Testing the dynamic properties and performance of a building under human-induced excitation

Emperor House is a modern office building currently under construction at Exeter Business Park, UK. The three-storey building has an internal floor space of 2400sqm, which consists of two wings and a central core.


In collaboration with Summerfield Developments (SW) Ltd (client), WSP-Parsons Brinckerhoff (consultant) and Midas Group (contractor), the Vibration Engineering Section (VES) at the University of Exeter successfully carried out a test of the building’s dynamic properties and performance under human-induced excitation.


State-of-the-art equipment was utilised in the test to identify the modal properties of the first floor of the building and perform extensive walking tests.



The test results will be analysed in detail. The final aim is to help structural engineers to design such buildings at minimal cost, while vibration serviceability requirements are maintained.

To find out more about the Vibration Engineering Section, visit our website.


To find out more about the Vibration Engineering Section, visit our website.

To find out more about the Vibration Engineering Section, visit our website.



VSimulators: Human factors simulation for motion and serviceability in the built environment

Vibration Engineering staff led by Professor James Brownjohn have been awarded a £3.25m grant by EPSRC to create a new simulator facility for study of interactions between humans and the moving built environment. The simulator will use a mechanical hexapod to drive a 4 metre square platform in all 6 axes with accelerations and displacements representing typical movements of a range of civil structures (floors, footbridges, grandstands) where comfort of human users and occupants is critical.

The simulator will be fully instrumented with an array of force plates, inertial and optical motion capture and head mounted virtual reality for nine occupants.

This grant is part of a large investment by EPSRC and both Universities of Exeter and Bath; a University of Bath team let by Anthony Darby have simultaneously been awarded a £1.65m grant for a complementary simulator for study of large amplitude building sway at low frequencies typical of tall and super-tall buildings.

Co-funding from Universities of Bath and Exeter for infrastructure, additional equipment and staffing beyond the three year initial EPSRC funding amounts to £2.42m, and the total project cost will be £7.25m.

VSimulators will provide cross-disciplinary capability to address deficiency of information on human factors, environment and structure motion on engagement with the built environment:

  • For slender sustainable structures, e.g. tall buildings, vibration serviceability is a critical design constraint poorly (if at all) addressed by design codes, hence a need for bespoke customised acceptance criteria.
  • Effects of low level vibrations coupled with sound/noise, light, pollution, smell, temperature, humidity, and other environmental factors which contribute to the mysterious sick building syndrome.
  • Mobility and rehabilitation in an aging population cost the National Health Service £bns per year. Rehabilitation of motion-impaired patients is a major problem.

The Exeter investigator team comprises:

James Brownjohn                   Principal Investigator, Structural Dynamics

Alex Pavic                               Co-Investigator, Vibration Serviceability

Paul Reynolds                         Co-investigator, Vibration Control

Vicki Goodwin                        Co-investigator, Healthcare, Rehabilitation

Mateusz Bocian                      Co-investigator, Virtual Reality

The Bath team comprises:

Antony Darby                         Principal Investigator, Structural Engineering

Sukumar Natarajan                Co-investigator, Environmental Design

David Coley                            Co-investigator, Building Occupant Behaviour

Ian Walker                              Co-investigator, Environmental Psychology

A facility manager is being recruited to work with research and commercial users to maximise facility use. Experimental officers will manage operations at the Exeter and Bath sites, James Bassitt at Exeter will supervise the Bath EO.

The international advisory team are:

Kenny Kwok                           University of Western Australia

Tracy Kijewski-Correa        University of Notre Dame

Yukio Tamura                        Tokyo Polytechnic University

Robert Brown                        Memorial University, Newfoundland

Industrial support for VSimulators is provided by AKT II, Arup, Atkins, Buro Happold, Emirates DNEC Engineering Consultants, Flint&Neill (now COWI), Foster and Partners, Swallow Acoustics Consultants (now part of Thornton Tomasetti), Waterman Structures and WSP|PB.

