Construction and LongConstruction and Long--Term Performance of Term Performance of Innovative GeotechnologiesInnovative Geotechnologies

Steven F. Bartlett Ph.D., P.E.Steven F. Bartlett Ph.D., P.E.Associate Professor University of Utah

II--15 Project Limits15 Project Limits

Approx. 100,000 cubic meters of geofoam was placed

II--15 Reconstruction 15 Reconstruction -- Quick FactsQuick Facts

• Single Largest Design-Build Highway Contract in U.S.

• 17 Miles of Urban Interstate17 Miles of Urban Interstate

• $1.5 Billion (Project Cost)

• Wasatch Constructors (Prime Contractor)

• 4 Year Construction Duration (1997 - 2001)

• 144 Bridges/Overpass Structures144 Bridges/Overpass Structures

• 160 Retaining Walls (mostly MSE Walls)

• $350 K Embankment Study

Geotechnical IssuesGeotechnical 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 ValleySubsurface Profile in Salt Lake Valley

Upper Bonneville Clay

Lower Bonneville Clay

Interbeds

Settlement of Soft Clays Settlement of Soft Clays in Salt Lake Valleyin Salt Lake Valleyyy

Approximate 2 years of primary settlement

II--15 Embankment Construction15 Embankment Construction22--stage MSE wall with surchargestage MSE wall with surchargeg gg g

Prefabricated Vertical DrainsPrefabricated Vertical Drains

Installed drain

PV Drain Spacing 1.5 to 2.5 m

Installed drain

PV Drain Spacing 1.5 to 2.5 mtriangular spacing

PV drain pushed into groundPlacement of anchor bar

22--Stage MSE WallsStage MSE Walls

Right-of-way constraints requiredmany slopes to be built vertically.y p y

Beginning of 2-stage MSE Wall

22--Stage MSE Wall ConnectionsStage MSE Wall Connections

Female threaded rod coupler

Attachment of Panels withthreaded rod Concrete

Fascia Panel

22--Stage MSE Wall withStage MSE Wall withPrefabricated Vertical DrainsPrefabricated Vertical DrainsPrefabricated Vertical DrainsPrefabricated Vertical Drains

Cost and Schedule ComparisonCost and Schedule Comparison

Total cost is for 10 m length of embankment

II--15 Embankment Construction15 Embankment Construction11 stage MSE wall with lime cement columnsstage MSE wall with lime cement columns11--stage MSE wall with lime cement columnsstage MSE wall with lime cement columns

Lime Cement Stabilized SoilLime Cement Stabilized Soil

Auger / Mixer for Limeand Cement

Lime Cement Column Rig 125 kg/m3 15% lime 85% cement

M = 30 Mpa (design); Su 300 to 400 kPa

Lime Cement Column Installation PatternLime Cement Column Installation Pattern

11--Stage MSE Wall ConstructionStage MSE Wall Construction

Finished MSE wall

1-stage MSE placed over columns

11--Stage MSE Wall withStage MSE Wall withLime Cement Stabilized SoilLime Cement Stabilized SoilLime Cement Stabilized SoilLime Cement Stabilized Soil

Cost and Schedule ComparisonCost and Schedule Comparison

Total cost is for 10 m length of embankment

II--15 Reconstruction15 ReconstructionGeofoam EmbankmentGeofoam EmbankmentGeofoam EmbankmentGeofoam Embankment

II--15 Reconstruction15 ReconstructionGeofoam PropertiesGeofoam Propertiespp

* I-15 used 1.25 pcf density exclusively (i.e., type VIII geofoam)

Geofoam (IGeofoam (I--80 State Street to 200 West St.)80 State Street to 200 West St.)

Geofoam Embankment ConstructionGeofoam Embankment Construction

Base SandBase SandFooting for Panel Wall andBlock Placement

Geofoam Embankment ConstructionGeofoam Embankment Construction

Geofoam cut and placed around piling at bridge abutment

Nearly Completed GeofoamEmbankment with Vertical Face

Transition Zone with MSE Wall

Geofoam Embankment ConstructionGeofoam Embankment Construction

Completed Load Distribution Slab

Reinforced ConcreteLoad Distribution Slab

Geofoam Embankment FinishedGeofoam Embankment Finished

Geofoam Embankment withGeofoam Embankment withTiltTilt up Panel Wallup Panel WallTiltTilt--up Panel Wallup Panel Wall

