{"id":5237,"date":"2022-09-08T11:23:12","date_gmt":"2022-09-08T09:23:12","guid":{"rendered":"https:\/\/www.iwim.it\/?p=5237"},"modified":"2023-10-24T12:35:01","modified_gmt":"2023-10-24T10:35:01","slug":"structural-monitoring-and-modal-testing-of-bridges-and-viaducts-now-it-is-possible-to-correlate-the-response-with-the-real-mass-in-transit","status":"publish","type":"post","link":"https:\/\/www.iwim.it\/en\/structural-monitoring-and-modal-testing-of-bridges-and-viaducts-now-it-is-possible-to-correlate-the-response-with-the-real-mass-in-transit\/","title":{"rendered":"Structural monitoring and modal testing of bridges and viaducts: now it is possible to correlate the response with the real mass in transit"},"content":{"rendered":"\n

The awareness, also following some tragic collapses, of the state of vulnerability and aging of the large number of works of art present on ordinary or motorway roads, is bringing more and more the attention of these infrastructures’ managers towards IBM <\/u><\/strong>( Intelligent Bridge Monitoring <\/u><\/strong>)<\/em> systems for the surveillance and monitoring of bridges and viaducts <\/strong>in operation.<\/p>\n\n\n\n

Intelligent monitoring systems involve the installation of one<\/strong> sensor network of <\/strong>different types, including accelerometers<\/strong>, inclinometers<\/strong>, strain gauges, displacement sensors, crackmeters, distance meters, <\/strong>etc. that positioned in specific points allow to detect the dynamic response<\/em><\/u> of the structure <\/strong>through the continuous monitoring of the same.<\/p>\n\n\n\n

The processing of the large amount of data collected allows to obtain the dynamic identification or modal test (Modal Testing or Modal Identification) <\/strong>of the structure and thus determine multiple real dynamic structural parameters , as generated on the basis of real operating data. Dynamic identification can be carried out according to OMA (Operation Model Analysis) <\/em>techniques <\/strong>that consider only the response <\/strong>of the “bridge system” or <\/strong>according to EMA (Experimental Model Analysis) <\/em>techniques <\/strong>that also consider the response of the system, but correlating it to the forcing action<\/strong> insistent on the structure <\/strong>. <\/p><\/blockquote><\/figure>\n\n\n\n

<\/span>\"\"
\n
<\/div>\n<\/div><\/div>\n\n\n\n

It is clear that, in the case of bridges and viaducts, the load represented by the mass in transit<\/u> instantaneously in the different points of the structure, represents the main component of the forcing action <\/strong>(“system entrance<\/em>“), but it is equally clear how problematic it is to be able to know this given<\/strong> in a precise, continuous way, referenced in space and time <\/strong>and referring to real traffic rather than to measurement campaigns carried out in a short time interval and often also with a fleet of vehicles in transit specifically prepared for the purpose <\/strong>and not at all representative of real traffic <\/strong>in transit.<\/p>\n\n\n\n

Although electronic technology, in its optical and electromagnetic declinations, has for some time now made it possible to detect numerous quantities relating to traffic with devices such as cameras, radar, lidar and coils, allowing to calculate the number of vehicles in transit, their speed and type, none of these systems is still able to determine the mass actually in transit on a stretch of road with precision and continuously over time.<\/p>\n\n\n\n

The enabling technology for the resolution of this age-old problem <\/strong>is represented by the use of a weigh-in-motion system<\/a>, <\/strong>placed on the bridge deck or in the immediate vicinity both upstream and downstream.of the work , <\/strong>which detects in real time and continuously the mass in transit on the totality of the lanes and carriageways <\/strong>characterizing the specific stretch of road network.<\/p><\/blockquote><\/figure>\n\n\n\n

\"\"
Sabbioncello Bridge connecting Croatia to Europe.<\/figcaption><\/figure>\n\n\n\n

BISON weigh in motion solution, the tool that allows you to know anytime the load on bridges and viaducts <\/h2>\n\n\n\n

The dynamic weighing system<\/strong> BISON, <\/strong>developed and produced by the Italian company IWIM<\/a><\/strong>, allows<\/strong> to calculate the real transit mass <\/u><\/strong>insistent on the work, thanks to the processing of weight and kinematic data detected by its system. It is therefore finally known both the space-time distribution of the real mass in transit and the composition of the same <\/strong>in terms of the type of means that can generate different tip loading situations.<\/p>\n\n\n\n

The user, by accessing a web interface in the cloud, can independently process the load status in the moments of his interest<\/strong> insisting on different sections of the work <\/strong>thanks to spatial goals that can be defined at will and which can therefore represent the entire bridge or the subdivision of the same into spans or sections under examination <\/strong>.<\/p>\n\n\n\n