# Experimental Research of the Structure Condition Using Geodetic Methods and Crackmeter
###### Abstract
The analytical part of the displacement determination process and the prediction of changes and planning of modernization work on the facilities can also be supported by intelligent monitoring systems based on artificial intelligence [24, 25, 26, 27]. The displacements and deformations of elements of engineering structures can be determined using modern laser devices. Today, these technologies are often used in industrial metrological measurements and are characterized by the high precision of distance measurement, up to \(+/-\) 15 \(\upmu\)m + 6 \(\upmu\)m/m when measured per retroreflector and the operating range of 120 m [28, 29]. The possibilities of using the coordinate laser station were presented [30]. Cyclical measurements of the structure geometry make it possible to compare its displacements in different periods of use. The correct results' interpretation, together with the assessment of the technical condition of the structure, gives a picture of the actual operation of the monitored facility [31]. An important aspect when measuring and monitoring the behavior of buildings is obtaining data with adequate accuracy in real-time [32]. For this purpose, non-geodetic methods can be used for this purpose, including measurement methods using analog and digital feeler gauges, industrial cameras, laser beam emitting devices, and radar sensors [33, 34, 35]. [PERSON] et al., in their article, reviewed the latest achievements in non-destructive research techniques, including sweep frequency approach, ground-penetrating radar, infrared technique, fiber optics sensors, camera-based methods, laser scanner techniques, acoustic emission, and ultrasonic techniques [36]. [PERSON] et al. presented an innovative technique for assessing moisture content and controlling the deterioration of concrete blocks using a smart antenna [37]. Sensor technology also allows for real-time monitoring of the structure's condition (damage of concrete due to corrosion of reinforcement) and the quantity and quality of natural resources. It enables precise monitoring of changes in environmental conditions and the depletion of natural resources over vast areas, which helps minimize the effects of natural disasters and prevent/minimize the serious pollution effects [38, 39]. To compare the results obtained with advanced geodetic measurement and calculation methods, it is possible to use a non-complicated method of testing the crack width using the SHM-X crackmeter. In engineering conditions, it is often used by direct measurement of pins with a caliper [40], but it is also possible to measure continuously using electronic sensors and appropriate software [41]. This approach allows for accuracy in obtaining real-time information and verifying the results obtained from geodetic methods. In long-span building structures, there may be periodic forced states of the structure resulting from a varying temperature gradient. This phenomenon is primarily significant for steel structures but may also occur in reinforced concrete structures characterized by low stiffness. The influence of temperature on the deformation phenomena of structural elements and entire structures, considering various materials, has been widely described in the literature [42; 43; 44; 45; 46; 47]. In recent years, along with new technologies, the temperature measurement of building objects, structural elements, and surroundings has been performed using thermovision [48; 49]. These are non-contact methods, using thermal imaging cameras, enabling the simultaneous observation of the temperature distribution on the surface of the tested object, temperature measurement, and its registration in the form of a thermogram [50; 51]. Since our previous research excluded the influence of soil factors on the displacement in the discussed object, an attempt was made to determine the changes taking into account the temperature gradient, which was determined on the basis of infrared images.