37

International Journal of Construction Engineering (IJCE)

Volume 1, Issue 1, January – June 2019, pp. 37-51, Article ID: IJCE_01_01_005

Available online at http://www.iaeme.com/IJCE/issues.asp?JType=IJCE&VType=1&IType=1

© IAEME Publication

DYNAMIC ANALYSIS OF CONCRETE GIRDER BRIDGES

UNDER STRONG EARTHQUAKES: THE EFFECT OF

COLLISION, BASE-ISOLATED PIER AND WING WALL

Desy Setyowulan1, Keizo Yamamoto2, ToshitakaYamao3, Tomohisa Hamamoto4

1Graduate School of Science and Technology, Kumamoto University,

2-39-1 Kurokami, Kumamoto, 860-8555, Japan,

2Department of Civil and Environmental Engineering, Kumamoto University,

2-39-1 Kurokami, Kumamoto, 860-8555, Japan,

3Graduate School of Science and Technology, Kumamoto University,

2-39-1 Kurokami, Kumamoto, 860-8555,

4Department of CivilEngineering, Gunma National College of Technology, 580, Tribamachi,

Maebashi, Gunma 371-8530, Japan,

ABSTRACT

This paper presents the dynamic analysis of concrete girder bridges taking into account the

effect of collision on parapet wall. In addition, adopting of seismic isolation rubber on pier structure

and wing wall on parapet were analyzed. Two spans concrete girder bridgeswith variation of gap

were examined in theoretically by 3D FEM model of ABAQUS. The abutment was simplified by

parapet wall which was modeled by 3D reinforced concrete structure. In order to examine the

seismic behavior of bridge, six different inputs of seismic ground accelerations were applied at

footing of pier structure.It has been suggested that allowing the collisionon abutment by restricting

the girder bridges displacement, the size of expansion joints can be reduced in order to reduce the

cost of construction and seismic reinforcement. According to the analytical results, it was found that

installation of the wing wall had a capability for the horizontal displacement resistance. The seismic

isolation rubber and the wing wall structure had a significant effect in reducing the response stress of

parapet wall on small gap. Furthermore, cracking was also affected by the wing wall.

Keywords:dynamic analysis, collision, gap, isolation rubber, concrete girder bridge, wing wall

I. INTRODUCTION

Before 1995 Kobe earthquake, theconsideration of 10 cm gap has been used in the real bridge

in Japan. However, several damages on bridges occurred, such as collision between adjacent decks

and between deck and abutment. Consequently, collision becomes one of the important aspects to be

evaluated in the seismic performance of the bridge. According to the seismic design by Japanese

Specification of Highway Bridges, it has been determined that necessary gap between the ends of

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two adjacent girders shall be taken in the design of the superstructure for preventing any loss of the

bridge caused by the collision between two adjacent superstructures, a superstructure and an

abutment, or a superstructure and the truncated portion of a pier head, when a bridge is subjected to

Level 2 Earthquake Ground Motion [1]. In the real bridges, gap varied from 20 cm to 50 cm.

However, the adoption of large gap into bridge will increase the construction and seismic

reinforcement cost since relatively large expansion joints have to be used.

Previous study [2] has carried out an investigation on the dynamic behavior of concrete

bridges with consideration of the pounding effect. The damage evaluation of abutment has been

conducted by using 3-dimensional FEM. Pounding has been simulated by setting initial velocity on

superstructure and applying 5 cases of impact velocities. In addition, frame analyses have been

conducted in order to clarify the dynamic behavior of whole bridge by pounding. From this research,

it has been confirmed that severe damage spreads over the entire parapet, the bottom of abutment and

the wing wall abutment in case of impact velocity 3.0 m/s. An effect of large gap on the construction

cost has been studied in another research [3]. The girder and pier have been modeled by beam

elements considering the shock absorber in the end of girder. It has been found that attaching rubber

shock absorber to the end of bridge girder reduce the response stress inthe end of girders and

response rotation angle at the bottom of pier. Moreover, total costs of the proposed seismic

reinforcement are 30% of that current seismic reinforcement.

