1. A survey of acoustical design of gymnasium buildings

With the development of sports and cultural undertakings, a large number of gymnasiums have been or will be built throughout the country. The vast majority of these gymnasiums are multipurpose gymnasiums. In addition to sports competitions and training, they can also be used for large-scale artistic performances, meetings, fashion shows, film screenings, acrobatics, circus performances, etc. These gymnasiums are actually multi-functional gymnasiums. In order to meet the requirements of multifunctional use of gymnasiums, professional acoustic design must be carried out.

The biggest feature of the gymnasium is its large volume, which causes the reverberation time of the hall to be too long. First of all, too long reverberation time will reduce the sound quality and clarity of the hall, make the audience's hearing turbid, and affect the performance effect and reputation. For athletes, they may lose their level due to the sound quality problem in the stadium. Secondly, too long reverberation time will make the sound reinforcement system howl. In addition, the parallel wall of the competition pool and the excessive free sound path will produce the sound quality defects of flutter echo and multiple echoes. It will make the footsteps and impact sound of players dribbling more intense, and even evolve into a strong noise. The configuration of contemporary gymnasiums is becoming more and more diversified, and architectural designers are no longer satisfied with the rectangular design in the past. Round, oval, polygon and so on emerge in endlessly. These curved walls and domed roofs often produce acoustic focusing.

2. Relevant standards and specifications for acoustical design of gymnasium buildings

(1) 《Code for Design of Gymnasium Buildings》（JGJ31-2003；J265-2003）
(2) 《Specification for reverberation time measurement in auditorium》GBJ76-84
(3) 《Load Code for Building Structures》（GB50009-2001）
(4) 《Code for Fire Protection Design of Buildings》GBJ16-1987（2001）
(5) 《Code for fire protection design of interior decoration of buildings》（GB50222-95）
(6) 《Acoustic environment quality standard》（GB 3096-2008）
(7) 《Code for acoustical design and measurement of gymnasiums》（JGJ/T131-2000；J42-2000）
(8) Ministry of Construction《Building sound insulation and absorption structure》（National Building Standard Design Atlas 08J931）

3. Acoustical design of gymnasium building

Specification requirements

《Code for Design of Gymnasium Buildings》（JGJ31—2003; J265—2003）

Sound quality defect

(1) The stadium has large volume and large free sound path, which is easy to generate echo and multiple echoes. Make one's voice muddy. Interference with normal operation of audio equipment.
(2) If the shape of the gymnasium is regular, such as rectangle and square, it is easy to produce flutter echo. If the shape of the gymnasium is irregular, such as round, arc, etc. (nowadays most gymnasiums are irregular), it is easy to produce acoustic focusing.
(3) Noise is generated when various functional rooms such as machine rooms with serious noise are set inside the gymnasium. Increase the background sound. It affects the normal use of the gymnasium.

Solution

(1) Reasonable reverberation time shall be designed according to the use function and purpose of the venue, and sound absorbing materials shall be installed at corresponding positions in the competition hall.
(2) The competition hall should be isolated from external noise by using the rest corridor, and the rest corridor should be treated with sound absorption and noise reduction.
(3) The air supply and return pipes leading to the competition hall, VIP lounge, sound reinforcement control room, TV comment room, sound reinforcement studio and other rooms shall be provided with noise elimination, noise reduction and vibration reduction measures.
(4) Air conditioning room, boiler room and other equipment rooms should be far away from the competition hall, VIP room and other rooms with quiet requirements. When it is adjacent to the main building, effective noise reduction and vibration isolation measures shall be taken.

4. Material Requirements for Acoustic Design of Gymnasium Buildings

(1) The ceiling and wall materials must meet the environmental protection requirements specified by the state.
(2) The indoor wall decoration and ceiling used for competition and training shall be made of non combustible materials. When an automatic fire extinguishing system and an automatic fire alarm system tree are set up in the site, refractory materials can be used for indoor wall and ceiling decoration.