This report aims to outline a number of attachment methods for the geophones used in vibration measurements. On behalf of Bjerking AB and their department for environmental control and vibration, a new attachment method has been developed that works on today’s building designs. Suggested mounting methods include some methods with their main stronghold in the foundation’s outermost layer and some with mounting in the concrete inside the foam. The best method is to drill through the foam and with a concrete screw - suitable for concrete drilling without plug - and anchor the geophone in the concrete. Due to the difficulty to get a hold of these screws with the required length and diameter for the current case, a similar approach with available material has been developed. This method includes a hammer drill, a threaded rod, an expander and two nuts. The conclusion drawn is that the attachment of the concrete is preferable and that this can be achieved with relatively simple means. Other methods require extensive knowledge of the building’s design as well as advanced and time-consuming tools.

This project has revolved around finding better ways of overseeing vibrations of the gearbox at a wind power station. The gearbox has been a huge problem at the stations located at Gässlingen and the sooner the warning of an incoming breakdown is at hand the more money you can save from preparations. The work has been carried out together with Askalon AB in cooperation with consults from ÅF. Askalon is a company with a department focused on overseeing vibrations and it is in collaboration with that department the work has been carried out.   During this work, new positions for the sensors and new methods of gathering and analyzing data have been worked out. This was then implemented at a wind power station to be tried out on site. The measurement has been overseen online via remote control and the results have been analyzed in a program called AMS Suite: Machinery Health Manager.   The new type of measurement shows that some kind of damage has been done to a specific part of the gearbox and that there is a risk it might escalate. However the measurement used today has not yet alarmed and therefor the conclusion made from this is that the project has been successful. Therefor it is time to refresh the overseeing of vibrations.

Vibrationsmätning är inget nytt fenomen men många företag anser sig ändå skeptiskatill den abstrakta metoden. Samma skepticism finns inte vid ett läkarbesök där doktornlyssnar efter oljud med sitt stetoskop, ändå är likheterna slående. Med dagens teknikär det möjligt att diagnostisera en maskins olika beståndsdelar efter skador genom attanalysera det unika vibrationsmönster de bidrar med. Detta arbete syftar att minska denna barriär med hjälp av en introduktion till de olikabegrepp och val som finns inom vibrationsteknisk analys som hjälpmedel för underhåll.Slutligen presenteras en implementeringsmall där ekonomi och tillgänglighet anses varamest vitala inför framtida beslut. / Even though vibration measurement is not a new phenomenon, many businesses stillremain sceptical towards the somewhat abstract method. Same scepticism does not existwhen you visit the doctor and he uses his stethoscope to listen after abnormalities inthe sound pattern, even though the similarities are striking. With todays technology it ispossible to diagnose a machine’s different parts in search for damages by analysing theunique vibrationpatterns they provide. This study aims to close this gap with the help off an introduction to the different termsand choices that exist in vibration analysis as a tool in preventive maintenance and finallyto present guidelines for implementation where economy and availability is consideredmost pivotal for future decisions.

