Seismic Control Research of the Multi-Ribbed Slab Structure Using the Ultra Low Yield Strength Steel Jie TIAN & Zhichao Yan Xi’an University of Technology, China

ABSTRACT: Multi-ribbed slab structure (MRSS) is a new type of composite structure with specific characteristics which is composed of prefabricated multi-ribbed composite wall slab, cast-in-place floor slab and cast-in-suit concealed outer frame. In this paper, ultra low yield strength steel panels are used in the multi-ribbed composite wall slab, seismic response control of the multi-ribbed slab structures using the ultra low yield strength steel was explored. The nonlinear dynamic time-history analysis of the MRSS seismic control systems under horizontal earthquakes waves were carried out. The earthquake responses and energy dissipation mechanisms as well as damage performance of the control structures were investigated. The effects of vibration reduction of the ultra low yield strength steel panel were discussed. The computing results show that the ultra low yield strength steel panel has obvious mitigation of seismic effects. MRSS with ultra low yield strength steel panels has a good energy dissipation and seismic capacity. Keywords: Multi-ribbed slab structure, ultra low yield strength steel panel, seismic response control 1. INTRODUCTION Ultra Low yield point steel has strong energy dissipation and stable performance, which is often used to make various types of energy-consuming or seismic damping device, attracting more and more attention in engineering field and becoming a hotspot for study [1-4]. Multi-Ribbed Slab Structure (MRSS) is a new type of composite structure with specific characteristics (see Figure 1) [5]. The MRSS is composed of prefabricated multi-ribbed composite wall slab, cast-in-place floor slab and cast-in-suit concealed outer frame, in which the multi-ribbed composite wall slab is the main bearing member of the MRSS that is composed of reinforced concrete frame made up of rib beams and rib columns as well as built-in infill silicate blocks or light-weight infill panels. In this paper, ultra low yield strength steel panels are used to partly replace built-in infill silicate blocks in the concrete frame of the multi-ribbed composite wall slab, thus a new kind of the seismic mitigation multi-ribbed composite wall slab are provided by locating ultra low yield strength steel panels within concrete frame. Seismic control technique of the multi-ribbed slab structure using the ultra low yield strength steel is explored. The nonlinear dynamic time-history analysis of the MRSS seismic control systems with ultra low yield strength steel panels under horizontal earthquakes waves were carried out. The earthquake responses and energy dissipation mechanisms as well as damage performance of the control structure were investigated. The effect of vibration reduction of the ultra low yield strength steel for MRSS were discussed, and the influence factors of seismic mitigation effects were carefully studied, which provides insight into earthquake responses of MRSS seismic control system. The computing results show that the ultra low yield strength steel has obvious mitigation of seismic effects. MRSS control system with ultra low yield strength steel panels has a good energy dissipation and seismic capacity.

floorslab

multi-ribbed composite slabconnecting column

end frame column

concealed beam

rib beam infill block or panel

rib column

Figure 1. Multi-ribbed slab structure 2. THE STRUCTURAL ANALYSIS MODELS 2.1. Calculating Analysis Model There are four calculating analysis models to been chosen. The model 1 is a 15-storey practical prototype building structure with the multi-ribbed composite wall slab built-in infill silicate blocks (see Figure 2 (a) and Figure 2 (b)). The model 2~model 4 are structural control systems using the ultra low yield strength steel that the location of the multi-ribbed composite wall slab built-in the ultra low yield strength panels are marked with dotted lines shown in Figure 2(a), in which the amount of the ultra low yield strength steel panel composite walls of model 2 are located from first storey to fifth storey(see Figure 2 (c)), the steel panel composite walls of model 3 are located from first storey to eighth storey(see Figure 2 (d)), the steel panels composite walls of model 4 are located from ninth storey to fifth storey(see Figure 2 (e)). The thickness of the steel panel composite walls is 300 mm. The ultra low yield strength steel (LYP100) is chosen which the computing yield stress 80=yσ N/mm2 and shear yield stress 380=yτ N/mm2 [6].The thickness of ultra low yield strength steel panels is 4mm. The construction diagrams of the multi-ribbed steel panel composite walls are shown in Figure 3. 2.2. Dynamic Analysis Method The nonlinear earthquake responses of the structures are calculated by using program IDARC2D Version 7.0 [7-8]. The nonlinear dynamic analysis models of the structures are established with retrogressive three-linear resilience model for beam and column elements, while a smooth hysteretic model is proposed for representing infill silicate blocks and low yield strength steel panels. The nonlinear dynamic time-history analysis of the structures under horizontal earthquakes has been carried out. The 4 natural earthquake ground motions El-Centro, Taft, San Fernando and Kobe waves were chosen(see Table2.1). Inputting peak ground motion acceleration is 0.4g being representative for design acceleration of ground motion at rare occurrence earthquake of Code in China [9] under seismic precautionary intensity 8 degree. Computing time =25s, time interval being =0.002s. t tΔ

