Construction and Long Construction and Long- -Term Performance of Term Performance of Innovative Geotechnologies Innovative Geotechnologies Steven F. Bartlett Ph.D., P.E. Steven F. Bartlett Ph.D., P.E. Associate Professor University of Utah
Approx. 100,000 cubic meters of geofoam was placed 15 Project Limits -15 Project Limits I-
I- -15 Reconstruction 15 Reconstruction - - Quick Facts Quick Facts • Single Largest Design-Build Highway Contract in U.S. • 17 Miles of Urban Interstate 17 Miles of Urban Interstate • $1.5 Billion (Project Cost) • Wasatch Constructors (Prime Contractor) • 4 Year Construction Duration (1997 - 2001) • 144 Bridges/Overpass Structures 144 Bridges/Overpass Structures • 160 Retaining Walls (mostly MSE Walls) • $350 K Embankment Study
Geotechnical Issues Geotechnical Issues • Large Primary Consolidation Settlement (1 to 1.5 m) g y ( ) • Time Rate of Consolidation (2 years to end of primary) • Creep Settlement (Bump at Bridge) • Creep Settlement (Bump at Bridge) • Foundation Stability (Large Embankments on Soft Soils) • Schedule Constraints (two 2-year projects) • Maintenance of Traffic (Had to be maintained) • New Technologies and Development of Specifications
Subsurface Profile in Salt Lake Valley Subsurface Profile in Salt Lake Valley Upper Bonneville Clay Interbeds Lower Bonneville Clay
Settlement of Soft Clays Settlement of Soft Clays in Salt Lake Valley in Salt Lake Valley Approximate 2 years of primary settlement
I- -15 Embankment Construction 15 Embankment Construction 2- -stage MSE wall with surcharge stage MSE wall with surcharge g g g g
Prefabricated Vertical Drains Prefabricated Vertical Drains Installed drain Installed drain PV Drain Spacing 1.5 to 2.5 m PV Drain Spacing 1.5 to 2.5 m triangular spacing Placement of anchor bar PV drain pushed into ground
2- -Stage MSE Walls Stage MSE Walls Right-of-way constraints required many slopes to be built vertically. y p y Beginning of 2-stage MSE Wall
2- -Stage MSE Wall Connections Stage MSE Wall Connections Female threaded rod coupler Attachment of Panels with threaded rod Concrete Fascia Panel
2- -Stage MSE Wall with Stage MSE Wall with Prefabricated Vertical Drains Prefabricated Vertical Drains Prefabricated Vertical Drains Prefabricated Vertical Drains Cost and Schedule Comparison Cost and Schedule Comparison Total cost is for 10 m length of embankment
I- -15 Embankment Construction 15 Embankment Construction 1 stage MSE wall with lime cement columns 1-stage MSE wall with lime cement columns stage MSE wall with lime cement columns stage MSE wall with lime cement columns
Lime Cement Stabilized Soil Lime Cement Stabilized Soil Auger / Mixer for Lime and Cement 125 kg/m 3 15% lime 85% cement Lime Cement Column Rig M = 30 Mpa (design); Su 300 to 400 kPa
Lime Cement Column Installation Pattern Lime Cement Column Installation Pattern
1- -Stage MSE Wall Construction Stage MSE Wall Construction Finished MSE wall 1-stage MSE placed over columns
1- -Stage MSE Wall with Stage MSE Wall with Lime Cement Stabilized Soil Lime Cement Stabilized Soil Lime Cement Stabilized Soil Lime Cement Stabilized Soil Cost and Schedule Comparison Cost and Schedule Comparison Total cost is for 10 m length of embankment
I- -15 Reconstruction 15 Reconstruction Geofoam Embankment Geofoam Embankment Geofoam Embankment Geofoam Embankment
I- -15 Reconstruction 15 Reconstruction Geofoam Properties Geofoam Properties p * I-15 used 1.25 pcf density exclusively (i.e., type VIII geofoam)
Geofoam (I Geofoam (I- -80 State Street to 200 West St.) 80 State Street to 200 West St.)
Geofoam Embankment Construction Geofoam Embankment Construction Base Sand Base Sand Footing for Panel Wall and Block Placement
Geofoam Embankment Construction Geofoam Embankment Construction Geofoam cut and placed around piling at bridge abutment Nearly Completed Geofoam Embankment with Vertical Face Transition Zone with MSE Wall
Geofoam Embankment Construction Geofoam Embankment Construction Completed Load Distribution Slab Reinforced Concrete Load Distribution Slab
Geofoam Embankment Finished Geofoam Embankment Finished
Geofoam Embankment with Geofoam Embankment with Tilt Tilt up Panel Wall Tilt Tilt-up Panel Wall up Panel Wall up Panel Wall Cost and Schedule Comparison Cost and Schedule Comparison Total cost is for 10 m length of embankment
Final Cost and Schedule Comparison Final Cost and Schedule Comparison p 160 140 140 Geofoam 120 100 LCC and 80 Wall 60 2-Stage MSE 2 St MSE 40 Wall 20 0 Cost $10 K Time (weeks) ( ) Cost represents total construction costs for each system for a 10-m long reach of interstate. Construction time is typical for embankments built on the I-15 Reconstruction Project.
