The Standing Committee on Foundations for Bridges and Other Structures has supported the implementation of the load and resistance factors (LRFD) design philosophy into practice. The committee has contributed by hosting discussions on the advantages, issues, and impact of the implementation of the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) into foundation design and other related fields. The background and a historical overview of the development of LRFD in bridge foundation design are presented in this paper. Several National Cooperative Highway Research Program (NCHRP) projects have been of paramount importance on this matter. Milestone research projects are described, and a perspective on the future of the field is drawn. This document is intended to be a roadmap through the most useful material to understand reliability analysis and its application to geotechnical engineering. It is intended to be of interest to those engineers charged with performing reliability-based calibration in need of a starting point. The primary literature and steps followed to develop the current AASHTO LRFD specifications are highlighted. This paper aims to contribute to the understanding and future improvement of the LRFD specifications.
AASHTO. LRFD Bridge Design Specifications, 9th ed.American Association of State Highway Transportation Officials, Washington, D.C., 2020.
2.
ANSI/AISC 360-16. Specification for Structural Steel Buildings. American Institute of Steel Construction, Chicago, IL, 2016.
3.
ACI Committee 318. Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19). American Concrete Institute, Farmington Hills, MI, 2019, p. 623.
4.
TMS 402/602-16. Building Code Requirements and Specifications for Masonry Structures. The Masonry Society, Longmont, CO, 2016.
5.
NDS. National Design Specification for Wood Construction. American Wood Council, 2018.
6.
ASCE/SEI-7. Minimum Design Loads for Buildings and Other Structures. ASCE/Structural Engineering Institute, Reston, VA, 2022.
7.
HartG. C.Uncertainty Analysis, Loads, and Safety in Structural Engineering. Prentice Hall, Hoboken, NJ, 1982.
BenjaminJ. R.CornellC. A.Probability, Statistics and Decision for Civil Engineers. McGraw-Hill, New York, NY, 1970.
10.
BaecherG. B.ChristianJ. T. Reliability and Statistics in Geotechnical Engineering. John Wiley & Sons, West Sussex, 2005.
11.
PaikowskyS. G.BirgissonB.McVayM.NguyenT.KuoC.BaecherG.AyyubB., et al. NCHRP Report 507: Load and Resistance Factor Design (LRFD) for Deep Foundations. Transportation Research Board, National Cooperative Highway Research Program, Washington, D.C., 2004, p. 87.
12.
PaikowskyS. G.CanniffM. C.LesnyK.KisseA.AmatyaS.MugangaR.NCHRP Report 651: LRFD Design and Construction of Shallow Foundations for Highway Bridge Structures. Transportation Research Board, National Cooperative Highway Research Program, Washington, D.C., 2010, p. 139.
13.
BarkerR. M.DuncanJ. M.RojianiK. B.OoiP. S. K.TanC. K.KimS. G.NCHRP Report 343: Manuals for the Design of Bridge Foundations: Shallow Foundations; Driven Piles; Retaining Walls and Abutments; Drilled Shafts; Estimating Tolerable Movements; Load Factor Design Specifications; and Commentary. Transportation Research Board, National Cooperative Highway Research Program, Washington, D.C., 1991, p. 320.
14.
AllenT. M.NowakA. S.BathurstR. J.Transportation Research Circular E-C079: Calibration to Determine Load and Resistance Factors for Geotechnical and Structural Design. Transportation Research Board, Washington, D.C., 2005, p. 93.
15.
PhoonK. K.KulhawyF. H.GrigoriuM. D.Development of a Reliability-Based Design Framework for Transmission Line Structure Foundations. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 129, No. 9, 2003, pp. 798–806.
16.
ZhangL.TangW. H.NgC. W. W.Reliability of Axially Loaded Driven Pile Groups. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 12, 2001, pp. 1051–1060.
17.
McVayM. C.BirgissonB.ZhangL.PerezA.PutchaS.Load and Resistance Factor Design (LRFD) for Driven Piles Using Dynamic Methods—A Florida Perspective. Geotechnical Testing Journal, Vol. 23, No. 1, 2000, pp. 55–66.
18.
AguilarV.NowakA. S.StallingsJ. M.AndersonJ. B.Safety Factor for Drilled Shaft Foundations Subjected to Wind-Induced Torsion. DFI Journal-The Journal of the Deep Foundations Institute, Vol. 14, No. 1, 2020, pp. 11–21.
19.
NowakA. S.LindN. C.Practical Code Calibration Procedures. Canadian Journal of Civil Engineering, Vol. 6, No. 1, 1979, pp. 112–119.
20.
