5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Consequences of Strong Vertical
Accelerations on Shear Behavior of
Reinforced Concrete Bridge Columns
Khalid M. Mosalam, Professor, UC Berkeley
Hyerin Lee, Post-doctoral researcher, UC Berkeley
Selim Günay, Post-doctoral researcher, UC Berkeley
Pardeep Kumar, PhD student, UC Berkeley
Shakhzod Takhirov, Lab. Manager, UC Berkeley
Sashi Kunnath, Professor and Chair, UC Davis
Sponsors: Caltrans and PEER
December 9, 2012
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Outline
Motivation
Test Specimens and Test Sequence
Test Results: Evidence of Axial Force Effect on Shear Strength
Test Results vs. Code Estimations
Post-Test Simulation
Concluding Remarks
Further Developments: Laser Scanning & Repair
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Motivation
Bridge Structures
- Do not have enough redundancy
- Columns are the most critical part
V   Mi  M j  L
Shear
Failure
Shear Demand
Shear Strength
- Unexpected increase of shear force
from P-M interaction
- Axial force or axial strain affects the
shear strength of RC members
Various codes and guidelines
Consensus?
RC structures damaged by past earthquakes
Papazoglou and Elnashai (1996)
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Specimens
¼ -scale Plumas-Arboga Overhead Bridge (prototype)
Two specimens (SP1 & SP2) with Aspect Ratio=3.5, D=20″, H=70″
Reinf. Ratio: Longitudinal=1.56%
Transverse=0.55% (SP1) > 0.47% by BDS
0.36% (SP2) < 0.47% by BDS
Weight of mass blocks = 85.6 kips (6.8% axial load ratio)
Periods: Lateral = 0.49 sec.
Rotational = 0.10 sec.
Vertical = 0.03 sec.
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Specimens
B
A-A
B-B
30”
42.4”
24”
A
B
A
109”
C-C
70”
C
C
hoops
#2@2” (SP 1)
#2@3” (SP 2)
16-#5
18”
D=20”
cover=1”
60”
84.85”
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Sequence
0
-1
(a) X direction
-2
2
Acceleration (g)
Acceleration (g)
Input: 1994 Northridge EQ at Pacoima Dam
 2D (X and Z) and 1D (X) excitations
2
1.585g
 ½ time-compressed
1
1.229g
1
0
-1
(b) Z direction
-2
0
2
4
6
8
Time (sec)
0
2
4
6
8
Time (sec)
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results: Evidence of Axial Force
Effect on Shear Strength
Shear force-lateral displacement relationships in the 125% tests
 Decrease in stiffness
 Shear degradation due to significant axial tension
0
0
1st X+Z
-2
X only
2nd X+Z
-4
-0.5
0
(a) SP1
1.5
Drift (%)
3
Drift Ratio = 1.82~2.34%
4
0.5
2
0
0
1st X+Z
-2
X only
2nd X+Z
-4
-0.5
-1
-1.5
0
(b) SP2
1.5
Drift (%)
3
Drift Ratio = 1.92~2.04%
Force (100 kN)
2
Force (100 kips)
0.5
-1
-1.5
1
4
Force (100 kN)
Force (100 kips)
1
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results: Evidence of Axial Force
Effect on Shear Strength
Shear and axial force histories in the 125% tests
 Shear degradation due to significant axial tension
100
1
0.5
0.5
77.4 kips
50
0.5
2
0
00
-2
-50
-0.5
0.195 s
-4
-100
-1
0.0
0.0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
56.7 kips
00
0.0
0.0
Shear Force
4
4
-100
