Seismic Imaging, Inc. offers a complete range of vibration monitoring services for construction and mining activities. In today's land development and construction market, it is essential to monitor and document vibration levels for compliance with project specifications, industry standards, or state regulations.
Our staff is also experienced in the assessment of potential problems, the review of blast plans, and in geophysical instrumentation. Establishing a friendly and informed relationship with the property owners in the vicinity of new construction is always a part of our monitoring program. The following table describes the most common services.
On-site vibration monitoring
Monitoring of vibration and acoustic levels is conducted by our personnel using
the latest digital instrumentation and processing software to verify compliance
with government and industry guidelines. Seismographs are installed near
structures close to blasting or other vibration producing activities, like pile
driving or vibratory rollers, to digitally record ground vibration and air
overpressure. The recording is analyzed by the instrument for peak particle
velocity, air overpressure and corresponding wave frequencies. If desired, peak
particle velocities can be converted to acceleration or displacement
records.
Long-term monitoring
Seismographs can be installed at a jobsite and programmed to record vibration
levels for weekly or monthly periods for projects that require long-term
monitoring. We use cable television boxes, modified to secure seismographs for
this type of monitoring. These seismographs can be programmed to self-trigger
or continuously monitor in bar graph mode. Self-triggering can provide a
sampling of the highest vibration levels in peak particle velocity with
accompanying frequencies and air overpressure levels in a waveform format. Bar
graph mode continuously records vibration in peak particle velocity and air
overpressure levels displaying the results in a bar graph format.
Pre-blast and construction surveys
Accurate and clear documentation of pre-existing conditions in structures
adjacent to the job site is often vital to handling damage claims. Our
personnel survey the interior and exterior of nearby buildings or structures and
record written and photographic evidence of cracks, separations and other
cosmetic or structural flaws present before the vibration producing activity
begins. Pre-blast and construction surveys aid in mitigating complaints of
changed conditions in the structure.
Post-blast and damage claim evaluations
In the event of a vibration-related damage claim, our personnel can analyze the blasting or construction records, survey the alleged damage, and submit an unbiased opinion on the validity of the claim. Technical support and expert witness in litigation can also be provided.
Blast design and vibration consulting
Years of blast vibration experience, knowledge of geology, and analysis of test
shot data provide the basis of our consulting services in blast design and
recommendations of effective monitoring programs. Statistical analysis of site
specific seismic data can aid in maximizing production while maintaining
acceptable vibration levels offsite.
Regression Analysis
After vibration levels for blasting conducted in a specific area have
been measured, we can analyze this data and make
predictions as to the expected vibration levels
at given distances to structures and pounds of
explosives detonated per delay.
Single Hole Study
By analyzing the frequency content of vibration generated by detonating one
hole, surface delays can be recommended to adjust vibration frequencies or
reduce the vibration intensities at nearby structures.