The behavior of concrete including the model verification of RC beam structures have been

investigated by some researchers using the damage identification by Concrete Damaged Plasticity

model in ABAQUS [4]. This code has shown to be an accurate method in performing nonlinear

behavior of RC structure in comparison with the experimental results [5-8].In addition, elasto-plastic

behaviors in abutments with four different approaches of the wing wall have been analyzed [9].

From this analysis, it has been found that installation of the wing wall had a capability in reducing

the displacement of abutment. Moreover, the initial cracking occurred in the intersection between

parapet wall and abutment wall.

From previous study, it is noted that further study is needed in order to clarify the dynamic

behavior of full bridges due to strong earthquake. However, the adoption of large gap will increase

the size of expansion joint affected the high cost of construction and seismic reinforcement. It has

been suggested that allowing the girder collision at the abutment by restricting the girder bridges

displacement, the size of expansion joints can be reduced in order to reduce the cost of construction

and seismic reinforcement.

This paper presents the dynamic analysis of concrete girder bridges taking into account the

effect of collision on abutment. In addition, adopting of base-isolated pier and wing wall on

abutment were analyzed. Two span concrete girder bridge was examined in theoretically by 3D FEM

model of ABAQUS. Parametric studies on dynamic analyses of bridges were investigated in 5

different gaps. Level 2 of earthquake ground motion was chosen as an input data in order to

investigate its behavior under strong earthquake. Effect of soil pressure during earthquake was not

taken into account. The numerical results represented that the parameters such as response stress,

cracking distribution and displacement were affected by displacement restriction of girder, seismic

isolation rubber and the wing wall. II. NUMERICAL PROCEDURES

2.1 General description of analytical method

The numerical modeling of bridge was conducted by using non-linear FE software,

ABAQUS [4]. Collision phenomenon was simulated by setting 6 different waves of Type 2 input

ground acceleration in X-direction at footing of pier, while the bottom of parapet wall was set to be

hinged (U1=U2=U3=0).

In this research, parametric study of bridges taking into account the effect of the wing wall

and seismic isolation rubber at the bottom of pier were investigated, as shown in Fig. 1 and Fig. 2,

39

respectively. The main parameter of this analysis was gap varied from 10, 20, 30, 40, and 50 cm

parallel with Level 2 input of seismic ground accelerations. Two types of loads were applied in

bridge; self-weight as a gravity load of 9.8 m/s2 and the external load from seismic ground

acceleration applied at footing of pier. In this modeling technique, the parapet wall, the reinforcing

bars and the box girder superstructure were idealized by eight-node solid (brick) elements with

reduced integration identified as C3D8R elements and three dimensional truss elements called T3D2

and linear shell elements called S4R.

2.2 Analytical model of bridge

An existing two spans concrete girder bridge adopted from the previous research [3] was

studied. The total length of two span superstructures was 80.0 m with pier (P1) as its center. Parapet

walls were located at both ends, depicted as A1 and A2. The bearing supports were fixed (F) and

movable (M) at Pier 1 and both abutments, respectively. Figs. 3(a) – 3(d) show the dimension and

view of the real bridge.

(a) Side view of the bridge (b) Front view of P1 pier

Figure 2. Model with parapet and wing wall in the first analysis

(a) Concrete element

Figure 1. Model with parapet only in the first analysis

L=12m

H=2.5m

B=0.5m

B=4m

(a) Concrete element (b)Rebar element

(b) Rebar element

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(c) Cross section of superstructure (d) Side view of P1 pier

Figure 3. Dimensions of the bridge (unit: mm)

In all modeling, it was assumed that no liquefaction occurred. Furthermore, constructing of

seismic isolation rubber at bottom of pier structure, called as base-isolated pier, was developed in

order to reduce the seismic response of abutment. The 3-dimensional FE models of bridge are shown

in Figs. 4(a) and 4(b), respectively.

