Reliability-based geotechnical resistance factors for axially loaded micropiles /

Micropiles are small-diameter drilled and grouted deep foundation elements used in various applications that often involve superstructure or ground conditions where construction of other foundation types is not practical. The TRB National Cooperative Highway Research Program's NCHRP Research Re...

Full description

Bibliographic Details
Main Author:	Loehr, J. Erik
Corporate Authors:	American Association of State Highway and Transportation Officials (sponsoring body.), United States. Federal Highway Administration (sponsoring body.)
Other Authors:	Boeckmann, Andrew Z., Ding, Dan
Format:	Book
Language:	English
Published:	Washington, D.C. : Transportation Research Board, [2022].
Series:	NCHRP research report ; 989.
Subjects:	Soil stabilization. Geosynthetics. Piling (Civil engineering)

Table of Contents:

Presumptive Model for Limestone
Presumptive Model for Karstic Limestone
Presumptive Model for Sandstone
Presumptive Model for Gneiss
Presumptive Model for Granite or Basalt
Predictive Models for Micropile Bond Resistance
Predictive Model for Cohesive Soils
Predictive Model for Clean Sand
Predictive Model for Gravelly Sand
Predictive Model for Silty or Clayey Sand
Summary of Recommended Predictive Models
Design Based on Site-Specific Load Tests
Establishing Nominal Resistance from Load Tests
Characterizing Uncertainty in Nominal Resistance from Load Tests
Chapter 3 Probabilistic Calibration of Resistance Factors
Target Probability of Failure
General Calibration Procedure for Strength Limit States
Resistance Factors for Presumptive Design Methods at Strength Limit States
Resistance Factors for Predictive Design Methods at Strength Limit States
Resistance Factors for Predictive Unit Resistance in Cohesive Soils
Resistance Factors for Predictive Unit Resistance in Sandy Soils
Resistance Factors for Design Considering Site-Specific Load Tests at Strength Limit States
Probabilistic Calibration for Unit Resistance from Site-Specific Load Tests
Practical Considerations for LRFD Considering Load Tests
Simulation of Resistance Factors for Load Tests to Failure
Simulation of Resistance Factors for Proof Load Tests
Evaluation of Alternative Resistance Factors
Recommended Approach for Design Based on Site-Specific Load Tests
Resistance Factors for Redundant Micropile Groups
Load Factors for the Service Limit State
Chapter 4 Recommended Design Methods
Recommendations for Design Using Presumptive Unit Bond Resistance
Recommendations for Design Using Predictive Unit Bond Resistance
Recommendations for Design Using Unit Bond Resistance from Load Tests
Recommendations for Service Limit State Design
An Illustrative Example
Chapter 5 Summary and Recommended Research
Summary and Conclusions
Recommendations for Future Research