Vibrations from Construction Activities
Vibrations from construction activities such as blasting, rock excavation, general excavation, pile driving, and tunneling can lead to property damage, litigation, project delays, and increased costs. Automated vibration monitoring provides a reliable and cost-effective way to control for excessive vibrations, protecting project owners, construction companies, and nearby properties.
Monitoring Construction Vibration
Construction activities generate ground vibrations that propagate outward in waves, causing particle motion at the wavefronts. The velocity and frequency of particle motion are the basis for most regulatory limits for vibration.
Monitoring Equipment: Essential components include a triaxial geophone to sense particle motion; a vibration monitor, also called a seismograph, to record and process signals from the geophone; and software to produce compliance reports.
Additional hardware and services, such as weatherproof enclosures, solar panels, wireless data retrieval, smartphone alerts, and automated reports, can increase the efficiency and reduce the cost of monitoring.
The Monitoring Process: The vibration monitor samples the three channels of the triaxial geophone continuously, checking incoming values against limit thresholds.
At regular intervals, the monitor stores the peak particle velocity (PPV) value for each channel. These values are used to generate a histogram report later. If any incoming value exceeds the limit threshold, the monitor records all of the incoming values for a few seconds. These values are used to generate a waveform report later.
Alerts: Any exceedance of the limit thresholds should generate an alert so that site engineers can take mitigating actions to bring vibrations within regulatory limits.
Compliance Reports: Histograms are used to demonstrate that the site has been actively monitored and that vibrations have complied with regulatory limits. Waveform reports show the distribution of velocities and frequencies during an exceedance event and are used for further analysis of the event.
Advantages of Automation
Automated Vibration Monitoring is a rental service from GEO-Instruments that provides reliable, cost-effective monitoring.
Unattended Monitoring: Automated systems can record, process, alert, and report without the presence of an operator. This autonomous operation provides significant cost savings.
Protected and Powered: Automated systems are supplied in weatherproof enclosures with larger batteries and solar or AC charging, allowing them to stay on site and on line for long periods of time. Manual monitors must be retrieved nightly for protection and battery charging.
Automated Data Transfers: Automated systems send data offsite for processing at regular intervals. Manual systems require hands-on data management, which typically delays processing until the end of the day.
Timely Alerts: Automated systems send alerts to smartphones and PCs when an exceedance event occurs. They also support on-site alarm units. Manual systems cannot send alerts.
Automated Reports: Automated systems generate compliance reports at specified intervals. This saves time, eliminates complicated workflows, and frees staff for less repetitive work. Reports can also be customized to the client’s requirements.
Easy Access to Data: Automated systems store data and reports on a secure server, ensuring that compliance records are safe and complete. Reports are accessed easily by browsing to the password-protected project website.
Enhanced Safety: Automated systems provide safe, unattended monitoring in high-risk areas such as tunnels, railways, and crowded construction sites.
PVM – Portable AVM
The PVM adds automation and a strong weatherproof case to a portable vibration monitor.
The AVM is supplied with a weatherproof enclosure for wall or pole mounting.
The SVM is a self-standing AVM supplied with a solar panel and weatherproof case.
RVM – Rugged AVM
The RVM features a heavy steel enclosure and shatterproof solar panel to provide extra protection and power autonomy.
Automated Vibration Monitors
AVM rentals eliminate nearly all handling of data and provide reliable, cost-effective monitoring for longer term projects. Powered by battery, solar panel, or AC, an AVM includes a weatherproof enclosure, an Instantel vibration monitor and geophone, and a cell modem with service. Recorded readings are automatically transferred offsite to a GEO server for processing. Alert notifications are automatically sent to PCs and smartphones. And finally, histograms and waveforms are automatically printed to PDF reports, optionally emailed to stakeholders, and stored on a secure project website for easy access.