Katsuo Inoue

Practical calculation of floor impact sound by impedance method

Abstract This paper describes a practical floor impact sound level calculation method for a heavyweight, soft impact source, such as children jumping and running. The floor impact sound for a heavy, soft impact source is strongly influenced by structural factors such as floor slab stiffness and peripheral support conditions. The manner of analysing these structural factors for performing the sound level calculation is described. A sample of measured values and calculated values from an actual structure is presented to show the accuracy of this method.

Trends for prediction methods of heavyweight floor impact sound

Trends of building structures of Japanese multifamily dwellings and prediction methods of heavyweight floor impact sound are introduced. Floor impact sound‐reduction performance caused by human action like stepping and jumping is considered to be a vital function for Japanese apartment complexes. There are quite a few cases where the floor thickness shall be designed from 200 to 300 mm because of acoustical performance, to assure the required performance. The practical prediction method, the so‐called impedance method, was been established in the 1970s, and it has been commonly used. Though there are many buildings that are out of the applicable scope of the ordinal impedance method with the rise of structural design technology, the outline shown is that of the revised practical prediction method that is under discussion by the working group of the Architectural Institute of Japan. And, examples of hybrid method are also introduced that substitute the impedances by numerical vibration calculation results ...

COMPATIBILITY OF FLOOR IMPACT SOUND LEVEL BY CHANGE OF HEAVY IMPACT SOURCE

鹿倉潤二ー ーーーー * 1 井上勝夫ー ーーーー* 2 天川恭一ー ーーーー * 3 大川周一郎ーーーー* 4 大川平一郎ー ーー* 5 キーワード: 床衝撃音,単一数値評価量,衝撃力暴露レベル

Vertical sensory evaluation on residential floor by traffic vibration

If vibration failures have occurred in building caused by traffic, in Japan, it is often evaluated by “Guidelines for the evaluation of habitability to building vibration.” This evaluation method has to be collated acceleration maximum value of 1/3 octave band analysis on the evaluation curve, to evaluate the response acceleration of adjacent frequency bands to reference curve. This performance evaluation curves are presented from experimental results based on sine vibration, under real environment, random vibration containing multiple frequency components. Therefore, it is necessary to consider the influence of the frequency components other than determination frequency, because it is considered to affect the vibration sense. Therefore, in this paper, as a basic study, we examined the good evaluation physical quantity of corresponding to vibration sense from relationship of the vibration sense and vibration response physical quantity for traffic vibration of railway and road. As a result, in the range of...

STUDY ON SIMPLE ESTIMATED METHOD OF HEAVY FLOOR IMPACT SOUND CONTROL GRADE

Inside of the Housing Performance Indication System, indications related with sound environment are highly demand by residents. These affect to claim and trouble, and become civil suit factor. Therefore, to promote spreading indication of house performance are much required. In this study, focusing to the heavy floor impact sound control grade, we simplify the evaluation method criteria and proposing slab thickness grade conversion. Slab thickness grade conversion is new method of calculation with the indicated slab thickness and consideration change of sound receiving room area.

Japanese standards and situation of studies about heavy and soft impact sources

This report describes standards of heavy and soft impact sources. They are used for measurement of floor impact sound insulation of buildings. In Japan, the method for field measurement of floor impact sound level (JIS A 1418) was revised in 2000 and separated into two parts. Part 1 uses a standard light impact source and corresponds to ISO 140‐7. Part 2 uses heavy and soft impact sources. At that time, a rubber ball was standardized along with a car‐tire source in JIS A 1418‐2. Moreover, JIS A 1440‐1 and JIS A 1440‐2 for laboratory measurement of the reduction of transmitted floor impact sound have been prepared. JIS A 1440‐1 corresponds to ISO 140‐8, and JIS A 1440‐2 uses heavy and soft impact sources. Floor impact sources characteristics are introduced. They include force characteristics, temperature dependence, stability, and others. In addition, among contents of JIS A 1440‐2, the measurement method, calculation method, and a laboratory of a box‐frame‐type reinforced concrete construction are explain...

Impact force characteristics by footsteps and the vibration characteristics in housing floors

Various experimental researches were conducted dealing with physical characteristics and sensation in order to be able to express quantitatively appropriate hardness in terms of comfortability in residential floors. From among these, the results of analyses of impact force time characteristics of a sole by footsteps and the production of a prototype impact source involving the impact force of the heel, which is a representative impact force generated by footsteps are indicated in this paper. Then, using the impact source to measure the amount of dynamic displacement in wooden floors of old construction and in the direct‐pasted wood flooring commonly used in recent multifamily housing, the dynamic spring coefficient of traditional wood‐construction floor structure, which had never before been clarified, was quantitatively determined.

Proposal for a standard heavy impact source for the measurement of floor impact sound insulation performance

The floor impact sound generated in multifamily dwellings frequently has a peak in the low‐frequency band (20–30 Hz). Because of that, in order to assess the floor impact sound insulation performance in real‐life situations, it is necessary to measure floor impact sound using a standard impact source, with an impact force characteristic corresponding to actual impact sources. However, in the current ISO standards, a ‘‘tapping machine’’ that is light and stiff with a weak impact force is the only one that has been approved as a standard floor impact source, which cannot be considered adequate as a method of measurement in solving problems of floor impact sound. Actual case examples of the measurement of impact force performance of floor impact sources generated in actual housing units are presented in this paper, together with a verification of the usefulness of the heavy floor impact source stipulated by current JIS standards in Japan and a proposal for the introduction of the same impact force characteri...

Analysis of occupancy evaluation of the multifamily housing sound environment

Single‐family wooden dwellings have formed the mainstream of housing in Japan because of climatic conditions. However, multifamily housing began a rapid and widespread expansion beginning in the mid‐1960s as one mode of housing and currently accounts for a proportion exceeding conventional single‐family dwellings, especially in major urban centers. In order to gain an understanding of the current conditions of environment performance of multifamily housing, an extensive questionnaire survey was conducted targeting the residents of 16 housing estates, all of recent construction and considered to have multifamily housing architectural properties standard in Japan at the present time. To summarize the results, there was an overall indication of a high evaluation of satisfaction with current housing. Meanwhile, regarding the desire for improvements or rebuilding within current housing, there is a greater demand for ‘‘dampness proofing’’ and ‘‘sound insulation.’’ In addition, the percentage of dwellers who felt dissatisfied with the sound environment as an actual sensation in their everyday lives accounted for approximately 30% in each of the public housing complexes. Overall, ‘‘noise in the surrounding environment is terrible’’ and ‘‘sound from the floor above is extremely loud’’ were given as the primary reasons for this.