| February 2019 |
Newsletter #1:
Identification of data points associated with the establishment of the Z curve.
|
C.H. Dowding |
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| March 2019 |
Newsletter #2:
Details of older, distressed structures whose cosmetic cracking define the lower bound of the Z curve. |
C.H. Dowding |
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| April 2019 |
Newsletter #3:
Linkage of the Z curve with response spectra demonstrates its consistency with the principles of structural dynamics. |
C.H. Dowding |
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| May 2019 |
Newsletter #4:
Reasons for the boundaries and corners of the Z curve in RI 8507. |
C.H. Dowding |
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| June 2019 |
Newsletter #5:
Nuances of choosing the pulse velocity and frequency to populate the Z curve and use of zero crossing to determine frequency
|
C.H. Dowding |
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| November 2019 |
Newsletter #6:
Threshold or Cosmetic, Hair Sized Cracks Form the Basis of Vibration Control limits
|
C.H. Dowding |
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| November 2019 |
Newsletter #7:
Probability of blast induced cracking below 12.7 mm/s (0.5 ips) is zero
|
C.H. Dowding |
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| January 2020 |
Newsletter #8:
Concrete, brick, and concrete masonry unit (CMU) portions of structures are stronger than plaster and gypsum drywall
|
C.H. Dowding |
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| February 2020 |
Newsletter #9:
Not even repetitive vibration at 12.7 mm/s (0.5 ips) can produce cosmetic cracking
|
C.H. Dowding |
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| March 2020 |
Newsletter #10:
Vibrating Roller Excitation of Residential Structures Produces Limited Numbers of Localized Peak Responses
|
C.H. Dowding |
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| April 2020 |
Newsletter #11:
Crack Response of Nevada Test House to Vibrations Induced by Construction Equipment Verifies Conservatism of Limits for Continuous Cyclic Excitation
|
C.H. Dowding |
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| May 2020 |
Newsletter #12:
Dynamic excitation of full scale CMU walls establishes a global strain criterion for cosmetic cracking by repetitive cyclic loading
|
C.H. Dowding |
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| June 2020 |
Newsletter #13:
Use of Response Spectra and Principles of Structural Dynamics to Verify the Shape of the Z Curve and to
Supply Guidance for Future Research
|
C.H. Dowding |
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| July 2020 |
Newsletter #14:
Extensive Search for Cosmetic Cracks Induced by Low Frequency Excitation Results in Observation of
Only Two Cosmetic Cracks at PPV's above 12.7 mm/s (0.5 ips)
|
C.H. Dowding |
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| September 2020 |
Newsletter #15:
Use of Pseudo Velocity Response Spectra (PVRS) to
Assess Possible Cases of Increased Probability of Cosmetic Cracking
|
C.H. Dowding |
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| November 2020 |
Newsletter #16:
Long-term or climatologically-induced crack response overwhelms vibratory response both
at ordinary and high vibration levels as well
|
C.H. Dowding |
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| December 2020 |
Newsletter #17:
Micro-meter crack response verifies
zero probability of cracking below peak particle velocities of 12.7 mm/s (0.5ips)
|
C.H. Dowding |
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| January 2021 |
Newsletter #18:
Use New NUVIB 2.1 User Manual to Calculate Response Spectra from Seismograph Data Files and
Strains from Velocity Response Time Histories.
