Standardizing the Pressuremeter Test for Determining p-y curves

Standardizing the Pressuremeter Test for Determining p-y curves for Laterally Loaded Piles Principal Investigators Paul J. Cosentino, Ph. D. , P. E. Edward H. Kalajian Ph. D. , P. E. Ryan Stansifer Ph. D. Florida Institute of Technology J. Brian Anderson University Of North Carolina Charlotte p Project Manager David J. Horhota, Ph. D. , P. E. State Geotechnical Materials Engineer Florida Department of Transportation y

Thanks to our Students Farid Messaoud – Civil Engineering Sunil Sundaram – Civil Engineering Kishore Katamuri – Computer Science TJ Misilo - Engineering Management M. Allen Cottingham- Civil Engineering

Objectives Instrument the Control Unit Standardize the Testing Method

Approach Test Sands and Clays PPMT, DMT, CPT, SPT Develop Software and Hardware Design Instrumentation System Pressure Volume Develop Data Acquisition System Software (APMT) Develop Second Software Package for Manually Recorded Data (Prova. FIT 2005) Analyze Raw and Reduced Data Manual versus Instrumented Data Comparisons to Published Data Develop Standard Testing and Reduction Method

Pencel Pressuremeter Tubing Pressure Gage Volume Counter Probe

Friction Reducer and Smooth Cone Tips Friction Reducer Cone Tip Smooth Cone Tip 1. 335 inch 33. 9 mm 1. 280 inch 33. 0 mm

Testing Sites Archer Landfill – Sands Cape Canaveral – Sands and Clays Florida Institute of Technology – Sands

Typical Results with Calibrations

Explanation of Test Results Limit Pressure Lift-off or Initial Pressure

Pushing the Pencel Pressuremeter Results in Significant Time Savings Conventional Boring and PMT Testing 50 feet per day including 5 PMT tests Cone Pushed PPMT Testing Ave: 1: 45 min per 50 ft sounding with 5 manual tests Does the PPMT give reliable results?

Elastic Modulus vs Limit Pressure FIT Sands

DMT and PPMT Lift-off FIT Sands

PPMT vs DMT Elastic Modulus FIT Sands

PPMT vs DMT Lift-Off Pressures Cape Canaveral Clays

Smooth vs Friction Moduli Cape Canaveral Clays 15 Smooth Cone Tip Friction Reducer Cone Tip Ratio of Er/Eo 12 9 6 3 0 2. 5 10. 5 12 Depth (m) 13. 5 15

Concerns Addressed by Automation Is resulting stress-strain data realistic? Can Pushed PPMT data be correlated to existing information Can Recording--Analyzing errors and time consumption be improved Can adjustments during testing be standardized Volume injection rate Time between readings Probe length and diameter Friction reducer cone tip or smooth cone tip Unloading sequence Total volume injected

Typical Test Procedure Insert probe to desired depth Inject equal volume increments of water & record pressures strain controlled Apply three calibrations to raw data; Membrane resistance Volumetric expansion Hydrostatic pressure About 75 pieces of data recorded

Instrumentation Data Collection Data collected with software Graphs from data acquisition Pressure - Volume, Volumetric Strain or Hoop Strain Pressure - Time Volume - Time Data Analysis Determine Engineering Properties Elastic Moduli (equations initial Eo and rebound Er) Limit Pressure pl Initial Pressure po

Typical APMT Screen

Automated Pencel PMT Laptop with Data Acquisition Electrical Connections

Automated Components Linear Potentiometer Spacer Blocks Pressure Transducer Cylinder Linkage LCD Monitor Electronics Module

Advantages of the Automated PPMT Improves data collection process. Reduces potential for human error. Improves the quality of the data. Results in significant cost savings.

Instrumented PPMT Time Savings Estimated Time per Task Manual Control Unit Instrumented Control Unit Collect Data Read + record; 5 min Automatically Recorded Data Transfer and Reduction 25 minutes Evaluate Engineering Parameters 20 minutes 10 minutes Total 50 minutes 10 minutes Performed during test

Field Evaluation Preliminary Testing – Lake Alice - UF Campus Final Testing in Sands and Clays PPMT – over 300 Tests CPT - 22 Soundings DMT - 50 Tests Conventional Borings - 6 Sand Sites at All Faiths Center - Florida Tech Campus at Archer Landfill - Near Gainesville Clay Site - Port Canaveral - Puerto Del Rio Condos

Analytical Evaluation Smooth Cone Tip versus Friction Reducer Tip Testing Procedure Engineering Properties

Analysis of Automated System in Sands Test Conducted above GWT at Archer Site, Gainesville Tip resistance qc values taken from CPT data Average from 20 tests Test Depth (m) Schmertmann’s Published Correlation qc/ Pl Schmertmann’s Published Correlation Eo /qc Automated Test Correlation Eo /qc 1. 80 5 -6 5. 01 2 1. 91 4. 00 5 -6 5. 78 2 1. 86 5. 80 5 -6 5. 16 2 2. 10 Automated Test Correlation qc / P l

P-y Curves P-y curve based on PMT Method using Robertson et al. (1985) method.

Lateral Load Case Histories Seven Sites Evaluated Driven Piles (4) and Drilled Shafts (3) Cohesionless (4) and Cohesive (3) Pressuremeter and Dilatometer Tests Performed by Dr. Anderson UNCC Developed Measured vs Predicted Load. Deflection Pile Head PPMT and DMT Non Standard Pressuremeter Testing

Broadway Bridge Daytona Beach

Salt Lake City Airport

Analyses Statistical Linear Regression with R 2 Qualitative Very Good < 10% error conservative Acceptable < 25 % error conservative Slightly Unconservative < 10 % over prediction Unconservative > 25 % over prediction

Statistical Results

Qualitative Results

Recording Record initial and final membrane lengths and diameters per sounding

Advantages of Prova. FIT 2005 File Management Data Import feature from MS Excel Data Export to MS Excel and Text file Ability to see all related files of a sounding at one place

Pressure vs Volume

Pressure vs Volumetric Strain

Pressure vs Radial Strain

Engineering Calculations

Conclusions The Pushed PPMT saves Time and Yields Accurate Soil Properties Standardization Use 32 mm (1. 26 inch) I. D. volume calibration tube Record initial and final membrane lengths Use Provafit Insitu® for data reduction after hand recorded test Use APMT for data reduction during automated test Automation Linear potentiometer with 6 -inch travel Stainless steel pressure transducer with -10 to +500 psi range In-situ s-e curves, along with critical properties for other analyses

Recommendations Develop correlations to soil classification, point bearing (qc) etc. , during test Develop software to directly give p-y curves based on a given pile size and shape Improve the PPMT Lateral Load database

The End Any Questions for the Professor(s)?