Download RM Term Project MEPFC113

6-STOREY COR JESU COLLEGE SCHOOL BUILDING INVESTIGATION
Submitted in Partial Fulfillment of the Requirements
Of the Course
MEPFC 113-Operations Research
College of Engineering
University of Southeastern Philippines
Obrero, Davao City
by
Rhea Marie D. Alabat
January 2022
Table of Contents
Page
I.Introduction
------------------------------------ 1-2
II. Review of Related Literature
------------------------------------ 3-4
III. Methodology
------------------------------------ 5-6
IV. Presentation, Model Formulation
And Sensitivity Analysis
------------------------------------ 7
i.Design Parameters
------------------------------------ 7-12
ii.Design Results and
Interpretations
------------------------------------ 13-22
V. Conclusion and
Recommendations
References
------------------------------------ 23-25
------------------------------------ 26-27
List of Figures
Figure 1:
Different Types of Bracing Systems
4
Figure 2:
Strengthening of Existing RC Frame
4
with Indirect Bracing
Figure 3:
Conceptual Framework
6
Figure 4:
Concrete Jacketing Method for damaged
15
structural members
Figure 5:
Damaged structural members required
18
for local retrofitting
Figure 6:
Sample Crack Injection Output
19
Figure 7:
Sample Epoxy Material and Kit
20
I.
INTRODUCTION
In the wake of earthquakes last October 2019, it alarmed people around
neighboring municipalities of North Cotabato and Davao Region. Series of
earthquakes has been felt on the same region. Last October 16, 2019 with a
magnitude 6.3 at 023 km S 62° E of Tulunan (Cotabato), October 29, 2019
with a magnitude 6.6 at 022 km S 79° E of Tulunan (Cotabato) and another
hit on October 31, 2019 with a 6.5 magnitude. Existing RC buildings
represent a structural type that has suffered the heavy damages on strong
earthquakes experienced in the area.
The awareness of the study of a reinforced concrete building subjected
to seismic events is a very important issue today. During the past seismic
events mentioned, damages on existing structures occurred. Post-earthquake
evaluation has been done which includes visual inspection and a thorough
structural detailed analysis. Retrofitting and upgrading the structure help
prevents damages and reduces hazard. Assessment of an existing building
will reveal the deficiencies at local and global level, the designer will use his
experience and engineering judgement to select the most appropriate measure
or combination of measures to improve the performance of the building.
In this paper, an existing 6-storey academic building designed based
on National Structural Code of the Philippines (NSCP) is investigated, before
and after the seismic retrofitting with steel bracings. Retrofitting is generally
a need for such structures and various strategies can be considered for
improving the seismic performance. Retrofitting both local and global are
modified. Global retrofitting increases lateral stiffness, stabilizes the modal
1
analysis and eliminates torsional irregularities. There are three mathematical
models made: (1) existing model before earthquake assessment; (2) retrofitted
model-based design requirements; (3) retrofitted model-based earthquake
requirements. In the present paper a performance-based procedure for
strengthening of seismically inadequate structures is presented as well.
2
II.
REVIEW OF RELATED LITERATURE
The seismic performance of existing reinforced concrete structures can
be significantly enhanced and promoted through a variety of reliable
retrofitting techniques. It has been reported that bracings significantly
increase stiffness to frame structures, and work together with the main
building structure to resist earthquake damage (Kitamura et al., 2007; Ash
and Bartoletti, 2009; Gu et al., 2011). Due to the recent earthquakes in the
Philippines happened in Mindanao last month of October year 2019. There
are casualties in North Cotabato and Davao Region. Mutiple buildings has
cracked and some eventually collapsed. One of the areas affected was in Digos
City, Davao del Sur. Thus, a study to post earthquake assessment and a
thorough structural analysis was conducted in the 6-storey building Cor Jesu
College located in Digos, Davao del Sur.
