International Workshop on Micropiles May 29 - 31, 2002 Venice, Italy Full Scale Field Tests on Single Micropiles and Groups/Networks of Titan Micropiles and Future Initiatives Dr. Donald A. Bruce – Geosystems, L.P. Gary M. Weinstein – Polytechnic University

SUMMARY - Full scale field tests funded by U.S. Military, installed and tested by Structural Preservation Systems (SPS) in Baltimore, MD, and designed and analyzed by Geosystems, L.P. - Bulk of tests used a total of 100 + “self-drilling” Titan Ischebeck micropiles, installed and tested in three discrete phases: > Phase I: Sept. 1999 - Feb. 2000 > Phase II: August 2001 > Phase III: September 2001 Phase I : 28 grouped/networked, 6 singles (9’) Phase II: 32 grouped/networked, 33 singles (4’/9’) Phase III: 8 grouped/networked

Solution: TITAN Injection Anchor Overall Program Goals UNIQUE Environment - Rock - Soil (Gravel, Sand, Silt, Clay) - Frozen Ground Loads - Concrete and Asphalt - Axial, Shear, Torsion (Static/Dynamic) Materials Equipment - One “Anchor” - One “Tool” - Grout - Self Contained Power Installation Logistics - One “Process” - Lightweight (threshold) - Clean - Packaging (threshold) - User Friendly - Economically Feasible - Time - Inventory/Field Reduction Solution: TITAN Injection Anchor Self-Drilling, Grouted, Continuously Threaded Tubular Anchor Superior Shear, Bending & Structural Characteristics Ultimate bond values for individual vertical Titans in sand ranged from 1.72 to 2.63 kips/ft (avg. 2.2 kips/ft). (21 to 27 psi: avg. 24 psi). For the two shortest piles in clayey fill with no other overburden cover, the values were several times lower.

Program Test Objectives Phase I: - Lateral and tensile testing of groups/networks. Tensile testing only of vertical elements. Phase II: - “Specialized” testing of groups/networks. Tensile testing only of vertical elements utilizing both cement and solution grouts. Phase III: - “Specialized” and Lateral testing of groups/networks utilizing both cement and solution grouts.

As-built pile group layout.

Plan view of various test elements (Phase I).

Cyclic Lateral Loading of Micropile Future Work Cyclic Lateral Loading of Micropile Groups/Networks (Theory & Field) Purpose? Design Standards and Specifications Who Benefits? Private Industry (Contractors, Engineers, Consultants) Federal/State Gov’t (FHWA, State DOTs, etc.) Academia (the cycle continues . . .) What Benefits? Transportation Projects (Highways, Bridges . . ) All Deep Foundation projects (new/retrofit/etc.) Industry in General > Future Work – based on lessons learned from Baltimore/FOREVER/Lizzi/Japanese, et. al. >>>> see email > The cycle continues: Applied Research => Analysis => Understanding + Lessons Learned = More Applied Research and Theory 1. FHWA State-of-Practice Review Including . . . Research Needs Assessment on Drilled and Grouted Micropiles (Contract No. FHWA-DTFH61-93-C-00128) - July 1995 Other undertakings, studies 2. FOREVER (1993 - 1999): French National Research Project $7,000,000 between French Gov’t, Partner, and FHWA Isolated, Groups & Networks (static and Seismic) Full-scale tests, Shaking table, Centrifuge, FEM, numerical studies 3. ADSC Involvement 4. TWG . . . . 5. National Geotechnical Experimentation Sites (NGES) 6. Private Industry (% of construction costs towards full-scale instrumentation and testing/research on site)

Future Work (cont..) How Do We Get There? Practical and Applied Research that . . . is Conducted in an Environment of Sharing & Cooperation incorporates Lessons Previously Learned is of Benefit to All Cooperative Environment =>> see IWM Vision Statement >> Philosophy of Information Sharing for Benefit of Community 1.

Future Work (cont..) With this Synthesis of Applied & Theoretical Research FHWA: Further Study of Micropile Network Experiments Review recently conducted full-scale experiments Interpret . . . Summarize similar experiments  Future Research Needs Academic Research: Lateral Loading of Micropile Networks Rigorous Cycled Tests Instrumentation & Monitoring Lab & Field Testing of Soils, FEA? Analyze, Predict, and Conclude 1. FULL CIRCLE