TECHNICAL ARTICLE Determination of Deformations as a Result of Seismic Loadings on Two-Dimensional Reinforced Concrete Frame via Terrestrial Laser Scanners A. Ceylan 1 and M. G ¨ um ¨ us ¸ 2 1 Department of Geomatics Engineering, Faculty of Engineering & Architecture, Selc ¸ uk University, Konya, Turkey 2 Provincial Directorate of Public Works and Settlement, Malatya, Turkey Keywords Terrestrial Laser Scanner, Deformation Measurements, Applications Correspondence A. Ceylan, Department of Geomatics Engineering, Faculty of Engineering & Architecture, Selc ¸ uk University, Konya, Turkey Email: aceylan@selcuk.edu.tr Received: June 15, 2011; accepted: September 13, 2011 doi:10.1111/j.1747-1567.2011.00789.x Abstract Parallel to the technological developments, methods of defining locational data are changing. Laser scanners bring new advantages to engineering mea- surements and geodesy. Terrestrial laser scanners, which have previously been used in map engineering, have become an alternative method of measurement, especially for terrestrial applications. A common characteristic of deformation measurements is the requirement to measure the location of sufficient refer- ence and object points established on the monitored structure. The number of reference and object points is limited when using classical methods, but not when using a laser scanner. Due to the limitations of classical geodetic sur- vey methods, such as difficulty of application, high costs and low production speed, the present study applied ground laser scanners to deformation mon- itoring. A two-dimensional (2D) deformation survey was made of a concrete frame placed on a loading wall. Cartesian coordinates, derived from survey and evaluations, were converted into a standard coordinate system using the Molodensky–Badekas 3D similarity transformation. Student’s t test has been used to determine whether it was significant with the difference of coordinates or not. The deformation amounts and directions obtained from the electronic tachymeter and ground laser scanners were found to be very similar. Introduction Laser technology has a long history of applications in various disciplines. Laser scanners have been commonly used in various fields of topographic engineering, especially in engineering measurements in a period when methods of position determination are becoming increasingly diverse in parallel with advancing technology. Three-dimensional (3D) modeling of objects is achieved more easily and accurately using electronic tachymeter and Global Navigation Satellite System (GNSS) technologies. A new method, laser scan- ning technology, has added a new dimension to 3D modeling. Terrestrially or remotely acquired 3D data of objects are gained very rapidly and presented by uniting the data with images of the object. Another important advantage of this method is that it provides more realistic spatial images than other imaging techniques. Therefore, laser technology is becoming increasingly used in documentation of cul- tural heritage, architectural studies, and engineering applications. As a result of the limitations of classical geodetic measurement methods used in 3D modeling of objects and surfaces, such as challenges, costs, and low pro- duction speed, this study examined the usability of a terrestrial laser scanner as an alternative method of measuring structural deformations in concrete frames. An electronic tachymeter (geodetic method) and terrestrial laser scanner were used to make two periodic measurements of a 2D reinforced concrete frame placed on a loading wall in the Quake Laboratory of the Engineering and Architecture Department, Selc ¸uk University. These measurements Experimental Techniques (2011)  2011, Society for Experimental Mechanics 1