In Japan, the Guideline for Post-Earthquake Damage Evaluation and
Rehabilitation (JBDPA) originally developed in 1991 was recently revised
considering damaging earthquake experiences in Japan (Yoshiaki NAKANO,
Masaki MAEDA, Hiroshi KURAMOTO, and Masaya MURAKAMI, 2004). A
series of studies on the seismic resistance of structures retrofitted with
damper systems has also been reported (Wu et al.,1998; Ramirez, 2002; Cho
and Kwon, 2004). A brief review of the state-of-practice and research on the
topic of upgrading RC frame buildings by steel braces is presented in this
Chapter. The addition of braces has been a popular method for the seismic
strengthening of RC frames and it has been the subject of several
investigations over the past decades. Steel bracings can be designed to provide
3
stiffness, strength, ductility, energy dissipation, or any combination of these.
Performance objectives ranging from drift control to collapse prevention can
be achieved. (Badoux 1987, fib 2003,Thermou and Elnashai 2006)
Concentric bracing systems are the most widely used for retrofitting
concrete frames. They contribute to the lateral-load resistance of the structure
through the horizontal projection of the axial force (mainly axial tension)
developing in their inclined members . (Seismic strengthening of RC buildings,
Georgios Tsionis, Roberta Apostolska, Fabio Taucer, 2014)
Fig.1 Different Types of Bracing Systems
Fig.2 Strengthening of Existing RC Frame with Indirect Bracing (Ishimura et
al.2012
4
III.
METHODOLOGY
OR Technique/Application Used
Operational Research has been applied in construction management
such as allocation of resources to projects, project scheduling, monitoring,
and control. First, strategic planning is a must. Gathering data, modeling
and analyzing those columns that had been affected by the recent
earthquakes. Hence, we can plan it precisely and verify the members that
need to be retrofitted.
Second, organize the schedule. As stated from the module, one of the
aspects of coordination is synchronization time. All activities in construction
must be scheduled well so it will not have any losses. An unscheduled event
in the construction site may cause profit-loss. Therefore, all the damaged
member will be simulated using a software ETABS (Extended ThreeDimensional Analysis of Building System) to determine where does it failed,
and must be followed by a schedule of visiting the actual site if earthquake
will occur.
In the situation that we have encountered, Operation Research
emphasizes our decision as an engineer. O.R. determine, analyze, and
predict the system's behavior by developing appropriate models through
structural software - ETABS. Through Operation Research also, it develops
our critical thinking skills on analyzing retrofitting methodology as a linear
programming in the field of structural designing.
5
EARTHQUAKE
VISUAL INSPECTION
REPAIRABLE
?
NOT
FINITE 3D MODELLING
DEMOLISH
EXISTING STRUCUTE MODEL
RETROFITTED MODEL
DESIGN PARAMETERS
ACTUAL DAMAGE
BUILDING DAMAGE
SIMULATED DAMAGE
DESIGN ANALYSIS
EFFECTIVENESS OF
THE PROGRAM
Fig. 3 Conceptual Framework
6
IV.
Presentation, Model Formulation and Sensitivity Analysis
After series of earthquakes, evaluation of the building is performed.
Quick inspection and thorough structural analysis. Norbert Building is
hereby recognized as subject for retrofitting design.
i. Design Parameters
Comparative Design based on Type SD Soil Profile
DESIGN REQUIREMENTS
EARTHQUAKE REQUIREMENTS
≥10km from known Seismic Source
1.6 km to known Seismic Source
Seismic Coefficients
Seismic Coefficients
Seismic Zone Factor
: 0.4
Seismic Zone Factor
: 0.4
Ca Value
: 0.44
Ca Value
: 0.572
Cv Value
: 0.64
Cv Value
: 1.024
Near Source Factor
Near Source Factor
Seismic Source Type
:B
Seismic Source Type
:B
Na Value
: 1.0
Na Value
: 1.3
Nv Value
: 1.0
Na Value
: 1.6
7
Code and Specifications
The following structural codes and specifications shall be used in
the design of the building:
a. National Structural Code of the Philippines (NSCP) C101-15, Volume
1, Buildings, Towers and Other Vertical Structures, 7th Edition, 2015
b. Building Code Requirements for Reinforced Concrete, ACI 318-89
(revised 1992), American Concrete Institute (ACI).
c. Uniform Building Code (UBC) 1997 Edition.
d. American Institute of Steel Construction Inc., AISC-ASD/LRFD.