-1
Force (100 kips)
Force (100 kips)
0.0
0.0
-4
1.0
1.5
2.0
1.0
1.5
2.0
Time (sec)
100
1
100
1
0.5
0.5
0
-4
1.0
1.5
2.0
1.0
1.5
2.0
Time (sec)
80.9 kips
50
0.5
2
0
00
-2
-50
-0.5
-4
-100
-1
0.0
0.0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
Time (sec)
Time (sec)
(a) SP2 1st X+Z (2-9)
(b) SP2 X only (2-10)
8
100
1
4
00
0
-63.3 kips
-100
-1
0.0
0.0
0.5
0.5
1.0
1.0
1.5
1.5
-4
2.0
2.0
Time (sec)
Shear Force
4
12
200
2
Force (100 kN)
-61.6 kips
-100
-1
8
300
3
100
1
Shear Force
4
67.0 kips
50
0.5
2
0
00
-2
-50
-0.5
0.180 s
-4
-100
-1
0.0
0.0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
Time (sec)
(c) SP2 2nd X+Z (2-11)
Force (100 kN)
0
00
200
2
Force (100 kips)
4
12
Force (100 kN)
100
1
300
3
Force (100 kN)
8
Force (100 kips)
200
2
Force (100 kN)
12
Force (100 kN)
Force (100 kips)
300
3
Axial Force
(+ → Compression)
Force (100 kips)
Axial Force
(+ → Compression)
Axial Force
(+ → Compression)
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
B
Test Results: Evidence of Axial Force
W
Effect on Shear Strength
C-C
S
SP1
W
60° 90°
180°
E
270°
N
0°
After 70%-scale (1-7) test
W
N
E
SP2
S
hoops
#2@2” (SP 1)
#2@3” (SP 2)
S
E
16-#5
D=20”
cover=1”
N
70”
70”
60”
60”
50”
50”
40”
40”
30”
30”
20”
20”
10”
10”
0”
60°
60° 90°
180°
270°
0°
After 70%-scale (2-7) test
0”
60°
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results: Evidence of Axial Force
Effect on Shear Strength
After 125%-scale
“1st X+Z” test
W
S
E
N
70”
60”
50”
40”
30”
20”
10”
Crack Pattern of SP2
60° 90°
180°
270°
0°
0”
60°
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results: Evidence of Axial Force
Effect on Shear Strength
After 125%-scale
“X only” test
W
S
E
N
70”
60”
50”
40”
30”
20”
10”
Crack Pattern of SP2
60° 90°
180°
270°
0°
0”
60°
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results: Evidence of Axial Force
Effect on Shear Strength
W
After 125%-scale
“2nd X+Z” test
S
E
N
70”
60”
50”
40”
rotation
lateral
translation
N
30”
S
(a) First shear peak
N
S
(b) Second shear peak
N
S
20”
(c) Third shear peak
Shear crack opening and closing at each
shear peak during the 125%-scale tests
10”
Crack Pattern of SP2
60° 90°
180°
270°
0°
0”
60°
Micro-cracks produced by tensile axial forces contribute to further widening of diagonal
cracks under combined effect of vertical & horizontal excitations.
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results vs. Code Estimations
Code Estimations: Different design approaches and code equations
Influences of axial load, flexural ductility, and size of members &
aggregates are not well agreed upon within different codes.
Three main approaches:
I. Axial force: ACI, Eurocode
II. Axial force + Ductility: SDC, Priestley et al.
III. Axial strain: AASHTO, CSA (based on MCFT)
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results vs. Code Estimations
Approach I: Axial force affects the estimated shear strength
 ACI (318-08)
Vn  Vc  Vs
Vs 
 Eurocode (2004)
Vn  Vc  Vs
Av f y (0.8D)
Vs 
s
Av f y 0.72 D 
s
Circular member: Axial compression

