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Vibration criteria for long-span concrete floors

Allen, D. E.; Rainer, J. H.; Pernica, G.

https://publications-cnrc.canada.ca/fra/droits

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National R e s e a r c h Council of Canada Conseil national d e r e c h e r c h e 6 du Canada

VIBRATION CRITERIA FOR LONG-SPAN CONCRETE FLOORS

by D.E. Allen,

J.H. R a i n e r , and

G.

P e r n i c a

Reprinted f r o m

P r o c e e d i n g s , ACI Symposium Vibrations of Concrete S t r u c t u r e s

held 20 October 1977 in New O r l e a n s , Louisiana p. 67

-

78

DBR P a p e r No. 858

Division of Building R e s e a r c h

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SO MMA IRE

Dans cet article, les critCres provenant des vibrations

causEes par les pas dans le cas des planchers B solives d'acier de longue port6e et B dalle de bEton sont appliqu6s avec quelques changements, aux planchers en beton de longue

portle.

A

cause de leur masse relativement grande et de leur resistance B des charges exercees B court terme, les constructions coul6es sur place ne sont g6neralement pas

susceptibles de faire l'objet de vibration Elevges pendant

l'occupation normale des bttiments. Cependant, l'utilisation

de planchers prlcoul6s de longue portee 3 supports simples

peut entrarner des problsmes de raisonance rgsultant

d'activitEs rEpgtEes, tels la dance et le battement des mains.

Des Etudes sur place de deux planchers pr6coul6s et d'un

plancher coulE sur place ont servi pour verifier les critsres

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Vibration Criteria for Long-Span

Concrete Aoors

By D. E. Allen, J. H. Rainer, and G. Pernica

Synopsis: C r i t e r i a d e r i v e d o r i g i n a l l y f o r walking v i b r a t i o n s i n long-span s t e e l j o i s t f l o o r s w i t h c o n c r e t e deck a r e a p p l i e d , w i t h some a d j u s t m e n t s , t o long-span c o n c r e t e f l o o r s . F i e l d s t u d i e s o f two p r e c a s t and one c a s t - i n - p l a c e f l o o r system a r e used t o v e r i f y c r i t e r i a and t o e s t i m a t e v i b r a t i o n parameters.

Because of i t s r e l a t i v e l y l a r g e mass and i n h e r e n t s t i f f n e s s t o s h o r t - t e n load, c a s t - i n - p l a c e c o n s t r u c t i o n g e n e r a l 1 y i s n o t prone t o u n s a t i s f a c t o r y v i b r a t i o n f o r normal human occupancy. The t r e n d toward

l o n g e r s p a n s , l e s s damping and t h i n n e r s e c t i o n s c o u l d r e s u l t i n problems i f s p e c i a l c a r e i s n o t t a k e n i n t h e d e s i g n . Also l o n g e r spans w i t h lower f r e q u e n c i e s c a n r e s u l t i n s e r i o u s resonance problems i n occupancies where r e p e a t e d human a c t i v i t i e s such a s dancing, c l a p p i n g o r stomping can o c c u r .

~ y w o r d s : beams (supports) ; concrete s

1

abs ; c r i t e r i a ; floors ; human actors engineering;

1

ong span ; precast concrete; reinforced concrete; vibrations.

(5)

Allen, Rainer, and Pemica

D.E. A l l e n , J . H .

Rainer

and G. P e r n i c a are r e s e a r c h o f f i c e r s w i t h t h e

Division

of

B u i l d i n g Research, N a t i o n a l Research

Council

o f Canada.

D.E.

Allen has been engaged i n s t r u c t u r a l e n g i n e e r i n g r e s e a r c h i n t h e a r e a s o f s t m c t u r a l s a f e t y and l i m i t s t a t e s d e s i g n , f l o o r v i b r a t i o n and f i r e r e s i s t a n c e

o f

w n c r e t e s t r u c t u r e s . J . H . Rainer has been a c t i v e i n e a r t h q u a k e e n g i n e e r i n g r e s e a r c h and measurement o f b r i d g e and b u i l d i n g v i b r a t i o n . G. P e r n i c a h a s been involved i n t h e dynamic a n a l y s i s o f s t r u c t u r e s end i n t h e measurement o f f l o o r and b u i l d i n g

vibrations.