8
Loads
Design loads and forces are those resulting from dead loads, live
loads and environmental loads acting in the most critical combination,
using the appropriate load factors recommended by the governing
codes. Reinforced concrete sections shall be designed using the
Ultimate Strength Design Method. Load factors are as specified with the
National Structural Code of the Philippines. The basic load types and
their corresponding magnitudes are taken as follows:
Dead Loads
9
Live Loads
10
Seismic Hazzard Assesment from PHIVOLCS
Design Requirement Response Spectrum
11
Earthquake Requirement Response Spectrum
12
ii. Design Results and Interpretation
Modal Analysis
Calculated static period,
3ൗ
4
𝑇 = 𝐶𝑡 (ℎ𝑛 )
3ൗ
4
𝑇 = 0.0731(22.7)
𝑇 = 0.7603 𝑠𝑒𝑐
Dynamic Period
Modal Period
Design
Scheme
Mode 1
Mode 2
Mode 3
Model 1
0.915 sec
0.887 sec
0.826 sec
Model 2
0.642 sec
0.549 sec
0.494 sec
Model 3
0.690 sec
0.551 sec
0.503 sec
13
Structural Irregularities
There are various types of irregularities in the buildings depending
upon their location and scope, but mainly, they are divided into two
groups―plan irregularities and vertical irregularities. As per thorough
calculation, the building has no vertical irregularities. But it has torsional
irregularity that makes the structure vulnerable.
Torsional irregularity to be considered to exist when the maximum story
drift, computed with design eccentricity, at one end of the structures
transverse to an axis is more than 1.2 times the average of the story drifts at
the two ends of the structure.
14
Retrofitting
Local Retrofitting
Reinforced concrete jacketing applied to damaged structural members.
Fig. 4: Concrete jacketing method/process for damaged structural
members
15
Concrete Jacketing
The steps for local retrofitting (concrete jacketing) of damaged structural
members are the following:
1. Prepare the surface of the existing RCC member to receive the
structural connection with a 15-lb chipping hammer. Hammers larger
than a 15-lb may cause damage to substrate and reinforcement.
2. Mark the new reinforcing bar locations on prepared surface so we can
drill.
3. Drill holes of specified diameter and depth in concrete at locations per
approved design calculation.
4. Clean the drilled hole in dry state with round brushes and by blowing
air through a tube inserted in
the hole and connected to hand operated
blow out pump.
5. Inject epoxy from the foil pack with the help of epoxy dispenser, epoxy
cartridge holder and disposable PVC mixing nozzle inserted inside the
drilled hole to fill it from ends up to the half of the holes.
6. Insert the reinforcing bar and allow the epoxy adhesive to cure.
7. Fixing the longitudinal and transverse reinforcement around the existing
columns.
8. Install and fixing formwork, the form must construct to fit tightly against
existing concrete surfaces. Formwork is best attached to directly to the
concrete surface with expansion anchors or standard form ties,
scaffolding can be used to support the formwork.
9. Application of the previous steps for all sides of the column.
16
10.
Drilling a port in the formworks is usually at upper areas to expel the
air during pumping sequence.
11.
To get a strong bonding should take the advantage of (pressure of
water) to clean the pores and saturate the prepared surfaces, existing
surfaces will permit the new pressurized materials to penetrate and
cohesion.
12.
Mixing the prepackaged repair materials which are designed for
pumping, according to datasheet of manufacturing.
13.
Start pumping. Pumping sequence is continued until the cavity is full.
