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TRANSCRIPT
Case Study: Rapid Embankment Construction of US 17 Bypass Interchange Over Soft Compressible Soils
Using Lightweight Aggregate Myrtle Beach, South Carolina
Ed Tavera, PE Jeff Speck, PE
February 17 - 20, 2013
Presented By:
Louisiana Transportation Conference
Big River Industries, Inc.
• Project Overview & Design Requirements
• Project Constraints
• Geotechnical Challenges
• Rapid Embankment Construction
• Lightweight Aggregate Borrow Proposed
• Compaction Verification
• Lightweight Aggregate Supply & Delivery
• Automated Geotechnical Instrumentation & Results
• Project Construction Pictures
• Closing
Presentation Agenda
PROJECT OVERVIEW
Project Location Myrtle Beach, SC
Project Location
Project Site
US17 Bypass
East
N. Myrtle Beach Murrels Inlet
SC 707
• Relieve growing traffic congestion
• Provide a facility to handle future development and growth
• Construct a safe, signature project for the stakeholders (Horry County, SC)
Purpose
US 17 Bypass
Farrow Parkway
SC 707
Ramp C
Ramp A
Ramp D
Ramp B
Project Layout
Proposed Interchange
175’ 225’ 300’ 175’ 140’ 225’
Bridge Span Lengths (Bridge Length 1,240 Feet)
Bridge Aesthetic Features
Bridge Features Interior Bent Cap Extensions
Retaining Wall Features (Rendering)
Wall Features
Columbia International Airport Interchange
• Local Funding - led to higher expectations for project completion
• Heavy traffic volumes necessitated accelerated construction
• Elimination of long settlement waiting period
– Led to innovative geotechnical design and construct techniques
Schedule
DESIGN REQUIREMENTS
AASHTO LRFD Design • Strength Limit State • Service Limit State • Extreme Event I Limit State (Seismic) • Extreme Event II Limit State (Collision)
Design Requirements
Performance Based Design
• Service Limit State
• Extreme Event I Limit State (Seismic)
• Extreme Event II Limit State (Collision)
AASHTO LRFD Design • Strength Limit State • Service Limit State • Extreme Event I Limit State (Seismic) • Extreme Event II Limit State (Collision)
Performance Based Design
• Service Limit State
• Extreme Event I Limit State (Seismic)
• Extreme Event II Limit State (Collision)
US Earthquakes 1705 - 1996 Seismic Hazard
1886 Charleston Earthquake
MW 7.3
• Charleston fault zone (“Woodstock” fault) and the “Zone of River Anomalies” (ZRA) fault source
• Moment magnitude from 7.0 to 7.5.
• 1886 Charleston Earthquake
SC Seismic Hazard
SC Seismic Hazard
FEE PGA 0.06g @ B/C Boundary
SEE PGA 0.24g @ B/C Boundary
• Safety Evaluation Earthquake (SEE), ground shaking having a 3% probability of exceedance in 75 years (2,500 year return period) PGA = 0.39g
• Functional Evaluation Earthquake (FEE), ground shaking having a 15% probability of exceedance in 75 years (500 year return period) PGA = 0.13g
Extreme Event I Limit State SC Design Earthquakes
PROJECT CONSTRAINTS
• High existing traffic volume
• No lane closures during summer months
• Maintaining access to numerous businesses
Traffic Control
• Complex construction traffic control plan • 8 proposed stages of construction • Maintain existing number of lanes • Temporary pavement • Multiple traffic shifts • Temporary alignments • Detour routes
• Traffic Control – Maintain Existing Number of Lanes & Access to Numerous Business
• Embankment Construction – Traffic Control Stages 2, 3, and 4
• Project Geometry and Layout
– Existing Alignment
– Limited R/W
• Limited Construction Staging Areas
• Construction Time Requirements – 3.5 years
Project Constraints
GEOTECHNICAL CHALLENGES
Fantasy Harbour
US 17/SC 707 (Backgate)
