTION In case the CLIENT carries out the foundation design, it shall fulfil with specification of this document. This document describes the requirements that CLIENT has to fulfil, the documents that CLIENT has to deliver, the documents that ALSTOM WIND has to deliver, the delivery time of this documents and the responsibilities. ALSTOM WIND shall review according its standard requirements and report the recommendations about the foundation design carried out by the CLIENT. The review and recommendations made by ALSTOM WIND do not imply the design responsibility but it continues being of the CLIENT or the engineering company subcontracted.

4. DOCUMENTS TO BE DELIVERED BY ALSTOM WIND ALSTOM WIND shall deliver the following documents:

- Drawings of embedded steel section (or similar systems) for the tower connection. - Drawings of interface requirements between tower and foundation. - Drawings of foundation grounding (earthing) - Foundation loads report (loads at tower base)

Once the foundation design is reviewed, ALSTOM WIND shall report the recommendations about the foundation design specifying the points reviewed according the ALSTOM WIND’s requirements. If ALSTOM WIND detects any point of the design that does not fulfil the requirements, it shall be reported to the CLIENT indicating the issue being the responsibility of the CLIENT to take the necessary measures to fulfil the requirements and recommendations. The CLIENT should not begin the works of foundations before ALSTOM WIND expresses the conclusions about the foundation design review. In case the CLIENT executes the foundation works according a foundation design that does not fulfil the ALSTOM WIND requirements, ALSTOM WIND will be exempted from the responsibilities of the guarantees about quality, service or others specified in the Contract Agreement.

5. DOCUMENTS TO BE DELIVERED BY THE CLIENT The CLIENT shall deliver the following documents:

- Geotechnical investigation report about the site of every Wind Turbine position. Topographic drawings and coordinates about positions shall be delivered as well.

- Detailed drawings of dimensions, materials and reinforcement of the foundation and the connection tower-foundation.

- Descriptive report of the project, describing detailed geotechnical and structural calculations and reference standards used.

- Any document related to the foundation design.

4 / 14

DST-0356 Rev. 01


If necessary, ALSTOM WIND could ask to the CLIENT for technical explanations or other questions during the review period.

6. DESIGN REQUIREMENTS

6.1 LOADS Foundation design and calculation verifications shall be carry out according to the loads delivered by ALSTOM WIND in the foundation loads report. The CLIENT has the responsibility to determine the local standards about seismic hazards. In case the standards demands the consideration of earthquake in the wind turbines loads calculation, the CLIENT shall inform and provide the necessary calculation parameters with sufficient prior notice as ALSTOM WIND can calculate the new load cases. These calculations will take 4 weeks from the reception of the parameters. If the calculations have to be subject to the approval of a certification body, 4 weeks more will be necessary. The maximum load cases combinations described in the foundation loads report are classified according to the sort of loads: extreme loads, operation loads and fatigue loads. Fatigue loads can be found in different formats. Due to the influence of the foundation in the dynamic behaviour of the wind turbine, the foundation loads report provide as well the minimum dynamic rotational stiffness, essential requirement that shall be fulfilled.

6.2 GEOTECHNICAL INVESTIGATION REPORT Foundation design and calculation verifications shall be carry out according to the ground conditions below each Wind Turbine and recommendations described in the geotechnical investigation report. The geotechnical investigation of the site shall be carry out under the responsibility of the CLIENT by a competent soil expert according to local standards, who shall provide the corresponding geotechnical investigation report. The soil expert, under the responsibility of the CLIENT, shall define the composition and amount of investigations based on the complexity of the site ground. In any case, the ground conditions of each Wind Turbine position shall be investigated at enough depth with the most appropriate methods. Geotechnical investigations shall provide sufficient data concerning the ground and the ground-water conditions at and around the construction site for a proper description of the essential ground properties and a reliable assessment of the characteristic values of the ground parameters to be used in design calculations. At least, the geotechnical report shall provide the following data for every Wind Turbine position:

- Description and identification of the strata under the foundation in a minimum depth equal to one diameter of the foundation.

- Recommended type of the foundation. - Possible effects of ground water. Need of drainage system. - Allowable soil pressure of the ground (indicating partial sector factors used and considering maximum

settlement allowed of 3 mm/m) and depth of foundation level. - Global site stability.


DST-0356 Rev. 01


- Static and dynamic elasticity parameters of the strata under the slab affecting the foundation: Elastic modulus E, Poisson’s coefficient, shears modulus G and maximum shear modulus GMAX or G0.

- Chemical aggressiveness of soil against concrete. - Density, angle of shearing resistance, cohesion.