V i b r a t i o n s have n o t been a problem i n t r a d i t f o n a l c o n c r e t e f l o o r c o n s t r u c t i o n under normal c o n d i t i o n s o f use and consequent1 y v i b r a t i o n c r i t e r i a have n o t been r e q u i r e d . The t r e n d toward l o n g e r s p a n s w i t h lower f r e q u e n c i e s , 1 i g h t e r p r e c a s t c o n s t r u c t j o n and fewer p a r t i t i o n s , however, may r e s u l t i n problems i n t h e f u t u r e .

nere

i s t h e r e f o r e

a

need t o i d e n t i f y where v i b r a t i o n pmblerns can o c c u r and

t o

develop c r i t e r i a t o p r e v e n t u n s a t i s f a c t o r y performance.

Experience shows t h a t

there

a r e

d i f f e r e n t s i t u a t i o n s i n which u n d e s i r a b l e v i b t a t i o n ~

can

a r i s e and design c r i t e r i a d e r i v e d f o r

one

set of

circumstances may n o t apply t o another. Sueh d i f f e r e n c e s a r i s e i n t h e n a t u r e o f t h e v i b r a t i o n source ( e . g . , machinery v s

.

f o o t s t e p s ) , t h e s t r u c t u r a l response (e.g., t h e damping e f f e c t s o f n o n - s t r u c t u r a l components and humans) and i n t h e s e n s i t i v i t y o f s p e c i a l equipment o r o f humans engaged i n d i f f e r e n t a c t i v i t i e s . T h i s paper w i l l b e concerned p r i m a r i l y w i t h walking v i b r a t i o n s

i n

long-span f l o o r s i n o f f i c e , r e s i d e n t i a l arid s i m i l a r "quiet" human occupancies.

CRITERIA FOR CONTINUOUS VIBRATION

A c o n s i d e r a b l e amount o f t e s t i n g h a s been c a r r i e d o u t on t h e r e a c t i o n o f humans t o continuous s i n u s o i d a l v i b r a t i o n ( 1 ) . The r e s u l t s shown by t h e hatched a r e a s i n F i g s . 1 and 2, i n d i c a t e t h a t humans v a r y c o n s i d e r a b l y i n t h e i r r e a c t i o n and a r e most s e n s i t i v e i n t h e frequency range o f 2 t o 8 H z .

Against t h i s background of h u m r e a c t i o n Figure 1 shows accept- a b i l i t y c r i t e r i a f o r " q u i e t t t occupancies, e . g . . r e s i d e n c e s , o f f i c e s , s c h o o l s , given i n t h e IS0 d r a f t

for

v i b r a t i o n i n b u i l d i n g s (2) and i n " S t e e l S t r u c t u r e s f o r Buildingstq, CSA S t a n d a r d 516.1-1974 (3)

.

F i e l d t e s t d a t a are a l s o shown i n Fig. 1 f o r continuous v i b r a t i o n o f s h o r t d u r a t i o n , e . g . . due t o t r a f f i c o r ongoing walking v i b r a t i o n , which i n d i c a t e agreement w i t h the CSA c r i t e r i o n o f 0.5% g a c c e l e r a t i o n . V i b r a t i o n s become more annoying the l o n g e r t h e y l a s t a d t h i s a c c o u n t s f o r t h e d i f f e r e n c e between the CSA c r i t e r i a and IS0 c r i t e r i a which are f o r continuous { e . g . , due t o machinery) a s well a s i n t e r m i t t e n t v i b r a t i o n .

Figure 2 shows IS0 (2) and USSR (4) c r i t e r i a f o r " a c t i v e u

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bng-Span

Concrete

Floors

f i e l d t e s t o b s e r v a t i o n s c a r r i e d o u t by t h e a u t h o r s . I t appears t h a t f o r "active" occupancies, t h e c r i t e r i a go up by a f a c t o r of 5 t o a b o u t 2.5% g. For v e r y s e n s i t i v e occupancies, e.g., o p e r a t i n g rooms and f l o o r s s u p p o r t i n g s e n s i t i v e measuring d e v i c e s , t h e c r i t e r i a should b e m o r e s t r i n g e n t t h a n t h o s e given i n Fig. 1 .

