Recommendations

The proposed design for temporary housing using HESCO bastions, filled with local indigenous soil, could be included as a standard design in the

Army Facilities Components System (AFCS) database. Also, a design pro-cedure incorporating HESCO technology could be incorporated into U.S.

standards and specifications such as the Unified Facility Criteria (UFC).

Applicability of the system could be improved or extended with follow-on testing or investigation addressing the following issues:

1. Further testing for the best design-value combination of normal and lateral load in terms of displacement effects

2. Use of additional mesh to better resist bowing of the basket, including the amount and placement of the mesh with respect to boundary con-ditions applied in structural designs

3. Testing of smaller HESCO unit cross sections to determine whether units smaller than the tested 3.5 x 3.5 ft dimensions would be applica-ble and as effective as the tested unit size.

Taking the average of the slopes and intercepts of the four design relation-ships stated in section 4.10, the recommended design relationship between lateral and normal stress is calculated as

𝑓𝑓𝐿𝐿 = 0.42𝑓𝑓𝑛𝑛− 0.91 where

𝑓𝑓𝐿𝐿 = allowable lateral stress (psi) 𝑓𝑓𝑛𝑛 = applied normal stress (psi)

This relationship is recommended with the assumption that shear stress in the sand fill is the primary lateral-force-resisting mechanism. However, the failure mode observed at the base of the unit (i.e., the elephant-foot buckling) suggests that there was, at least, some degree of compression in the welded-wire-mesh caused by an overturning moment. A wire with the properties listed in section 2.1 will have a significant yield stress of nearly 2 ksi. However, for the dimensions of the tested wire, this figure translates to a compressive force of approximately 40 lb. As noted in section 4.9, the tendency for elephant-foot buckling is exacerbated by the lateral earth pressure caused by the self-weight of the sand fill, and as buckling did oc-cur, the yield stress and, therefore, yield load in the wire is probably signif-icantly lower than the pure compressive yield stress. Follow-on work

would be needed to investigate the relationship between shear stress, over-turning moment, lateral earth pressure, and wire buckling/yielding. How-ever, in this study, the effects of overturning moment were deemed insig-nificant.

References

[1] U.S. Department of Defense. 2014. Detail Specification: Expeditionary Barrier System (EBS). Washington, DC: U.S. Department of Defense.

[2] ASTM International. 2012. Standard Specification for GALFAN (Zinc-5%

Aluminum-Mischmetal) Alloy in Ingot Form for Hot-Dip Coatings. ASTM B750-12. West Conshohocken, PA: ASTM International.

[3] ASTM International. 2014. Standard Specification for Zinc-5% Aluminum-Mischmetal Alloy-Coated Carbon Steel Wire. ASTM A856/A856M-03. West Conshohocken, PA: ASTM International.

[4] Redbuilt Engineered Wood Products. 2015. Red I-Joists Product Brochure. Boise, ID: Redbuilt.

[5] ASTM International. 2011. Standard Test Methods for Cyclic (Reversed) Load Test for Shear Resistance of Vertical Elements of the Lateral Force Resisting Systems for Buildings. ASTM E2125-11. West Conshohocken, PA: ASTM International.

ERDC/CERL TR-17-4

Ap pe ndi x A: H ES CO B ui ld ing D es ign

ERDC/CERL TR-17-4

ERDC/CERL TR-17-4

ERDC/CERL TR-17-4

Appendix B: MIL-DTL-32488

REPORT DOCUMENTATION PAGE

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

February 2017 2. REPORT TYPE

Final Technical Report 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE

Performance of HESCO Bastion Units Under Combined Normal and Cyclic Lateral Loading

5a. CONTRACT NUMBER 5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S)

Ghassan K. Al-Chaar, Marion L. Banko, Brian Eick, and Thomas A. Carlson 5d. PROJECT NUMBER

P2 445442; MIPRW58XUW41133620 5e. TASK NUMBER

5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

U.S. Army Engineer Research and Development Center Construction Engineering Research Laboratory

P.O. Box 9005

Champaign, IL 61826-9005

8. PERFORMING ORGANIZATION REPORT NUMBER

ERDC/CERL TR-17-4

9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Army Engineer District–Kansas City

601 E. 12th Street Kansas City, Mo 6410

10. SPONSOR/MONITOR’S ACRONYM(S)

11. SPONSOR/MONITOR’S REPORT NUMBER(S)

12. DISTRIBUTION / AVAILABILITY STATEMENT

Approved for public release; distribution is unlimited.

13. SUPPLEMENTARY NOTES

14. ABSTRACT

To help reduce the costs and logistical requirements for establishing forward operating bases (FOBs), the U.S. Army investigates construction methods that use indigenous materials in place of commercial materials manufactured far away. An established con-struction system called the HESCO bastion, currently used in theater for force protection, derives its mass and load resistance from indigenous soils placed in manufactured steel and geotextile containment modules. Using this system for other FOB struc-tures, such as soldier housing, could greatly reduce costs and logistical burdens for Class 4 construction materials. Before devel-oping such applications, however, the load-resisting characteristics of HESCO units must be tested for incorporation into new engineering guidance.

In this study a HESCO unit was filled with dry, coarse sand and subjected to combination of normal and lateral loads at four sep-arate intensities. The interaction of normal and lateral loads was investigated, as well as the cyclic loading hysteresis. A lateral load capacity for HESCO bastions was determined based on the applied normal load. The results validated the suitability of HESCO units as load-bearing structural members for temporary soldier housing in FOBs located in remote areas of operation.

15. SUBJECT TERMS

Military bases, Barracks, Military construction operations, Building materials, Geotextiles, Load factor design 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

OF ABSTRACT 18. NUMBER

OF PAGES 19a. NAME OF RESPONSIBLE PERSON

Unclassified SAR 79 19b. TELEPHONE NUMBER (include area code)

Standard Form 298 (Rev. 8-98)

Prescribed by ANSI Std. 239.18