2013 USU Pile Driving

Pile Instrumentation

Dynamic Vibrating Wire Measurements

Introduction

Outline

• Campbell Scientific Background

• Pile Instrumentation

– Sensors

– Lateral Loading

– Pile Driving

• Data

– Collection

– Real Time Viewing

• Questions

Campbell Scientific Inc.

Founded 1974

Data Acquisition Systems and Sensors

– Quality Measurements

– Rugged, Reliable

– Support

Training

– General programming for DAQ

– Infrastructure instrumentation

CR5 (1975)

Datalogger

CR1000 (2005)

Datalogger

CDM-305

Dynamic Vibrating Wire Reader

Representative Projects

Bridges – Tappan Zee

– Brooklyn

Foundations – Minneapolis I-35

Dams – Wolf Creek

– TVA

Slope Stability – Kennecott

– I-70

0

500

1000

1500

2000

2500

3000

3500

4000

4500

2/4/08 3/5/08 4/4/08 5/4/08 6/3/08 7/3/08 8/2/08 9/1/08

Load (K

ips)

Sh2Lev1

Sh2Lev2

Sh2Lev3

Sh2Lev4

Begin

Footing

Construction

Begin

Column

Construction

Begin Box Girder Segment

Cantilevering

Closure jacking to

close 3" gap

Removal of false

work under span 1

I-35 Foundation Response

6 month time history

Bottom of shaft.

Soft rock

Competent rock

Surface

Applications generally driven by users – Owners

– Researchers

– Engineers

– Regulators

Systems are like legos – Rugged

– Flexible

Geotechnical Instrumentation

Typical System

2013 PDPI Instrumentation Goals

Lateral pile test

– Load

– Deflection

– Vertical Load Test

Pile Driving

– Gauge Survival

– Observations

Lateral Monitoring

Monitoring Equipment

– CR1000 Datalogger

– AVW200 Vibrating

Wire Interface

– Multiplexer

Instruments

– Tiltmeter

– Stringpot

– Inclinometer

– Strain Gauge

Dynamic Pile Monitoring

Monitoring Equipment

– Laptop

• Observe live data

• Record Data

– CDM-VW305

• Dynamic Vibrating Wire Interface

– Sample Rate: 20Hz to 333Hz

– Geokon Vibrating Wire Strain

Gauges

Vibrating Wire for Pile Driving

Vibrating Wire, never used dynamically

Campbell CDM-VW300

– 20-333 MHz

Geokon 4000 series gauges

Test Objectives

– Sensor durability

– See what we see

DVW Tool

PC Based

– Live Graphs, PC based acquisition

Data Acquisition and Logging

Collect during testing

Campbell Real Time

Monitoring and Control

(RTMC)

Static data on CR1000

Dynamic data on PC

Static Axial RTMC Dashboard

Static Lateral RTMC

Output

-50

0

50

100

150

200

250

-0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1

L

O

A

D

K

I

P

s

DISPLACEMENT Inches

AXIAL DISPLACEMENT vs LOAD

Geokon_3000

Output Data

-0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0 20 40 60 80 100 120 140 160 180 200

DIS

PL

AC

EM

EN

T (

INC

HE

S)

LOAD (KIPs)

DIAL GAGE READINGS VS STRING POTENTIOMETER MEASUREMENTS

Potentiometer Average

Dial Gage Average

-2.5

-2

-1.5

-1

-0.5

0

0.5

0 5 10 15 20 25 30

Dis

pla

ce

me

nt (in

ch

es)

Load (KIPS)

LATERAL LOAD VS DISPLACEMENT

Top…Bottom…

Output Data

-0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0 20 40 60 80 100 120 140 160 180 200

DIS

PL

AC

EM

EN

T (

INC

HE

S)

LOAD (KIPs)

DIAL GAGE READINGS VS STRING POTENTIOMETER MEASUREMENTS

Potentiometer Average

Dial Gage Average

Output Data

-0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0 20 40 60 80 100 120 140 160 180 200

DIS

PL

AC

EM

EN

T (

INC

HE

S)

LOAD (KIPs)

DIAL GAGE READINGS VS STRING POTENTIOMETER MEASUREMENTS

Potentiometer Average

Dial Gage Average

Data Analysis

Data will be provided on Friday

Thank You

Questions