Ps
Ps
Ps
By
Somera, Karen Consolacion S.
Sta. Marina, Jonas D.
Tamondong, Joy G.
Tillo, Pol Hendrix V.
APPROVAL SHEET
This PROJECT STUDY entitled “PROPOSED COUNTERFORT RETAINING
WALL AT STATION 247+775 TO STATION 248+165 CAMP 8, KENNON ROAD,
BAGUIO CITY” prepared and submitted by KAREN CONSOLACION SALAZAR
SOMERA, JONAS DELA CRUZ STA. MARINA, JOY GARCIA TAMONDONG, and POL
HENDRIX VILLANUEVA TILLO in partial fulfillment of the
requirements for the degree of BACHELOR OF SCIENCE IN CIVIL
ENGINEERING, has been examined and is recommended for acceptance
and approval for oral examination.
ABSTRACT
and efficient enough to hold the material and save more money for
the construction.
ACKNOWLEDGEMENT
This study would not have been a success if it were not for
part in this success and those who made this research study
possible.
study.
to the researchers.
study.
TABLE OF CONTENTS
PAGE
TITLE PAGE . . . . . . . . . . . . . . . . . . . . . . i
APPROVAL SHEET . . . . . . . . . . . . . . . . . . . . ii
ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . iii
ACKNOWLEDGEMENT. . . . . . . . . . . . . . . . . . . . iv
TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . v
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . vii
LIST OF FIGURE/S . . . . . . . . . . . . . . . . . . . viii
LIST OF EQUATIONS. . . . . . . . . . . . . . . . . . . ix
CHAPTER
1 THE PROBLEM
Background of the Study . . . . . . . . . . . 1
Conceptual/Theoretical Framework . . . . . . 11
Research Paradigm . . . . . . . . . . . . . . 24
Significance of the Study . . . . . . . . . . 25
Statement of the Problem. . . . . . . . . . . 26
Scope, Limitation and Delimitation. . . . . . 27
2 DESIGN AND METHODOLOGY
Research Design and Methodology . . . . . . . 28
Sources of Data . . . . . . . . . . . . . . . 33
Population and Locale of the Study. . . . . . 34
3 RESULTS AND DISCUSSIONS
Geotechnical Properties at Camp 8, Kennon 35
Road Baguio City. . . . . . . . . . . . . . .
External Stabilities of the Retaining Wall. . 40
4 CONCLUSIONS AND RECOMMENDATIONS
Conclusions . . . . . . . . . . . . . . . . . 42
Recommendations . . . . . . . . . . . . . . . 43
REFERENCES. . . . . . . . . . . . . . . . . . . . . . . 44
vi
APPENDICES
A Cantilever Retaining Wall . . . . . . . . . . 48
B Counterfort Retaining Wall. . . . . . . . . . 52
C Geogrid Retaining Wall. . . . . . . . . . . . 56
D Gabion Gravity Retaining Wall . . . . . . . . 58
E Geotechnical Properties from DPWH . . . . . . 61
F Letter to DPWH-Baguio City District 62
Engineering Office. . . . . . . . . . . . . .
G Letter to Mines and Geosciences Bureau-CAR. . 63
CURRICULUM VITAE
vii
LIST OF TABLES
Table No. Table Title Page
1 Data Gathered from Department of Public Works 35
and Highways . . . . . . . . . . . . . . . .
2 Trial Dimensions for Cantilever Retaining 36
Wall . . . . . . . . . . . . . . . . . . . .
3 Typical Dimensions of Counterfort Retaining 37
Wall . . . . . . . . . . . . . . . . . . . .
4 Typical Dimensions of Geogrid Retaining Wall 38
. . . . . . . . . . . . . . . . . . . . . .
5 Typical Dimensions of Gabion Gravity 39
Retaining Wall . . . . . . . . . . . . . . .
Factor of Safety of the Cantilever Retaining
6 Wall and Counterfort Retaining Wall Using the 40
DPWH design data . . . . . . . . . . . . . .