(a) Without wing wall (b) Wing wall

Figure 4. FE-modeling of bridge

2.3 Input seismic waves

Level 2 earthquake ground motions were considered for taking into account in the dynamic

analysis of bridge. Ground type I was chosen as representation of the real soil type, with six input

seismic waves shown in Table 1 and Fig. 5.

Table 1. Acceleration waveform list

Level / Type Earthquake name Nickname Abbreviation

II / I 2003 Tokachi-oki earthquake I – I – 1 L2T1G1-1

Northeastern Pacific Ocean off the coast

earthquake FY 2011

I – I – 2

I – I – 3

L2T1G1-2

L2T1G1-3

II / II Hyogo-ken Nanu Earthquake 1995 II – I – 1

II – I – 2

II – I – 3

L2T2G1-1

L2T2G1-2

L2T2G1-3

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(a) Type I-I-1 wave

(b) Type I-I-2 wave

(c) Type I-I-3

(d) Type II-I-1

(e) Type II-I-2 wave

(f) Type II-I-3 wave

Figure 5. Input JSHB seismic waves Level II earthquake ground motions

2.4 Material properties and material model

Material properties of bridges were shown in Table 2. In this analysis, rebar elements were

treated as elasto-plastic model and concrete of parapet wall was developed by concrete damaged

plasticity (CDP).

Table 2. Material properties of the structure

Material Properties Pier Parapet Wall Bridge

girder Concrete Rebar Concrete Rebar

Young's modulus (GPa) 20.60 206.00 25 200 20.6

Poisson's ratio 0.20 0.30 0.167 0.3 0.20

Density(kg/m3) 2450 7850 2400 7850 2450

Compressive Strength(MPa) 29.40 294.00

(Yield

Stress )

27.5 375.3 29.40

Tensile Strength(MPa) 2.94 3.315 (Yield

stress) 2.94

2.5 Interaction properties and Rayleigh damping

The interacting surfaces between end surface of superstructure and face of parapet wall was

determined as general contact surface algorithm with the friction coefficient of 0.45 and hard contact

for pressure-over closure. Furthermore, an embedded constraint was used to constrain rebar element

into solid element. In the numerical analysis, a damping model of Rayleigh type is used with the

constant damping of 0.02.

2.6 Eigenvalue analysis

The eigenvalue analysis was carried out in order to investigate the effect of seismic isolation

rubber on the natural periods ofthe bridge.The natural periods and the effective mass ratio of each

0 50 100

-400

-200

0

200

400

時間(s)

加速度

(gal

)

0 100 200

-500

0

500

時間(s)

加速度

(gal)

0 100 200

-500

0

500

時間(s)

加速度

(gal)

0 10 20 30

-500

0

500

時間(s)

加速度

(gal)

0 10 20 30

-500

0

500

加速度

(gal)

時間(s)

0 10 20 30

-500

0

500

加速度

(gal)

時間(s)

Ac

c

(ga

l)

Ac

c

(ga

l)

Ac

c

(ga

l)

Ac

c

(ga

l)

Ac

c

(ga

l)

Ac

c

(ga

l)

Time (s)

Time (s) Time (s)

Time (s)

Time (s)

Time (s)

42

predominant mode were investigated in order to understand the fundamental dynamic characteristics

of the structure. The maximum effective mass ratios in X, Y and Z directions imply the order of the

predominant natural period.

2.7 Seismic response reduction measurement

In order to improve the seismic performance of structures, the seismic isolation and energy

dissipating systems are frequently used. These techniques are required to reduce the seismic forces

by changing the stiffness and/or damping in the structures, whereas conventional seismic design is

required for an additional strength and ductility to resist seismic forces [10]. In addition, the research

and development works on these devices are being developed extensively.

In this study, one layer and double layer of seismic isolation rubber have been placed at base

of the pier in order to perform the analytical model in reducing the collisionbetween parapet wall and

girder, as shown in Fig. 6. Rubber bearing was modeled by bilinear element in Figure 7 with the

bearing stiffness of K1 and K2were calculated by the following equation.

