High resolution ground vibration monitoring system satisfies residential and local authority requirements

The robust Menhir ground vibration monitor eficiently measures vibrations, shocks and tremors.

Bedford-based AcSoft Sound & Vibration (www.acsoft.co.uk) has recently supplied two Menhir (Modular Enhanced Intelligent Recorder) ground vibration monitors from Semex Engcon to long-standing customer, Pace Consult, for a Rydon Construction Ltd project at The Broadway in Ealing, which comprised demolition work on residential properties and derelict warehouses.

Pace Consult is a multidisciplinary consultancy, offering a full suite of ‘concept to completion’ services across three dedicated divisions: acoustics, vibration and air tightness. From consultancy practices nationwide, Pace Consult delivers innovative, competitive and practical solutions, ensuring projects achieve the necessary compliance on time and within budget.

The simple, flexible and robust Menhir ground vibration monitor efficiently measures vibrations, shocks and tremors generated by construction and building works, as well as mining, demolition and quarrying activities.

Joan-Carles Blanco, Associate Director at Pace Consult comments: “We have been working with AcSoft’s sister business Svantek for five years and used its leading noise and vibration instrumentation very successfully across a wide range of projects during that time.

He continues: “When we were asked to provide ground vibration monitoring to satisfy both resident and local authority requirements during major demolition works, Svantek referred us to AcSoft and its web-based, high resolution Menhir system.

“When used in conjunction with smart data centre software, the Menhir is capable of accurately recording, analysing and transferring data from complex vibration monitoring applications in harsh environments.”

The two AcSoft Menhir systems were installed at an adjacent property within the residential corridor of the construction site and inside the derelict warehouse being demolished where they provided continuous ground vibration monitoring for five months.

An optional complete analysis module is also available, allowing reports to be automatically generated and transmitted electronically in freely adjustable intervals. It incorporates a selectable alarm output to designated personnel using SMS or email.

Joan-Carles continues: “The smart data centre software offers a fully integrated cloud solution which proved invaluable when power to the Menhir devices on the demolition site was cut for a period of time. It enabled us to still get quick access to data and device status at any time from PC, tablet or smartphone.

“At one point the Menhirs detected increased ground vibration when heavy plant machinery was being used and immediately sent an alarm to the site manager via SMS.”

Allowing easy operation with minimal training, the intuitive Menhir can be customised to suit individual monitoring requirements and configured for immediate set up and use. A simple configuration tool means settings can be changed at any time, with quick and full access to the monitor’s parameters and values, as well as all analytical options and results.

For maximum flexibility, the Menhir is available with internal and external SIM card slots. The latter enables the user to determine which provider is transmitting data, without having to open the device. The system can also be equipped with a low cost M2M solution.

An internal battery provides up to 48 hours operating autonomy, depending on transmission requirements. The Menhir can be placed with up to 15° offset on the ground. The innovative measurement device detects the offset and corrects it automatically. It can also be aligned with the three integrated levelling screws so no mounting platform is required.

The Menhir offers a dynamic range > 130dB at 100 measurements per second per channel, as well as a bandwidth from 1 to 400 Hz.

Joan-Carles concludes: “Overall the Menhir ground vibration monitors worked extremely well across this project and we were given the same excellent level of service and support from the team at AcSoft that we have come to expect of their sister business, Svantek.”