STGEC – Baton Rouge, LA

December 2013

Controlled Modulus Columns (CMCs)

Support for Mechanically Stabilized Earth Walls

STGEC – Baton Rouge 2013

Geographical Presence in North America GSP – Mullica River NJDOT – I-295

NJDOT – I-78

GSP – Bass River

NJDOT – Rt. 52

MassDOT - CSX

VDOT – Erickson Ave Ext.

Miami Dade Expressway

TNDOT – I-55

TXDOT – I-35

MNDOT – I-35

WVDOT DH Bridge

NJDOT – SR 17

GSP – Egg Harbor

PennDOT Engle Rd

STGEC – Baton Rouge 2013

What is ground improvement?

The Deep Foundations Institute (DFI) defines it as:

the “application of special foundation techniques to

improve in-situ shear strength, stiffness or density

and drainage characteristics” of a soil mass.

Usually, it involves economical and/or time-saving design and construction

techniques for supporting structures on compressible soil strata

For most projects the objective is settlement control or bearing capacity

Support of MSEW with CMC Ground Improvement

STGEC – Baton Rouge 2013

Use of CMC for Support of MSE Walls

• What is a Controlled Modulus Column?

• Rigid inclusions ( grout )

• Displacement tool

• Virtually no spoils or vibration

• Share of load between soil and columns

• High production rates

• Depths up to 110’ (single stroke)

• Typically an alternate to: ACIPs, stone

columns, VCCs, driven piles, RAPs, etc.

STGEC – Baton Rouge 2013

APPLICABILITY OF CMCS

Treatable Soil Types

• soft clays & silts

• controlled & uncontrolled fill

material (including landfills)

• contaminated sites &

Brownfields

• peat & other organics

• loose sand & gravel

Suitable Construction

• industrial, residential,

commercial and retail buildings

• bulk storage tanks

• embankments & MSE Walls

• utilities and pipelines

• large storage slabs

• roadways, culverts and bridge

abutments

• wind turbines

STGEC – Baton Rouge 2013

Use of CMC for Support of MSE Walls

STGEC – Baton Rouge 2013

STGEC – Baton Rouge 2013

Controlled

Modulus

Columns

STGEC – Baton Rouge 2013

Ready mix truck

CMC Drill Rig

Concrete Pump

Backhoe or bobcat for

low cutoff & platform maint.

STGEC – Baton Rouge 2013

Comparison: Piles vs. CMCs

STGEC – Baton Rouge 2013

Controlled

Modulus

Columns

Uniform Load ( MSE Wall / Embankment )

5 to 30% of load on soil

70 to 95% of load in CMC 70 to 95% of load in CMC

Load Transfer by Arching Load Transfer by Arching

Load Transfer

by skin

friction

Load Transfer

by skin friction

Limited settlement

LOAD

TRANSFER

PLATFORM

CONTROLLED

MODULUS

COLUMNS

STGEC – Baton Rouge 2013

STANDARD DESIGN METHODS

• Plaxis finite element software

• 2D axisymmetric models

• 2D plane strain models

• Global 3D models

• SLIDE (and others) slope/global stability software

• SHAKE earthquake & seismic evaluation software

• LPILE (structural analysis for shear & bending)

• In-house footing analysis and CMC design programs

• Traditional deterministic analyses

STGEC – Baton Rouge 2013

STANDARD DESIGN METHODS

STGEC – Baton Rouge 2013

Controlled

Modulus

Columns

QUALITY CONTROL

STGEC – Baton Rouge 2013

STGEC – Baton Rouge 2013

Controlled

Modulus

Columns

STGEC – Baton Rouge 2013

1. Erickson Ave. Connector – Harrisonburg, VA

• CMC support of double-sided MSEW

2. Bass River Bridge – Bass River, NJ

• CMC support of complex MSEW project for NJDOT

3. Elba Island Containment Dike – Savannah, GA

• CMC support of MSEW containment dike at LNG facility

DESIGN CASE HISTORIES

STGEC – Baton Rouge 2013

CMC Case History: Erickson Avenue – Harrisonburg, VA

Project Summary

• New roadway & bridge structure built on MSEW

• Wall loads close to 5 ksf at max wall height (36ft)