The c r i t e r i a shown i n F i g s . 1 and 2 a r e q u i t e g e n e r a l b u t a s y e t a r e n o t d i r e c t l y a p p l i c a b l e i n d e s i g n , e x c e p t p o s s i b l y f o r d e s i g n by performance t e s t i n g . One reason i s t h a t t h e l o a d i n g , p a r t i c u l a r l y t h a t

due t o walking, i s n o t amenable t o simple s t r u c t u r a l d e s i g n c a l c u l a - t i o n s . The o t h e r reason i s t h a t t h e c r i t e r i a do n o t t a k e i n t o account v i b r a t i o n decay (damping) which h a s been found t o b e p a r t i c u l a r l y important f o r walking v i b r a t i o n s .

CRITERIA FOR WALKING VIBRATIONS

Problems w i t h walking v i b r a t i o n s have r e c e n t l y o c c u r r e d i n new forms of long-span c o n s t r u c t i o n , p a r t i c u l a r l y long-span s t e e l j o i s t f l o o r s w i t h t h i n c o n c r e t e deck and open f l o o r p l a n . The t r a d i t i o n a l s t i f f n e s s r u l e s , such a s l i m i t i n g d e f l e c t i o n under l i v e load t o span/ 360 o r l i m i t i n g r a t i o o f span t o depth o f a s u p p o r t i n g s t e e l beam t o 20, have r e s u l t e d i n u n s a t i s f a c t o r y v i b r a t i o n s i n a number o f c a s e s .

Experience w i t h walking v i b r a t i o n s i n long-span f l o o r s h a s shown t h a t discomfort i s caused p r i n c i p a l l y by v i b r a t i o n a t o r n e a r t h e fundamental frequency and t h a t annoyance i s s t r o n g l y a f f e c t e d by damping

-

t h e l e s s t h e damping t h e more t h e v i b r a t i o n s from s u c c e s s i v e f o o t s t e p s merge t o g e t h e r and t h e more annoying i s t h e v i b r a t i o n . V i b r a t i o n s i n t h e h i g h e r modes g e n e r a l l y damp o u t q u i c k l y and do n o t c a u s e discomfort.

S u b j e c t i v e e v a l u a t i o n s o f many e x i s t i n g f l o o r s have been r e l a t e d t o t h e f l o o r v i b r a t i o n r e s p o n s e a s measured by t h e h e e l impact t e s t (up on t h e t o e s , down on t h e h e e l s ) , t h a t i s t o t h e measured frequency, damping and peak a c c e l e r a t i o n from h e e l impact a f t e r f i l t e r i n g o u t t h e h i g h e r modes. C r i t e r i a r e l a t e d t o t h e s e f l o o r p r o p e r t i e s a r e shown by t h e hatched l i n e s i n Fig. 3 f o r "quiet" occupancies ( r e s i d e n c e s , o f f i c e s , e t c . ) . These c r i t e r i a a r e based on a v a i l a b l e f i e l d t e s t r e s u l t s (5). and a r e an e x t e n s i o n t o t h o s e proposed by Lenzen i n 1965

( 6 ) . Most o f t h e f l o o r s were o f s t e e l j o i s t and beam c o n s t r u c t i o n w i t h c o n c r e t e s l a b , b u t t h e c r i t e r i a should b e a p p l i c a b l e t o any type of long-span f l o o r c o n s t r u c t i o n . They w i l l s u b s e q u e n t l y b e a p p l i e d t o c o n c r e t e c o n s t r u c t i o n .

The c r i t e r i a i n Fig. 3 a r e , however, r e s t r i c t e d t o s p a n s g r e a t e r t h a n 25 f t (8 m) and f r e q u e n c i e s l e s s than 10 Hz; t h e y a r e n o t

a p p l i c a b l e t o short-span o r l i g h t f l o o r s . The main reason f o r t h i s

i s

t h a t humans a c t a s shock a b s o r b e r s which a r e e f f e c t i v e i n damping o u t walking v i b r a t i o n s i n l i g h t f l o o r s , b u t n o t i n heavy f l o o r s . The c r i t e r i a f o r l i g h t , short-span f l o o r s a r e r e l a t e d more t o t h e m t i o n caused b y r e p e a t e d s t a t i c d e f l e c t i o n than t o v i b r a t i o n response i n t h e fundamental modes. C r i t e r i a r e l a t e d t o s t a t i c d e f l e c t i o n under p o i n t l o a d a r e t h e r e f o r e more a p p r o p r i a t e f o r d e s i g n . Short-span c o n c r e t e s l a b s a r e g e n e r a l l y v e r y s t i f f t o suddenly a p p l i e d p o i n t load and,

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Allen,

Rainer,

and

Pemica

consequently, walking v i b r a t i o n s a r e n o t a problem.