Reference standards: o EN 1997-1 Eurocode 7: Geotechnical design – Part 1: General Rules or equivalent local standard o DIN 1054 Ground - Verification of the safety of earthworks and foundations or equivalent local standard o Guideline for the Certification of Wind Turbines by Germanischer Lloyd o Guideline for Design of Wind Turbines by Det Norske Veritas/RISØ

6.3 FOUNDATION DESIGN The foundation design shall be carried out by a civil engineer or engineer company with legal competence for this purpose. It shall be developed according to the enclosed loads at tower base and to the soil parameters and recommendations of the geotechnical investigation report. The foundation shall provide adequate serviceability, strength and stability for a design service life of 20 years of the Wind Turbine according to the IEC standard for which has been certified. It is the CLIENT or civil engineer’s responsibility to determinate the local standards related to foundations of wind turbines and to carry out a design according to them. It is the CLIENT or civil engineer’s responsibility to carry out any type of certification about the foundation design required by the local law, providing all the necessary documents and sources required to the certification body. The connection between tower and foundation will be done by the elements supplied by ALSTOM WIND (embedded steel section or similar). In order to guarantee the correct operation and installation of the Wind Turbine, the foundation design shall fulfil the interface requirements described in the enclosed drawings Connection tower-foundation, embedded steel section (or similar system) and foundation grounding. In order to fulfil the ALSTOM WIND requirements, it is recommended to carry out, at least, the following assessments: Geotechnical calculations:

- Stability: o The stability actions vs. instability actions shall fulfil a minimum global safety factor of 1,5 (taking

into account ground water level if proceed). o The maximum eccentricity produced by the characteristic extreme loads shall be less than 0.3·b

(squared foundations or 0.59·e (circular foundations) being b and e the dimension of the slab. o In relation to the negative compression under the slab:

It is not allowed gap under operational loads of the foundation loads report. It is not allowed a gap > 50% of the slab surface under characteristic extreme loads of the

foundation loads report. - Sliding shall be assessed. - The soil pressure at the point of resultant load shall not be higher than the allowable soil pressure provided

by the geotechnical investigation report. The partial safety factors used either in actions and soil strength shall be taken according to local standards. The peak soil pressure shall not be higher than 1,25 allowable soil pressure.

6 / 14

DST-0356 Rev. 01


- Maximum settlement shall not be higher than 3mm/m. - The foundation design shall fulfil the dynamic rotational and translational stiffness of the foundation

indicated in the foundation loads report.

Structural calculations:

- The structural elements shall fulfil the verification of Ultimate State Limits under extreme loads and according to local standards.

- The structural elements shall fulfil the verification of Serviceability State Limits under operational loads and according to local standards.

- The structural elements shall fulfil the verification of Fatigue under fatigue loads and according to local standards.

- The structural elements shall fulfil the any other verification according to local standards. - The structure shall be suitable to fulfil the interface requirements described in the enclosed drawings

Connection tower-foundation. Reference standards: o EN 1990 Eurocode 0: Basis of structural design or equivalent local standard o EN 1991 Eurocode 1: Basis of design and actions on structures or equivalent local standard o EN 1992 Eurocode 2: Design of concrete structures or equivalent local standard o EN 1993 Eurocode 3: Design of steel structures or equivalent local standard o EN 1994 Eurocode 4: Design of composite steel and concrete structures or equivalent local standard o EN 1997 Eurocode 7: Geotechnical design or equivalent local standard o IEC 61400-1:1999 Wind turbine generator system. Part 1: Safety requirements o Guideline for the Certification of Wind Turbines by Germanischer Lloyd o Guideline for Design of Wind Turbines by Det Norske Veritas/RISØ


DST-0356 Rev. 01


7. DELIVERABLES AND TIMING

DELIVERABLE RESPONSIBLE TIMING

1. Drawings of embedded steel section (or similar systems) for the tower connection. Drawings of interface requirements between tower and foundation. Drawings of foundation grounding (earthing).

ALSTOM WIND

To be defined by agreement

2. Foundation loads report (loads at tower base) ALSTOM WIND

To be defined by agreement

3. Complete geotechnical investigation report. CLIENT To be defined by agreement

4. Foundation project: geotechnical calculations, structural calculations, construction drawings.

CLIENT 8 weeks before beginning of works

5. Conclusions about foundation review. ALSTOM WIND

4 weeks later

6. Answers/explanations about points defined in conclusions. CLIENT 1 week later

8 / 14

DST-0356 Rev. 01


8. APPENDIXES


DST-0356 Rev. 01


10 / 14

DST-0356 Rev. 01



DST-0356 Rev. 01


12 / 14

DST-0356 Rev. 01



DST-0356 Rev. 01


14 / 14

DST-0356 Rev. 01