17
Ultimate Load/Design Load
Model 2 (Design Requirements)
Ultimate Load/Design Load
Model 3 (Earthquake Requirements)
COMPARISON OF INDIVIDUAL COLUMN MEMBERS RECOMMENDED FOR LOCAL RETROFITTING
Ultimate Load/Design Load
Model 1 (Original Structure)
12
11
10
9
8
7
6
5
4
3
2
1
3rd
3rd
3rd
2nd
2nd
2nd
2nd
2nd
2nd
2nd
2nd
2nd
2nd
2nd
C-212
C-12
C-30
C-275
C-51
C-50
C-295
C-294
C-102
C-9
C-239
C-212
C-12
C-30
C-275
C-5
C-5
C-5
C-3A
C-3A
PC-4
PC-4
PC-4
PC-4
C-6
C-5
C-5
C-5
C-5
C-3A
C-3A
938.7
938.7
938.7
938.7
938.7
2200.1
2200.1
600.8
600.8
600.8
600.8
600.8
938.7
938.7
938.7
938.7
2200.1
2200.1
ØNn
Axial,
31.6
132.1
132.1
132.1
132.1
132.1
132.1
331.3
331.3
31.6
31.6
31.6
31.6
76.6
132.1
132.1
132.1
132.1
331.3
331.3
ØMn
Moment,
60.7
124.4
124.4
124.4
124.4
124.4
124.4
230.8
230.8
60.7
60.7
60.7
60.7
100.9
124.4
124.4
124.4
124.4
230.8
230.8
ØVn
Shear,
4.4
18.1
18.1
18.1
18.1
18.1
18.1
38.6
38.6
4.4
4.4
4.4
4.4
12.1
18.1
18.1
18.1
18.1
38.6
38.6
ØTcr
Torsion,
767.5242
-
723.7742
1092.3060 146.1817
1266.2270 179.1176
994.8001
1104.5090
2004.2260
27.8013
26.4537
86.7560
95.6854
1707.6860 265.3914
Axial,
29.9798
1848.3800 300.5456
Nu
32.4857
2958.2440 126.3372
1251.0360
31.0553
2999.6960 142.9546
1215.6500
110.0153
1272.0670 181.9378
1091.3000
108.8231
2306.5460 135.4527
890.8048
49.6637
1103.6410 144.2978
895.8777
-
2319.7730 147.6904
870.1538
49.1956
Mu
Moment,
63.2855
-
63.9039
181.4640
167.2034
169.6363
70.7613
166.3054
72.9371
129.2347
122.1269
33.9581
30.9851
32.8397
26.8173
10.5001
127.8660
50.2642
112.7175
54.7500
120.8260
101.8830
Vu
Shear,
2.2038
-
2.0516
2.3627
4.5419
4.6869
1.3580
2.0750
1.3794
1.6682
1.6492
1.8663
2.1659
2.0479
2.2461
0.5308
3.0614
0.5966
2.8539
0.5698
1.1828
1.1120
Tu
Torsion,
-
-
-
-
-
-
844.8700
-
856.8297
-
-
1438.9910
-
-
-
-
-
-
90.8234
-
90.8774
-
-
-
-
17.2327
-
-
-
-
1837.0940 168.4501
Axial,
-
1992.5070 187.3493
Nu
-
1398.4430 173.5897
-
-
1406.6920 191.3196
-
-
Mu
Moment,
-
-
-
-
-
-
-
59.0064
-
59.1489
131.1138
122.4728
-
-
-
-
6.8513
-
-
-
-
81.5763
69.5241
Vu
Shear,
0.5613
0.5764
-
-
-
-
-
-
-
0.4433
-
0.5019
0.2158
0.2445
-
-
-
-
0.3513
-
-
-
-
0.1979
0.2421
Tu
Torsion,
849.8170
843.6795
420.2505
784.3032
410.7147
752.5061
-
-
-
947.6404
-
962.3656
-
-
1949.9586
-
1301.2730
-
1316.4165
65.3472
43.0409
-
-
-
106.9948
-
106.8292
-
-
-
-
22.1359
-
68.5544
-
72.4549
1893.7412 213.3664
Axial,
42.3537
2026.3855 236.1082
Nu
63.9590
1483.1919 197.1143
-
158.8206
1491.1968 214.2809
-
157.8694
Mu
Moment,
85.7257
86.2844
121.2913
54.0405
123.0790
54.9764
-
-
-
68.8632
-
68.8640
147.5065
139.2423
-
-
-
-
8.7705
-
41.9568
-
43.9481
97.2914
83.6126
Vu
Shear,
0.7363
0.7484
20.8471
1.9300
22.0675
1.8530
-
-
-
0.5760
-
0.6502
0.2822
0.3141
-
-
-
-
0.4427
-
0.5633
-
0.5339
0.2669
0.3327
Tu
Torsion,
Section Capacity
13
3rd
C-5
938.7
4.4
67.0148
Section
Name
14
C-239
C-5
600.8
4.4
-
66.4153
Column
Name
15
3rd
C-282
C-5
60.7
128.5092
Floor
16
3rd
C-38
PC-4
60.7
-
127.4807
18
No.