Also Visit the Revitalized ACM Website to Explore Its New Content
|
C.H. Dowding |
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| January 2021 |
Newsletter #19a:
Scaled Distance Relationships in 8507 and the
Origin of the High Confidence Equation PPV = 438(ft/W1/2)
-1.52
|
C.H. Dowding |
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| January 2021 |
Newsletter #19b:
Challenges of use of standard log-log presentation of measured
decay or attenuation of peak particle velocity with scaled distance
|
C.H. Dowding |
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| January 2021 |
Table 1 of RI 8507
|
C.H. Dowding |
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| February 2021 |
Newsletter #20:
Full Scale Field Testing of Buried Pipe Integrity Demonstrates that a
Variety of Steel Pipe Sizes Can Withstand Peak Particle Velocities Well Above 125 mm/s
|
C.H. Dowding |
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| March 2021 |
Newsletter #21:
Stresses in compliant (flexible) pipes can be calculated from peak particle velocities
based upon the assumption that pipe and plane wave ground strains are equal
|
C.H. Dowding |
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| July 2021 |
Newsletter #22:
Smaller diameter pipes with smaller flexibility ratios behave
in a manner similar to those with larger diameters and larger flexibility ratios
|
C.H. Dowding |
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| August 2021 |
Newsletter #23:
Stresses in Buried Pipe with Large Diameter to Thickness Ratios Can Be Calculated
from Ground Strains for Comparison with Allowable Levels of Specified Minimum Yield Stress (SMYS)
|
C.H. Dowding |
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| October 2021 |
Newsletter #24:
Whenever Blasting Occurs Closer Than Two Blast Hole Depths (within crater zone)
Explosive Gas Pressure Induced Rock Block Movement Becomes a Major Concern
|
C.H. Dowding |
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| November 2021 |
Newsletter #25:
Allowable Peak Particle Velocities for Segmental Pipe through
Limitation of Angular Rotation and Compressive Stresses in Pipe Joints
|
C.H. Dowding |
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| December 2021 |
Newsletter #26:
Employing USBM RI 8507 Recommendations for
Assessing the Possibility of Cosmetic Cracking in Engineered Structures
|
C.H. Dowding |
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| January 2022 |
Newsletter #27:
Measurement of Occupant Induced Crack Response Shows
Larger Incidence of Occupant Induced than Blast-Induced Events
|
C.H. Dowding |
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| February 2022 |
Newsletter #28:
Importance of Yearly Cycles of Crack Response and An Extreme
Weather or Occupant Induced Event that Caused a Cosmetic Crack
|
C.H. Dowding |
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| February 2022 |
Newsletter #29:
Inclusion of Amplitude in Calculation of the Probability
of Occurrence of a Dynamic Event during the Single, Yearly Period of Vulnerability
|
C.H. Dowding |
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| March 2022 |
Newsletter #30:
Measurement of both Occupant- and Blast- Induced Crack Response Allows Calculations of their Relative Probabilities of Exceeding the Maximum Yearly Crack Response
|
C.H. Dowding |
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| April 2022 |
Newsletter #31:
Earthquakes Differ by Orders of Magnitude from Construction Vibrations in Energy, Dominant Frequency and Waveform
|
C.H. Dowding |
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| May 2022 |
Newsletter #32:
Peak Ground Motions Produced by Earthquakes and Construction Depend upon Energy and Distance from the Source
|
C.H. Dowding |
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| June 2022 |
Newsletter #33:
Both Earthquake and Construction Vibration Design Spectra Are Based on Strain from Relative Displacement Response
|
C.H. Dowding |
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| July 2022 |
Newsletter #34:
Large Urban Structures Respond Little to
Blast Induced High Particle Velocities with Ultra High Dominant Frequencies
|
C.H. Dowding |
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| August 2022 |
Newsletter #35:
Measurements of Low Relative Displacements and Deamplification with Ultra High Frequency Excitation Validate Use of Single Degree of Freedom and Impulse Models
|
C.H. Dowding |
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| September 2022 |
Newsletter #36:
Non-synchronous Excitation & Differences in Ratios of Wavelength to Structure Size Can Lead to
Differences in Type of Response for Large Urban and Residential Structures
|
C.H. Dowding |
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| October 2022 |
Newsletter #37:
Structural Strains Induced in Large Urban Structures by High Frequency Excitation Pulses Are Small when
Calculated from Time Correlated Velocity Time Histories of Structural Response
|
C.H. Dowding |
|
| November 2022 |
Newsletter #38:
Response of Three Story (Three Degree of Freedom) Model Shows that the
Highest Strains Are Produced by Excitation Motions at the Fundamental (Natural) Frequency
|
C.H. Dowding |
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| December 2022 |
Newsletter #39:
Successful Blasting Within Grand Central Station Train Shed New York City. NY
|
C.H. Dowding |
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| January 2023 |
Newsletter #40:
High Particle Velocities at Ultra High Frequencies Do Not Produce High Strains
|
C.H. Dowding |
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| February 2023 |
Newsletter #41:
Rapid attenuation of column strains with distance shows that large urban structures like the train shed and buildings along Park Ave. are not coherently or synchronously excited by high frequency blast excitation
|
C.H. Dowding |
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