A method for calculating uncomfortable rates of people due to vertical floor vibrations using corresponding assessment values based on fuzzy reliability theory

This paper presents a method for calculating uncomfortable rates of people subject to vertical floor vibrations, based on fuzzy reliability theory. In the first section, the membership function of the uncomfortable rate is determined based on fuzzy statistical experiments; the relationship between acceleration data and degrees of membership conforms to Stevens' power law. A formula for the uncomfortable rate is given using membership and lognormal distribution functions. The expression considers both the ambiguity of people's judgment and diverse perceived levels of different people to building vibrations. A design factor method based on the uncomfortable rate model is then given to optimize the design method. In the next section, parameters for the membership function are determined based on ISO 2631 and ISO 10137, and then the calculated curves for uncomfortable rates in buildings are derived. Curves for log-normal accumulation distributions are used to fit the original curves for uncomfortable rates. Changes in the coefficients of variations have little impact on the curves. Uncomfortable rates corresponding to different acceleration limits and functions for the design factor method of buildings are then obtained. In the last section, experimental verification of the method for calculating uncomfortable rates is performed via vibration measurements and questionnaire surveys. Thus, the rationality and correctness of the curves for uncomfortable rates are demonstrated.