N
Vc  2 1 
 2000 A
g


'
2
 f c  0.8D 

Circular member: Axial tension

N
Vc  2 1 
 500 A
g


'
2
 f c  0.8D 

N: axial force (+ if compression, - if tension)
Vc   rd k 1.2  40 l   0.15 cp 
Dc  D  2c  2dbw

 rd  0.25 0.7 fc'
 cp 
N
Ac
k 1

 Dc 2
4
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results vs. Code Estimations
Approach II: Axial force and ductility affect the estimated shear strength.
 Priestley et al. (1996)
 Caltrans SDC (2010)
Vn  Vc  Vs
'
 Av f y D
Vs 
cot 
2
s
Vn  Vc  Vs
Vc  k f c' Ae
Vc   c Ae
   1: k  0.29



1    3 : k  0.10  0.19(3   ) 2 
 3    7 : k  0.05  0.05(7   ) 4 


 7   : k  0.05

Vp  P tan  
Dc
P
2a
shear strength increase by axial compression
Vs 
Av f y D '
s
'
'
Inside PHZ  c  Factor1 Factor2  fc  0.33 fc
'
'
Outside PHZ  c  0.25  Factor2  fc  0.33 fc
 f
0.025  Factor1  s yh  0.305  0.083d  0.25
12.5
Factor2  1 
Pc
 1.5
13.8 Ag
 c  0 for axial tension
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Test Results vs. Code Estimations
Approach III: Longitudinal strain at the centroid of the section affects
the estimated shear strength.
 AASHTO (2010)
Vn  Vc  Vs
Vn  Vc  Vs
Vs 
 CSA (2004)
Av f y d v cot   cot  sin 
s
Vs 
: angle of inclination of transverse rebars
Vc  0.083 f c' bv dv
bv  D
dv  0.9de
,  : function of /f’c and 
Av f y d v cot 
s
Vc   f c' bv dv
de 
D Dr