<p>In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box. Measures have been taken to protect the prototype against external disturbances such as inappropriate supply voltages and transients on the input stages.Software has been written for the microcontroller to perform the various measurements required by the prototype. These include RMS, integration and filtering. Special attention was paid to the latter by implementing filters based on lattice wave digital structures. This structure results in a very efficient implementation. Consideration is taken to be able to generate arbitrary filters independent of the characteristics and design method. To save time the microcontroller implements all the algorithms without any floating point numbers.Furthermore, both hardware and software are adapted for future industrial use. The finished prototype supports a number of communication interfaces in which Modbus (RS-485) and current loop communication can be mentioned.The final result is a very good performing platform with strong future potential.The work was commissioned by the consulting firm Syncore Technologies AB at their office in Mjärdevi, Linköping. The project has, in total, taken 10 weeks and occurred during spring 2010.In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box. Measures have been taken to protect the prototype against external disturbances such as inappropriate supply voltages and transients on the input stages.Software has been written for the microcontroller to perform the various measurements required by the prototype. These include RMS, integration and filtering. Special attention was paid to the latter by implementing filters based on lattice wave digital structures. This structure results in a very efficient implementation. Consideration is taken to be able to generate arbitrary filters independent of the characteristics and design method. To save time the microcontroller implements all the algorithms without any floating point numbers.Furthermore, both hardware and software are adapted for future industrial use. The finished prototype supports a number of communication interfaces in which Modbus (RS-485) and current loop communication can be mentioned.The final result is a very good performing platform with strong future potential.The work was commissioned by the consulting firm Syncore Technologies AB at their office in Mjärdevi, Linköping. The project has, in total, taken 10 weeks and occurred during spring 2010.</p>

In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box. Measures have been taken to protect the prototype against external disturbances such as inappropriate supply voltages and transients on the input stages.Software has been written for the microcontroller to perform the various measurements required by the prototype. These include RMS, integration and filtering. Special attention was paid to the latter by implementing filters based on lattice wave digital structures. This structure results in a very efficient implementation. Consideration is taken to be able to generate arbitrary filters independent of the characteristics and design method. To save time the microcontroller implements all the algorithms without any floating point numbers.Furthermore, both hardware and software are adapted for future industrial use. The finished prototype supports a number of communication interfaces in which Modbus (RS-485) and current loop communication can be mentioned.The final result is a very good performing platform with strong future potential.The work was commissioned by the consulting firm Syncore Technologies AB at their office in Mjärdevi, Linköping. The project has, in total, taken 10 weeks and occurred during spring 2010.In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box. Measures have been taken to protect the prototype against external disturbances such as inappropriate supply voltages and transients on the input stages.Software has been written for the microcontroller to perform the various measurements required by the prototype. These include RMS, integration and filtering. Special attention was paid to the latter by implementing filters based on lattice wave digital structures. This structure results in a very efficient implementation. Consideration is taken to be able to generate arbitrary filters independent of the characteristics and design method. To save time the microcontroller implements all the algorithms without any floating point numbers.Furthermore, both hardware and software are adapted for future industrial use. The finished prototype supports a number of communication interfaces in which Modbus (RS-485) and current loop communication can be mentioned.The final result is a very good performing platform with strong future potential.The work was commissioned by the consulting firm Syncore Technologies AB at their office in Mjärdevi, Linköping. The project has, in total, taken 10 weeks and occurred during spring 2010.

Skanska driver cirka 30 asfaltverk i Sverige. Något alla dessa verk har gemensamt är att driftsäkerheten är viktig då ett driftstopp på asfaltverket kan leda till höga kostnader ifallbeläggningsarbetet blir stillastående. Syftet med examensarbetet är att undersöka olika teknikersom används inom tillståndsbaserat underhåll och hur de kan appliceras på ett av Skanskas asfaltverk.Datainsamling skedde genom litteratursökning, dokumentstudier, observationer och intervjuer. Resultatet av litteratursökningen visade att det finns flera tekniker inom tillståndsbaserat underhåll. Några av de vanligaste teknikerna är mätning av vibrationer, temperatur och ultraljud. Alla inrapporterade driftstörning på Skanskas asfaltverk i region väst under 2022 kategoriserades efter vilken utrustning som orsakat stoppet. Analysen av störningarna visade att siktutrustningen stod för den största procentuella andelen av driftstoppstimmarna. Vid observationer och intervjuer framkom att haveri av sikten ofta leder till långa driftstopp och att det är svårt att upptäcka felen innan de inträffar. För att undersöka sikten på