NowakA. S.LindN. C.Practical Bridge Code Calibration. Journal of the Structural Division, Vol. 105, No. 12, 1979, pp. 2497–2510.
21.
EllingwoodB.GalambosT. V.MacGregorJ. G.CornellC. A.Development of a Probability Based Load Criterion for American National Standard A58: Building Code Requirements for Minimum Design Loads in Buildings and Other Structures. NBS Special Publication 577. Department of Commerce, National Bureau of Standards, Washington, D.C., 1980.
22.
NowakA. S.NCHRP Report 368: Calibration of LRFD Bridge Design Code. Transportation Research Board, National Cooperative Highway Research Program, Washington, D.C., 1999.
23.
AllenT. M.Development of the WSDOT Pile Driving Formula and its Calibration for Load and Resistance Factor Design (LRFD). Washington State Transportation Center, Seattle, 2005.
24.
AllenT. M.Development of Geotechnical Resistance Factors and Downdrag Load Factors for LRFD Foundation Strength Limit State Design: Reference Manual.US Department of Transportation, Federal Highway Administration, National Highway Institute, Washington, D.C., 2005.
25.
DuncanJ. M.Factors of Safety and Reliability in Geotechnical Engineering. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 126, No. 4, 2000, pp. 307–316.
26.
MayerM.Die Sicherheit der Bauwerke und ihre Berechnung nach Grenzkräften anstatt nach zulässigen Spannungen. J. Springer, Berlin, 1926.
27.
StreletskiiN.Foundations of Statistical Account of Factor of Safety of Structural Strength. State Publishing House for Buildings, Moscow, 1947.
28.
WierzbickiW.Safety of Structures as a Probabilistic Problem. Przeglad, Technivzny, (Polish), 1936.
29.
FreudenthalA. M.The Safety of Structures. Transactions of the American Society of Civil Engineers, Vol. 112, No. 1, 1947, pp. 125–159.
30.
FreudenthalA. M.Safety and the Probability of Structural Failure. Transactions of the American Society of Civil Engineers, Vol. 121, No. 1, 1956, pp. 1337–1375.
HasoferA. M.LindN. C.An Exact and Invariant First-Order Reliability Format. Journal of the Engineering Mechanics Division - ASCE, Vol. 100, No. 1, 1974, pp. 111–121.
33.
RackwitzR.FlesslerB.Structural Reliability Under Combined Random Load Sequences. Computers & Structures, Vol. 9, No. 5, 1978, pp. 489–494.
34.
AASHTO. LRFD Bridge Design Specifications. American Association of State Highway Transportation Officials, Washington, D.C., 1994.
35.
SabolS.NCHRP Digest 198: Development of Comprehensive Bridge Specifications and Commentary. Transportation Research Board, National Academies of Sciences, Engineering, and Medicine, Washington, D.C., 1998.
36.
KulickiJ. M.MertzD. R.Development of Comprehensive Bridge Specifications and Commentary. Modjeski and Masters. Transportation Research Board, Washington, D.C., 1988.
37.
Myint LwinM. Why the AASHTO Load and Resistance Factor Design Specifications?Transportation Research Record: Journal of the Transportation Research Board, 1999. 1688: 173–176.
38.
McVayM. C.KuoC. L.SingletaryW. A. Calibrating Resistance Factors in the Load and Resistance Factor Design for Florida Foundations. Report No. WPI 0510772. University of Florida, Gainesville, 1998.
39.
GobleG.NCHRP Synthesis 276: Geotechnical Related Development and Implementation of Load and Resistance Factor Design (LRFD) Methods. National Academy Press, Washington, D.C., 1999, p. 69.
40.
McVayM.BirgissonB.NguygenT.KuoC.Uncertainty in Load and Resistance Factor Design Phi Factors for Driven Prestressed Concrete Piles. Transportation Research Record: Journal of the Transportation Research Board, 2002. 1808: 99–107.
41.
KuoC. L.McVayM. C.BirgissonB.Calibration of Load and Resistance Factor Design: Resistance Factors for Drilled Shaft Design. Transportation Research Record: Journal of the Transportation Research Board, 2002. 1808: 108–111.
42.
YoonS.Abu-FarsakhM. Y.TsaiC.ZhangZ.Calibration of Resistance Factors for Axially Loaded Concrete Piles Driven Into Soft Soils. Transportation Research Record: Journal of the Transportation Research Board, 2008. 2045: 39–50.
43.
YuX.Abu-FarsakhM.YoonS.TsaiC.ZhangZ.Implementation of LRFD of Drilled Shafts in Louisiana. Journal of Infrastructure Systems, Vol. 18, 2012, pp. 103–112.
44.