21 5.6 KK = (1)

e

d

uB

QFK

−=2 (2)

whereF is the maximum shear force (kN), Qdis calculated from the yield load and uBe is effective

design displacement of the seismic isolation bearing (m). The stiffness of seismic isolation rubber

was set to be K1 = 2.27 x 104kN/m2 and K2= 0.35 x 104kN/m2 with Qy = 131.00 kN.

(a) 1 layer (R-1) (b) 2 layer (R-2)

Figure 6. Analytical model of seismic isolation pier Figure 7. Bilinear model

III. RESULTS AND DISCUSSIONS

3.1 Modal analysis

Tables 4 and 5 summarizes the natural frequencies, the natural periods and the effective mass

ratios of each predominant mode of the bridge without seismic isolation rubberand one layer of

seismic isolation rubber (R-0 and R-1 model), then two layer of seismic isolation rubber (R-2),

respectively.

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Table 4. Eigenvalue results for R-0 and R-1 model

Order R-0 model R-1 model

of f (Hz) T (sec)

Effective Mass Ratio (%) f (Hz)

T

(sec)

Effective Mass Ratio (%)

Periods X Y Z X Y Z

1 1.32 0.76 98.14 0.00 0.00 0.45 2.20 99.97 0.00 0.00

2 2.68 0.37 0.20 0.00 0.00 2.90 0.34 0.00 0.00 0.00

3 2.82 0.35 0.00 70.30 12.83 3.03 0.33 0.00 76.54 8.64

4 2.95 0.34 0.00 23.49 40.26 3.19 0.31 0.00 17.24 40.93

5 4.69 0.21 0.00 0.02 38.31 5.02 0.20 0.00 0.02 40.86

6 5.92 0.17 0.00 0.00 0.00 6.30 0.16 0.00 0.00 0.00

7 6.89 0.15 0.00 0.18 0.00 7.48 0.13 0.00 0.32 0.00

8 8.79 0.11 0.00 0.00 0.00 8.36 0.12 0.03 0.00 0.00

9 9.48 0.11 0.00 0.00 0.00 9.13 0.11 0.00 0.00 0.00

10 9.76 0.10 0.00 0.00 2.77 10.36 0.10 0.00 0.00 3.13

11 10.20 0.10 0.83 0.00 0.00 10.61 0.09 0.00 0.00 0.00

12 10.20 0.10 0.83 0.00 0.00 14.09 0.07 0.00 0.00 0.00

13 11.73 0.09 0.00 0.00 0.00 15.66 0.06 0.00 0.48 5.24

14 11.73 0.09 0.00 0.00 0.00 15.78 0.06 0.00 5.31 0.33

15 13.14 0.08 0.00 0.00 0.00 17.95 0.06 0.00 0.02 0.35

Table 5. Eigenvalue results for R-2 model Order R-2 model

of f (Hz) T (sec)

Effective Mass Ratio

(%)

Periods X Y Z

1 0.33 3.00 99.67 0.00 0.00

2 2.90 0.34 0.00 0.00 0.00

3 3.05 0.33 0.00 91.35 0.96

4 3.43 0.29 0.00 2.51 40.32

5 5.25 0.19 0.00 0.01 48.61

6 5.99 0.17 0.33 0.00 0.00

7 6.58 0.15 0.00 0.00 0.00

8 7.49 0.13 0.00 0.31 0.01

9 9.22 0.11 0.00 0.00 0.00

10 10.51 0.10 0.00 0.00 3.80

11 10.56 0.09 0.00 0.00 0.00

12 11.58 0.09 0.00 0.00 0.00

13 14.16 0.07 0.00 0.00 0.00

14 15.74 0.06 0.00 0.66 5.32

15 15.82 0.06 0.00 5.07 0.48

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Figure 7. Predominant mode of R-0 model

Figure 8. Predominant mode of R-1 model

Figure 9. Predominant mode of R-2 model

The predominant Eigen modes deflecting in the longitudinal, vertical and transverse direction

of bridge are shown in Figs. 7-9. According to these figures, it can be seen that seismic isolation

rubber has a capability in reducing the frequency of bridge. R-0 model is possible to vibrate

sympathetically at the 1st mode in longitudinal direction, the 3rd mode in in-plane direction and the

4th mode in transverse direction, similar to R-1 model. However, installing of seismic isolation

rubber in two layers leads the bridge to vibrate sympathetically in transverse direction at the 5th

mode, a slightly changed comparing to other models.