VSimulators is affiliated to UKCRIC and will be a national research facility available to RCUK-funded researchers for research projects as well as to private industry at commercial rates.

Links to publicity in national and local media can be found here.

Impact of wobbly bridges and sky-scrapers on human health to be tested in government-funded research centre

The impact of vibrations from very tall buildings and wobbly bridges and floors on people’s health and wellbeing is to be researched in a new £7.2 million government-funded national research facility.

Check out the rest of the story about the launch of VSimulators on the University of Exeter’s website


In the meantime, here is some other coverage of the story:

Wobbly skyscrapers may trigger motion-sickness and depression, warn experts (Source: The Telegraph)

Did you feel the earth move? (Source: The Plymouth Herald)

Exeter and Bath get £7.2m to find out if wobbling is bad for us (Source: Devon Live)

Do YOU work in a skyscraper? Wobbly high-rise buildings may trigger motion-sickness, insomnia and depression (Source: Daily Mail)

Wobbly skyscrapers may trigger motion-sickness and depression, warn experts (Source: MSN Health)
Are skyscrapers making you sick? A new £7 million study is trying to find out (Source: Architecture magazine)
Are tall buildings good for your health? (Source: About Manchester)
VR vibration simulators set up to study effects of working in a skyscraper (Source: Engineering & Technology)
Universities to set up lab to measure fear and nausea caused by tall buildings (Source: Global Construction Review) http://bit.ly/2nr89Rc


Launch of Novel Vibration Control System for Floor Structures

The result of many months’ work on an EPSRC funded project was revealed on 16th February at a launch event for a novel vibration control system. The event attracted directors, associates and senior engineers from major companies including WSP, Atkins, Foster and Partners and Arup. They witnessed the launch of a proof-of-product system, which was developed by Professor Paul Reynolds and Dr Emma Hudson to address the current gap between the proven academic successes of active vibration control for floor structures and the lack of adoption by industry to date.

The technology works in a similar way to that of popular noise-cancelling headphones: an accelerometer is used to measure the vibrations of the structure; the resulting signal is processed by a real-time computer and then an actuator generates the required force to cancel out the measured vibrations.

Graphic KM

This new product combines all these components into one standardised compact unit that can be more easily installed within structures. Crucially, the system has been developed with robustness and minimised cost as priorities, to complement the proven high performance of this technology. In this way, the system is significantly more commercially attractive to potential adopters, meaning that the benefits of enhanced vibration performance are now a step closer to being realised.

Graphic 2

A lunchtime seminar was organised at the Institute of Structural Engineers HQ in London to highlight the potential benefits of this new product to key industry contacts. A joint presentation by Paul Reynolds and Emma Hudson was followed by a live demonstration of the new system.

Graphic 3

Graphic 4

To find out more about the Vibration Engineering Section, visit our website.


Vibration survey of Fastnet Lighthouse, December 2016

To find out more about the Vibration Engineering Section, visit our website.


On Monday  5th December a team of researchers for the EPSRC STORMLAMP were flown from Castletown-Bearhaven, Ireland to Fastnet Rock, 6 miles off the Irish mainland.

James Bassitt, Karen Faulkner and Ian Moon from University of Exeter, along with Alessandro Antonini from Plymouth University and Athanasios Pappas from UCL planned to stay overnight after carry out a modal test of the lighthouse, while James Bassitt installed a remote acceleration monitoring system.

Test team on Fastnet Rock. From left: Athanasios, Alessandro, Karen, Ian, James

Following a series of modal tests on lighthouses at Les Hanois (Guernsey), Wolf Rock (Cornwall), Longships (Cornwall) and Bishop Rock (Scilly Isles), James, Ian and Alessandro had developed skills in modal testing using an array of accelerometers and an electrodynamic shaker. While these lighthouses are accessed via a helideck constructed above the lantern, Fastnet is accessed by a helipad on a utility building constructed on the cramped space of the rock with stone steps up to the lighthouse. A team of five was used at Fastnet to manage the equipment transfer to and from the upper level of the lighthouse and to allow James Bassitt to install and commission the monitoring system.