APPLICATION OF VIBRATION CRITERIA

TO CONCRETE STRUCTURES

Table

1 c o n t a i n s case s t u d i e s o f t h r e e t y p e s o f long-span c o n c r e t e c o n s t r u c t i o n : p r e c a s t double T f s i n a p a r k i n g a r e a , p r e c a s t s t a n d s i n a

stadium and a c a s t - i n - p l a c e two-way beam and s l a b o f f i c e f l o o r . The f i r s t two r e p r e s e n t " a c t i v e t ' occupancies and t h e t h i r d a "quiet" occupancy. Table 2 c o n t a i n s measured v i b r a t i o n c h a r a c t e r i s t i c s

for

d i f f e r e n t tests c a r r i e d o u t on t h e s e f l o o r s . Peak a c c e l e r a t i o n s

f r o m

normal use a c t i v i t y , i . e . , walking o r d r i v i n g , a l o n g w i t h a s d j e c t i v e assessment o f v i b r a t i o n a c c e p t a b i l i t y , a r e i n c l u d e d i n F i g s . 1 and 2. Measured h e e l impact a c c e l e r a t i o n f o r t h e o f f i c e f l o o r , p l o t t e d i n Fig. 3, f a l l s s l i g h t l y below t h e c r i t e r i o n for 3% damping; i n t h i s c a s e t h e v i b r a t i o n , which was b a r e l y n o t i c e a b l e t o most people, annoyed o n e s e n s i t i v e person l o c a t e d n e a r the i n t e r s e c t i o n o f two walkways. Such c a s e s a r e b e t t e r r e s o l v e d by r e l o c a t i o n than by using c o n s e r v a t i v e d e s i g n c r i t e r i a .

To use t h e v i b r a t i o n c r i t e r i a o f F i g . 3 f o r f l o o r d e s i g n , one has t o e s t i m a t e fundamental frequency, f , damping and h e e l impact

a c c e l e r a t i o n , a

.

These parameters w i l l now b e d i s c u s s e d .

Fundamental frequency f o r simply- supported one-way systems i s e s t i m a t e d from t h e beam formula:

f = 3 1 F (= 0 . 0 0 4 9 6 i n S I u n i t s ) w L where E = t h e modulus o f e l a s t i c i t y , p s i (gPa), I = t h e moment o f i n e r t i a , i n . (mm4), w = t h e dead weight, l b / i n . (kN/m), L = t h e span, i n . (m)

.

For the p r e c a s t

T's,

t h e c a l c u l a t i o n

is

s t r a i g h t f o w a r d . For t h e p r e - c a s t s t a n d s , which are t i e d t o g e t h e r t o p r e v e n t t w i s t i n g o f t h e unsymmetric c r o s s - s e c t i o n s , t h e frequency was determined a b o u t t h e minor p r i n c i p a l axis, i . e . , v i b r a t i o n t h a t is normal t o the p l a n e o f t h e s t a n d s . For t h e c a s t - i n - p l a c e beam and s l a b system, t h e c a l c u l a - t i o n of frequency was based on a n assumed simply-supported T s e c t i o n with f l a n g e w i d t h equal t o t h e t r i b u t a r y area o f the beam. As seen i n Table 2, the assumption o f simple support g e n e r a l l y u n d e r e s t i m a t e s t h e frequency, even f o r p r e c a s t elements. Although more s o p h i s t i c a t e d a n a l y t i c a l t e c h n i q u e s a r e a v a i l a b l e t o determine frequency, t h e s e

a r e

g e n e r a l l y n o t warranted u n l e s s resonance i s l i k e l y t o b e a problem. Damping depends p r i m a r i l y on the presence o f n o n - s t r u c t u r a l components such a s p a r t i t i o n s . The damping r a t i o s suggested for j o i s t f l o o r s

131

a r e 3% of

c r i t i c a l

f o r t h e bare f l o o r , 6% f o r f u l l y f i n i s h e d f l o o r w i t h open o f f i c e f l o o r p l a n . and 1 2 % f o r f u l l h e i g h t p a r t i t i o n s .