komponentnivå genomfördes en FEMA som visade att sprickbildning i plåtar, motorhaveri och felmonterade såll är de mest kritiska felorsakerna. För att mäta dessa fel valdes vibrationsmätning då denna metod ansågs ha störst sannolikhet att upptäcka de kritiska felen. Tre företag som arbetar med vibrationsmätning kontaktades för att diskutera olika lösningskoncept. Utifrån dessa tre lösningsförslag rekommenderades två koncept för fortsatt arbete. Det som skiljer lösningarna från varandra är att den ena innebär en större investering ekonomiskt och kompetensmässigt men ger möjlighet till mer detaljerad information. / Skanska operates approximately 30 asphalt plants in Sweden. One thing all these plants have in common is that operational reliability is important, as unplanned downtime at the asphalt plant can lead to high costs if asphalt paving work is interrupted. The purpose of the thesis is to investigate various techniques used in condition-based maintenance and how they can be applied to one of Skanska's asphalt plants.Data was collected through literature searches, document studies, observations, and interviews.The literature search showed that there are many technologies used in condition-basedmaintenance. Some of the most common techniques are vibration measurement, temperature measurement, and ultrasonic testing. All reported equipment failures at Skanska's asphalt plants in the west region in 2022 were categorized by the equipment that caused the downtime. Analysis of the failures showed that the screening equipment accounted for the largest percentage of downtime. Observations and interviews revealed that shutdowns of the screens are often long and that it is difficult to detect faults before they occur.To investigate the screen at the component level, a FMEA was carried out, which showed that cracking in plates, motor failures, and incorrectly installed screens are the most critical causes of failure. Vibration measurement was chosen to measure these faults as this method was considered to have the highest probability of detecting the critical faults. Three companies working with vibration measurement were contacted to discuss different solution concepts. Based on these three proposals, two concepts were recommended for further study. What differentiates the solutions from each other is that one entails a greater investment both financially and in terms of expertise but provides the opportunity for more detailed information.

From 2000 to 2015, the cost of operation and maintenance (including reinvestment) and traffic control has increased from approximately three billion to over nine billion Swedish kronor annually. By making more frequent measurements of track irregularities and identifying trends earlier, accurate and effective maintenance can be performed. Therefore, in the industry and academy, different measurement solutions are tested to measure the state of railroad tracks in a simple and more frequent manner. One of the solutions is to use measuring systems mounted on trains in regular traffic. By using regular scheduled services, a higher cost effectiveness regarding inspection frequency can be achieved. When the measuring equipment is mounted on freight trains, a measurement with considerably higher axle load can also be performed. In the course of this work, a literature study have been conducted and a number of scientific articles and reports have been studied at depth. There is a number of different systems that have been manufactured to be mounted on rolling stock in regular service. Different solutions are applied to perform the measurements. Acceleration sensors are robust and reliable, which is necessary because they will be mounted in an exposed environment. A difference that has been identified is the installation of accelerometer sensors that are either mounted before or after the primary suspension. Before suspension the sensors are mounted on the axle box and, after suspension the sensors are mounted on the train bogie. The engineering company Damill is working within monitoring solutions and has developed equipment for mounting on trains in regular traffic called Tracklogger. Earlier evaluations of the equipment have been made with focus on comparison with machine inspections. There is a difference between the technology used in track recording vehicles and the technology that Tracklogger uses, such comparison is not entirely appropriate. In discussion with Damill the focus of this work has been to see if recordings of switches can be linked to maintenance actions. Since the equipment is in the development stage it is important that the measurement data collected is critically reviewed with regard to what information it delivers. The measurements have been carried out on switches in the main train track on track number 119 between Luleå and Boden and the mining company LKAB's ore wagon has been a tool carrier.  Five out of eight cases, a maintenance action can be linked to reduced measured values of switches with fixed crossing points. In one case, maintenance action has increased the measured value. In two cases, there is no signifcant difference in the measured value associated with maintenance actions. In previous evaluation, it was determined that it is good repeatability in the measured position, but not as high repeatability in the measured size. A number of switches have been studied to check the repeatability of the measurement. As the train runs in acircle run in Luleå harbor, there will be a limited number of occasions the equipment is running in the same direction in combination with the sensors on the same axle in the bogie, which may effect the measurement results. When analyzing the repeatability of five passages where the direction of travel is not taken into account, it is determined that three out of five passages show a good repeatability. The repeatability of the measurement is suspected of being related to the condition, as significantly greater differences in the measured signal are obtained just before a maintenance action has been taken.