2 Miles Away!
Myrtle Beach, SC Regional Experience
• 2 Miles North of US 17 /SC 707 Interchange
• New Alignment
• Bridge Over the Atlantic Intracoastal Waterway
• 3.1 Miles Roadway Approaches and Bridge
Fantasy Harbour
Fantasy Harbour West Abutment Subsurface Soils
SB2 RB-24 RB-25 RB-27 SB1 RB-28 RB-29
0 ft-msl
-50 ft-msl
Pee Dee Formation
Very soft to medium CLAYs (CL/CH)
Very loose to medium SANDs (SP/SC/SM)
Fantasy Harbour East Abutment Subsurface Soils
RB-13 SB6 SB1 RB-11 RB-16 SB2-A
SB3-A
SB5
0 ft-msl
-50 ft-msl
Very loose to medium SANDS (SP/SM/SC
Pee Dee Formation
Very soft to medium CLAYs (CL/CH)
• 10’ – 42’ Embankment, Settlement 9” to 67”
• Liquefaction – Loose Sands • Embankment Slope
Instability (Static/Seismic)
Fantasy Harbour Geotechnical Experience
• Ground Improvement!!! • 2 Year Embankment Construction Contract • 2-3 Year Bridge Construction Contract
North Bridge Approach
South Bridge Approach
Let’s Return To US 17/ SC707 Interchange (Backgate)
South Bridge Approach Subsurface General Profile
North Bridge Approach Subsurface General Profile
• 30’ to 60’ - Soft to Firm Clay
• Pockets of Loose Sands in upper 10’
• Intermediate Medium Sands (253+00 to 256+00)
• Loose Sands above Dense Sands (Liquefiable)
• Pee Dee Formation
Geotechnical Challenges
Bridge Abutment Settlement (Normal Weight Fill 120 pcf)
• Poor Site Subgrade (2’ – 3’ Bridging Required)
• Excessive Settlement – (Total & Differential)
• Static Slope Embankment Instability/Bearing
• Seismic Slope Embankment Instability (Liquefaction)
Geotechnical Challenges
RAPID EMBANKMENT CONSTRUCTION
Geotechnical Challenges
Project Constraints
Rapid Embankment Construction
• Settlement – Total & Differential
• Embankment Slope Instability / Bearing (Static/Seismic)
• Bridge Abutment Foundation Performance - Extreme Event I and II Limit States
• MSE Wall Construction Over Soft Soils
Geotechnical Key Design Issues
• Lightweight Aggregate Borrow – Reduce Magnitude of Settlement
• Prefabricated Vertical Drain (PVD) / Granular Surcharges – Increase Rate of Settlement and Facilitate Rapid Construction
• Deep Soil Mixing – Improve Seismic Slope Stability and Bridge Abutment Foundation Performance
• Mechanically Stabilized Earth (MSE) Walls
2-Stage and 3-Stage MSE Wall Construction
Vertical Slip Joints
Geotechnical Design Approach
Granular Surcharge Properties: • = 32 degrees • Unit Weight: 125 pcf
Granular Surcharge
Lightweight Aggregate
Borrow Material
Lightweight Aggregate Properties: • = 40 degrees • Short Term Unit Weight: 60 pcf • Long Term Unit Weight: 70 pcf • MSE Wall Backfill Properties
½ Normal Weight
Normal Weight
Lightweight Aggregate
Granular Surcharge & Lightweight Aggregate Borrow
Lightweight Aggregate Borrow (Rotary Kiln Produced)
226,000 CY
3 Million LF
PVD Installation
PVD
PVD Triangular Installation Pattern
PVD
S
2’ Drainage Sand Layer
Geotextile Separator Fabric
s = 3’ and 4’
PVD Installation
Predrilling PVD Installation 309,000 LF
PVD Installation Obstructions!!!
Permanent MSE Walls • Two-Stage Construction • Three-Stage Construction (w/Drainage Structures)
Temporary MSE Walls (Welded Wire Mesh Facing)
30,500 SF
51,500 SF
MSE Walls
• Seismic Slope Stabilization – Shear Key • Improved Performance of Bridge Abutment Foundations • 2013
35,600 CY
Deep Soil Mixing Columns (Overlap – Block Pattern)
Bridge Abutment DSM Longitudinal DSM Longitudinal DSM
Deep Soil Mixing Columns (Overlap – Block Pattern)
Legend
Test Lime-Cement Columns (Test LCC)
DSM-LCC Test Section 1
(Block Type Pattern)
DSM-LCC Test Section 2
(Single Line Pattern)
10 Feet Min.
10
Fe
et M
in.
