1.1 This norm specifies the acoustical design and acoustical property measurement method of noise barriers.
1.2 This norm is mainly applicable to such projects as urban roads and track traffic, and the noise barriers erected at other outdoor sites, such as highways and railways may also be made reference to this norm.
2 Normative References
The following standards and codes contain provisions which, through reference in this text, constitute provisions of this norm and are equivalent to this norm.
GBJ 005-96 "Specifications for Environmental Impact Assessment of Highways"
GBJ 47-83 "Acoustics-Sound-absorption Coefficient Measurement by Method of Reverberation Room"
GBJ 75-84 "Acoustics-Measurement of Sound Insulation in Buildings-Specifications"
GB 3096-93 "Standard of Environmental Noise of Urban Area"
GB 3785-83 "Sound Level Meters"
GB/T 3947-1996 "Acoustical Terminology"
GB/T 14623-93 "Measuring Method for Environmental Noise of Urban Area"
Within the stipulated time limit, A [-weighted] sound pressure of a certain continuous stationary sound has the same mean square A [-weighted] sound pressure as the time-varying noise, so the sound level of this continuous stationary sound is the equivalent sound level of this time-varying noise, and the unit is decibel (dB).The Formula of equivalent sound level is:
Contents Foreword III 1 Subject Content and Application Scope 2 Normative References 3 Terms 4 Acoustical Design of Noise Barriers 5 Measurement of the Acoustical Property of Noise Barriers 6 Environmental Protection Acceptance of Noise Barrier Engineering Appendix A (Normative) Calculation of the Correction ΔLr of Reflected Sound Appendix B (Normative) Calculation of Equivalent Frequency fe Appendix C (Informative) Bibliography
