Brief description of the project
The gymnasium is a multifunctional gymnasium. It is an indoor basketball stadium with a floor area of 2945 square meters and a fixed stage. The volume of the competition hall is about 48,060 cubic meters. The acoustic design should meet the acoustic requirements of various small and medium-sized competitions, large-scale conferences, performances and ceremonies. Its main demands for acoustic design is clear language, full music, and no acoustic defects.
On-site situation
The existing gymnasium uses perforated gypsum board and polyester fiber acoustic panels. We found that some of the perforated gypsum board were damaged, the polyester fiber acoustic panel had a large area of mildew and the surface was easy to absorb dust, breed bacteria and was difficult to handle. The material was deformed by moisture, which affected the overall aesthetics and sound absorption performance of the material.
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| (perforated gypsum board) | (polyester fiber acoustic panel) |
Basis and related standards
Including but not limited to:
GB 22337 Noise emission standard for social living environment
GB 3096 Acoustic Environmental Quality Standard
GB/T 50378 Green Building Evaluation Standard
JGJ31 Sports Building Design Code
JGJ/T131 J42 Gymnasium acoustic design and measurement regulations
GBJ76—84 Hall reverberation time measurement specification
Acoustic design objectives
1) Full frequency reverberation is balanced, and there is no obvious drop in the frequency point;
2) The sound energy distribution in the whole venue is reasonable and even;
3) Silent focusing problem;
4) No standing wave phenomenon;
5) Suitable for all kinds of competitions and sports activities, and sound construction materials are required to have better anti-impact and anti-wear capabilities
Determine the reverberation time
According to the information provided by the customer, the indoor volume of the gymnasium is about 48,060 square meters, with 1800 fixed auditorium seats, each with a volume of 26.7 square meters. The architectural acoustics design is mainly to reasonably control the reverberation time and eliminate the interference of harmful reflections on hearing. According to the specific, physical, functional requirements and acoustic conditions of the hall, it can meet the functional requirements of various competitions, large-scale conferences and various performances. The following table of this project is now used as the basis for architectural acoustics design according to the material selection and requirements of the customer.
Reverb time simulation calculation
Renovation plan
After removing the perforated gypsum board and polyester fiber acoustic panels, the wall adopts wooden perforated acoustic panel (size: 128*2440*15 (mm), pattern :13-3 ).
The overall area is about 3726 sqm to solve the low frequency reverberation.
Install the supporting keel, keep at least 150mm cavity from wall, and fill with 50mm thick 48K/m³ fiberglass wool panel wrapped with glass fiber cloth.(Installation details are in the shop drawing)
The elevation of the keel after the removal of the perforated gypsum board and polyester fiber acoustic panels is as follows:
Important note
The acoustic effect of the gymnasium after the completion of the renovation shall not be lower than the acoustic effect before the existing improvement. The acoustic renovation does not damage existing facilities (such as fire-fighting facilities, electrical sockets, air ducts, etc.).
Before renovation:
After renovation (on-site reverberation time detection)
Selection of on-site test points
The test points T1-T8 are selected according to the position of the auditorium, and the test points reflect the reverberation time of the auditorium in this area.
Reverberation time after renovation:
Test data analysis
The empty field test data of T1-T8 test points are as follows:
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| (1/3 octave band) | (1/1 octave band) |
Test conclusion
1/3 octave frequency conversion 1/1 octave band data, the reverberation time obtained from the T1-T8 empty field test is superimposed with the 80% full field reverberation time area designed by our company, and the reverberation time value is based on the initial acoustic design The upper limit is very close. Considering that the test is empty field data, the audience’s absorption of sound energy is not considered. When 80% of the field is full, the reverberation time will be further reduced, and the reverberation time of 500-1000Hz will be improved by more than 0.3 seconds. About 1.6-1.7 seconds. The reverberation time falls within the range of the design area and meets the design requirements.
After Renovation