Table2.1. Input Earthquake Ground Motions

Earthquake wave File name Station Comp. Mag.

(Ms)PGA(g)

PGV (cm/s)

PGA/ PGV Duration

1 Imperial Valley(1940) ELC El Centro Array #9 S00E 6.7 0.342 33.5 1.02 53.76

2 Kern County(1952) TAFT Taft Lincoln

School S69E 7.7 0.176 17.7 0.99 54.40

3 San Fernando(1971) SANF Castaic-Old Bridge

Route ORR021 6.6 0.324 15.6 2.08 61.80

4 Kobe(1995) KOBE Shin-Osaka SHI000 6.9 0.243 37.8 0.64 40.96

 

(a) Plans of model structures

(b) The elevation of the ~ ① ⑨ axis in model 1 (c)The elevation of the and ① ⑨axis in the model 2

or the ~ axis in model 2~ m② ⑧ odel 4

(d)The elevation of the① and ⑨axis in model 3 (e)The elevation of the① and ⑨axis in the model 4

Figure 2. The diagram of model structures

 

(a) built-in infill silicate blocks (b) built-in ultra low yield strength steel panels Figure 3. The construction diagram of a multi-ribbed composite wall slab

3. THE NONLINEAR EARTHQUAKE RESPONSES ANALYSIS OF THE STRUCTURE The maximum displacement, interstorey drift, storey shear and acceleration responses of the structures subjected to El-Centro, Taft , San Fernando and Kobe waves are shown in Figure4~Figure 7.

   

 

0 5 10 15 20 25 300

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

ELC 0.4g

Stor

ey L

evel

Displacment(cm)0 5 10 15 20 25 30

0

2

4

6

8

10

12

14

16

Stor

ey L

evel

Displacement(cm)

Model 1 Model 2 Model 3 Model 4

TAFT 0.4g

 

 

 

 

  (a) El-Centro (b) Taft

 

0 5 10 15 20 25 300

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

SANF 0.4g

Stor

ey L

evel

Displacement(cm)0 10 20 30 40 50 60 70

0

2

4

6

8

10

12

14

16

 

Model 1 Model 2 Model 3 Model 4

KOBE 0.4g

Stor

ey L

evel

Displacement(cm)

 

 

 

(c) Sanf (d) Kobe

Figure 4. The maximum displacement responses of the models with different waves

 

 

0.0 0.5 1.0 1.50

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

ELC 0.4g

orey

Lev

el

Interstorey Drift(%)

St

0.0 0.5 1.0 1.50

2

6

8

10

12

14

16     

 

4 Model 1 Model 2 Model 3 Model 4

TAFT 0.4g

Stor

ey L

evel

Interstorey Drift(%)

 

 

   

 

 

  (a) El-Centro (b) Taft

 

0.0 0.5 1.0 1.50

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

SANF 0.4g

Stor

ey L

evel

Interstorey Drift(%)0 1 2 3

0

2

4

6

8

10

12

14

16 Model 1 Model 2 Model 3 Model 4

KOBE 0.4g

Stor

ey L

evel

Interstorey Drift(%)