17
3rd
C-9
31.6
777.9644
18
C-294
31.6
-
784.3093
3rd
600.8
1.8431
3rd
600.8
-
1.8684
19
PC-4
74.9909
20
PC-4
-
76.1568
C-50
153.7058
C-295
-
157.4857
-
0.0783
3rd
4.4
750.6082
69.1074
-
3rd
60.7
756.4155
-
21
31.6
38.6
103.5794
-
22
600.8
38.6
-
PC-4
230.8
684.3018
-
C-51
230.8
-
3rd
331.3
-
-
23
331.3
-
2200.1
-
-
2200.1
-
C-3A
-
-
-
16.3998
C-3A
-
-
-
162.5494
C-30
0.7198
-
-
62.4706
C-275
74.5451
-
-
401.1124
4th
109.1471
-
-
4th
616.5331
0.7198
-
24
18.1
1.7447
-
25
124.4
74.1493
-
132.1
61.7898
-
938.7
48.2058
110.0538
-
C-5
604.3038
-
C-12
451.3061
-
4th
4.4
18.1
-
26
60.7
124.4
1.8966
31.6
-
132.1
61.3503
938.7
-
600.8
47.8530
C-5
-
29
PC-4
484.4329
30
C-239
4.4
6.4050
16.1230
C-294
4.4
162.8531
4th
60.7
61.0384
4th
60.7
399.4731
4th
27
31.6
-
31
28
31.6
-
3.0376
600.8
-
161.8968
600.8
-
148.6026
C-282
PC-4
-
628.5476
5th
PC-4
-
4.4582
32
C-50
-
112.9793
2.4522
C-295
-
103.4856
70.7039
PC-4
4th
4.4
549.0265
54.9184
C-294
4th
60.7
4.0677
365.2137
5th
31.6
138.0173
-
33
600.8
125.8846
-
3.0541
600.8
PC-4
560.5918
-
54.5035
PC-4
C-51
18.1
-
51.7996
C-295
124.4
1.4171
612.5805
5th
31.6
60.7
132.1
57.1024
-
34
600.8
31.6
938.7
44.5723
-
2.4559
PC-4
600.8
C-5
251.0751
-
70.2146
C-50
PC-4
4.4
-
54.6427
5th
C-51
60.7
-
408.5372
35
5th
31.6
-
-
0.1844
36
600.8
-
-
53.4842
3.5734
-
-
84.6614
4.4
-
50.7156
158.2497
60.7
1.5217
607.5568
124.9534
31.6
56.3598
-
151.8596
44.1008
-
262.1526
-
278.0032
-
298.4984
18.1
4.4
-
-
-
60.7
-
2.5208
124.4
-
-
-
-
112.2203
132.1
-
-
-
4.4
107.6749
-
-
-
271.9447
938.7
-
-
2.3544
C-5
-
-
105.3182
C-282
-
6th
102.8125
6th
-
37
267.5678
38
Fig. 5: Damaged structural members required for local retrofitting
CHB Wall Crack Injection
This retrofitting is effective only in minor cracks. Epoxy sealants are
used to inject inside the cracks and plaster the exterior part of the crack.
Thus, major cracks in the CHB are advised to be demolished and replaced.