The measurements i n Table 2 i n d i c a t e t h a t the damping r a t i o f o r f u l l y contintmus c a s t - i n - p l a c e c o n c r e t e f l o o r s i s o f the o r d e r of 2 to 3% and

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Long-Span Concrete

Floors

f o r i n t e r c o n n e c t e d p r e c a s t beams i s about 4 % . F u r n i t u r e , c e i l i n g , rug, low p a r t i t i o n s , e t c . used i n open o f f i c e f l o o r p l a n s i n c r e a s e t h e damping r a t i o by about 1 t o 3%. F u l l h e i g h t p a r t i t i o n s i n c r e a s e t h e damping r a t i o by a f u r t h e r 2 t o 4%. Non-structural elements, such a s p a r t i t i o n s , t h e r e f o r e appear t o b e l e s s e f f e c t i v e i n i n c r e a s i n g t h e damping r a t i o o f c a s t - i n - p l a c e c o n c r e t e a s compared w i t h j o i s t f l o o r s . T h i s can b e a t t r i b u t e d t o t h e g r e a t e r mass and l e s s o p p o r t u n i t y f o r f r i c t i o n a l damping i n t h e connections.

Peak a c c e l e r a t i o n from h e e l impact f o r long-span s t r u c t u r e s can b e e s t i m a t e d by c a l c u l a t i n g t h e fundamental mode response o f an e q u i v a l e n t

I

simply-supported beam t o a h e e l impulse, (67 W a s ) . The r e s ~ i l t i n g a c c e l e r a t i o n is c l o s e l y approximated by ( 5 ) : I , ( F i g , 4 ) , o f 15 l b - s

where M i s t h e e q u i v a l e n t mass o f a simple o s c i l l a t o r , which i n t h i s c a s e is 0.64 times t h e mass o f t h e beam. I f t h e beam mass i s r e p l a c e d by W/g where W i s t h e weight i n k i p s (kN) and g

is

t h e a c c e l e r a t i o n due t o g r a v i t y , t h e n

a (%g) = 1 3 . 3 f / W (= 59 f/W i n S I u n i t s )

I

I

T h i s formula can b e used f o r i s o l a t e d beams o r narrow b r i d g e s . I t can a l s o b e used f o r f l o o r systems i f a r e a s o n a b l e e s t i m a t e i s made o f t h e " e f f e c t i v e " width o f " e f f e c t i v e " number o f a d j a c e n t elements t h a t p a r t i c i p a t e i n r e s p o n s e t o h e e l impact.

For j o i s t f l o o r s , t h e e f f e c t i v e width was taken a s 0.64 (60 t c ) where tc i s t h e c o n c r e t e s l a b t h i c k n e s s and 60 tc r e p r e s e n t s t h e d i s t a n c e between nodal l i n e s o f v i b r a t i o n ( 5 ) . For c a l c u l a t i n g a, i n Table 2, i t was assumed t h a t f o r t h e p r e c a s t T ' s and s t a n d s t h r e e elements were l o c a t e d between t h e nodal l i n e s o f v i b r a t i o n . For t h e c a s t - i n - p l ace beam system, t h e t r i b u t a r y width supported by t h e beam (20 f t ) was taken a s t h e e f f e c t i v e width. More a c c u r a t e methods o f e s t i m a t i n g e f f e c t i v e width a r e c o n t a i n e d i n Ref. 7 .

An a c c u r a t e c a l c u l a t i o n o f f l o o r response t o h e e l impact, p a r t i c u l a r 1 y f o r c a s t - i n - p l a c e continuous c o n s t r u c t i o n , can b e v e r y d i f f i c u l t . In g e n e r a l , however, continuous c o n s t r u c t i o n should b e assumed t o b e simply-supported, o r n e a r l y s o , s i n c e i n t h e fundamental mode a d j a c e n t f l o o r p a n e l s v i b r a t e i n o p p o s i t e d i r e c t i o n s . Also, approximate e s t i m a t i o n s o f response parameters a r e g e n e r a l l y adequate f o r a s s e s s i n g v i b r a t i o n comfort.