2 
  29o  7000
 0.4  1300 
dv  0.72 D   

 1  1500  1000  s ze 
35sz
sze 
 0.85sz
sz  300 mm or dv
15  ag
bv  D
Vn,max  0.25 fc'bv dv
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
SP1
Test Results vs. Code Estimates
h=60”
Comparison of 1-10 and 1-11, 125% Northridge EQ
h=10”
1-10: X only, 1-11: 2nd X+Z
2nd X+Z (1-11) at h=10”
200
200
180
180
160
160
140
140
120
120
Force (kips)
Force (kips)
X only (1-10) at h=10”
100
80
60
Shear Force
ACI
Eurocode
AASHTO
CSA
SDC
100
80
60
40
40
20
20
0
Shear Force
ACI
Eurocode
AASHTO
CSA
SDC
0
6.5
7
7.5
8
8.5
9
Time (sec)
9.5
10
10.5
11
11.5
6.5
7
7.5
8
8.5
9
Time (sec)
9.5
10
10.5
11
11.5
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
SP1
Test Results vs. Code Estimates
h=60”
Comparison of 1-10 and 1-11, 125% Northridge EQ
h=10”
1-10: X only, 1-11: 2nd X+Z
2nd X+Z (1-11) at h=60”
X only (1-10) at h=60”
200
200
Shear Force
ACI
Eurocode
160
CSA
AASHTO
160
SDC
140
140
120
120
Force (kips)
Force (kips)
Shear Force
ACI
Eurocode
AASHTO
CSA
SDC
180
180
100
80
100
80
60
60
40
40
20
20
0
0
6.5
7
7.5
8
8.5
9
Time (sec)
9.5
10
10.5
11
11.5
6.5
7
7.5
8
8.5
9
9.5
10
10.5
11
Time (sec)
Significant difference between AASHTO/CSA estimations at h=10” & 60”
ACI, Eurocode/SDC are similar, but there are transient differences due to axial
tension or large displacement ductility.
11.5
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
SP2
Test Results vs. Code Estimates
h=60”
Comparison of 2-10 and 2-11, 125% Northridge EQ
h=10”
2-10: X only, 2-11: 2nd X+Z
2nd X+Z (2-11) at h=10”
X only (2-10) at h=10”
200
200
Shear Force
ACI
180
Eurocode
160
CSA
AASHTO
160
SDC
140
140
120
120
Force (kips)
Force (kips)
Shear Force
ACI
Eurocode
AASHTO
CSA
SDC
180
100
80
100
80
60
60
40
40
20
20
0
0
7
7.5
8
8.5
9
9.5
Time (sec)
10
10.5
11
11.5
12
7
7.5
8
8.5
9
9.5
Time (sec)
10
10.5
11
11.5
12
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
SP2
Test Results vs. Code Estimates
h=60”
Comparison of 2-10 and 2-11, 125% Northridge EQ
h=10”
2-10: X only, 2-11: 2nd X+Z
2nd X+Z (2-11) at h=60”
X only (2-10) at h=60”
200
200
180
Shear Force
ACI
Eurocode
AASHTO
180
160
ACI
Eurocode
AASHTO
CSA
SDC
160
CSA
SDC
140
140
120
120
Force (kips)
Force (kips)
Shear Force
100
80
100
80
60
60
40
40
20
20
0
0
7
7.5
8
8.5
9
9.5
Time (sec)
10
10.5
11
11.5
12
7
7.5
8
8.5
9
9.5
10
10.5
Time (sec)
A similar trend is observed, but AASHTO/CSA estimations are lower
due to larger strains, especially at h=10”
11
11.5
12
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Post-Test Simulation
OpenSees ACI/SDC shear spring:
 Based on the “Test Results vs. Code Estimations”, two methods chosen from
Approaches I and II
 Incorporates ACI & SDC code equations for shear capacity as a new material
implemented into source code.
 Within a zero-length element connected to a beam-column element, this material
can be effectively used.
Depends on
axial load,
… etc.
Force
Vy
0
Kelastic
rKelastic
-Vy
0
Displacement
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Post-Test Simulation
OpenSees ACI/SDC shear spring:
1. Before the shear demand reaches the capacity (i.e. before yielding):
0
Vy
Kelastic
0
-Vy
0
Displacement
Vy
Force
Kelastic
Force
Force
The yield force is updated at each integration time step.
2. At the time step where the demand reaches the capacity:
Yielding takes place & force-displacement relationship follows a post-yield behavior.
3. After 2: Yield force is not updated & kept constant unless the column experiences
any axial tension for Caltrans SDC spring & a predetermined tension for ACI
spring. The yield force is kept constant after this final modification.
0
-Vy
0
Displacement
rKelastic
0
Displacement
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Post-Test Simulation
