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HARBOR BLVD. MIXED USE TRANSIT CORRIDOR PLAN FINAL FIR <br />CITY OF SANTA ANA <br />5. Environmental Analysis <br />NOISE <br />The City of Santa Ana exempts noise associated with construction, repair, remodeling, or grading of any zeal <br />property from the noise limitations of the municipal code, provided that construction activities do not take <br />place between the hours of 8:00 PM and 7:00 AM on weekdays, including Saturdays, or any time on Sundays <br />or federal holidays. <br />FTA Vibration Criteria <br />Vibration Annoyance <br />Ground borne noise is the vibration of floors and walls that may cause rattling of items such as windows or <br />dishes on shelves, or a rumbling noise. The rumbling is created by the motion of the room surfaces, which <br />act like a giant loudspeaker. The FTA provides criteria for acceptable levels of ground borne vibration based <br />on the relative perception of a vibration event for vibration - sensitive land uses (see Table 5.9 -5). <br />Table 5.9 -5 Ground -bome Vibration and Noise Impact Criteria: Human Annovance <br />Land Use Caterlory <br />Max 6 dB <br />Description <br />Workshop <br />90 <br />Distinctly felt vibration. Appropriate to workshops and nonsensitive areas <br />Office <br />84 <br />Felt vibration. Appropriate to offices and nonsensitive areas. <br />Residential - Daytime <br />78 <br />Barely felt vibration. Adequate for computer equipment. <br />Residential - Nighttime <br />72 <br />Vibration not felt, but groundborne noise may be audible inside quiet rooms. <br />SouRR. IF I A Nlxi <br />1 As measured in V3adave bands of frequency oeer the frequency ranges of 8 to 80 Hz <br />Vibration- Related Structural Damage <br />The level at which ground borne vibration is strong enough to cause structural damage has not been <br />determined conclusively. The most conservative estimates are reflected in the FTA standards, shown in Table <br />5.9 -6. <br />Table 5.9 -6 Ground -Borne Vibration and Noise Impact Criteria: Structural Damaqe <br />Building Category <br />PPV (in/sec) <br />VdB <br />I. Reinforced concrete, steel, or timber (no plaster) <br />0.5 <br />102 <br />II. Engineered concrete and masonry (no plaster) <br />0.3 <br />98 <br />III. Nonengineered timber and masonry buildings <br />0.2 <br />94 <br />IV. Buildings extremely susceptible to vibration damage <br />0.12 <br />90 <br />SouRR. IF I A ZM. <br />Note. RIMS eelocity calculated from vibration leeel (VdB) using the reference of one micreinc[Vs ond. <br />Vibration related problems generally occur due to resonances in the structural components of a building. The <br />maximum vibration amplitudes of the floors and walls of a building will often be at the resonance <br />frequencies of various components of the building. In other words, structures amplify ground borne <br />vibration. Resonant response is frequency dependent, and 1 /3- octave band charts are best for describing <br />vibration behavior. Wood frame buildings, such as typical residential structures, are more easily excited by <br />Page 5.96 PlaceWorkr <br />