Detta arbete har genomförts på uppdrag av SCA Munksund, för att undersöka möjligheten att tillståndsövervaka hydraulpumpar med hjälp av smarta sensorer som mäter vibrationer och temperatur. Hydraulpumpar är svåra att tillståndsövervaka, och möjligheten att prediktera ett haveri i ett tidigt skede är väldigt svårt. Haverier på hydraulpumpar sker oftast inte direkt efter att ett fel har uppstått, utan efter en längre period, med däremot sker haverier på hydraulpumpar oftast utan förvarning och är mycket kostsamma för processindustrin, där materialkostnaden utgör en liten del jämfört med kostnaden som följd av produktionsförlusten. En möjlighet för bättre och effektivare tillståndsövervakning är att använda vibrationssensorer som i ett tidigt skede indikerar när pumpen avviker från sitt normaltillstånd, och på så sätt planera in underhållsarbete vid exempelvis nästkommande underhållsstopp, utan att behöva stoppa produktionen. Just därför har det valts att undersöka olika sensorparametrar för att identifiera hydraulpumparnas normaltillstånd, och utifrån det bestämma lämpliga larmgränser. Vibrationsmätningarna har genomförts under ca en månad på två hydraulpumpar, en som är relativt ny och en som är äldre. Huvudfokuset har varit att övervaka vibration och temperatur under varierande pumpbelastning/effekt och även att övervaka kolvslitage och lagertillstånd. Med användning av smarta vibrationssensorer har larmgränser kunnat identifierats för båda pumparna. Däremot måste fler mätningar utföras för att säkerställaatt de larmgränser som presenteras i denna rapport är korrekta och kan användas i framtiden. SCA Munksund har nu tillgång till alla mätningar och dokumentation som har utförts för båda hydraulpumparna, och kan nu arbeta vidare för att på sikt tillhandhålla mer specifika larmgränser. / This work has been carried out on behalf of SCA Munksund, to investigate the possibility of condition monitoring hydraulic pumps using smart sensors that measure vibrations and temperature. Hydraulic pumps are difficult to condition monitor, and the ability to predict a failure at an early stage is very difficult. Breakdowns on hydraulic pumps usually do not happen immediately after a fault has occurred, but after a longer period, but on the other hand, breakdowns on hydraulic pumps usually happen without warning and are very costly for the process industry, where the cost of materials constitutes a small part compared to the cost resulting from the loss of production. One possibility for better and more efficient condition monitoring is to use vibration sensors that indicate at an early stage when the pump deviates from its normal state, and in this way plan maintenance work at, for example, the next maintenance stop, without having to stop the production. Precisely for this reason, it has been chosen to investigate various sensor parameters to identify the normal state of the hydraulic pumps and based on that to determine suitable thresholds. Vibration measurements have been carried out for about a month on two hydraulic pumps, one that is relatively new and one that is older. The main focus has been on monitoring vibration and temperature under varying pump load/effect and also to monitor piston wear and bearing condition. With the use of smart vibration sensors, thresholds have been identified for both pumps. However, more measurements must be performed to ensure that the thresholds presented in this report are correct and can be used in the future. SCA Munksund now has access to all measurements and documentation that have been carried out for both hydraulic pumps and can now work further to provide more specific thresholds.