Fig. 6 – Sample Crack injection output
CHB Wall Crack Injection Methodology
1. Clean the crack using a wire brush. Vigorously clean the concrete
surface surrounding the crack so that the crack is not plugged with
debris.
2. Blow out the crack with compressed air.
3. Repair epoxy would be used to seal the crack on the outside. This is
also referred to as capping the crack. Prepare the cartridge according
to the label instructions and apply epoxy over the crack leaving spaces
for the poured installation. Place the ports eight to ten inches apart.
4. Press the epoxy and smooth with a putty knife. It should be applied
one to two inches wide along the length of the crack.
19
5. Using a plastic putty knife, apply epoxy underneath the outer half of the
poured base. Ensure that the poured passageway is not obstructed or
blocked when applying the epoxy.
6. Center the port over the crack face in each gap and attach. Be sure to
seal any pinholes or voids between the ports and the substrate being
injected. Allow epoxy to fully cure prior to starting the injection.
7. Prepare the cartridge by shaking for 60 seconds and then stand the
cartridge upright for 60 seconds.
8. Insert the cartridge into a dispensing tool. Remove the cap and the end
plug.
9. Dispense material into a disposable container until both sides are
flowing equally.
10. Remove the flow control that’s packaged in each nozzle. Insert the
flow control onto the end of the cartridge.
11. Attach the nozzle. Hold the cartridge upright while dispensing to
purge out any air bubbles.
12. Dispose one short stroke of material into a disposable container. Do
not use the material in the container.
13. Firmly attach the tubing to the nozzle. Attach the opposite end of the
tubing tightly over the tip of the first port that needs to be injected. The
flow clip should always be closed and only open while dispensing
material.
14. Start with the lowest port when injecting vertical cracks. Inject until
epoxy reaches the next port.
20
15. Remove the tubing adapter from the port and attach to the second
port.
16. Use the cap to plug the port. Begin injection at the second port and inject
until the epoxy reaches the third port. Repeat until finished.
17. After curing is complete, remove the ports with a hammer. For a more
finished look, the epoxy cap can be ground smooth finish by smoothing
out the miracle bond capping material using a grinder.
Fig. 7 – Sample Epoxy Material and Kit
21
Global Retrofitting
Inverted V steel bracing with metallic dampers is used for the global
retrofitting of the building.
Exterior frame addition adds stiffness to the building and eliminates
torsional irregularities. The retrofitting method reduces seismic demand of the
structure due to the increase in the effective damping of the structures.
Additional advantage of using the method is that after an earthquake, steel
frame dampers can easily be replaced for retrofitting structures for future
earthquakes.
22
V.
CONCLSION AND RECOMMENDATIONS
After a thorough structural investigation, the Norbert Building is
recommended for retrofitting. The columns had damaged concrete cores
and buckled vertical reinforcement, beams and columns were severely
cracked by the series of four strong earthquakes including numerous big
aftershocks in Southern Philippines.
But by Earthquake Engineering
Design there are solutions that can be done to the building, to make it
serviceable and can be safely occupied by retrofitting this both locally and
globally to restore its system stiffness and strength or its seismic over-all
performance. Global retrofitting will start by repairing the individual
members to restore the possible recoverable percentage of the original
capacities considering that it is impossible to restore the original capacity
of the concrete cracked members through Epoxy Injections. In the actual
condition some concrete cracks were “closed cracks” where the Epoxy
cannot penetrate through the cracks therefore it cannot repair the concrete
section.
For the Buckled or Damaged Reinforcing Bars, Epoxy cannot
repair or restore the strength and stiffness of the reinforcement, its
application is mainly to concrete elements. Considering the weaken
reinforced concrete column and beam elements, the original over-all
structural system lateral stiffness was also reduced; under such condition
additional lateral elements should be added to reinforced and strengthen
the Over-All Structural System Earthquake or Lateral stiffness and the
Seismic Performance. Steel Jacketing and CFRP Jacketing were proposed
to reinforced the local members and Steel Bracing Systems must be added
23
to the building to redirect the earthquake load path and to reduced the
earthquake load of the Individual Concrete elements, being considered to
have reduced capacity due to cracking and rebar buckling, to prevent it
from failure when future strong earthquake will happen.
