PME’s Geotechnical Instrumentation Monitoring System ODOT 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 4

Geotechnical Instrumentation 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 5

Geotechnical Instrumentation Basic Level – Standpipe piezometers Basic Instrumentation Program 6

Geotechnical Instrumentation Basic Level – Standpipe piezometers – Inclinometers Basic Instrumentation Program 7

Geotechnical Instrumentation Basic Level – Standpipe piezometers – Inclinometers – Survey Markers Basic Instrumentation Program 8

Geotechnical Instrumentation Intermediate Level – Vibrating wire piezometers Intermediate Instrumentation Program 9

Geotechnical Instrumentation Intermediate Level – Vibrating wire piezometers – In-place inclinometers Intermediate Instrumentation Program 10

Geotechnical Instrumentation Intermediate Level – Vibrating wire piezometers – In-place inclinometers – Settlement Systems Intermediate Instrumentation Program 11

Geotechnical Instrumentation Intermediate Level – Vibrating wire piezometers – In-place inclinometers – Settlement Systems – Others Extensometers Strain gauges Tilt sensors Pendulums Displacement Rainfall Soil moisture And more! Intermediate Instrumentation Program 12

Geotechnical Instrumentation Intermediate Level – Vibrating wire piezometers – In-place inclinometers – Settlement Systems – Others Extensometers Strain Gauges Tilt sensors Pendulums Displacement Soil moisture And more! Intermediate Instrumentation Program 13 Simple dataloggers – Single or multi-sensor dataloggers

Geotechnical Instrumentation Advanced Level – Same sensors – Advanced datalogging system with radio network Advanced Instrumentation Program 14

Geotechnical Instrumentation Advanced Level – Same sensors – Advanced datalogging system with radio network Advanced Instrumentation Program 15

Geotechnical Instrumentation Advanced Level – Same sensors – Advanced datalogging system with radio network Advanced Instrumentation Program 16

Geotechnical Instrumentation Advanced Level – Same sensors – Advanced datalogging system with radio network Advanced Instrumentation Program 17

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 18

Examples from PME Piezometers – Monitoring Effects of Drain Installations 19 Pre-drainage water levels Spike Caused by Horizontal Drain Installation Water level decrease Dampened winter storm spikes

Examples from PME Inclinometers – Decreased movement rates post drainage 20 Pre-drainage movement rates Drainage installation and induced movement Reduced Landslide Movement Rates Post Drainage

Examples from PME Drain Weir Monitoring – Groundwater Withdrawal after Storms 21

Examples from PME Settlement Monitoring – Test Fill Foundation Settlement 22

Examples from PME Settlement Monitoring – Culvert Foundation Settlement 23

Next up, the Observational Approach 24