Factor of Safety of the Cantilever Retaining
7 Wall and Geogrid Retaining Wall Using the 40
DPWH design data . . . . . . . . . . . . . .
Factor of Safety of the Cantilever Retaining
8 Wall and Gabion Gravity Retaining Wall Using 41
the DPWH design data . . . . . . . . . . . .
viii
LIST OF FIGURES
Figure Figure Title Page
No.
1 Satellite Location of the Project Study Area. 3
2 Existing Damaged Retaining Wall. . . . . . . 10
3 Conceptual Framework Diagram 11
4 Theoretical Framework Diagram. . . . . . . . 12
5 Active Earth Pressure for Granular Soil. . . 13
6 Generalized Case for Rankine Active Pressure. 14
7 Location of Force Pa for Pure Sand . . . . . 16
8 Failure of the Structure Against Sliding . . 18
9 Failure of the Structure Against Overturning 20
. . . . . . . . . . . . . . . . . . . . . .
10 Failure of the Structure Against Bearing 22
Capacity Failure . . . . . . . . . . . . . .
11 Research Paradigm. . . . . . . . . . . . . . 24
12 Schematic Diagram of Cantilever Retaining 36
Wall . . . . . . . . . . . . . . . . . . . .
13 Schematic Diagram of Counterfort Retaining 37
Wall . . . . . . . . . . . . . . . . . . . .
14 Schematic Diagram of Geogrid Retaining Wall 38
. . . . . . . . . . . . . . . . . . . . . .
15 Gabion Gravity Retaining Wall Schematic 39
Diagram. . . . . . . . . . . . . . . . . . .
ix
LIST OF EQUATIONS
Equation Equation Title Page
No.
1 Active Pressure Coefficient. . . . . . . . . 13
2 Active Earth Pressure Force General Cases 15
for Granular Soil Only . . . . . . . . . . .
3 Active Pressure Coefficient General Cases 15
for Granular Soil Only . . . . . . . . . . .
4a Active Earth Horizontal Pressure Force . . . 15
. . . . . . . . . . . . . . . . . . . . . .
4b Active Earth Vertical Pressure Force . . . . 15
. . . . . . . . . . . . . . . . . . . . . .
5 Active Earth Pressure Force General Cases 16
for Pure Sand. . . . . . . . . . . . . . . .
6 Active Pressure Coefficient General Cases 16
for Pure Sand . . . . . . . . . . . . . . .
7 Passive Pressure Coefficient . . . . . . . . 17
8 Factor of Safety Against Sliding . . . . . . 18
9 Passive Earth Pressure . . . . . . . . . . . 18
10 Active Earth Pressure. . . . . . . . . . . . 18
11 Surcharge Pressure . . . . . . . . . . . . . 19
12 Factor of Safety against Overturning . . . . 20
13 Resisting Moment . . . . . . . . . . . . . . 21
14 Overturning Moment . . . . . . . . . . . . . 21
13 Factor of Safety against Bearing Capacity. . 23
14 Pressure Distribution at Base . . . . . . . 23
The Problem 1
Chapter 1
THE PROBLEM
because the force of gravity on water and ice may lower the shear
Brunsden, 1988; Clague and Robert, 2012; Goudie and Viles, 1997;
landslide happened.
the roads. For the damages caused by several typhoon including the
for any calamity. But we cannot really estimate what calamity will
Works and Highways Secretary Mark Villar who was the guest of honor
using the hazard map and at this point, we have sent out a memo to
never new for us to hear that Camp 8, Kennon Road is closed during
retaining wall has been built on a particular area but was damaged
by soil erosion due to the too much rainfall caused by the strong
They are the most common type used as retaining walls. Cantilever
expected to keep and not fail but since worst case has happened,
with counter forts monolithic with the back of the wall slab and
the wall slab and the base to reduce the bending and shearing
forts are used for high walls with heights greater than 6 to 12 m.