As per structural analysis, Norbert Building needs to be retrofitted
not only through the use of epoxy injection but also with another
retrofitting strategy such as global and local retrofitting otherwise the
building must be out of service. The damages caused by earthquake to a
certain structure cannot be fully repaired, its original capacity cannot be
fully restored by a single retrofitting approach. The building structural
system has its design capacity unique to the architectural requirements,
intended usage, site location and all natural and manmade hazard
expected to be resisted by the building. For a building with Reinforced
Concrete Moment Resisting Frame, its lateral or Seismic Resisting System
is the assemblage of Columns and Beams forming the Framing Network
combined to act as a unit in absorbing the Horizontal and Vertical
Earthquake Forces. Failure and weakness of a single structural element
can be the cause of failure of the total system that may even lead to the
collapse of the entire building. Reinforced concrete buildings structures in
Davao Region presents a unique case as it suffered not just a single
earthquake but a series of four strong earthquakes with numerous strong
aftershocks damage by strong earthquake. Working to retrofit severely
damage Reinforced concrete building would be very critical. There is
impossibility to check the current stiffness and strength of a severely
24
damaged Reinforced Concrete Building after being shaken by the series of
earthquakes. Without the use of earthquake devices to measure the modal
response to understand and know the actual stiffness and vibration
characteristics of the actual damaged structure, a prudent engineering
judgement and conservatism by penalizing weaken members through
reduction of its capacity and adding new components to resist the
earthquake forces by engineering the new load path of the seismic lateral
load. Furthermore, discovery of new concrete damages after the
implementation of the Initial retrofitting is very alarming, even with the
temporary supports, smaller earthquake (4.8Mw) or Service Level
Earthquakes can inflect new damages to the building. And upon thorough
structural assessment, the Norbert 6 Story Reinforced Concrete Building
of Cor Jesu College, Inc. will not be safe for occupancy if not retrofitted
globally and locally.
25
REFERENCES
1. G. S. Harsha and H. Sudarsana Rao, “shear wall analysis & design
optimization in high rise buildings,” vol. 4, no. 8, pp. 333–341, 2015.
2. N. Gupta, P. Dhiman, and A. Dhiman, “Design and Detailing of RC
Jacketing for Concrete Columns,” pp. 54–58, 2013. 3. S. S. Raval and
U. V. Dave, “Effectiveness of various methods of jacketing for RC
beams,” Procedia Eng., vol. 51, no. NUiCONE 2012, pp. 230–239,
2013.
3. (Kitamura et al., 2007; Ash and Bartoletti, 2009; Gu et al., 2011).
4. S. S. Raval and U. V. Dave, “Effectiveness of various methods of
jacketing for RC beams,” Procedia Eng., vol. 51, no. NUiCONE 2012,
pp. 230–239, 2013.
5. Yoshiaki NAKANO, Masaki MAEDA, Hiroshi KURAMOTO, and Masaya
MURAKAMI, 2004
6. Wu et al.,1998; Ramirez, 2002; Cho and Kwon, 2004
7. Badoux 1987, fib 2003,Thermou and Elnashai 2006
8. Kai Marder, Mehdi Sarrafzadeh, and Ken Elwood (Effectiveness of
Repair via Epoxy Injection of Earthquake Damaged Reinforced
Concrete Element)
9. Quantifying The Effects Of Epoxy Repair Of Reinforced Concrete
Plastic Hinges
10. Structural Assessment
Report
for
Paulino
Hospital.
WMCABARDO ENGINEERING & CONSULTING 363, 3rd St., Phase 1
Ecoland Subdivision, Davao City. January, 2020.
26
11. Eduardo N, Fernando A, B. Branco, and Vítor D. Silva. (2005).
Reinforced Concrete
Monotonic
Jacketing
Interface
Influence
on
Loading Response. ACI Structural Journal/March April
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Engineers of the Philippines: C101-10; ISBN 2094-5477
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