Attachment 7 - Structural Calculations Guidelines_ AOR AFRICOM.pdf

DEPARTMENT OF THE ARMY

U.S. ARMY CORPS OF ENGINEERS

EUROPE DISTRICT

CMR 410, BOX 1

APO AE 09096-0001

CENAU-EC-E June 2019

ENGINEERING GUIDELINE 01/2016

SUBJECT: PREPARATION OF STRUCTURAL CALCULATIONS FOR

AOR AFRICOM

I. BACKGROUND

The intent of the Guideline is to provide a standard format to be used for all structural calculations prepared for construction projects within the USACE NAU Area of Responsibility for Africa Projects. The application of this guideline for all Structural Calculation Submittals will guarantee a reviewable and executable structural submittal at a standard quality level. This Engineering Guideline must be read in conjunction with the Project Statement of Work.

II. DETAILED REQUIREMENTS

A. For all structural calculations, the following requirements apply:

Each calculation must be self-contained and complete.

It must enable further use by third-parties.

It must be clearly and fully structured.

It must be readable and reviewable.

It must be able to be copied and scanned.

Stress and deflection of the loadbearing system is to be verified in a complete, clearly presented and reviewable way for all construction components and connections.

It must contain all information required for the connection design.

Print-outs of digitally supported calculations must be complete, comprehensible and reproducible. They shall clearly define input data such as the magnitude and location of all loads, member sizes, support locations and fixity, and the units of measure. The essential results of the calculations shall be highlighted (e.g. the internal forces used for follow on calculations)

B. Structural calculations are to be structured as follows:

1. Cover sheet

2. Table of contents

3. Preliminary remarks

4. Overview drawings, position plans,

5. Load assumptions/approaches

6. Calculations and verification, construction sketches

7. Bearing reaction (connection force table)

CENAU-EC-E ENGINEERING GUIDELINE 01/2016

8. Signed final sheet

9. Attachments

C. The following paragraphs provide more detailed descriptions on the outline of the subsequent items:

1. Cover sheet

Project name Project number Ordering party / responsible construction agent Designer Date

2. Table of contents

3. Preliminary remarks

Short description of the building/structure (dimensions, use, structural systems for the transfer of vertical and horizontal loads, special characteristics of the supporting structure), deflection limits, positioning of expansion joints etc.

Information on the location (e.g. wind load zones, snow load zones, elevation above MSL, special geographic location (e.g. on a mountain top), seismic zone,…

Materials used Information on subgrade conditions Codes and literature used Computer software used, under indication of the version number and the name of the company Listing of the drawings that belong to the structural assessment

4. Overview drawings, position plans Drawings that enable the review of the feasibility of the structure and the bracing elements, the location of the designed element positions in the overall supporting structure as well as all structural drawings/sketches:

Well viewable depiction of the structural stability systems Axis and row denominations as well as height marks (height above datum) Global coordinate system System dimensions Position numbers Joint layout

5. Load assumptions/approaches

Information on load assumptions/approaches such as self-weight, snow loads, wind loads, seismic loads, live loads etc.

Wind load calculations must consider peak wind loads in the corners and the edges of the roof and walls. An example for the correct determination of external wind pressure coefficients for duopitch roofs is given in Att. #1. The same Figures and Tables can be found in EN 1991-1-4 (EC1) for different roof shapes and walls.

Wind pressures must be based on the location, shape and the height of the building. The designer-of-record (DOR) must provide all relevant information for his wind load calculation as part of his design. Detailed information for determining the applicable wind load for walls and roofs can be found for example in EN 1991-1-4, Section 7.

6. Calculations, verification and structural sketches

Calculations for all internal forces and deflections as well as the verification of load-bearing capacity, usability, fatigue, position stability etc. The layout shall look as follows for each item:

Indication of the position number and name of the supporting structure components (e.g. eaves purlin, gable wall strut etc.)

System drawing with dimensioning, load-bearing situation and information on bracing quality

List of loads and load combinations Calculations of structural capacity, if applicable insert computerized/digital print-outs The design of the roof cover and purlins must be included in the calculations.

A detailed design of all connections of the roof cover to the purlins and the purlins to the load bearing superstructure of the building must be included. The design for the connection of the roof cover to the purlins must consider all possible failure modes. Possible failure modes of those connections are shown in Att. #2.

Detailed information for fastening screws for metal members and sheeting can be found for example in the European Assessment Document EAD 330046-01-0602.

The DOR must design those connections with certified screws for the anticipated use and the Certificates specifying the allowed tension and shear force for those screws must be included in the Structural Calculations.

Assessment of structural capacities Verifications Information on cambering Structural sketches on all verified details Verification of all connections to include the structural sketches or reference to connection force tables

7. Bearing reaction (connection force tables), delegated design components

If the transfer of loads is interrupted at some point of the design (e.g. designer calculates the structural system and provides loads to another to design the foundations), then the forces to be transferred must be presented in such a way that third parties can conduct corresponding design or review/verification of these loads at all times. These loads shall be presented in foundation load tables and connection force tables for all connections that are not a part of the detailed structural design. Forces for f = 1.0 from each load condition are to be indicated with reference to the global coordinate system.

For delegated design components the design shall provide applicable load and deflection Criteria.

8. Final page

Designer’s name plus stamp and signature.

9. Attachment e.g. computerized/digital print-outs

Points of Contact

CENAU POC for this Engineering Guideline 01/2016 PREPARATION OF STRUCTURAL CALCULATIONS FOR AOR AFRICOM is:

Achim Knacksterdt, Chief, Technical Engineering Section

STEVE CARTER

CHIEF, ENGINEERING BRANCH

CENAU-EC-E

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