Tornado-induced vibration assessment of construction elevator attached to high-rise buildings

As one of major construction facilities, the safety concern about elevator outer-attached to slender high-rise buildings during construction needs to be seriously addressed. To specifically identify the risk of such slender building-elevator systems in extreme tornado wind field, a safety assessment strategy using the critical velocity envelope is systematically developed. To overcome the difficulties in modeling such building-elevator system, a modified generalized flexural-shear model developed previously was employed to reach an efficient estimate on the response of a case high-rise building under simulated tornado wind excitations. To account for the effect of the flexibility of high-rise building on the response of its attached construction elevator, the response of the elevator was obtained by finite element analysis with applied wind forces, as well as the displacement excitations at its supports with the building. To simulate the typical failure modes of elevator in all states, some critical reference velocity-based envelopes were generated for the safety assessment where the factors of wind velocity, wind direction, and cage level are systematically addressed. The safety envelopes of the building-elevator system were proved to be instinctively efficient for the assessment of its wind resistance under various scenarios.