(a) 1st mode (b) 3rd mode (c) 4th mode

(a) 1st mode (b) 3rd mode (c) 4th mode

(a) 1st mode (b) 3rd mode (c) 5th mode

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3.2 Response stress of the parapet wall

Comparison result between the maximum response stressesat base of parapet wall(A1)for

bridge with seismic isolation rubber and wing wall structure as parametric in different input ground

motion are shown in Figs. 10(a)-10(f). R-0, R-1 and R-2 denote as the bridge without, with one layer

and two layers of seismic isolation rubber, respectively. In addition, the response stresses of parapet

wall (A2) are shown in Figs. 11(a)-11(f). W denotes the wing wall which is constructed in both sides

of parapet wall.

From these figures, it can be seen that input ground acceleration of L2T2G1 lead the structure

to vibrate horizontally. It tend to move toward right direction and the maximum response occur in

A2, with the exception of bridge in 10 cm of gap with L2T2G1-2. No collision occurs when the

response stress is zero. Input ground acceleration of L2T1G1-2 and L2T1G1-3 cause the bridge to

vibrate continuously in horizontal direction. Installing of the wing wall reduce the maximum

response stress of parapet wall at a maximum percentage of 65%, as shown in Fig. 11(c). Different

input ground motion lead the different effect on the behavior of parapet wall. As an example is the

input of L2T2G1-1 in bridge with 10 cm of gap, the response stress increase from 6.4 MPa to 39.7

MPa. In general,installing of the wing wall will decrease the response stress of parapet wall. Most of

the results show the tendency of large response stress at the smallest gap of 10 cm, which is possibly

due to increasing number of collision. On the other hand, gap does not give a significant effect on

reducing the response stress in most cases of bridge analyses, as the exception of increasing gap from

10 cm to 20 cm from bridge without seismic isolation rubber.

(a) L2T1G1-1 (b) L2T1G1-2

(c) L2T1G1-3 (d) L2T2G1-1

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(e) L2T2G1-2 (f) L2T2G1-3

Figure 10. Maximum response stress at base of parapet wall in A2

(a) L2T1G1-1 (b) L2T1G1-2

(c) L2T1G1-3 (d) L2T2G1-1

(e) L2T2G1-2 (f) L2T2G1-3

Figure 11. Maximum response stress at base of parapet wall in A1

47

In analysis of bridge with one layer and two layers of seismic isolation rubber, the response

stresses due to collision between girder and parapet wall reduced at a range up to 76% at the smallest

gap of 10 cm.Increasing gap from 10 cm to 50 cm raise the maximum response stress of parapet wall

in general.However, in comparison between both layers, two layers seismic isolation rubber does not

give a significant reduction effect on parapet wall. From these results, it was found installing of the

wing wall or seismic isolation rubber on pier is one of an effective way to diminish the response

stress of parapet wall on bridge.

3.3 Horizontal displacement of parapet wall

Fig. 12 shows the maximum horizontal displacement at the top of parapet wall with the input

seismic ground acceleration of L2T2G1. From this figure, it can be seen that the displacement of

parapet wall in A1 positionis smaller than A2 position. Increasing the gap in bridge without seismic

isolation rubber will diminish the displacement of the parapet wall. The displacement behavior of

parapet wall in left and right side without and with consideration of the wing wall are shown in Fig.

13 and Fig. 14. The deformation scale is 10 times the real deformation.

(a) A1 position (b) A2 position

Figure 12. The maximum horizontal displacement at top of parapet wall in L2T1G1-2

(a) A1 position (b) A2 position

Figure 13. Displacement behavior of parapet wall for bridge with L2T1G1-1-R0-10cm

48

(a) Left side (b) Right side

Figure 14.Displacement behavior of parapet wall with L2T1G1-3-R0W-10cm

From these figures, it can be described that wing wall part contributes greatly to the

horizontal resistance of abutment against load. During the collision, a large displacement amount

towards the central parapet occurs.

