Micropiles Design Guidance

Preferred Design Procedure

<h2>Preferred Design Procedure</h2>Micropiles can be categorized by their behavior as either Case 1 or Case 2. A different design method exists for each of these categories. Case 1 micropiles are directly loaded to provide structural foundation support or to provide slope stabilization. Case 2 micropiles are used to circumscribe and internally reinforce a coherent composite reinforced soil structure. The design methodology for Case 2 micropiles greatly differs from that used for Case 1. Design guidance is provided for Case 1 structural foundations, Case 1 slope stabilization and Case 2 micropiles in this document. The Federal Highway Administration (FHWA) has a set of design documents for this technology. The documents are summarized below.<table class='tablepress' id='tablepress-308'><thead><th><center>Publication Title</th><th><center>Publication
Year
</th><th><center>Publication Number</th><th><center>Available for Download</th></thead><tbody><tr><td >Micropile Design and
Construction </td><td ><center>2005</td><td ><center>FHWA-NHI-05-
039</td><td ><center>No1</td></tr><tr><td >Micropile Design and
Construction Guidelines</td><td ><center>2000</td><td ><center>FHWA–SA-97-
070 </td><td ><center>Yes2</td></tr><tr><td >Drilled and Grouted Micropiles:
State-of Practice Review </td><td ><center>1997</td><td ><center>FHWA-RD016/019
</td><td ><center>No3</td></tr></tbody></table> 1<a href="https://www.nhi.fhwa.dot.gov/training/course_search.aspx">https://www.n… class="disclaimer"> 2<a href="http://isddc.dot.gov/OLPFiles/FHWA/009966.pdf">http://isddc.dot.gov/OLP… class="disclaimer"> 3<a href="http://www.ntis.gov/search">http://www.ntis.gov/search </a>

References

<h2>References</h2>AASHTO (2008). “AASHTO LRFD Bridge Design Specifications, Customary U.S. Units, 4th Edition, 2008 Interim Revisions.” American Association of State Highway and Transportation Officials, ISBN Number: 1-56051-392-6, 652 pages.Armour, Groneck, Keeley, and Sharma (2000) “Micropile Design and Construction Guidelines Implementation Manual.” Federal Highway Administration, Publication No. FHWA –SA-97- 070, June 2000.Bruce, D.A. (1997b). “Ground Improvement, Reinforcement, and Treatment: Developments 1987-1997”, Chapter 2.6 on Micropiles, Proc. of Sessions Sponsored by the Committee on Soil Improvement and Geosynthetics of the Geo-Institute of the American Society of Civil Engineers, Logan, UT, July 17-19, Ed. by V.R. Schaefer, Geotechnical Special Publication No. 69, pp. 151-175.Bruce, D.A. and Chu, E.K. (1995). "Micropiles for Seismic Retrofit" Proc. National Seismic Conference on Bridges and Highways. Sponsored by FHWA and Caltrans. San Diego, CA, Dec. 10-13, 17 pp.Bruce, D.A. and Juran, I. (1997). "Drilled and Grouted Micropiles: State of Practice Review, Volumes I, II, III, and IV." Prepared for the Federal Highway Administration, Publication Nos. FHWA-RD-96-016. –017, -018, and –019, July.Cadden, A., J. Gómez, D.A. Bruce, and T. Armour. (2004). "Micropiles: Recent Advances and Future Trends," Current Practices and Future Trends in Deep Foundations, Geotechnical Special Publication No. 125, ASCE Geo-Institute GSP Honoring Dr. George Goble, GeoTrans Conference, Los Angeles, CA, July 27, 27 pp.Cadden, A.W. and Gómez, J.E. (2002). “Buckling of Micropiles - A Review of Historic Research and Recent Experiences,” ADSC-IAF Micropile Committee, 2002.Deep Foundations Institute & ADSC-IAFD Micro Pile Committee, Thomas D. Richards Jr., P.E., DFI Committee Chair; Tom Armour, ADSC Committee Chair (2002). “Guide to Drafting a Specification for Micropiles.” DFI publication #TM-MP-1.Gómez, J.E., Rodriguez, J., Mikitka, J., and Robinson, H.D. (2008b) “Hollow Core Bar Micropile-Design Parameters Interpreted from 404 Load Tests.” Proceedings of the 33rd Annual and 11th International Conference on Deep Foundations, 2008, New York, NY, USA, (DFI)IBC (2009). “International Building Code.” International Code Council, Inc. ISBN: 9781580017251, 01-Feb-2009, 701 pages.Juran, I., D.A. Bruce, A. DiMillio, and A. Benslimane. (1999). "Micropiles: The State of Practice. Part II: Design of Single Micropiles and Groups and Networks of Micropiles." Ground Improvement, 3 (July) pp. 89-110.Kleih, J., Schwar, P., and Vogt, N. (2009). “Note to Actual Design of Micropiles under Axial Cyclic Loading in Germany According to DIN 1054:2005-01 and Further Guidelines.” ISM's 9th International Workshop on Micropiles in London, England, May 10-13, 2009. Paper #16. (Available on CD)Lizzi, F. (1982). “The Static Restoration of Monuments.” Sagep Publishers, Genoa, Italy, 146 pages. ISBN: 88-7058-025-3.Mason, J.A. and Bruce, D.A. (2001). "Lizzi’s Structural System Retrofit with Reticulated Internal Reinforcement Method." Journal of the Transportation Research Board, No. 1772, Soil Mechanics, National Academy Press, Washington, D.C., pp. 107-114.Noorzad, R. and Saghaee, G.R. (2009). “Seismic Analysis of Inclined Micropiles Using Numerical Method.” Contemporary Topics in Deep Foundations. Proceedings of IFCEE 2009, ASCE, Geotechnical Special Publication No. 185, Orlando, FL, March 15-19, 2009, pp. 406- 413.Sabatini et al. (2005). “Micropile Design and Construction (Reference Manual for NHI Course 132078).” Federal Highway Administration, Publication No. FHWA-NHI-05-039, December 2005.Shields, D.R. (2007). “Buckling of micropiles.” Journal of Geotechnical and Geoenvironmental Engineering, 133(3), 334-337.Titan (2005). "CTS/TITAN IBO Micropile Documents." CTS/TITAN Micropiles. 24 June 2005. 14 Sep. 2009. www.micro-piles.com/Docus/TMiPi.pdfTraylor, R.P., A.W. Cadden, and D.A. Bruce. (2002). "High Capacity Micropiles in Karst™: Challenges and Opportunities." Deep Foundations 2002: An International Perspective on Theory, Design, Construction, and Performance, American Society of Civil Engineers, Geotechnical Special Publication No. 116, Orlando, FL, February 14-16, pp. 743-759.Vanderpool, W.E. (2006). “Observations from the instrumentation of a micropiled and tied back reticulated grid.” 7th International Workshop on Micropiles, Schrobenhausen, Germany, May 3-7, 2006.

Technology

Micropiles