Test LCC No. 1 2 3 4
Test Pile 1 (HP 14x117)
Test LCC Sampling Quadrants
1
2
4
3
Deep Soil Mixing Test Sections
CONSTRUCTION SEQUENCE
Ramp B Stage 2
Ramp D Stage 3
Bridge Approach Embankment Stage 4
Project Construction Stages (North Abutment 252+01)
Bridge Abutment Construction (North Abutment – End Bent 7)
HP 14x117 22 Piles/row
30 Feet
DSM-LCC Block Type Pattern MSE Wall Leveling Pad
PVD (Wick Drains)
MSE Wall Concrete Panel Facing
Bridge Wing Wall Vertical Slip Joints
Bridge Abutment Construction
LIGHTWEIGHT AGGREGATE
BORROW PROPOSED
Lightweight Aggregate Borrow (Proposed New Material)
Lightweight Aggregate Borrow (Rotary Kiln Produced)
0
10
20
30
40
50
60
70
80
90
100
0.0100.1001.00010.000100.0001000.000
% P
assi
ng
Grain Size (mm)
LWF Min
LWF Max
713 Min
713 Max
BR Min
BR Max
LWA (S15922)
Section 713 MSE Wall
Big River Proposed Lightweight Aggregate
1 ½" ¾" 3/8" # 4 # 100 # 40 # 30 # 200
Grain Size Curve
Lightweight Aggregate Borrow Soil Properties (Item 2033020)
Soil Properties SCDOT Specified Proposed
Minimum: Dry Unit Weight, gDry (pcf) 55 43*
Maximum: Dry Unit Weight, gDry (pcf) 60 45**
Minimum: Wet Unit Weight, gWet (pcf) 60 55**
Maximum: Wet Unit Weight, gWet (pcf) 70 60**
* 95% Maximum Density **Estimated based on laboratory testing submitted by Big River Industries
Lightweight Aggregate Density Properties
• Higher Fines Content
• Lower Dry Unit Weight
• Total Unit Weight 15% Less Than Designed
• High Absorption
• Gradation – Coarse Sand Vs. Aggregate
• Compaction Verification Required by SCDOT
Lightweight Aggregate Borrow (Proposed New Material Differences)
Test Section #1 (Dry)
Test Section #1 (Wet)
Granular Surcharge
Granular Backfill
Lightweight Aggregate
Borrow Material
• Design Team Performed a Redesign
• Reduced the Lightweight Quantity by 15%
• Saved Horry County $2 Million
Granular Surcharge & Lightweight Aggregate Borrow
COMPACTION VERIFICATION
Interparticle Moisture
Interparticle Voids
Particle Absorbed Moisture
Particle Pore Voids
Particle Ceramic Solids
Lightweight Aggregate Borrow Compaction Verification Challenges
• Laboratory Compaction Curves
• Target 95% Max Dry Density = 43 pcf
• Moisture Content Varied Significantly for the same Dry Density
Compaction Control
• Test Section #2 - Evaluate Compaction Control Methods
• Compaction Control - 1 Cu. Ft. Steel Box, Calibrated Nuclear Density Gauge, Sand Cone, and EDG.
Test Section #2 Compaction Control
SC = Sand Cone NG = Nuclear Gauge EDG = Electric Density Gauge STB = Steel Test Box
EDG-1
Compacted Lightweight Aggregate
Borrow MC-3
STB
EDG-2 SC-1
SC-2
SC-3
MC = Hot Plate & Oven Moisture Content MT = Moisture Tester MTB = Moisture Tester in Steel Box
MC-1 MC-2
EDG-3
NG-1
NG-2
NG-3
MT-1
MT-2
MT-3 MT-4
MTB-1 MT-5 MT-6
MT-7 MT-8 MTB-2
MTB-3
Test Section #2 Field Testing Set
Test Section #2 1 Cu. Ft Steel Box (Control Test)
Test
Set Moisture Added Process Compaction Effort
1 As delivered Compact 3 passes with vibratory roller
2 No Water Added Scarify & Compact 4 passes with a vibratory roller
3
Added Water - 1 Pass Scarify & Compact 8 passes with a walk behind
vibratory flat plate compactor
4 Added Water - 2 Passes Scarify & Compact 3 passes with a vibratory roller
5 No Water Added Scarify & Compact 4 passes with a vibratory roller
6 No Water Added Scarify & Compact 8 passes with a vibratory roller
7
Added Water- 2.5 Passes
(Saturated) Scarify & Compact