 

 

 

  

(c) Sanf (d) Kobe Figure 5. The maximum interstorey drift of the models with different waves

 

0 2000 4000 6000 8000 100000

2

4

6

8

10

12

14

16 Model 1 Model 2 Model 3 Model 4

TAFT 0.4g

Stor

ey L

evel

Shear Force(kN)0 2000 4000 6000 8000 10000

0

2

4

6

8

10

12

14

16 Model 1 Model 2 Model 3 Model 4

ELC 0.4g

Stor

ey L

evel

Shear Force(kN)

 

 

 

 

(a) El-Centro (d) Taft

 

0 2000 4000 6000 8000 100000

2

4

6

8

10

12

14

16 Model 1 Model 2 Model 3 Model 4

SANF 0.4g

Stor

ey L

evel

Shear Force(kN)0 2000 4000 6000 8000 10000

0

2

4

6

8

10

12

14

16 Model 1 Model 2 Model 3 Model 4

KOBE 0.4g

Stor

ey L

evel

Shear Force(kN)

 

 

 

 

(c) Sanf (d) Kobe Figure 6. The maximum interstorey shear force of the models with different waves

 

0 200 400 6000

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

TAFT 0.4g

Stor

ey L

evel

Acceleration(gal)0 200 400 600

0

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

ELC 0.4g

Stor

ey L

evel

Acceleration(gal)

 

 

 

 

 

      (a) El-Centro (b) Taft

 

0 200 400 6000

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

KOBE 0.4g

Stor

ey L

evel

Acceleration(gal)0 200 400 600

0

2

4

6

8

10

12

14

16

Model 1 Model 2 Model 3 Model 4

SANF 0.4g

Stor

ey L

evel

Acceleration(gal)

 

 

 

 

(c) Sanf (d) Kobe

Figure 7. The maximum acceleration responses of the models with different waves

Figure 4 (a)~(d) show that the maximum displacement responses of the model 2~model 4 at top storey under El-Centro, Taft , San Fernando and Kobe waves decrease, which reflects that the ultra low yield strength steel panels have obvious seismic mitigation effects. From Figure 5 (a)~(d) it can been seen that the maximum interstorey drift angles of the model 2~model 4 with the ultra low yield strength steel panel walls under different waves have big decreases, especially in model 2 when the ultra low yield strength steel panels composite walls are evenly located from first storey to fifth storey it have obvious advantage of seismic control which is a proposal of priority. Figure 6~Figure 7 indicated that the maximum interstorey shear force and acceleration responses have some decrease in the model 4 but have increase in the model 2 and model 3. Figure 8~Figure 9 give the time-history responses of displacement and acceleration at top storey.

0 5 1 0 1 5 2 0 2 5- 3 0

- 2 0

- 1 0

0

1 0

2 0

3 0

Top

Disp

lace

men

t(cm

)

T i m e ( s )

M o d e l 1 M o d e l 2 M o d e l 3 M o d e l 4

E L C 0 . 4 g

(a) El-Centro

 

0 5 1 0 1 5 2 0 2 5- 3 0

- 2 0

- 1 0

0

1 0

2 0

3 0 T

op D

ispla

cem

ent(c

m)

T i m e ( s )

M o d e l 1 M o d e l 2 M o d e l 3 M o d e l 4

T A F T 0 . 4 g

(b)Taft Figure 8. Displacement time-history responses at top storey

0 5 1 0 1 5 2 0 2 5- 5 0 0- 4 0 0- 3 0 0

- 2 0 0

- 1 0 00

1 0 02 0 0

3 0 04 0 0

5 0 0

Acc

eler

atio

n(ga

l)

T i m e ( s )

M o d e l 1 M o d e l 2 M o d e l 3 M o d e l 4

E L C 0 . 4 g

(a) El-Centro

0 5 1 0 1 5 2 0 2 5- 5 0 0- 4 0 0- 3 0 0

- 2 0 0

- 1 0 00

1 0 02 0 0

3 0 04 0 05 0 0

Acc

eler

atio

n(ga

l)