NelsonC. R.McGrathT. J.KitaneY.LiG.PetersenD. L.NCHRP Report 647: Recommended Design Specifications for Live Load Distribution to Buried Structures. Transportation Research Board, National Cooperative Highway Research Program, Washington, D.C., 2010.
45.
LazarteC. A.NCHRP Report 701: Proposed Specifications for LRFD Soil-Nailing Design and Construction. Transportation Research Board, National Cooperative Highway Research Program, Washington, D.C., 2011.
46.
SmithT. D.Comprehensive Recalibration of Pile Resistance With WEAP Software in Initial and Restrike Conditions for Load and Resistance Factor Design. Transportation Research Record: Journal of the Transportation Research Board, 2012. 2310: 29–37.
47.
Abu-HejlehN. M.Abu-FarsakhM.SuleimanM. T.TsaiC.Development and Use of High-Quality Databases of Deep Foundation Load Tests. Transportation Research Record: Journal of the Transportation Research Board, 2015. 2511: 27–36.
48.
GobleG. G.Load and Resistance Factor Design of Driven Piles. Transportation Research Record: Journal of the Transportation Research Board, 1996. 1546: 88–93.
49.
YoonG. L.O’NeillM. W. Resistance Factors for Single Driven Piles From Experiments. Transportation Research Record: Journal of the Transportation Research Board, 1997. 1569: 47–54.
50.
DiMaggioJ.SaadT.AllenT.ChristopherB.DimillioA.GobleG.PasseP.PersonG.SaadT.ShikeT.Geotechnical Engineering Practices in Canada and Europe - International Technology Exchange Program. Report No.: FHWA-PL-99-013. FHWA, Washington, D.C., 1999, p. 74.
51.
Abu-HejlehP. E.MahmoodN.DimaggioJ.KramerW. K.AASHTO Load and Resistance Factor Design Axial Design of Driven Pile at Strength Limit State. Transportation Research Board, Washington, D.C., 2009.
52.
MillerL. J.DurhamS. A.Comparison of Standard Load and Load and Resistance Factor Bridge Design Specifications for Buried Concrete Structures. Transportation Research Record: Journal of the Transportation Research Board, 2008. 2050: 81–89.
53.
FHWA. Load and Resistance Factor Design for Highway Bridge Substructures: Reference Manual and Participant Workbook. Publication No. FHWA HI-98-032. Federal Highway Administration, US Department of Transportation, Washington, D.C., 2001.
54.
D’AndreaA. W.TsaiC.Louisiana Department of Transportation and Development’s Experience With LRFD. In TR Circular E-C136: Implementation Status of Geotechnical Load and Resistance Factor Design in State Departments of Transportation, Transportation Research Board, Washington, D.C., 2009, pp. 1–10.
55.
LaiP. W.Florida Department of Transportation’s Experience With LRFD. In TR Circular E-C136: Implementation Status of Geotechnical Load and Resistance Factor Design in State Departments of Transportation, Transportation Research Board, Washington, D.C., 2009, pp. 11–20.
56.
WainainaN.KimK. J.ChenC.North Carolina Department of Transportation’s Experience With LRFD. In TR Circular E-C136: Implementation Status of Geotechnical Load and Resistance Factor Design in State Departments of Transportation, Transportation Research Board, Washington, D.C., 2009, pp. 21–28.
57.
KimK. J.KreiderC. A.NCDOT Experience in Load and Resistance Factor Design and Construction of Driven Pile Foundations. Transportation Research Board, Washington, D.C., 2011.
58.
MillerB.Pennsylvania Department of Transportation’s Experience With LRFD. In TR Circular E-C136: Implementation Status of Geotechnical Load and Resistance Factor Design in State Departments of Transportation, Transportation Research Board, Washington, D.C., 2009, pp. 29–32. https://onlinepubs.trb.org/onlinepubs/circulars/ec136.pdf
Transportation Research Board. Research in Progress. TRB, 2019. https://rip.trb.org/
61.
McVayM.WasmanS.HuangL.CrawfordS. Load and Resistance Factor Design Resistance Factors for Augercast in Place Piles. Report No.: FDOT Contract No: BDV31-977-1. University of Florida, Gainesville, 2016.
62.
ThiyyakkandiS.McVayM.LaiP.HerreraR.Full-Scale Coupled Torsion and Lateral Response of Mast Arm Drilled Shaft Foundations. Canadian Geotechnical Journal, Vol. 53, No. 12, 2016, pp. 1928–1938.
63.
LiQ.StuedleinA. W.BarbosaA. R.Torsional Load Transfer of Drilled Shaft Foundations. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 143, No. 8, 2017, p. 04017036.
