Instructional Objectives WHAT CAN WE MEASURE? Applications. GE 5471 ROCK ENGINEERING CH 12 Monitoring WHY DO WE NEED MONITORING?

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GE 5471 ROCK ENGINEERING CH 12 Monitoring Dr. Norbert H. Maerz Missouri University of Science and Technology (573) 341-6714 norbert@mst.edu Instructional Objectives 1.

Fully compare the pros and cons of optical and mechanical monitoring methods for a rock slope that may be failing. 4.

6. List all the mechanical monitoring devices that could be used on a rock slope. 7. Propose a response chart for a give set of monitoring instruments in a given scenereo. 8.

1 GE 5471 ROCK ENGINEERING CH 12 Monitoring Dr. Norbert H. Maerz Missouri University of Science and Technology (573) Instructional Objectives 1. Justify the additional expense of monitoring in rock engineering projects. 2. For a given situation, propose a monitoring program, with appropriate monitoring devices. 3. Fully compare the pros and cons of optical and mechanical monitoring methods for a rock slope that may be failing. 4. Fully compare the pros and cons of pneumatic and electrical measurements for measuring water pressure at the base of a dam. 5. Explain why vibrating wire devices make the best monitoring transducers. 6. List all the mechanical monitoring devices that could be used on a rock slope. 7. Propose a response chart for a give set of monitoring instruments in a given scenereo. 8. Explain the pitfalls of individual monitoring systems. 9. Explain installation issues in monitoring. WHAT CAN WE MEASURE? Displacement ( deformation, movement, strain) Water pressure (head) Load (stress) Sound (vibrations) Applications Investigation of on going instability Get design data Verify data predicted by numerical modeling, and used in design Protection of construction workers To evaluate the effectiveness of ground treatment/stabilization Monitor long term stability WHY DO WE NEED MONITORING? 1

2 Components of Monitoring Sensor or transducers Data transmission system (mechanical rods, hydraulic tubes, wires, radio telemetry) Readout or recording device (dial gauge, digital readout, data transfer) Types of Monitoring Devices Optical Mechanical Pneumatic Electrical Optical Surveying Optical Photogrammetry Optical LIDAR Mechanical Systems Extensiometer Crack meters Faro.com 2

3 Tape Extensiometer Crackmeter Pneumatic Hydraulic 3

4 Electrical Systems Strain Gauges Strain gauges LVDT s Vibrating Wire Systems LVDT (Linear Velocity Displacement Transducers) VIBRATING WIRE SYSTEMS BOREHOLES Extensiometers Electrical shear strips Time domain reflectometry Inclinometers 4

5 Extensiometers Rod Extensiometer Extract: Pg. 387, Rock Engineering, Franklin & Dussealt.. Settlement Hook Electrical shear strips Time domain reflectometry Inclinometer Extract: Pg. 391, Rock Engineering, Franklin & Dussealt.. 5

6 Monitoring of Ground Vibrations Groundwater Stress Change Temperature Sensors Thermocouples Thermistors 9d/Ceramic_disc_capacitor.png PLANNING, INSTALLATION, AND OPERATION OF MONITORING SYSTEMS Response Chart What is normal behavior? What constitutes unacceptable behavior? Need an appropriate response. 6

7 PLACEMENT-COVERAGE- ORIENTATION INSTRUMENT FEATURES Adequate? Reliable? Manual or digital monitoring? Calibration? Instrument drift? Installation Who installs? Contractor quality control. Timing. Accessibility. Protection Reading and Reporting Slide Show Who? Training? Frequency? Graphic Presentation of Data. 7

8 EDM Settlement, Crack Tell-tales Demec Gauge Tape Extensometer 8

9 González de Vallejo and Ferrer 9

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Chapter 1. Introduction

Chapter 1. Introduction 1.1 Background of the Proposed Research The measurement of temperature has been playing a critical role in various technical areas from civilian to military applications. According to all recent major