T i m e ( s )

M o d e l 1 M o d e l 2 M o d e l 3 M o d e l 4

T A F T 0 . 4 g

(b)Taft Figure 9. Acceleration time-history responses at top storey

4. HYSTERETIC ENERGY DISSIPATION AND DAMAGE PERFORMANCE 4.1. Hysteretic Energy Dissipation Figure 10 give the hysteretic curves of a built-in ultra low yield strength steel panel numbered 73 in the model 2 subjected to El-Centro wave and Taft wave (see Figure 2(c)). It can be seen that the ultra low yield strength steel panel have full shape of hysteretic curve and stable energy dissipation. Figure 11~ Figure 12 give separately the hysteretic curves of the storeies and the structures of model 1 and model 2. Because the ultra low yield strength steel panels have strong energy dissipation the structures and storeies of the model 2 have better energy dissipation capability.

 

-8 -6 -4 -2 0 2 4 6 8-300

-200

-100

0

100

200

300

Shea

r For

ce(k

N)

Displacement(mm)

TAFT (No.73)

-8 -6 -4 -2 0 2 4 6 8-300

-200

-100

0

100

200

300

Shea

r For

ce(k

N)

ELC (No.73)

D isplacement(mm)

(a)El-Centro (b)Taft Figure 10. Hysteretic curves of an ultra low yield strength steel panel

-30 -20 -10 0 10 20 30-8000-6000-4000-2000

02000400060008000

Shea

r For

ce(k

N)

Displacement(mm)

Model 1(ELC)

-30 -20 -10 0 10 20 30-8000-6000-4000-2000

02000400060008000

Shea

r For

ce(k

N)

Displacement(mm)

Model 2(ELC)

 

 

 

 

(a) Model 1(El-Centro) (b) Model 2(El-Centro)

-30 -20 -10 0 10 20 30-8000-6000-4000-2000

02000400060008000

Shea

r For

ce(k

N)

Displacement(mm)

Model 1(TAFT)

-30 -20 -10 0 10 20 30-8000-6000-4000-2000

02000400060008000

Shea

r For

ce(k

N)

Displacement(mm)

Model 2(TAFT)

(c) Model 1(Taft) (d) Model 2 (Taft) Figure 11. Hysteretic curves of the second storey

-300 -200 -100 0 100 200 300-8000-6000-4000-2000

02000400060008000

Base

She

ar F

orce

(kN

)

Top Displacement(mm)

Model1(ELC)

-300 -200 -100 0 100 200 300-8000-6000-4000-2000

02000400060008000

Model2(ELC)

Base

She

ar F

orce

(kN

)

Top Displacement(mm)

(a) Model 1(El-Centro) (b) Model 2(El-Centro)

 

-300 -200 -100 0 100 200 300-8000-6000-4000-2000

02000400060008000

Bas

e Sh

ear F

orce

(kN

)

Top Displacement(mm)

Model 2(TAFT)

-300 -200 -100 0 100 200 300-8000-6000-4000-2000

02000400060008000

Bas

e Sh

ear F

orce

(kN

)

Top Displacement(mm)

Model1(TAFT)

   

(c) Model 1(Taft) (d) Model 2 (Taft) Figure 12. Hysteretic curves of model structures

4.2. Damage Performance The damage assessment method was built by employing the dual-failure model of structural components considering both deformation and accumulative hysteretic energy, a fatigue based damage model introduced by Reinhorn and Valles (1995) was proposed in the paper [7-8].Figure 13 give damage index distribution of beam and floor slab as well as wall slab and column of model 1 and model 2 along storey. Figure 14 give damage time-history response curves of model 1 and model 2 at third storey. Table4.1 gives the structural overall damage index of model 1 and model 2. The results shows that damage index of members and structures of model 2 are much smaller than damage index of model 1,which indicated that the ultra low yield strength steel panel can reduce and postpone damage of members and structures.

