Acoustics design characteristics of gymnasium buildings

First, the gymnasium launches the "multi function" method.

The opening of reform has brought colorful cultural and entertainment days. The entertainment methods such as Cara OK and song and dance hall, which arose in 80s, have never been bad. In recent years, with the improvement of the economic conditions of the broad masses and the promotion of the level of civilization, great changes have taken place in the concept of quality of life and leisure enjoyment.

A nationwide upsurge of new and improved stadiums and gymnasiums has emerged as a result of increased physical fitness and physical exercise, coupled with government-led (national fitness) and, in particular, the success of the Olympic bid (2008) and Shenya (2010). In the meantime, it is noteworthy that from home to abroad, both new and old museums have been extensively planned as "multi-functional" methods.

It not only has the function of sports training and competition, but also undertakes various functions such as assembly, exhibition, celebration, literary and artistic performance and even film. According to the materials, in a sports facility in San Francisco, 51.7% of the use of sports, 19.4% of concerts, 7.1% of circuses, ice dancing, exhibitions and other activities accounted for 21.8%. A stadium in Melbourne, Australia, accounts for about 50% of the music. This is the intention of sports industrialization and socialization.

Two, the most important feature of multi function gymnasium.

Compared with the "pure" Sports Gymnasium, the multi function gymnasium has the following characteristics:

1. A fixed stage is usually set on one side of the venue to serve as a platform for meetings and a place for performing arts activities.

2. In addition to the special lighting system for sports competitions and the sound amplification system for speech broadcast, the sound amplification system for setting stage lights and performing arts (both speech and music) should be added according to the theatre method.

3, the requirements for building sound planning should be higher than that of "pure" sports venues. This is the theme of this article.

Three. The relevant standards of the stadium acoustics planning.

In recent years, the Ministry of Construction has issued two documents, JGJ/T131-2000 < Code for Acoustic Planning and Measurement of Gymnasiums > and JGJ/31-2003 < Code for Planning of Sports Buildings >.

[1] the architectural acoustics condition of the gymnasium should be based on the assurance of clear language.

[2] no sound quality defects such as loud ensemble, echo, flutter echo, etc. can occur.

[3] the reverberation time of small and medium-sized gymnasium should be set in the range of 500-1000Hz: 1.3-1.5s.

The ratio of reverberation time to reverberation time of 500-1000Hz is:

Acoustic planning of multi function Gymnasium

[4] sound absorbing material or sound absorption structure should be installed above the hall.

[5] glass windows around the hall should be provided with window cloth with sound absorption effect.

[6] large area wall should be treated with sound absorption.

[7] The low walls and balustrades around the venue should be equipped with sound absorption structure, or the inclination angle and shape should be controlled.

Four. Common acoustic defects in Gymnasium

In recent years, many building models and structures of gymnasiums use exposed space truss, no ceiling or even transparent roof materials, and arc vaults, circular walls and large areas of glass windows or glass curtain wall methods are prevalent, which easily constitute a more serious acoustic defect. And architectural acoustics planning projects are often involved in building civil planning, decoration planning and even construction later, because the fundamental architectural modeling has been difficult to change, only the way is to adjust and transform the acoustic decoration structure. This greatly increases the difficulty of planning and construction.

These common structural defects such as:

1. Sound set

When meeting concave wall or ceiling roof, the sound gathering will occur, so that the sound pressure level of some points or areas is far greater than that of other directions, resulting in very uneven distribution of sound field, such as "sound dyeing" and "sound echo screaming" sound quality defects. The arched vault and circular wall of the gymnasium are typical easy to assemble structures.

2, trembling echo

In the room between a pair of parallel walls, a dynamic and static reflection between the two walls occur repeatedly, called vibratory echo. This is most likely to occur in large areas of the gymnasium walls, as well as in low walls and balustrades around the venue.

3. Reverberation time is long.

Compared with theatres, concert halls, conference halls and other halls, the surface area of the gymnasium can be absorbed is relatively small, so the reverberation time is generally longer.

Five. Feasible ways to deal with acoustic defects in Gymnasium

To sum up, the acoustical defects of gymnasium generally include two problems: firstly, the reverberation time is too long, and secondly, there is a more severe sound set and trembling echo. The first problem is not very difficult to deal with, just add the appropriate amount of sound absorption materials (make full use of the wall and top), that is, reduce the reverberation time, the technical difficulties are the accuracy of planning and accounting and the rigorous construction process.

The major difficulty in dealing with the acoustical defects of gymnasium is how to eliminate the severe sound collection and trembling echo caused by arc-shaped vaults and circular walls without changing the overall shape, appearance, lighting function and architectural style determined by the original building planning and decoration planning of the gymnasium. This is the most important part of the architectural acoustical planning. The key to challenge and creativity.

There are several common ways of dealing with these problems in recent years:

1) a large area of ceiling acoustical ceiling in roof top equipment. Many of these methods are used in theaters, auditorium and rooftops as flat shaped gymnasiums. But if it is used in a gymnasium with a curved vault or a transparent roof, this method will completely destroy the original style and lighting function, and is not desirable.

2) Hanging a large area of sound absorber under the arch space truss, but it is not advisable to change the orientation of the original planned or well-equipped lighting fixture when it is used in the gymnasium with arc arch or transparent roof materials.

3) Hanging a large sound absorber in the center of the roof to deal with defects such as sound collection, along the vault grid equipment strip sound absorber (sound absorption strip), this method was used in the main venue of the Ninth National Games - Guangzhou Stadium, the use of German patented sound absorber strip, a large amount of expensive, but the effect has not yet reached very ambitious.

4) spray the sound absorbing paste (plant cellulose) onto the vault. It is not suitable for reverberation time requiring accurate reverberation planning for gymnasium.

5) In recent years, the more common method is to select the space sound absorber (prefabricated parts) which has been tested beforehand and hang along the shape of the grid on the roof. It can reach an excellent and more accurate sound absorption effect. This plan will not overheat the impact of architectural style, assuming that the space sound absorber modelling and color appropriate combination, there will be certain beautification effect.