DESIGN TO PREVENT FLOOR VIBRATIONS

Farzad Naeim

John A. Martin & Associates

DESIGN TO PREVENT FLOOR VIBRATIONS

AGENDA:

What Causes Floor Vibrations?

What Causes Floor Vibrations?

What Causes Floor Vibrations?

What Controls the Magnitude of Vibrations?

Factors Influencing Perception:

TABLE 1. Ranges of Multiplying Factors to Specify Satisfactory Magnitudes of Building Vibration with Respect to Human Response (SOURCE: ISO 2631-2 International Standard, Annex A, 1989.)

TABLE 2. "Fatigue-Decreased Proficiency Boundaries" (1.0 to 2.0 Hz plateau) (SOURCE: ISO 2631-1 International Standard, Part I, General Requirements, 1989.)

Categories of Human Response*

Design Criteria in Use

How do these methods correlate?

Notes on Natural Frequency

Modified Reiher-Meister Scale Analysis Procedure

Modified Reiher-Meister Scale Example

Murray's Acceptability Criterion Assumptions

Murray's Acceptability Criterion Analysis Procedure

Murray's Acceptability Criterion Analysis Procedure 1. Estimate the total amount of damping available.

Murray's Acceptability Criterion Analysis Procedure 2. Calculate Transformed Moment of Inertia

Murray's Acceptability Criterion Analysis Procedure 3. Calculate the Natural Frequency

Murray's Acceptability Criterion Analysis Procedure 3. Calculate the Natural Frequency

Murray's Acceptability Criterion Analysis Procedure 4. Compute the initial maximum amplitude of the beam, Aot.

Murray's Acceptability Criterion Analysis Procedure 5. Account for stiffness contribution of adjacent beams

Murray's Acceptability Criterion Analysis Procedure 7. Compute the required damping.

Murray's Acceptability Criterion Analysis Procedure 8. Compare the required and the available levels of damping.

Murray's Acceptability Criterion If the available damping can not be estimated

DESIGN EXAMPLE

Design Example 1. Estimate the total amount of damping available.

Design Example 2. Calculate Transformed Moment of Inertia

Design Example 3. Calculate the Natural Frequency

Design Example 4. Compute the initial maximum amplitude of the beam, Aot.

Design Example 5. Account for stiffness contribution of adjacent beams

Design Example 7. Compute the required damping.

Canadian Standards Association

Canadian Standards Association Example

Wiss-Parmelee Rating Factor The Formula

Wiss-Parmelee Rating Factor The Criterion

Wiss-Parmelee Rating Factor Example

ASCE/ Ellingwood et. al. Criterion

ASCE/ Ellingwood et. al. Example

Tolaymat's Criterion

Floor Vibration from Rhythmic Activities

Vibration from Rhythmic Activities Formulas

Recommended acceleration limits for vibration due to rhythmic activities (based on Allen, D.E., 1985.)

Minimum Recommended Natural Frequencies for Assembly Floors (based on Allen, Rainer and Pernica, 1985.)

TABLE 5. Suggested design parameters for rhythmic events (based on Canadian research work)

Rhythmic Activities Example

Rhythmic Activities Example