Soil-Rock sounding (jb-sounding) is a common method in Sweden, used to determine soil layering. An extension of this method, referred to as Acoustic Soil-Rock sounding, is currently under developement at KTH in Stockholm. This method uses the ground vibrations induced by drilling during jb-sounding. The aim is to investigate if additional information on the soil can be obtained by analysis of the vibrations, e.g. thin layers that cannot be registered by conventional jb-sounding.In this Master’s thesis, a further study of the method Acoustic Soil-Rock sounding has been undertaken to see whether the method is applicable or not. Furthemore, it is investigated whether it is possible to perform the vibration measurements on asphalt covered ground and obtain reliable results, alternatively whether it is possible to detect some systematic difference. This has been conducted as a field observation where the data has been collected during jb-sounding. The data, i.e. the vibration signal, was registered using geophones, one placed on asphalt and one on soil. Measurements from nine boreholes were performed in total; however, only eight of these have been analysed due to failing to register the depth signal properly in one case. The vibration signals have been processed using MATLAB to obtain the frequency spectra and spectrograms, to which the results of the jb-sounding and previous acoustic measurements have been compared.After analysis and comparison of the results, the conclusion was that Acoustic jb-sounding is an applicable method that ought to be developed further and the results from the measurements performed on asphalt were reliable. That is to say, no discernible difference could be deduced between measurements conducted on asphalt and soil. / Jord-bergsondering (jb-sondering) är en i Sverige vanlig metod för att undersöka jordens uppbyggnad. En påbyggnad av denna metod, kallad akustisk jb-sondering, håller för tillfället på att studeras vid KTH i Stockholm. Denna metod går ut på att mäta de vibrationer som uppstår vid markytan till följd av borrning, i samband med jb-sondering. Syftet är att undersöka huruvida kompletterande information från jordlager kan erhållas genom analys av vibrationerna, såsom tunnare lager som annars inte kan registreras av den konventionella jb-sonderingen.I det här masterarbetet har ytterligare undersökning om metoden akustisk jb-sondering genomförts för att först se huruvida metoden är applicerbar eller inte. Vidare studeras om det är möjligt att utföra mätningar även på asfalt och då erhålla tillförlitliga resultat, alternativt om det är möjligt att utläsa någon systematisk skillnad. Detta har genomförts som en fältstudie där data har samlats in i samband med jb-sonderingar. Vibrationssignalerna registrerades med geofoner placerade på jord samt asfalt. Totalt genomfördes mätningar vid 9 stycken borrhål, men endast 8 av dessa har analyserats då djupsignalen från ett borrhål inte registrerades. Vibrationssignalerna har sedan bearbetats i MATLAB för att ta fram frekvensspektrum och spektrogram som sedan har jämförts med resultat från jb-sonderingar samt tidigare studier.Efter analys och jämförelse av resultaten drogs slutsatsen att akustisk jb-sondering är en applicerbar metod som bör utvecklas vidare och att resultaten från mätningar utförda på asfalt var tillförlitliga. Det vill säga ingen större skillnad mellan mätningarna på jord respektive asfalt kan ses.

Trafikinducerade vibrationer: En studie om busskuddars påverkan på vibrationsnivåer i mark och byggnader. Erika Johansson Kling I Uppsala används busskuddar som en form av medveten ojämnhet i vägbanan för att sänka hastigheten och öka trafiksäkerheten på olycksdrabbade vägsträckor. Boende i bostäder belägna nära busskuddar har dock rapporterat att de ibland kan uppleva vibrationer kopplade till då tunga fordon passerar busskuddar som störande. Denna studie syftade till att kvantifiera vibrationsnivåer i mark och byggnader nära busskuddar samt utreda centrala faktorer som kan påverka vibrationsnivån och vibrationsutbredningen. Genom vibrationsmätningar i fält på fyra platser i Uppsala samlades data in och analyserades utifrån angivna frågeställningar. Resultatet bekräftade det som litteraturstudien belyste, att det är svårt att på ett generellt sätt beskriva vibrationsutbredningen och att den tydligt är platsspecifik. Vid samtliga undersöka platser kunde dock konstateras att vibrationsnivån i marken tenderar att vara en faktor mellan 2,5–32 högre då ett tungt fordon passerar en busskudde, jämfört med då det passerar en opåverkad referenspunkt längs med samma väg. Generellt avtog dessutom vibrationsnivån i marken med ökat avstånd från källan. Vilken vibrationsled som dominerade varierade dock både mellan platserna och för olika avstånd från källan. Vid en av de fyra mätplatserna förstärktes vibrationsnivån i byggnaden, jämfört med i marken utanför. Vid samma mätplats överskreds dessutom känseltröskeln inomhus, och en skyddsvibrationsnivå på 0,5 mm/s kan behöva tillämpas vid busskudden för att förhindra detta. Mätningarna visade att både vibrationer med låga och höga frekvenser