Abstract Summary
The construction of a new industry building was stopped halfway due to the concerns about the structural quality by the developer. It is a four-storey steel frame structure with a composite floor system. Majority of structure has been accomplished besides finishing layer and internal equipment. Various technical methods can be used for quality assessment of a structure, e.g. visual inspections, radar tests, vibration tests, etc. Among them, vibration tests have gained a special interest. It is a non-destructive method and can be performed without the interruption of the construction, which is especially suitable for a half-built building. The principal of the tests is identifying the dynamic behavior of the structural element by the measurement of structure response (acceleration or velocity) under certain excitations. Artificial excitations, e.g. heel-drops, jumps, etc., are used as the excitation source for the tests. The measurements are easily performed with a relatively simple equipment. Specific elements and system elements can be assessed through the test. Any structural deviation or damage is reflected by the dynamic re-sponses, e.g. a very high/low eigenfrequency or a large deviation to theoretical estimation. In this assessment, various floor locations are chosen for the evaluation of specific structural ele-ments, e.g. main beams, secondary beams, composite floors, etc. Natural eigenfrequencies of the tested structure are extracted by the frequency analysis. For the comparison and verifica-tion purpose, numerical and analytical methods are also employed for the structural analysis. By the comparison between theoretical estimations and tested results on a referenced structure, different methods are verified each other. It shows the eigenfrequency of (complex) structural elements/systems can be estimated accurately with simple analytical formulas. Therefore, the analytical method is further used for comparison with the vibration tests. In this way, the struc-tural quality of main structure was successfully assessed.