3 passes with a vibratory roller
Test Section #2 Field Testing Sets
Test Section #2
Compaction Control Calibrated Nuclear Gauge
LIGHTWEIGHT AGGREGATE
SUPPLY & DELIVERY
Big River Industries Livingston, AL – Myrtle Beach, SC
Big River Industries 500 Mile Radius – Livingston, AL
Livlite Big River Industries
Lightweight Aggregate Borrow Pre-conditioning
Lightweight Aggregate Borrow Pre-conditioning
CONSTRAINTS
Ramp B Construction Pre-conditioned Lightweight Aggregate
CONSTRAINTS
Ramp B Construction Pre-conditioned Lightweight Aggregate
GEOTECHNICAL INSTRUMENTATION
Settlement Monitoring • 4 Magnetic Extensometer • 10 Settlement Plates • 12 VW Settlement Sensors • 17 VW Piezometers • 2 VW Data Collection Centers
Slope Stability • 6 Slope Inclinometers
Geotechnical Instrumentation
Spider Magnet Pre-Assembled ME Telescoping Section
VW Magnetic Extensometers
-70
-60
-50
-40
-30
-20
-10
0
10
20
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.01.0
Ele
vati
on
(fe
et)
Settlement (Inches)
12/1/2011
12/7/2011
12/14/2011
12/19/2011
12/21/2011
12/27/2011
12/29/2011
1/4/2012
1/12/2012
1/18/2012
1/25/2012
2/1/2012
12-22-2011 Embankment Construction
Finished
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
0 7 14 21 28 35 42 49 56 63 70
Emb
ankm
en
t H
eig
ht
(Fe
et)
Days
EmbankmentHeightTop of LWF
Datum Magnet
SA-1
SA-2
Sett
lem
en
t (I
nch
es)
Instrumentation Results ME Extensometers
VW Piezometers
Instrumentation Results VW Piezometers
Settlement Plates
VW Settlement Sensors
VW Settlement Sensor Data Collection
VW Data Collection
Logger
VW Settlement
Sensors
VW Piezometers Engineer
Internet
Power Source (Solar Power)
Database Server
Cellular Phone
VW Device Connection
Board
VW Data Collection Center
Automated Data Collection
VW Devices connected to 16-channel Board
VW Device Connections
iSite Logger with Solar Controller Charging Battery
Inside DCC Enclosure & Solar Panel
Data Collection Center
X-Section End Bent 1 (South Bridge Abutment, 237+50)
Ramp A
Settlement Transverse Profile (South Bridge Abutment – 237+83)
Ramp A Settlement Measurements
2-12-2011 Embankment Construction
Finished
2-14-2012 Surcharge Removed
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0 7
14
21
28
35
42
49
56
63
70
77
84
91
98
10
5
11
2
11
9
12
6
13
3
14
0
14
7
15
4
16
1
16
8
17
5
18
2
18
9
19
6
20
3
21
0
21
7
22
4
23
1
23
8
Emb
ankm
en
t H
eigh
t (F
eet)
Days Since VWSS Installed
US-17 Bypass Settlement Sensor A-VWSS-2
Embankment Height
Lightweight Fill Height
SS Reading No. 1- 5:00
SS Reading No. 2- 12:00
SS Reading No. 3- 19:00
SS Reading No. 4- 23:00
Sett
lem
en
t
Ramp C
Settlement Transverse Profile (South Bridge Abutment – 237+83)
Ramp C Settlement Measurements
9-13-2012 Emankment Construction Finished
12-14-2012 Surcharge Removed
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
0 7
14
21
28
35
42
49
56
63
70
77
84
91
98
10
5
11
2
11
9
12
6
13
3
14
0
14
7
15
4
16
1
16
8
17
5
18
2
18
9
19
6
20
3
21
0
21
7
22
4
Emb
ankm
en
t H
eigh
t (F
eet)
Days Since VWSS Installed
Embankment Height
Lightweight Fill Height
SS Reading No. 1- 5:00
SS Reading No. 2-11:00
Sett
lem
en
t (I
nch
es)
X-Section End Bent 7 (North Bridge Abutment, 250+26)
Ramp B
Settlement Transverse Profile (North Bridge Abutment - 250+26)
12-22-2011 Embankment Construction
Finished
4-10-2012 Surcharge Removal
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
0 7
14
21
28
35
42
49
56
63
70
77