(9)

Allen, Rainer, and Pemica

RESONANCE PROBLEE

I f t h e frequency o f t h e f l o o r i s c l o s e t o t h e frequency o f t h e d i s t u r b a n c e , l a r g e o s c i l l a t i o n s can b u i l d up. Dancing, c l a p p i n g and o t h e r s i m i l a r r e p e t i t i v e human a c t i v i t i e s can c r e a t e p e r i o d i c f o r c e s i n

t h e frequency range 1 t o 4 Hz. A commentary t o t h e National Building Code o f Canada (8) t h e r e f o r e recommends t h a t f l o o r s s u p p o r t i n g such a c t i v i t i e s should n o t have n a t u r a l f r e q u e n c i e s l e s s than a b o u t 5 Hz, (8 Hz i n t h e c a s e of dance f l o o r s s i n c e some resonance can b u i l d up i f t h e dance b e a t corresponds t o every second c y c l e o f n a t u r a l frequency). The Netherlands code (9) recommends t h a t f l o o r s should n o t have

f r e q u e n c i e s 3 Hz o r l e s s f o r walking (walking f o o t s t e p s o c c u r a t about 2 Hz), and n o t l e s s t h a n 5 Hz f o r jumping; t h e s e l i m i t a t i o n s may b e waived i f t h e p e r m n e n t l o a d i s 5 kPa (100 p s f ) o r m r e f o r f l o o r s l a b s o r 150 kN (35 k i p s ) o r m r e f o r f l o o r beams.

The w o r s t frequency f o r dance f l o o r s i s i n t h e neighborhood o f 1 1/2 t o 3 Hz; a number o f t h e s e have been b u i l t i n r e c e n t y e a r s and have experienced l a r g e u n s a t i s f a c t o r y v i b r a t i o n l e v e l s . Figure 5

( c a s e 28 of Tables 1 and 2) shows an example o r resonance measured i n a p r e c a s t grandstand ( n a t u r a l frequency 2 1 / 2 Hz and dead weight >

100 p s f ) d u r i n g a rock and r o l l c o n c e r t where a c c e l e r a t i o n s up t o 34% g b u i l t up during c l a p p i n g and stomping.

T h i s p a p e r i s a c o n t r i b u t i o n from t h e D i v i s i o n o f Building

Research, National Research Council o f Canada and i s p u b l i s h e d w i t h t h e approval of t h e D i r e c t o r o f t h e D i v i s i o n .

REFERENCES

1 . H a r r i s , C.M. and C.E. Crede. Shock and Vibration Handbook, Vol. 111, Ch. 44, p . 22, McGraw H i l l , 1961.

2.. D r a f t Recommendations f o r V i b r a t i o n s and Shock L i m j t s f o r Occupants o f B u i l d i n g s , IS0 TC108, 1974.

3. Guide o n F l o o r V i b r a t i o n s , Appendix G t o S t e e l S t r u c t u r e s f o r B u i l d i n g s , CSA Standard S16.1-1974. Can. S t a n d a r d s Assoc., Rexdal e O n t a r i o .

4. Environment Standards f o r t h e Design o f I n d u s t r i a l E n t e r p r i s e s ( i n Russian) SN 245-1971, GOSSTROI, USSR.

5 . Allen, D.E. and J . H . Rainer. V i b r a t i o n C r i t e r i a f o r Long-Span F l o o r s . Can. J . Civ. Eng., Vol. 3 , No. 2, June 1976.

6. Lenzen,

K.H.

Vibration of S t e e l J o i s t s . AISC Engineering J o u r n a l , No. 3, Vol. 3, p . 133, 1966.

7. Galambos, T. V. V i b r a t i o n o f S t e e l J o i s t - C o n c r e t e S l a b Floors. Techn., Dig. No. 5, S t e e l J o i s t I n s t . , Arlington, Va, 1973.

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Long-Span Concrete

Floors

73

8. S e r v i c e a b i l i t y C r i t e r i a f o r D e f l e c t i o n s and V i b r a t i o n s .

Commentary A, Supplement 4 t o National Building Code o f Canada 1977. Nat. Res. Council o f Canada, Assoc. Com. Nat. Bldg. Code, Ottawa.

9. Regulations f o r t h e C a l c u l a t i o n o f Building S t r u c t u r e s

-

General C o n s i d e r a t i o n s and Loading ( i n Dutch). TGB 1972. NEN 3850.

Nederlands N o r m a l i s a t i e - I n s t i t u u t , R i j s w i j k .

Table 1

-

F i e l d S t u d i e s o f Long-span Concrete F l o o r Systems

1 f t = 0.305 m 1 p s f = 0.048 kPa

(11)

Table 2

-

V i b r a t i o n C h a r a c t e r i s t i c s f o r Cases i n Table 1

Frequency, Hz Measured

.