meters above the foundation level. The wall is located near Sangli
retain earth on the side for 5 meters’ height. The type of soil to
be retained was B.C. soil. Also, there is a road along the wall on
the retained earth where two lane traffic was expected. (Padhye,
2008).
geogrid system has the higher adapting ability with the deformation
and steepness are created with the help of reinforced soil system.
the height can be increased with the help of using woven synthetic
face of the wall. Layers are positioned and anchored into the
retaining walls can be constructed for height more than 12m. There
joints at one end and in-situ soil beyond the backfill to achieve
retaining walls, and dikes. Gabions have been used for several
larger, the more angularthe fill, the better interlock and the
and blocky or flatquarried stone have been used to fill the baskets
retaining wall. It was found that the eafth pressure behind the
Conceptual Framework
structure.
Existing Evaluation
Damaged of Different Effective
Retaining Type of Retaining
Wall Due to Retaining Structure
Soil Erosion Structures
Theoretical Framework
Geotechnical
Properties at
the site
Various
Retaining
Structures
Rankine Method
Allowable
Coefficient Resisting
Bearing
of Friction Moment
Capacity
Weight of Maximum
Overturning
the Pressure at
Moment
Structure Base
Lateral
Earth
Pressure
Surcharge
friction between the soil and the wall, so no shear forces are
developed on soil particles. The soil in this case pushes the wall
Ka = tan2(45-Ø/2) eqn’(1)
Where:
From trigonometry, the angle between the normal to the wall and
horizontal is θ.
Calculation of Pa:
Pa = 1/2ɣH2Ka eqn’(2)
equation:
Where:
φa = sin-1(sinα/sin∅)
β = tan-1(sin∅sinφa/1-sin∅cosφa)
vertical pressure = γH
Pa = 1/2γH2Ka eqn’(5)
cos∝-√COS2∝-COS2∅
Ka = cos∝ eqn’(6)
cos∝+COS2∝-COS2∅
The Problem 17
The wall in this case pushed into the soil. The transformation
Kp = tan2(45+Ø/2) eqn’(7)
of calculating K.
exposed to lateral pressures from the retained soil plus any other
the backfill side will push the wall outward, which will tend to
slide on its footing. The driving force from the applied loads
the footing base and the underlying soil, produced by the bearing
against the front face of the wall and footing may be considered
for the passive force calculation. When the friction plus passive
forces are not high enough to counteract the pushing force, a shear
The Problem 18
key can be designed under the wall footing. This structural element
equal to 1.5.
μ∑W+Fp
FSsliding = ≥ 1.5 eqn’(8)
Fa +Fq
1
Fp = γ k H2 eqn’(9)
2 s p
1
Fa = γ k H2 eqn’(10)
2 s a
The Problem 19
Fq = qka H eqn’(11)
Where:
µ = Coefficient of friction
Fq = Surcharge Pressure
q = Surcharge
defined as the ratio between the sum of resisting moments and the
that both these definitions are false because the safety factor
pressures on the backfill side will push the wall outward, which
will tend to overturn around the end of the toe, as shown at the
including the wall self-weight and the weight of the backfill over
Where:
RM = Resisting Moment
OM = Overturning Moment
Wi = Weight of Strucuture
vertical pressure transmitted by the base slab into the soil. Note
that qtoe and qheel are the maximum and the minimum pressures
Note that ∑V includes the soil weight and that, when the value of
the heel section. This stress is not desirable because the tensile
redone.
∑W 6e
Qmax = 1+ eqn’(16)
B B
Where:
B = Base of Structure
e = eccentricity
The Problem 24
Research Paradigm
more rain fall or even stronger earthquakes which may cause the
problem to arise that may damage properties and even cause the
loss of life of people who live in Baguio City. This study will
area that will be sufficient enough to hold the material save more
retaining structure where this study can help them to adopt which
following questions:
retaining wall?
factors of safety?