Unloading the helicopter
View of helipad from lighthouse lantern room

First measurements started at 2PM on Monday and continued until 9.30PM, with the APS shaker providing a narrow-band swept sine signal to excite structural modes that are typically in the range 4-6 Hz for this type of structure. The accelerometer array was left recording data overnight as storm winds and occasionally waves battered the lighthouse.

Shaker and bi-axial accelerometer pair in lighthouse kitchen.
Lighthouse acceleration and shaker force data used for modal identification.

While on site James Bassitt deployed a drone for aerial footage at medium and close range.

Weather conditions of wind and sea spray overcame the drone after 11 minutes of flying the machine was returned to base with full manual control after which it was unserviceable. The short flight provided spectacular views of the rock and lighthouse.

James Bassitt operating Phantom drone from helipad

Fastnet Rock is notorious for bad weather, particularly fog, hence its existence. From Tuesday 6th until Friday 9th fog was severe enough to prevent helicopter landing, stranding the team. While having more than the mandatory supply of emergency rations the team were very happy when a break in the fog allowed the pilot to make two trips to pick up crew and equipment. The Exeter team, who travel with the equipment by van and ferry arrived in Exeter late on Saturday 10th.

Without a retrofitted helideck, Fastnet Lighthouse is a relatively ‘clean’ structure for which to create a mathematical model.  Using the experimental modal test data and masonry stiffness estimates obtained on site using a Schmidt Hammer UCL researchers on the STORMLAMP project will be able to create a high-fidelity model which is intended to be used to estimate wave loads using response data provided by the monitoring system.

Two more lighthouse modal tests are lined up for 2017; one is likely to be Dubh Artach off the Scottish West coast and Eddystone Lighthouse off Plymouth.

To find out more about the Vibration Engineering Section, visit our website.



Modal test of Bishop Rock Lighthouse

STORMLAMP researchers from Exeter and Plymouth concluded a sequence of measurements on an offshore rock lighthouse in the South West with a modal test of Bishop Rock lighthouse.

Bishop Rock is a massive structure, built on a rocks four miles south west of the Scilly Isles, that sheer from 45m deep in the Atlantic Ocean. The first structure, completed in 1858, was strengthened in 1881 by building a new structure around the existing lighthouse and extending the height by 12m to 44m above mean high water.

The present structure is by far the largest of the the four lighthouses studied in the STORMLAMP project, which also include: Les Hanois ,Wolf Rock and Longships.


On a very wet and windy September Monday, James Bassitt, Ian Moon (Exeter ian_james_selfie.jpg) and Alessandro Antonini (ale_daq.jpg) flew from St Just (Land’s End) airport to carry out a sequence of vibration measurements using accelerometers aligned horizontally at the top of the lighthouse.


After an energetic exercise laying out, connecting and configuring the sensors, horizontal accelerations were measured in the lower entrance level, engine rooms, bedroom, kitchen, service and battery rooms, lantern level and helideck (ian_helideck.jpg).


Response due to ambient conditions of strong winds and relatively benign waves was measured, as well as the effect of artificial excitation using a 140 N electro-dynamic shaker (shaker.jpg). Measurements started at around 1PM and were completed within two hours.


Unfortunately, the strong winds were quickly followed by low visibility on Monday afternoon, shutting down Trinity House helicopter flights and stranding the team overnight. Happily the fog horn no longer operates at Bishop Rock, dining facilities were available (dinner.jpg) and the eerie effect of the powerful twin lantern beams

provided some entertainment. The team escaped when the fog lifted on the Tuesday afternoon.


The modal test data are being used to evaluate the structure and provide the means for inverse identification of wave loads. The next STORMLAMP mission will be to Fastnet Lighthouse in December.

The video is by Peter Cox a wonderful landscape photographer based in Ireland.