Peak

From Measured Peak Acceleration,

Heel Impact, % g

Case

.

-

Damping,

.

% g, From

Measured Calculated (1) % C r i t i c a l Measured C a l c u l a t e d (2)

I 1 A 5.4 4.0 3-4 1.6 0 . 8 ( 1 . 1 0.5 (walking) 1.7 ( d r i v i n g ) 1 B 9 . 3 9.2 4-4.5 2.8 2.8 (2.8) 0.7 (walking) 3.4 ( d r i v i n g ) 2A 4.8 2.6 4-5 1.1 1 . 2 ( 2 . 2 ) O . S ( w a l k i n g ) 2B 2.6 2.2

- -

--

--

34 (rock & r o l l ) 3A 7.2 5 . 3 2-2.6 1.2 0 . 8 ( 1 . 1 0 . 3 (walking) 38 6.7 5.3 3- 5 1-1.5 0.8 (1.0) 0.3 (walking) 3C 7.7 5 . 3 6.3-6.9 0.9 0 . 8 (1.2)

----

Notes: (1) Assumes simple s u p p o r t .

(12)

Long-Span

Concrete

Floors

'OOr----l

F I E L D TEST D A T A F O R S H O R T - T E R M C O N T I N U O U S V I B R A T I O N : J O I S T F L O O R S ' ~ ' 0 S A T I S F A C T O R Y U N S A T I S F A C T O R Y R/C F L O O R ( C A S E 3 ) B O R D E R L I N E C S A ~ 1 6 . 1 ' ~ ) ( S H O R T TERM V I B R A T I O N ) : O F F I C E S , R E S I D E N C E S A N D S C H O O L S

,-.

1 ~ 0 " ' ( C O N T I N U O U S O R I N T E R M I T T E N T V I B R A T I O N ) : O F F I C E S R E S I D E N T I A L 1 2 4 6 1 0 2 0 F R E Q I J E N C Y , H z F I G U R E I H U M A N R E S P O N S E C R I T E R I A F O R C O N T I N U O U S V I B R A T I O N : " Q U I E T " O C C U P A N C I E S

(13)

Wen,

Rainer,

and

kmica

l o o

7

F I E L D TEST D A T A FOR SH0FiT'-

TERM C O N T I N U O U S V I B R A T I O N

F R E Q U E N C Y , H z

F I G U R E 2

H U M A N RESPONSE C R I T E R I A FOR C O N T I N U O U S V I B R A T I O N : " A C T I V E " O C C U P A N C I E S

(14)

---

C R I T E R I A F O R W A L K I N G V I B R A T I O N S A S G I V E N B Y H E E L I M P A C T TEST

-

C R I T E R I A F O R C O N T I N U O U S V I B R A T I O N F R E Q U E N C Y , H z F I G U R E 3 A N N O Y A N C E C R I T E R I A FOR F L O O R V I B R A T I O N S : ' " Q U I E T " O C C U P A N C I E S

(15)

Allen,

Rainer,

and

Pemica

-

-

2

-

4 0 0

-

-

lil U =

2

300

-.

2 0 0

--

I = 15 1b.r 100

-

a l o 20 S O 4 0 S O 6 0 TIME. mt FIGURE 4

HEEL IMPACT (REF. 9 )

FIGURE 5

(16)

This publication is being d i r t r i b u t e d by the Division of Building R e s e a r c h of the National R e s e a r c h Council of Canada. I t should not be reproduced in whole o r in p a r t without p e r m i r e i o n of the original publirher. The Di- vision would be glad to be of a s s i s t a n c e in obtaining such p e r m i e r i o n .

Publicationr of the Divirion m a y be obtained b y m a i l - iag the a p p r o p r i a t e r e m i t t a n c e (a Bank, E x p r e r r , o r

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A l i s t of allpublicationr of the Division i s available and m a y be obtained f r o m the Publicatione Section, Division of Building R e s e a r c h , National R e s e a r c h Council of Canada, Ottawa. KIA 0R6.

(17)

Authorized Reprint From

American

Concrete Institute

Figure

Figure  2  shows  IS0  (2)  and  USSR  (4)  c r i t e r i a   f o r   " a c t i v e u
Table  1  -  F i e l d   S t u d i e s   o f   Long-span  Concrete  F l o o r   Systems
Table  2  -  V i b r a t i o n   C h a r a c t e r i s t i c s   f o r  Cases  i n  Table  1

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