The Problem 27
its external stability using the gathered design data from the
considered. Also, the method that will use in this is only one
Design and Methodology 28
Chapter 2
source of data, and population and locale of the study are also
Research Methodology
equation.
compute the lateral force resultant, Pa, due to the active earth
pressure minus two times the soil cohesion times the square root
soil is cohesion less, the active earth pressure along the depth
height squared times one-half times the unit weight of the backfill
known. But in most cases, the retaining wall and soil are broken
weights and centroids of the retaining wall and soil, the moments
their self-weights exert about the toe of the retaining wall are
moment quantity.
Design and Methodology 32
The resultant of all the forces should fall within the middle
the total weight of the retaining wall and soil divided by the
Design and Methodology 33
Sources of Data
given site and was obtained from the written reports and records
mountainous area where slopes are present and soil erosion is high
due to soil’s soft nature and can result to road closure which
and access road below the given site. The length of the roadway
wall was damaged due to strong typhoon Ompong last year 2018.
Results and Discussions 35
CHAPTER 3
from Department of Public Works and Highways and this will be used
structures.
walls are compared to each other to come up with the most efficient
retaining wall from DPWH and gabion gravity retaining wall from
Chapter 4
Conclusions
cantilever retaining wall passed all the limiting values for the
safety also passed except for geogrid retaining wall, the result
failure.
Recommendation
are as follows.
Rankine’s theory.
structures that were not checked on this study using the same
parameters.
References
https://researchgate.net/publication/321698939_LANDSLIDES_IN_THE
_PHILIPPINES_ASSESING_THE_ROLE_OF_BIOENGINEERING_AS_AN_EFFECTIVE
_ALTERNATIVE_MITIGATION_TECHNIQUE
https://www.researchgate.net/Institution/Indian_Institute_of_Tec
hnology_Gandhinagar
https://www.scribd.com/document/293993679/Comparative-Study-of-
Cantilever-and-Counter-Fort-Retaining-Wall-46768
https://www.scribd.com/document/381197527/COUNTERFORT-RETAINING-
WALL-MCN.pdf
References 45
https://www.academia.edu/12042876/design_of_counter_fort_retaini
ng_wall
https://www.researchgate.net/publication/272308503_Behavior_of_c
antilever_and_counterfort_retainingw_walls_subjected_to_lateral_
earth_pressure
Counterfort_retaining_walls_under_earthquake_force
counterfort-retaining-walls/
tent.cgi?article=2712&content=icchge
http://site.jugaza.edu.ps/ahmedagha/files/2014/10/Foundation-
Ch.7.pdf
References 46
http://site.jugaza.edu.ps/ymadhoun/files/2016/09/Chapter-12.pdf
from https://www.researchgate.net/publication/289857945_Analy
tical_Study_for_Stability_of_Gabion_Walls
hulagrawal05/retaining-walls-21085895
_Geotechnical_Approaches_for_Slope_Stabilization_in_Residential_
Area
https://books.google.com.ph/books?id=v3Mq9szzE1YC&printsec=front
cover&dq=foundation+engineering&hl=en&sa=X&ved=0ahUKEwjV6o6O_anh
AhVDJHIKHa0VCUcQ6AEIPDAD#v=onepage&q=foundation%20engineering&f=
false
ing-walltypesuse/24566/?fbclid=IwAR0uOj8VPCIQT
jOwpq_TP783LmWjUCRQlD6bzy12a0KurgI54emGA7yXBY0
References 47
https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.
