PME’s Geotechnical Instrumentation Monitoring System ODOT GEO-ENVIRONMENTAL CONFERENCE April 21 – 23, 2015 Presented by: Mike Tardif, R.G., C.E.G. ODOT.

PME’s Geotechnical Instrumentation Monitoring SystemODOT

GEO-ENVIRONMENTAL CONFERENCE

April 21 – 23, 2015

Presented by:

Mike Tardif, R.G., C.E.G.ODOT Region 2 Engineering Geologist

Darren Beckstrand, R.G., C.E.G.Cornforth Consultants Senior Associate

Geologist

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Geotechnical Instrumentation

• Instrumentation is used to answer geotechnical engineering questions– How far down is groundwater?– Will dewatering be required for excavation?– How should the bridge foundation be designed?– Is the ground moving? Where? How fast? Should the

road be closed?– Is the embankment settling?– Are my structures moving? Is the ground also moving?– Are groundwater levels making the ground move?

• The criticality of these questions dictate the sophistication of a geotech instrumentation program

Scaling Instrumentation Program to Fit Needs

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• Basic Level– Simple instruments, short time periods, lower risk

• Standpipe piezometers, survey hubs, inclinometers, manual readings

• Intermediate Level– Electronic instruments, short to moderate time period,

no real time data collection needs• Vibrating wire piezometer sensors, in-place

inclinometer tilt sensors, continuous datalogging without comms

• Critical Level– Electronic instruments, moderate to long duration, real

time data collection• Comm network with real time collection, alarms and

notification protocol

Scaling Instrumentation Program to Fit Needs

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• Basic Level– Standpipe piezometers

Basic Instrumentation Program

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• Basic Level– Standpipe piezometers– Inclinometers


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• Basic Level– Standpipe piezometers– Inclinometers– Survey Markers


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• Intermediate Level– Vibrating wire piezometers

Intermediate Instrumentation Program

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• Intermediate Level– Vibrating wire piezometers– In-place inclinometers


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• Intermediate Level– Vibrating wire piezometers– In-place inclinometers– Settlement Systems


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• Intermediate Level– Vibrating wire piezometers– In-place inclinometers– Settlement Systems– Others

• Extensometers• Strain gauges• Tilt sensors• Pendulums• Displacement • Rainfall• Soil moisture• And more!


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• Intermediate Level– Vibrating wire piezometers– In-place inclinometers– Settlement Systems– Others

• Extensometers• Strain Gauges• Tilt sensors• Pendulums• Displacement • Soil moisture• And more!


• Simple dataloggers– Single or multi-sensor

dataloggers

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• Advanced Level– Same sensors– Advanced datalogging system with radio network

Advanced Instrumentation Program

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Geotechnical Instrumentation at PME

• Basic Level (Preconstruction)– 41 Standpipe Piezometers– Two Inclinometers

• Intermediate Level (Construction, 2008 to now) – 234 Vibrating Wire Piezometers– 166 Inclinometers (18,323 ln ft)– 39 In-place Inclinometers– 6 Weir Level Monitors– 25 Settlement Systems

• Advanced Level (2013 to now)– 13 MCUs, 2 radio repeaters, 1 Satellite Modem– 7 Continuous Inclinometer Strings

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Examples from PMEPiezometers – Monitoring Effects of Drain Installations

Pre-drainage water levels

Spike Caused by Horizontal Drain Installation

Water level decrease

Dampened winter storm spikes

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Examples from PMEInclinometers – Decreased movement rates post drainage

Pre-drainage movement rates

Drainage installation and induced movement

Reduced Landslide Movement Rates Post Drainage

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Examples from PMEDrain Weir Monitoring – Groundwater Withdrawal after Storms

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Examples from PMESettlement Monitoring – Test Fill Foundation Settlement

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Examples from PMESettlement Monitoring – Culvert Foundation Settlement

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Next up, the Observational Approach

PME’s Geotechnical Instrumentation Monitoring System ODOT GEO-ENVIRONMENTAL CONFERENCE April 21 – 23, 2015 Presented by: Mike Tardif, R.G., C.E.G. ODOT.

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