Note: Long-duration shaking with dominant horizontal component is the most damaging to buildings!

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1 Marlin Mine, Guatemala Interpretation of Blast-, Earthquake-, and Traffic- Induced Vibrations at and in the Vicinity of the Mine by: Neven Matasovic Geosyntec Consultants 2100 Main Street, Suite 150 Huntington Beach, California (714) MEM Offices, Guatemala City, Guatemala May 2010

2 Outline Introduction Vibration Types Marlin Mine Location, Layout and Relevant Site Information Blasting Available Data and Recording Procedure Approach to the Interpretation of the Blasting Records Interpretation of the Blasting Records and Development of Site-Specific Specific Attenuation Relationship Interpretation of Earthquake- and Traffic- Induced Vibrations Conclusions 2

Not all Vibrations are the Same Low Intensity / Short Duration / Horizontal Component Dominant Blasting Low Intensity / Medium Duration / Vertical Component Dominant Traffic

3 Not all Vibrations are the Same Low Intensity / Short Duration / Horizontal Component Dominant Blasting Low Intensity / Medium Duration / Vertical Component Dominant Traffic High Intensity / Long Duration / Horizontal Component Dominant Earthquakes Note: Long-duration shaking with dominant horizontal component is the most damaging to buildings! 3

4 Marlin Mine - Location 4

5 Marlin Mine Layout Blasting Locations and Landmarks 5

6 Marlin Pit - Blasting Videos 6

7 Interpretation of Blasting Records - Approach n./s) Peak Particle Velocity (i Possible Damage in. Disturbingor Annoying Perceptible Imperceptible p Strongly Perceptible 0.75 in./s Drywall Barely Perceptible 0.50 in./s Plaster in. 2.0 in./s NoDamage Frequency (Hz) Chart to the left was developed d by the United States Bureau of Mines; based upon 50 years of experience. Chart is used globally to limit and/or assess blast-induced damage. Safe Level for Blasting Vibration for Houses (USBM, 1980) Human Perception Thresholds (TRRL, 1986) 7

8 Interpretation of Blasting Records rticle Velocity (in./s) in. Possible Damage 0.75 in./s Drywall 0.50 in./s Plaster in. 2.0 in./s No Damage Legend Safe Level for Blasting Vibration for Houses (USBM, 1980) 2008: 180 m m 2008: 250 m m 2008: > 300 m 2009: 90 m m 2009: 250 m m 2009: > 300 m 2010: 100 m m 2010: 250 m m 2010: > 300 m Peak Par Frequency (Hz) 8

9 Extrapolation Blast-induced vibrations at a distance can be assessed based upon the principles used in Earthquake Engineering develop an Attenuation Relationship Site-specific ifi attenuation ti relationship can be developed from blasting data as explained on subsequent slides 9

11 Site--Specific Attenuation Model Site 0.5 in./s - Possible Plaster Cracking (USBM, 1980) Best Fit 2 x Best Fit 4 x Best Fit 8 x Best Fit 2008: 180 m m 2008: 250 m m 2008: > 300 m 2009: 90 m m 2009: 250 m m 2009: > 300 m 2010: 100 m m 2010: 250 m m 2010: > 300 m Peak Particlle Velocity (in./s) P Distance (m )

12 Predictions based on 8x Best Fit i 0.50 in./s Plaster in in./s Drywall in. Possible Damage 2.0 in./s No Damage /s) e Velocity (in./ Peak Particl in./s (400 m from Blast) 0.23 in./s ( m from Blast) Legend q y( ) Safe Level for Blasting Vibration for Houses (USBM, 1980) Blast Vibration Calculated using Attenuation Model 2008: 180 m m 2008: 250 m m 2008: > 300 m 2009: 90 m m 2009: 250 m m 2009: > 300 m 2010: 100 m m 2010: 250 m m 2010: > 300 m 0.14 in./s (1200 m from Blast) Frequency (Hz) 12

13 Earthquake-Induced Vibrations in./s Drywall Possible Damage 2.0 in./s Legend Safe Level for Blasting Vibration for Houses (USBM, 1980) Peak Pa rticle Velocity (i in./s) in./s Plaster 0030in in in. No Damage 2010 Earthquake Records Earthquake Data (Calculated using Attenuation Relationshio) PPV from the 23 February 2010 Earthquake exceed blast-induced vibrations (vector sum of 3 components) estimated values include 11 strongest events Frequency (Hz)

14 Traffic-Induced Vibrations 14

15 Traffic-Induced Vibrations - Interpretation Peak Parti icle Velocity (in n./s) Possible Damage in. Disturbing or Annoying Perceptible Strongly Perceptible 0.75 in./s Drywall Barely Perceptible 0.50 in./s Plaster in. 2.0 in./s NoDamage Legend Safe Level for Blasting Vibration for Houses (USBM, 1980) Human Perception Thresholds (TRRL, 1986) Site-Specific Traffic-Induced Vibration Records (3.5 m - 16 m from centerline of the road) Imperceptible Frequency (Hz) 15

16 Engineering Interpretation - Buildings Horizontal Shaking Vertical Shaking Buildings Can Sustain Significantly ifi Larger Loads in a Vertical than in a Horizontal Direction 16

17 Engineering Interpretation - Buildings Horizontal Shaking Vertical Shaking Buildings Can Sustain Significantly ifi Larger Loads in a Vertical than in a Horizontal Direction 17

18 Engineering Interpretation - Slopes Horizontal component of shaking is far more damaging to slopes than its vertical counterpart 18

19 Conclusions By far, the largest-intensity/damage potential ti vibrations at and in the vicinity of the Marlin Mine were induced by historic and recent ( ) earthquakes. Blasting-induced induced vibrations are of short duration and of insignificant intensity at distances exceeding 400 m from the blast. Traffic-induced induced vibrations are mostly in vertical direction, of short duration, and of lower intensity than their blasting and earthquake-induced counterparts. 19

20 Questions? 20

Modeling Fault Reactivation, Induced Seismicity, and Leakage during Underground CO2 Injection

Modeling Fault Reactivation, Induced Seismicity, and Leakage during Underground CO2 Injection Jonny Rutqvist A.P. Rinaldi 1, F. Cappa 1,2 1 Lawrence Berkeley National Laboratory, California, USA 2 Geoazur,