kan uppstå i marken nära busskudden då tunga fordon passerar. Dock var det enbart vibrationer med låga frekvenser som spreds vidare i marken vid ett ökat avstånd från källan. Studien visade dessutom att det kan krävas ett skyddsavstånd mellan busskudde och byggnad på cirka 100 meter för att känseltröskeln inte ska riskera att överskridas inomhus. Trots att ett sådant avstånd är platsspecifikt, belyser det vilka krav det skulle kunna ställa på samhällsbyggnaden i ett växande Uppsala. Det faktum att busskuddar kan förhöja vibrationsnivån i marken vid passage av tunga fordon ter sig något märkligt, då busskuddarna ska vara utformade på ett sätt som tillåter tunga fordon att passera relativt obehindrat. Fler studier kring busskuddarnas utformning och/eller grundläggning är därför av stor relevans. Det är vidare relevant att exempelvis utreda hur fordonens hastighet över busskuddar påverkar vibrationsnivån i marken, då litteraturstudien belyser att det främst är då tunga fordon passerar ojämnheter med hög hastighet som betydande vibrationer kan uppstå. Busskuddar anses vara en av de mest effektiva hastighetssänkande åtgärderna, men studien visar att det kan ske på bekostnad av ökade vibrationsnivåer. En grundläggande helhetsbedömning bör därför göras av busskuddarnas lämplighet vid kommande stadsplanering. Nyckelord: markvibration, vibrationsmätning, busskudde, trafik, samhällsbyggnad. Institutionen för geovetenskaper, Uppsala Universitet, Villavägen 16, SE-752 36 Uppsala. ISSN 1401–5765. / Traffic induced vibrations: A study on the effect of speed control cushions on vibration levels in surrounding land and buildings. Erika Johansson Kling In Uppsala, speed control cushions are used as a form of conscious unevenness in the road surface to reduce speed and increase road safety on accident-affected road sections. However, housing in residences located near speed control cushions have reported that they can sometimes experience vibrations linked to when heavy vehicles pass speed control cushions as disturbing. This study aimed to quantify vibration levels in land and buildings near speed control cushions and to investigate key factors that can affect the vibration level and vibration propagation. Through vibration measurements at four places in Uppsala, data was collected and analyzed based on the stated research questions. The result confirmed what the literature study highlighted, that it is difficult to describe the propagation of vibrations in a general way and that it is clearly site-specific. However, it was found at all the measurement sites that the vibration level in the ground tends to be a factor between 2.5 and 32 higher when a heavy vehicle passes a speed control cushion, compared to when it passes an unaffected reference point along the same road. Generally, the vibration level in the ground also decreased with increased distance from the source. However, the level of vibration that dominated varied between the locations and for different distances from the source. At one measurement site, the vibration level in the building was amplified compared to in the ground outside. At the same measurement site, the sensing threshold was also exceeded indoors, and a protection vibration level of 0.5 mm/s may have to be applied nearby the speed control cushions to prevent this from happening. The measurements showed that both vibrations with low and high frequencies can occur in the ground near the speed control cushions when heavy vehicles pass. However, it was only vibrations with low frequencies that propagated further in the ground at an increased distance from the source. The study also showed that a safety distance between speed control cushions and buildings of approximately 100 meters may be required in order for the sensitivity threshold not to be exceeded indoors. Although such a distance is sitespecific, it highlights what requirements it could put on the urban planning in a growing Uppsala. The fact that speed control cushions can increase the level of vibration in the ground when heavy vehicles pass seems somewhat strange, since the speed control cushions are supposed to be designed in a way that allows heavy vehicles to pass relatively unobstructed. Additional studies on the design and/or foundation of the speed control cushions are therefore of great relevance. It is furthermore relevant to investigate, for example, how the speed of the vehicles when passing over speed control cushions affects the vibration level in the ground, since the literature study highlights that it is primarily when heavy vehicles pass an unevenness in the road surface at high speed that significant vibrations can occur. Speed control cushions are considered to be one of the most effective speed reducing measures, but the study shows that they may lead to increased vibration levels. An overall 3 evaluation should therefore be made regarding the suitability of speed control cushions in future urban planning. Keywords: ground vibration, vibration measurement, speed control cushion, traffic, urban planning. Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala. ISSN 1401–5765.