VES team completes another successful data gathering exercise, at Wolf Rock

Following a successful modal test at Les Hanois lighthouse, off the coast of Guernsey, the Vibration Engineering Section embarked on a data gathering exercise at Wolf Rock lighthouse 15km southwest of Land’s End, Cornwall. This was the second in a planned sequence of modal tests of offshore rock mounted lighthouses around the British Isles, as part of the EPSRC-funded project STORMLAMP (STructural behaviour Of Rock Mounted Lighthouses At the Mercy of imPulsive waves).

After fears that the testing would be delayed, due to a dense blanket of fog over the sea at Sennen Cove, the team for Wolf Rock, comprising James Bassitt (photo 5), VES Experimental Officer, Research Fellow Emma Hudson (photo 7), Laboratory Technician Ian Moon (photo 4) and Alessandro Antonini, Research Fellow in the School of Marine Science and Engineering at the University of Plymouth (photo 8) set off for the lighthouse from St Just Airport by helicopter.

Photo 2


Due to the bulk of the 350kg equipment, including a horizontal shaker, amplifiers, laptops, cabling, cameras and accelerometers, it took two helicopter journeys, courtesy of Trinity House, to transport the Wolf Rock team to the lighthouse where, on arrival, they decanted the equipment into the service room at the top of the lighthouse and installed the computers in the battery room, lowering equipment throughout the levels by rope.

Photo 3 – inside the lighthouse

As well as carrying out modal tests in real time, the team installed accelerometers throughout the levels of the lighthouse, to capture data and measure the response of the structure during stormy weather.

Despite high winds coming off the land across the sea, the modal tests were successful, and the team left the lighthouse after seven and a half hours.

James Bassitt, who managed the data acquisition and on-site modal analysis, said: “The whole exercise was logistically harder than at Les Hanois, because the lighthouse was narrower, taller and access to the helideck was restricted.

“It was difficult to carry out the modal testing, because the background noise from the wind was far outweighing the forces we were generating. But we persevered and completed the testing successfully.”

The next data gathering exercise will take place at Longships Lighthouse, off the coast of Lands End, in August 2016.


World experts converge in Exeter to tackle structural vibration as ‘global challenge’

Millenium BridgeExperts in vibration serviceability of civil engineering structures from across the globe met at the University of Exeter over two days to discuss the growing challenge of vibrating structures. The best known example of this problem was the ‘wobbly’ Millennium Bridge in London, a case that brought the field of vibration serviceability from obscurity into the limelight 16 years ago.

To read more, see

Transverse Load Distribution characteristics of Exe North Bridge

The Exe North Bridge (Figure 1) is one of the two almost identical adjacent bridges crossing River Exe and forming a big roundabout in Exeter, UK. It is 60m long and consists of three spans, resting on two wall type pier structures in the river and abutments at the ends. It was constructed in 1969, so it is very close to its 50 years of designed service life.

Figure 1
Figure 1. Exe North Bridge spanning the River Exe

The Vibration Engineering Section supported The University of Exeter undergraduate engineering student project “Analysis of transverse load distribution of Exe North Bridge superstructure”.

Figure 2
Figure 2. Undergraduate engineering student Nick Trump installing strain transducers on the deck soffit.

The north span of the test structure was instrumented with 12 strain transducers, which made it possible to study the load shedding characteristics of the deck structure under moving load. As a test vehicle, a four-axle, 32 tonne lorry was used to obtain a quasi-static strain response. The load test was performed overnight to avoid disturbing traffic. The truck made several passes in each lane, stopping every time for 30-45 seconds to record static strain (Figure 2.).

Figure 3
Figure 3. 32 tonne, 4-axle lorry remaining stationary over the bridge to record static strains.

The load test revealed that, although the structure is nearing its 50 years of designed life, it still retains significant strength reserves.

Figure 4
Figure 4. VES researchers Zandy Muhammed and Farhad Huseynov supervising undergraduate student Nick Trump.