By Jian Kang
Acoustics is an important challenge in lots of lengthy areas, resembling street or railway tunnels, underground/railway stations, corridors, concourses and concrete streets. the categorical difficulties of such irregularly formed areas, starting from noise toxins in streets and tunnels to bad speech intelligibility of public handle structures in railway stations usually are not handled via vintage room acoustic theory.
This cutting-edge exposition of acoustics of lengthy areas offers the basics of acoustic thought and calculation formulae for lengthy areas in addition to giving directions for sensible layout
Read Online or Download Acoustics of long spaces : theory and design guidance PDF
Best civil & environmental books
This publication addresses the characterization of circulate and shipping in porous fractured media from experimental and modeling views. It presents a finished presentation of investigations played and analyzed on diversified scales.
Written by way of a famous authority within the topic region, this booklet is a complete research of the speculation and useful program of noise aid to varied fields. it can be used as a reference through scientists and engineers or in a senior-undergraduate or graduate-level direction. the 1st six chapters take care of the fundamental mechanisms of sound absorption wherein acoustic strength is switched over into warmth in viscous and thermal barriers in a legitimate box.
Nineteen peer-reviewed papers tackle the most recent concerns affecting the resilient modulus try and use of the attempt effects. Resilient modulus shows the stiffness of a soil lower than managed confinement stipulations and repeated loading. The try is meant to simulate the tension stipulations that happen within the base and subgrade of a pavement procedure.
Volcanic rocks and soils express a unusual mechanical behaviour at either laboratory and in-situ scale because of their normal structural characters. Volcanic rocks and soils includes keynote lectures and papers from the overseas Workshop held in Ischia (Italy), 24-25 September 2015. The publication offers with fresh advancements and developments, in addition to case histories, within the geotechnical characterization and engineering purposes relating to volcanic formations.
Additional resources for Acoustics of long spaces : theory and design guidance
1 the unsuitability of classic room acoustic theories for long enclosures is discussed. 2, by applying the image source method, theoretical formulae and computer models for long spaces with geometrically re¯ecting boundaries are given. 3 considers diusely re¯ecting boundaries using the radiosity method. 4. 5 presents a method to predict the temporal and spatial distribution of train noise in underground stations. 6, a practical method is given for predicting acoustic indices in long enclosures, especially the speech intelligibility of multiple loudspeaker PA systems in underground stations.
Unfortunately, no experimental results were given to demonstrate that the above consideration of the angle-dependent absorption could enable better predictions. 2. Line source Corresponding to the above investigations on a single source, line sources have also been considered. 16] ER PH X 1 ÿ c g 1 ÿ f h 1 ÿ w q a1 4a1 c g;h;q aghq x0 L ÿ x0 Â arctan arctan aghq aghq 2:38 where ER is the sound energy density from image sources, P H is the sound power per unit length of the line source, g, h and q are the orders of image sources on the ceiling, ¯oor and side walls, a1 1 m is the reference distance, aghq is the distance between the receiver and the image source g, h, q, x0 is the horizontal distance between the receiver and a tunnel end, and L is the tunnel length.
6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. References EGAN M. D. Architectural Acoustics. McGraw-Hill, New York, 1988. LEONARD R. , DELSASSO L. P. and KNUDSEN V. O. Diraction of sound by an array of rectangular re¯ective panels. Journal of the Acoustical Society of America, 1964, 36, 2328ÿ2333. TEMPLETON D. ) Acoustics in the Built Environment. Butterworth Architecture, Oxford, 1993. INSTITUTE OF BUILDING PHYSICS. Handbook of Architectural Acoustics. China Building Industry Press, Beijing, 1985 (in Chinese).