OpenSees model: BWH element (Model A) or NLBC elements (Model B)
Nodal Mass
Rigid
End Zone
Lp
Lp
Case A-1
Rigid
End Zone
15”
Lp
Section
BWH
Element
70”
Nodal Mass
Nodal Mass
Mx, My, Mz
Imx, Imy, Imz
at integration points
Lp
Shear Spring
NLBC
Elements
Shear Spring
Rigid
End Zone
Rigid
End Zone
Rotational Spring
Rotational Spring
Case A-2
(a) Beam With Hinges Element
Case B-1
20”
20”
15”
Case B-2
(b) Nonlinear Beam Column Elements
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
100
100
test data
B-1
50
shear force (kip)
50
shear force (kip)
No
Shear
Spring
0
-50
0
-50
A-1 and Run 2-11
-100
247
248
249
time (sec)
250
B-1 and Run 2-11
-100
251
100
247
248
249
time (sec)
250
test data
B-2-ACI
50
shear force (kip)
50
shear force (kip)
ACI
Shear
Spring
0
-50
0
-50
A-2-ACI and Run 2-11
-100
247
248
249
time (sec)
250
B-2-ACI and Run 2-11
-100
251
100
247
248
249
time (sec)
250
test data
B-2-SDC
50
shear force (kip)
50
0
-50
0
-50
A-2-SDC and Run 2-11
-100
251
100
test data
A-2-SDC
SDC
Shear
Spring
251
100
test data
A-2-SDC
ACI
shear force (kip)
Beam with Hinges Element (Model A)
test data
A-1
247
248
249
time (sec)
250
251
B-2-SDC and Run 2-11
-100
247
248
249
time (sec)
250
251
(c) 125% 2 X+Z
SP2 125%-scale “2nd X+Z”
test data and simulation results
nd
Nonlinear Beam-Column Elements (Model B)
Post-Test Simulation
shear force
0
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
-50
Post-Test Simulation
A-1 and Run 2-11
-100
100
247
248
249
time (sec)
250
251
100
100
test data
A-1
test
data
test
data
B-1
A-2-SDC
Effect of OpenSees ACI/SDC shear spring
shear force (kip)
shear force (kip)
5050
shear force (kip)
50
0
00
 Close resemblance in shear
force responses
 Notable difference in the inelastic response of the shear spring for the peak values.
-50
-50
-50
 SDC shear spring provides more conservative estimates than ACI spring does
and springs
Run 2-11 observed in the hysteresis.
B-1and
andRun
Run2-11
2-11
A-2-ACI
due to the different yielding patterns ofA-1the
-100
100
247
248
249
time (sec)
00
249
time (sec)
250
251
250
250
00
B-1and
andRun
Run2-11
2-11
A-2-ACI
-100
-100
247
247
248
248
249
249
time
(sec)
time
(sec)
250
250
251
251
B-2-ACIand
andRun
Run2-11
2-11
A-2-SDC
-100
-100
247
247
248
248
249
249
time(sec)
(sec)
time
100
100
nd X+Z” test data and simulation results
SP2 125%-scale
“2100
from Model A
test data
data
testtest
data
A-2-SDC
B-2-ACI
A-2-SDC
5050
50
ip)
ip)
kip)
50
251
251
-50
-50
A-1 and Run 2-11
248
249
249
time(sec)
(sec)
time
5050
-50
-50
247
248
248
test
data
test
data
B-2-ACI
A-2-SDC
shear force (kip)
shear force (kip)
shear force (kip)
shear force (kip)
shear force (kip)
0
247
247
100
100
5050
-50
kip)
-100
-100
data
testtest
data
B-1
A-2-SDC
ACI
50
100
251
100
100
test data
A-1
-100
250
250
250
251
251
(c) 125% 2
test data
B-2-SDC
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Post-Test Simulation
100
100
(a-1) 1st X+Z
A-2-ACI
(a-2) 1st X+Z
0
-50
-100
-1.5
-50
-1
-0.5
0
0.5
displacement (in)
1
-100
-1.5
1.5
100
A-2-ACI
shear force (kip)
shear force (kip)
0
1.5
A-2-SDC
0
-50
-1
-0.5
0
0.5
displacement (in)
1
-100
-1.5
1.5
100
-1
-0.5
0
0.5
displacement (in)
1
1.5
100
(c-1) 2nd X+Z
A-2-ACI
(c-2) 2nd X+Z
A-2-SDC
50
shear force (kip)
50
0
-50
-100
-1.5
1
50
-50
2nd X+Z
-0.5
0
0.5
displacement (in)
(b-2) X only
50
-100
-1.5
-1
100
(b-1) X only
X only
0
0
SDC shear spring hysteresis
50
shear force (kip)
shear force (kip)
125%
1st X+Z
shear force (kip)
ACI shear spring hysteresis
50
A-2-SDC
-50
-1
-0.5
0
0.5
displacement (in)
1
1.5
-100
-1.5
-1
-0.5
0
0.5
displacement (in)
1
1.5
ACI/SDC spring hysteresis obtained from Model A (SP2 125%-scale simulations)
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Concluding Remarks