84
91
98
10
5
11
2
11
9
12
6
13
3
14
0
14
7
15
4
16
1
16
8
17
5
18
2
18
9
19
6
20
3
21
0
21
7
22
4
23
1
23
8
24
5
25
2
25
9
26
6
Emb
ankm
en
t H
eigh
t (F
eet)
Days Since VWSS Installed
Settlement Sensor
Embankment Height
Lightweight Fill Height
SS Reading No. 1 - 5:0:0
SS Reading No. 2 - 12:0:0
SS Reading No. 3 - 19:0:0
SS Reading No. 4 - 23:0:0
Sett
lem
en
t
Ramp B Settlement Measurements
Ramp D
Settlement Transverse Profile (North Bridge Abutment - 250+26)
Ramp D Settlement Measurements
10-26-2012 Emankment
Construction Finished
2-5-2013 Surcharge Removed
-14-13-12-11-10
-9-8-7-6-5-4-3-2-10123456789
101112131415161718192021222324
0 14 28 42 56 70 84 98 112 126 140 154 168 182
Emb
ankm
en
t H
eigh
t (F
eet)
Days Since VWSS Installed
EmbankmentHeightLightweight FillHeightSS Reading No. 1-5:00SS Reading No. 2-12:00SS Reading No. 3-19:00
Sett
lem
en
t
PROJECT CONSTRUCTION
• MSE Walls • Lightweight Aggregate Borrow Material • 2’, and 3’ Granular Surcharge (Normal Weight) • 3’ and 4’ Triangular Spacing PVD • Geotechnical Instrumentation
Ramp B Ramp A
Traffic Control Stage 2
Traffic Control Stage 2
Ramp A Construction
US 17 Bypass NB
Traffic Control Stage 2
Ramp B Construction
US 17 Bypass NB
Construction Ramp A & B (PVD Installation)
Construction Ramp A & B (PVD Installation)
Construction Ramp A & B (MSE Wall Embankment Construction)
Construction Ramp A & B (MSE Wall Embankment Construction)
2 Feet Thick Cover of Borrow Silty or Clayey Soil Materials
Lightweight Aggregate Borrow Material
4 Feet Long Biaxial Geogrids Placed on 2 Feet Vertical Spacing
Sloped Lightweight Aggregate Embankment
Sloped Lightweight Aggregate Embankment
Ramp C Ramp D
• MSE Walls • Lightweight Aggregate Borrow Material • 1’, 2’, and 4’ Granular Surcharge (Normal Weight) • 3’ and 4’ Triangular Spacing PVD • Geotechnical Instrumentation
Traffic Control Stage 3
Constructed Ramps A/B (Completed – Stage 2)
Existing NB = Stage 3 SB
Ramps C/D Under Construction -Stage 3
Traffic Control Stage 3 (Ramps A & B Completed)
Traffic on Ramp A
Existing NB = Stage 3 SB
Traffic Control Stage 3 (Ramps A & B Completed)
Traffic on Ramp C
Construction Ramp C
US 17 Bypass SB
Traffic on Ramp C
Construction Ramp C
US 17 Bypass SB
Ramp D
Construction Ramp C
US 17 Bypass SB
Traffic on Ramp B
Ramp D
Construction Ramp D
South Bridge Approach North Bridge Approach Backgate Bridge
• MSE Walls • Lightweight Aggregate Borrow Material • 1’, 2’, and 3’ Granular Surcharge (Normal Weight) • 3’ Triangular Spacing PVD • Geotechnical Instrumentation • Bridge Abutment DSM (South 30’ x 133’ x 50’deep – North 30’ x 141’ x 70’deep ) • Longitudinal DSM (South 5’ Wide / North 8’ Wide)
Traffic Control Stage 4
CLOSING
Project Status
• Preliminary Engineering: 2008 - 2009
• Right of Way Acquisition: 2009 - 2011
• Construction: 2011 – 2014
– Approximately 33% complete
Under Construction
• Traffic Stage 3 – Ramps C/D have been constructed and will be ready to be paved in the near future
• Traffic Stage 4 – Scheduled to Start April 2013
– Deep Soil Mixing : Test Section / Test Pile / Production
– Bridge Abutment Foundation Construction
– Construct Bridge Approach Embankment & MSE Walls
• Geotechnical techniques are speeding up construction
• Positive feedback regarding construction traffic congestion and shifts
• Estimated project completion: Fall 2014
• Project Cost $75.8 Million
Closing
Thank You Any Questions?