Performance Monitoring Performance Monitoring Objectives of Geofoam Arrays Objectives of Geofoam Arrays j j y y • Measure Creep Settlement of Geofoam Mass (10 yr.) M C S ttl t f G f M (10 ) • Measure the Pressure Distribution within Geofoam • Measure Differential Settlement in Transition Zones M Diff i l S l i T i i Z • Measure Lateral Earth Pressure at Abutments • Monitor for Differential Icing at Geofoam / Embankment Transition Zones • Model Stress / Strain Behavior Model Stress / Strain Behavior
Typical Geofoam Array Typical Geofoam Array ROW OF SURVEY POINTS AT FACE OF WALL 25 MM - PVC STAND PIPE ROW OF SURVEY POINTS ALONG INSIDE EDGE OF MOMENT SLAB ROW OF SURVEY POINTS ALONG OUTSIDE EDGE OF EMERGENCY LANE CONCRETE PAVEMENT ROAD BASE LOAD DISTRIBUTION SLAB LEVEL 7.5 LEVEL 6 SQUARE PLATE WITH MAGNET RING 6.5 TO 7.3 m LEVEL 4 HEIGHT VARIES GEOFOAM BLOCKS LEVEL 2 GRANULAR BACKFILL LEVEL 0 VIBRATING WIRE TOTAL PRESSURE CELL 2.5 m BEDDING SAND
3300 South Geofoam Array Installation 3300 South Geofoam Array Installation Magnet Extensometer and Pressure Cell Installation Pressure Cell Installation Hotwire Cut for Pressure Cell Pressure Cell Cast in Bridge Abutment Pressure Cell in Base Sand
3300 South Array Settlement Data 3300 South Array Settlement Data 01/20/99 9 9 03/21/99 9 05/20/99 9 07/19/99 9 09/17/99 9 11/16/99 0 01/15/00 03/15/00 0 0 05/14/00 07/13/00 0 09/11/00 0 11/10/00 0 01/09/01 1 03/10/01 1 1 05/09/01 1 07/08/01 1 09/06/01 0 10 20 mm) 30 tlement (m 40 50 60 Sett 70 80 90 100 Construction Completed (7/28/99) Level 0 Level 2 Level 4 Level 6 Level 8 L l 8 Approx. Level 9 Load Distribution Slab placed 1% Construction Strain Load Distribution Slab Curb placed Granular Borrow Open Graded Base PCCP Pavement
3300 South Geofoam Array 3300 South Geofoam Array Damage to Connections During Construction Damage to Connections During Construction g g g g Loading Loading Damaged Connection • Approximately 1% loading strain can be loading strain can be expected. • Strain due to seating of untrimmed block and elastic compression. • Damaged connection g was later repaired by dowels. • Rigid connect should be • Rigid connect should be avoided.
Settlement at Toe of Wall Settlement at Toe of Wall
Geofoam Transition Zones Geofoam Transition Zones Post Post- -Construction Settlement Construction Settlement Transition slope 3.5 H : 1 V face of wall Transition zone 5/30/00 face of wall ent 25.0 3/18/01 e uction Settlem inside edge of 20.0 moment slab MSE Wall Geofoam 5/30/00 inside edge of 15.0 ) m moment slab (m 3/18/01 Post-Constru ( outside edge 10.0 of emergency lane 5/30/00 5.0 outside edge of emergency lane 3/18/01 0.0 0 25340 0 25350 25360 0 25370 0 0 25380 25390 0 0 25400 0 25410 25420 0 0 25430 0 25440 0 25450 0 25460 25470 0 25480 0 25490 0 baseline survey completed on 11/10/99. Mainline Stationing (m)
Settlement Monitoring 100 South Street Settlement Monitoring 100 South Street 1% construction strain projected 0.5 % additional 50 yrs.
Pressure Cell Measurements in Geofoam Pressure Cell Measurements in Geofoam Pressure Versus Time 3300 South Street Geofoam Array Sta. 25+315, Level 0 80.0 Sta. 25+347, Level 0 Sta. 25+315, Level 6 70.0 Sta. 25+347, Level 5 a) Sta. 25+315, Level 9 , essure (kPa 60.0 60 0 Sta. 25+347, Level 8 50.0 40.0 Pre 30.0 20.0 10 0 10.0 0.0 /20/99 /21/99 /20/99 /19/99 /17/99 /16/99 /15/00 /15/00 /14/00 /13/00 /11/00 /10/00 1/9/01 /10/01 5/9/01 7/8/01 9/6/01 1/5/01 1 5 7 9 11 1/ 3/ 5/ 7/ 9/ 11/ 1/ 3/ 5/ 7/ 9/ 11/ 3/ Date
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