Cost and Schedule ComparisonCost and Schedule Comparison

Total cost is for 10 m length of embankment

Final Cost and Schedule ComparisonFinal Cost and Schedule Comparisonpp

140160

100120140

Geofoam

6080 LCC and

Wall2 St MSE

2040 2-Stage MSE

Wall

0Cost $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 MonitoringPerformance MonitoringObjectives of Geofoam ArraysObjectives of Geofoam Arraysj yj y

M C S ttl t f G f M (10 )• Measure Creep Settlement of Geofoam Mass (10 yr.)• Measure the Pressure Distribution within Geofoam

M Diff i l S l i T i i Z• Measure Differential Settlement in Transition Zones

• Measure Lateral Earth Pressure at Abutments

• Monitor for Differential Icing at Geofoam /Embankment Transition Zones

• Model Stress / Strain BehaviorModel Stress / Strain Behavior

Typical Geofoam ArrayTypical Geofoam ArrayROW OF SURVEY POINTS AT FACE OF WALL

25 MM - PVC STAND PIPE

ROW OF SURVEY POINTS ALONG OUTSIDE EDGE OF EMERGENCY LANE

ROW OF SURVEY POINTS ALONG INSIDE EDGE OF MOMENT SLAB

CONCRETE PAVEMENT

ROAD BASELOAD DISTRIBUTION SLAB

LEVEL 7.5

SQUARE PLATE WITH MAGNET RINGLEVEL 6

6.5 TO 7.3 m

GEOFOAM BLOCKS

LEVEL 4

LEVEL 2

HEIGHT VARIES

GRANULAR BACKFILL

LEVEL 0

BEDDING SAND2.5 m

VIBRATING WIRE TOTAL PRESSURE CELL

3300 South Geofoam Array Installation3300 South Geofoam Array Installation

Magnet Extensometer andPressure Cell InstallationPressure Cell Installation Hotwire Cut for Pressure Cell

Pressure Cell Cast in Bridge Abutment Pressure Cell in Base Sand

3300 South Array Settlement Data3300 South Array Settlement Data

9 9 9 9 9 9 0 0 0 0 0 0 1 1 1 1 1

001

/20/

99

03/2

1/99

05/2

0/99

07/1

9/99

09/1

7/99

11/1

6/99

01/1

5/00

03/1

5/00

05/1

4/00

07/1

3/00

09/1

1/00

11/1

0/00

01/0

9/01

03/1

0/01

05/0

9/01

07/0

8/01

09/0

6/01

102030m

m)

405060tle

men

t (m

708090

Sett

100Level 0Level 2Level 4Level 6L l 8

Construction Completed (7/28/99)

Level 8Level 9Load Distribution Slab placedLoad Distribution Slab Curb placedGranular BorrowOpen Graded BasePCCP Pavement

Approx. 1% Construction Strain

3300 South Geofoam Array3300 South Geofoam ArrayDamage to Connections During ConstructionDamage to Connections During Constructiong gg g

LoadingLoading

Damaged Connection

• Approximately 1% loading strain can beloading strain can be expected.

• Strain due to seating of untrimmed block and elastic compression.

• Damaged connection gwas later repaired by dowels.

• Rigid connect should be• Rigid connect should be avoided.

Settlement at Toe of WallSettlement at Toe of Wall

Geofoam Transition ZonesGeofoam Transition ZonesPostPost--Construction SettlementConstruction Settlement

Transition slope3.5 H : 1 V

25.0

ent

face of wall5/30/00

face of wall3/18/01

Transition zone

15.0

20.0

uctio

n Se

ttlem

e(m

m)

inside edge ofmoment slab5/30/00inside edge ofmoment slab3/18/01

Geofoam MSE Wall

0.0

5.0

10.0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Post

-Con

stru ( outside edge

of emergencylane 5/30/00outside edgeof emergencylane 3/18/01

baseline survey completed on 11/10/99.

2534

0

2535

0

2536

0

2537

0

2538

0

2539

0

2540

0

2541

0

2542

0

2543

0

2544

0

2545

0

2546

0

2547

0

2548

0

2549

0Mainline Stationing (m)

Settlement Monitoring 100 South StreetSettlement Monitoring 100 South Street

projected 0.5 % additional 50 yrs.1% construction strain

Pressure Cell Measurements in GeofoamPressure Cell Measurements in GeofoamPressure Versus Time

3300 South Street Geofoam Array

60 0

70.0

80.0

a)

Sta. 25+315, Level 0Sta. 25+347, Level 0Sta. 25+315, Level 6Sta. 25+347, Level 5

Sta. 25+315, Level 9

40.0

50.0

60.0

essu

re (k

Pa

,Sta. 25+347, Level 8

10 0

20.0

30.0Pre

0.0

10.0

/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/ 3/ 5/ 7/ 9/ 11/ 1/ 3/ 5/ 7/ 9/ 11/ 1 3/ 5 7 9 11

Date

Geofoam Performance SummaryGeofoam Performance SummaryGeofoam Performance SummaryGeofoam Performance Summary1. Geofoam fills are performing as expected

2 A i l 1 i l i d d i2. Approximately 1 percent vertical strain occurred during construction.

a. Strain due to seating and compression of geofoam.

b. This strain can damage rigid connections.