• CMC alternate to EPS blocks, piles and CIP walls

STGEC – Baton Rouge 2013

Erickson Avenue Connection – Harrisonburg, VA

STGEC – Baton Rouge 2013

Erickson Avenue Connection – Harrisonburg, VA

STGEC – Baton Rouge 2013

Erickson Avenue Connection – Harrisonburg, VA

STGEC – Baton Rouge 2013

Erickson Avenue Connection – Harrisonburg, VA

STGEC – Baton Rouge 2013

Erickson Avenue Connection – Harrisonburg, VA

STGEC – Baton Rouge 2013 24

STGEC – Baton Rouge 2013 25

STGEC – Baton Rouge 2013

Project Summary

• Roadway widening project along a 1-mile (1.6 km) stretch of the NJ Turnpike

• MSE embankments to be used for approaches on both sides of a new bridge

• CMCs used to control settlement and improve stability beneath MSEW

CMC CASE HISTORY – Bass River Bridge, New Jersey

STGEC – Baton Rouge 2013

• Max wall height of 40’

• Shallow layer of organics

• Stability concerns

• Two working bench elevations

• Target long-term settlement 2”/1”

• Tight construction schedule

CMC CASE HISTORY – Bass River Bridge, New Jersey

Project Challenges

STGEC – Baton Rouge 2013

CMC CASE HISTORY – Bass River Bridge, New Jersey

Loose Sand

N_avg = 7

Organic Silt & Clay

N_avg < 5

Dense Sand

N_avg > 25

Soil Profile

Medium Sand

N_avg < 15

STGEC – Baton Rouge 2013

Construction Staging

• Cut slope to lower working pad

• Install temporary sheeting, lower

working pad

• Install CMCs for lower wall

• Backfill lower wall to upper bench

elevation

• Install CMCs for upper wall

• Backfill upper wall to roadway

elevation

• Finish grade, place pavement

CMC CASE HISTORY – Bass River Bridge, New Jersey

NJ TURNPIKE - MULLICA RIVER BRIDGE

Mullica River

Typical section

t

STGEC – Baton Rouge 2013

Soil Profile with Geometry

CMC CASE HISTORY – Bass River Bridge, New Jersey

STGEC – Baton Rouge 2013

3D Model Plan View – Slice Through Entire Embankment

CMC CASE HISTORY – Bass River Bridge, New Jersey

STGEC – Baton Rouge 2013

Plaxis Results

CMC CASE HISTORY – Bass River Bridge, New Jersey

STGEC – Baton Rouge 2013

Results of Calibration Models for Varied CMC Spacings

CMC CASE HISTORY – Bass River Bridge, New Jersey

STGEC – Baton Rouge 2013

R&D Program – CMC Supported MSEW

STGEC – Baton Rouge 2013

R&D Program – CMC Supported MSEW

STGEC – Baton Rouge 2013

R&D Program – CMC Supported MSEW

STGEC – Baton Rouge 2013

R&D Program – CMC Supported MSEW

STGEC – Baton Rouge 2013

R&D Program – CMC Supported MSEW

STGEC – Baton Rouge 2013

R&D Program – CMC Supported MSEW

STGEC – Baton Rouge 2013

CMC CASE HISTORY – Bass River Bridge, New Jersey

STGEC – Baton Rouge 2013

Project Summary

• CMC support of 0.75 mile-long containment dike at LNG facility

• 15’ tall double-sided MSEW used to form the dike

• CMCs used to control settlement and maintain stability during seismic event

CMC CASE HISTORY – Elba Island Containment Dike

STGEC – Baton Rouge 2013

Project Challenges

• Difficult soil conditions – soft clay underlain by liquefiable sand

• Very strict seismic design criteria set forth by FERC

• Complex FEM modeling to be used to determine system response

CMC CASE HISTORY – Elba Island Containment Dike

STGEC – Baton Rouge 2013

STGEC – Baton Rouge 2013

TYPICAL SOIL BORINGS

STGEC – Baton Rouge 2013

CMC CASE HISTORY – Elba Island Containment Dike

STGEC – Baton Rouge 2013

3D – PLAIN STRAIN MODEL

STGEC – Baton Rouge 2013

PLOT OF SETTLEMENT PROFILE

STGEC – Baton Rouge 2013

PLAN VIEW OF SETTLEMENT ACROSS DIKE SECTION

STGEC – Baton Rouge 2013

EFFECT OF SEISMIC FORCES ON DESIGN

STGEC – Baton Rouge 2013

EFFECT OF SEISMIC FORCES ON DESIGN

STGEC – Baton Rouge 2013

STGEC – Baton Rouge 2013

STGEC – Baton Rouge 2013

STGEC – Baton Rouge 2013

THANK YOU

Any

Questions?