new products for static load testing ... - pile dynamics · vibrating-wire strainmeters (“sister...

New Products for Static Load Testing – Vibrating-Wire Strain

Gages, and the Static Load Tester (SLT) System

Van E. Komurka, P.E., D.GE

Pile Dynamics, Inc. Representative Days

September 27 – 29, 2017

New Products for Static Load TestingTopics Outline

• New PDI Product – Vibrating-Wire Strain Gages• Surface-Mounted

• Strainmeters

• What is a Static Load Test?

• Static Load Test Instrumentation

• New PDI Product – Static Load Tester (SLT) Datalogger System• SLT Data Acquisition Box (DAB)

• SLT Computer

Surface-Mounted Vibrating-Wire Strain Gages

• Mounts to the surface of a driven or bored pile

• Mounts above-grade on concrete and steel piles to provide additional information on applied load and/or the test pile’s elastic modulus

• Can be mounted below-grade on steel piles to determine load in a static load test pile at different elevations – determine shaft resistance distribution – correlate to dynamic testing results – refine design (potentially shorten piles)

• Gages will come with a smart connector

Vibrating-Wire Strainmeters (“Sister Bars”)

• Are cast into the concrete of a prestressed concrete pile, a concrete-filled pipe pile, or a bored pile

• Are generally tied to other reinforcing

• Can be installed below-grade within concrete to determine load in a static load test pile at different elevations – determine shaft resistance distribution –correlate to dynamic testing results – refine design (potentially shorten piles)

• Gages will come with a smart connector


• New PDI Product – Vibrating-Wire Strain Gages• Surface-Mount

• Strainmeters




• SLT Computer

• Load is applied at the pile head

• Potential instrumentation:• Above-Grade:

• Jack Pressure

• Applied Load

• Head Movement (test pile, and reaction piles)

• Pile Strain (test pile, and reaction piles)

• Tilt

Top-Loading Static Load Test

Top-Loading Above-Grade Instrumentation

Top-Loading Static Load Test

• Load is applied at the pile head

• Potential instrumentation:• Below-Grade:

• Pile Strain

• Telltales

• Tilt

Top-Loading Below-Grade

Instrumentation

Top-Loading Below-Grade

Instrumentation

For prestressed concrete piles, sister bar

strainmeters are installed in the casting yard

Bi-Directional Static Load Test

• Load is applied somewhere along the pile length (below-grade)

• Instrumentation potentially read:• Above-Grade:

• Head Movement

Bi-Directional Static Load Test

• Load is applied somewhere along the pile length (below-grade)

• Instrumentation potentially read:• Below-Grade:

• Jack Pressure

• Jack Expansion

• Pile Strain

• Telltales

Bi-Directional Below-Grade Instrumentation

Need for a Datalogger

• Static load tests may require many types of instrumentation to be read by a datalogger

• Static load tests may require many numbers of instrumentation to be read by a datalogger

• In photo at right:

• Test pile had 74 below-grade strain gages alone

• Took an entire day to wire the datalogger in the field



• Strainmeters




• SLT Computer

Static Load Tester (SLT) Data Acquisition Box

(DAB)• Compact, lightweight, water-

resistant

• Reads virtually all types of static load test instrumentation

• 30 hours of battery life

• Storage capacity for 4,000 readings (more coming soon)

• 16 input channels per box: 12 analog, and 4 digital

Static Load Tester (SLT) Data Acquisition Box

(DAB)• Additional boxes can be

connected together to provide as many channels as required (coming soon)

• All channels can be configured by user, or automatically when using PDI sensors with a smart chip

• PDI will install smart-chip connectors on customers’ existing instrumentation at no charge



• Sister Bars




• SLT Computer

Static Load Tester (SLT) Computer

• Currently consists of a dedicated SLT computer

• With an SLT module installed, a PDA-8G unit can be used (coming soon)

• Interfaces with SLT Data Acquisition Box via proprietary serial data cable, or Bluetooth®, (WiFi coming soon)

• Saves all readings it receives

• SiteLink® capable

Static Load Tester (SLT) Computer

• Programmable save intervals

• User-configurable real-time plots of:

• Load vs. Displacement

• Load vs. Time

• Strain vs. Displacement (coming soon)

• Strain vs. Time (coming soon)

• Generates user-configurable data tables, and plots, in PDF and JPG format for download to user’s PC

Questions / Comments?

new products for static load testing ... - pile dynamics · vibrating-wire strainmeters (“sister...

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