0.0 0.2 0.4 0.6 0.8 1.002468

10121416   

0.00 0.01 0.02 0.03 0.04 0.0502468

10121416

Model 1(ELC) Model 1(TAFT) Model 2(ELC) Model 2(TAFT)

Stor

ey L

evel

Damage Index of Wall Slab and Col.

Stor

ey L

evel

Damage Index of Beam and Floor Slab

Model 1(ELC)

Model 1(TAFT) Model 2(ELC) Model 2(TAFT)

(a) Beam and floor slab (b) Wall slab and column Figure 13. Damage indexes of models along storey

   

0 5 10 15 20 25-0.10.00.10.20.30.40.50.60.70.80.91.0

Time (s)

Dam

age

Inde

x

Model 1(Beam) Model 2(Beam) Model 1(Col.) Model 2(Col.)

TAFT 0.4g

0 5 10 15 20 25-0.10.00.10.20.30.40.50.60.70.80.91.0

Model 1(Beam) Model 2(Beam) Model 1(Col.) Model 2(Col.)

ELC 0.4g

Time (s)

Dam

age

Inde

x

(a)El-Centro (b)Taft Figure 14. Damage time-history response curves at third storey

 

 

Table 4.1. The structural overall damage index

Damage index El-Centro Taft Sanf Kobe

Model 1 0.490 0.504 0.451 >1

Model 2 0.261 0.279 0.335 0.826

5. CONCLUSIONS The computing results show that the ultra low yield strength steel panels have obvious mitigation of seismic effects. The ultra low yield strength steel panel composite walls being evenly located along storey have obvious advantage of seismic response control which is a proposal of priority. The ultra low yield strength steel panels have full shape of hysteretic curve and stable energy dissipation, which can reduce and postpone damage of members and structures. MRSS control structure with ultra low yield strength steel panel composite walls has a good energy dissipation and earthquake collapse resistance capacity to encounter earthquake motions. AKCNOWLEDGEMENT Current research has been financially supported by the National Natural Science Foundation of China Research Project（No.51078310）and Scientific Research Program Funded by Shaanxi Provincial Education Department (No. 2010JK729). REFERENCES [1] Manoru Ohashi,Haruo Mochizuki,Tanemi Amaguchi,et al (1989).Development of new steel plates for

building structural use. Steel Research. Vol 334,17-28. [2] Kiyoshi TANAKA and Yasuhito SASAKI(2000). Hysteretic performance of shear panel dampers of ultra

low yield strength steel for seismic response control of building. New Zealand:12WCEE, PaperNo.1248. [3] H.B. Ge, K. Kaneko and T. Usami(2008). Capacity of stiffened steel shear panels as a structural control

damper. China: 14WCEE, Paper ID: 05-05-0129. [4] Tian Jie,Yao Qianfeng (2010). Study on seismic energy dissipation control of multi-ribbed slab structure

with ultra low yield strength steel.The ninth China-Japan symposium on structures, Tokyo Japan.VolⅠ: 707-714

[5] Scientific and Technical Report (2000). Study on Theory and application of multi-ribbed wall slab structure with light-weight outer frame, Xi’an University of Architecture & Technology, China.

[6] Passive Damping Structure Design and Construction Manual(2008).Japan Association of Isolated Structures.

[7] Reinhorn A.M., Roh H., Sivaselvan M., Kunnath S.K.,Valles R.E.,Madan A., Lobo C. Li, R.and Park Y.J. (2010). IDARC2D version 7.0: A program for the inelastic damage analysis of structures. State University of New York at Buffalo.

[8] Reinhorn A.M., Roh H., Sivaselvan M., Kunnath S.K.,Valles R.E.,Madan A., Lobo C. Li, R. and Park Y.J. (2010). IDARC2D version 7.0: User＇s guide. State University of New York at Buffalo.

[9] GB 50011-2010.Code for Seismic Design of Buildings (2010).China Architecture and Building Press.