There exists an apparent evidence of shear strength reduction due to
the presence of axial tension from:
 The shear force measurements
 The crack patterns
Shear strength reduction is mainly due to the degradation of
concrete contribution to this strength.
ACI & SDC capture the shear strength degradation due to axial force.
Both approaches provide results on the conservative side with SDC
predictions being more conservative. They can be enhanced by:
 Modifying ACI to consider effect of ductility
 Replacing the sharp tensile force effect in SDC to be more gradual
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Further Developments: Laser Scanning
Lab. (nees@berkeley)
Measured
@10.8%
Measured
@11.8%
Leica
ScanStation C10
Filed (Haiti)
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Point Cloud: Specimen SP1, Undamaged
Configuration
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Point Clouds at the Center of Column in Loading
Direction: Raw Data
Top
Block
W
N
S
E
Column
Footing
Undamaged
Damaged
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Point Clouds at the Center of Column in Loading
Direction: Processing
100
Damaged configuration
60
40
Column
20
0
40
30
20
10
Footing
0
-20
Steel
Plate
-6.5
-40
-15
Damaged
50
Longitudinal coordinate, inch
Longitudinal
inch
coordinate, inch
Longitudinal coordinate,
80
Undamaged
Top
Block
60
Undamaged
configuration
Damaged
configuration
Undamaged
configuration
Damaged configuration
Undamaged
configuration
-10
-5
0
5
10
15
20
Transversal coordinate, inch
25
30
-6
35
-5.5
-5
Transversal coordinate, inch
-
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Point Clouds at the Center of Column in Loading
Direction: Interpretation
Deformed Shape from Point Clouds
70
70
70
70
70
70
70
70
70
Undamaged
configuration
Undamaged
configuration
Undamaged
configuration
inch
coordinate, inch
Longitudinal coordinate,
Longitudinal
Longitudinal coordinate, inch
50
50
50
50
50
50
40
40
40
50
50
50
40
40
40
30
30
30
40
40
40
30
30
30
20
20
20
30
30
30
20
20
20
10
10
10
000
000
60
60
60
inch
coordinate, inch
Longitudinal coordinate,
Longitudinal
Longitudinal coordinate, inch
60
60
60
inch
coordinate, inch
Longitudinal coordinate,
Longitudinal
Longitudinal coordinate, inch
60
60
60
Damaged
configuration
Damaged
configuration
Damaged
configuration
20
20
20
10
10
10
0.1
0.2
0.3
0.1
0.2
0.3
0.1
0.2
0.3
Transversal
coordinate,
inch
Transversal
coordinate,
inch
Transversal
coordinate,
inch
000
000
10
10
10
0.1
0.2
0.3
0.1
0.2
0.3
0.1
0.2
0.3
Residual
Displacement,
inch
Residual
Displacement,
inch
Residual
Displacement,
inch
000
000
0.1
0.2
0.3
0.1
0.2
0.3
0.1
0.2
0.3
Transversal
coordinate,
inch
Transversal
coordinate,
inch
Transversal
coordinate,
inch
Points with squares are from averaging points in the cloud within 2 inches
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Point Clouds at the Center of Column in Loading
Direction: Interpretation
Deformed Shape from Point Clouds
70
70
n
(W-L)/W×100
Damaged configuration
60
h=55”
Longitudinal coordinate, inch
Longitudinal coordinate, inch
60
50
40
40
h=35”
30
20
30
20
h=15”
10
0.3
50
0
10
0
0.1
0.2
Residual Displacement, inch
0.3
0
0
0.15” (Laser Scanner)
0.18” (Wire Potentiometer)
16.7%
0.10” (Laser Scanner)
0.11” (Wire Potentiometer)
9.1%
0.05” (Laser Scanner)
0.04” (Wire Potentiometer)
-25.0%
0.1
0.2
Transversal coordinate, inch
0.3
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Further Developments: Repair
1
2
Remove Loose Concrete
Grind Surface
3
4
Mortar and Epoxy Gel
SP2
SP1
Before
Epoxy Injection
After
After
Before
5th Kwang-Hwa Forum, Tongji University, Shanghai, China, December 8-10, 2012
Thank You!
Questions? Comments?