3. Approximately 0.3 percent creep strain (15 mm) has occurred in the geofoam for an 8-year post construction period. This is acceptable and within the expected performance.

4. The vertical stress distribution that develops in a geofoam wedge p g gfill is complex, but generally diminishes with depth.

5. Pressure cell measurements suggest that approximately 45 kPa of vertical stress has developed in the center of the geofoam massvertical stress has developed in the center of the geofoam mass. This is approximately 50 percent of the compressive strength of the geofoam.

Settlement Comparison Settlement Comparison II--15 Geotechnologies15 Geotechnologiesgg

Settlement ConclusionsSettlement ConclusionsGGII--15 Geotechnologies15 Geotechnologies

• Geofoam has met the 75 mm (3 inch) in 10-yr settlement goal in all cases.

• LCC Treated soil has met the 75 mm in 10-yr settlement goal.

2 Stage MSE Walls ha e not met the 75 mm in• 2-Stage MSE Walls have not met the 75 mm in 10-yr settlement goal for the MSE wall and embankments monitored. The expected range of settlement for these system is 100 (4 in) to 150 mm (6 in) for a 10-year post construction period.period.

Principal InvestigatorsPrincipal Investigators

bartlett@civil.utah.edu@

Published ReportsPublished Reports

Farnsworth C. F., Bartlett S. F., Negussey, D. and Stuedlein A. 2008, “Construction and Post-Construction Settlement Performance of Innovative Embankment Systems, I-15

i j S l k Ci h ” l f G h i l d i lReconstruction Project, Salt Lake City, Utah,” Journal of Geotechnical and Environmental Engineering, ASCE (Vol. 134 pp. 289-301).

Bartlett, S. F. and Lawton E. C., 2008, “Evaluating the Seismic Stability and Performance of , , , g yFreestanding Geofoam Embankment,” 6th National Seismic Conference on Bridges and Highways, Charleston, S.C., July 27th –30th 2008, 17 p.

N M P B tl tt S F L t E C “N i l M d li f G fNewman, M. P., Bartlett S. F., Lawton, E. C., “Numerical Modeling of Geofoam Embankments,” Journal of Geotechnical and Environmental Engineering, ASCE (final review).

Bartlett S. F., Farnsworth, C., Negussey, D., and Stuedlein, A. W., 2001, “Instrumentation and Long-Term Monitoring of Geofoam Embankments, I-15 Reconstruction Project, Salt Lake City, Utah,” EPS Geofoam 2001, 3rd International Conference, Dec. 10th to 12th, 2001, Salt Lake City Utah 23 pSalt Lake City, Utah, 23 p.

Published ReportsPublished Reports

Negussey, D., Stuedlin, A. W., Bartlett, S. F., Farnsworth, C., “Performance of Geofoam Embankment at 100 South, I-15 Reconstruction Project, Salt Lake City, Utah,” EPS G f 2001 3 d i l C f 10th 12th 2001 S l k Ci hGeofoam 2001, 3rd International Conference, Dec. 10th to 12th, 2001, Salt Lake City, Utah, 22 p.

Bartlett, S. F., Negussey, D., Kimball, M., 2000, “Design and Use of Geofoam on the I-15 , , g y, , , , , gReconstruction Project,” Transportation Research Board, January 9th to 13th, 2000, Washington, D.C., 20 p.

B tl tt S F 2005 “Li ht i ht S l ti ” I f t t T h l S i 2005Bartlett, S. F., 2005, “Lightweight Solution,” Infrastructure Technology, Spring 2005, pp. 36-40 (Chinese and English).

Bartlett, S. F., Negussey, D. and Kimble, M., 2000, “Design of Geofoam Embankments for g y gthe I-15 Reconstruction,” Conference on Application and Design of Expanded Polystrene, Sponsored by Taiwan Area National Expressway Engineering Bureau and China Engineering Consultants, Inc., March 3rd, 2000, Taipei, Taiwan, 20 p. (in Chinese).