Finite element analysis of ground borne vibrations in sensitive buildings using inputs from free field measurements

摘要

The development in modem fabs manufacturing of micro-electronics components like chip processors and laboratories fully equipped with high resolution devices requires very low level of vibration due to small allowable tolerances of the size of the equipment. As a result, the generated vibration level at the site is critical for estimating and providing suitable conditions for vibration sensitive facilities. For this purpose, ground borne vibration levels at specified locations are considered as input for the simulation analysis which is used in assessing the response of the structure in time domain and also in one third octave band frequency domain. This paper investigates the transmission of the amplitude of ground borne vibrations generated by external sources, into low rise structures housing sensitive facilities. Finite element analyses of the structure are used to predict the dynamic response of the structure, which is then compared with the free field measurements (input). The results of FE analyses are checked against the generic vibration criteria guidelines for vibration sensitive equipment. The results show that prediction based on dynamic response analysis can be used for selecting and designing an effective foundation system. The effect of the foundation system will provide guidelines for designing new vibration sensitive facilities.