3.4 Cracking distribution of parapet wall

The cracking distribution of parapet wall due to tensile stress for parapet without and with

consideration of the wing wall are shown in Figs. 15-16, respectively. Cracking starts when it has a

positive value, depicted as initial cracking. Then, it propagates up to the maximum value of 0.9. The

area of no cracking and maximum cracking are figured out as “dark blue” regions and “white”

regions, respectively. From these results, it can be explained that cracking propagates from center

part through its width in parapet wall. This propagation leads cracking in edge section between

parapet wall and wing wall.

(a) Initial cracking at 1.15 sec

(b) Final cracking at 30.00 sec

Figure 15. Contour plot of tensile damage in parapet wall for L2T2G1-1-R0-10

(a) Initial cracking at 23.65 sec

(b) Final cracking at 80.00 sec

(c)

Figure 16. Contour plot of tensile damage in parapet wall for L2T1G1-3-R0W-10

No-cracking

Initial cracking Final cracking

No-cracking

Initial cracking Final cracking

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3.5 Effect of gap on number of collision

Effect of the increasing gap to the number of collision between end of girder and parapet wall

in bridge without wing wall are shown in Figs. 17(a)-17(e). Results are compared between response

stress of parapet wall and end of girder. From these figures, it can be described that increasing the

gap will decrease the number of collision. On the other hand, reverse effect occur when installing of

seismic isolation rubber, as shown in Figs. 18(a)-18(e). In addition, seismic isolation rubber causes

the bridge with input of L2T1G1 to sway in one direction with an evidence of increasing number of

stress continuously after the final impact.

(a) Gap 10 cm

(b) Gap 20 cm

(c) Gap 30 cm

(c) Gap 40 cm

(e) Gap 50 cm

Figure 17. Response stress on bridge of L2T1G1-1-R0

50

(a) Gap 10 cm

(b) Gap 20 cm

(c) Gap 30 cm

(c) Gap 40 cm

(d) Gap 50 cm

Figure 18. Response stress on bridge of L2T1G1-1-R1

IV. CONCLUSIONS

The seismic behavior of concrete girder bridges subjected to strong ground motions

considering the effect of collision, base-isolated pier and wing wall were investigated by dynamic

response analysis. Numerical studies were carried out in bridges with the parameters of gap, seismic

isolation rubber and wing wall. Two types of Level 2 seismic ground motions according to JSHB

seismic waves were simulated and discussed. The conclusions of this study are summarized as

following.

1) Installation of the wing wall in parapet had a capability in reducing the maximum response

stress of parapet wall. In addition, it contributed greatly to the horizontal resistance of abutment

against load.

2) Adopting of seismic isolation rubber on pier structure had a great effect on the response

behavior of bridge. In the smallest gap of 10 cm, it diminished the response stress of abutment up to

76%. Generally, increasing the gap was also increase the maximum response stress of parapet wall.

51

3) In comparison between installation of one layer and two layers of seismic isolation rubber,

the effect of reducing the response stress due to collision was obtained. However, considering to the

cost of structure, sufficient reduction effect was found in behavior of one layer seismic isolation

rubber.

4) Increasing of gap from 10 to 50 cm in bridge with and without installation of wing wall

decreased the number of collisionon parapet wall. On the other hand, reverse effect occurred in

bridge with seismic isolation rubber.

5) Initial cracking was found at the bottom of parapet wall and spread through the parapet

width. Installation of the wing wall caused cracking at the edges of parapet wall which was

connected to the wing wall.

6) Further study is necessary in order to investigate the effect of soil pressure during earthquake

on the behavior of bridge.

ACKNOWLEDGEMENT

The first author acknowledges DIKTI (Directorate General of Higher Education) in Indonesia

as the financial supporter of the scholarship and University of Brawijaya as the home university.

Their support in completing the doctoral study in Kumamoto University is gratefully appreciated.

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