gbv.de/dms/goettingen/351118926.pdf&ved=2ahUKEwifrCC8s_hAhUbfXAK
HY6RCPsQFjAPegQlBxAB&usg=AOvVaw2y7DqEBfyLoacX4wV2Gma
ads/Lecture%2032.pdf
fy = 415 N/mm2
γs = 19 kN/m3
γc = 24 kN/m3
μ = 0.55
Ø = 35°
C = 0
Against Overturning
W1 = 24(0.30)(0.3)(1m)= 2.16 Kn
W2 = 24(1/2)(1.2-0.3)(7-0.80)(1m)= 66.96 Kn
W3 = 24(4.2)(0.8)(1m)= 80.64 Kn
W4 = 19(0.3)(7-0.80)(1m)= 35.34 Kn
W5 = 19(2.7)(1.5)(1m)= 76.95 Kn
W6 = 9.80(0.3)= 2.94
∑W = 264.99 Kn
Fa = 1/2kaɣ(H+h’)2
Fa = 1/2(0.271)(19)(7)2 = 126.151 kN
Fp = 1/2kpɣh2
Fp = 1/2(3.69)(19)(2.3)2 = 185.441 kN
RM = 2.16(3.75)+66.96(2/3(0.9)+2.7)+80.64(4.2/2)+35.34(0.3/2+3.9)
+76.95(1.35)+9.8(1/2(0.3)+2.7+1.2)= 685.115
OM = Fa(1/3)(7.52)
OM = 126.105(1/3(7.52)) = 316.217
Against Sliding
FSSL = µ∑W/(Fa+fq)
Q = (∑W/b)+(1±6e/b)
fy = 415 N/mm2
γs = 19 kN/m3
γc = 24 kN/m3
μ = 0.55
Ø = 35°
C = 0
1-sinØ
ka = = 0.271
l+sinØ
1+sinØ
kp = = 3.690
l-sinØ
H = 4.7+2.30 = 7m
L = 0.3-0.6H = 3.5 m
Against Overturning
γH2ka 19x(7)2(0.271)
Pah = = = 126.15 kN
2 2
H H H
M0 = (Pahx )+(Plhx )-(Pphx )
3 2 3
Appendices 55
7 7 2.3
M0 = (126.15x )+(18.610x )-(185.44x ) = 217.31 kN
3 2 3
∑M .
F.SO = = = 5.17 > 1.5 SAFE!
MO 217.31
Bearing Capacity
∑W 6e
P= (1± )
b b
417.557 6X-0.07
PA= 1+ = 89.477 kN/m2 < PALL (294 kN/m2) SAFE!
4.2 4.2
417.557 6X-0.07
PD = 1- = 109.37kN/m2 < PALL (294 kN/m2) SAFE!
4.2 4.2
(2.50+0.30)
PB = 89.447+(109.37-89.447)X = 102.729 kN/m2
4.20
2.50
PC =89.447+(109.37-89.447)X = 101.305 kN/m2
4.2
0.43
PE = 89.447+(109.37-89.447)X = 91.487 kN/m2
4.2
Pall 294
F.SBC = = = 2.69 > 2 SAFE!
Pmax 109.37
Appendices 56
fy = 415 N/mm2
γs = 19 kN/m3
γc = 24 kN/m3
μ = 0.55
Ø = 35°
C = 0
1-sinØ
ka = = 0.271
l+sinØ
1+sinØ
kp = = 3.690
l-sinØ
Pressure Distribution
Fa = 1/2ɣH2ka
Fa = 1/2(19)(0.271)(7)2= 126.151 kN
Fq = 9.81(0.271)(7) = 18.591 kN
FT = 126.151+18.591 = 144.742 kN
W = 19(4.20)(7)tan25 = 260.479 kN
OM = Fa(7/3)+(Fq)(7/2)
OM = 126.151(7/3)+18.591(7/2) = 359.421
e = OM/W+Fq(L)
fy = 415 N/mm2
γs = 19 kN/m3
γc = 24 kN/m3
μ = 0.55
Ø = 35°
C = 0
1-sinØ
ka = = 0.271
l+sinØ
1+sinØ
kp = = 3.690
l-sinØ
Fa = 1/2ɣH2ka
Fa = 1/2(19)(0.271)(7)2= 126.151 kN
Fq = 9.81(0.271)(7) = 18.591 kN
Fp = 1/2kpɣh2
Fp = 1/2(3.69)(19)(2.3)2 = 185.441 kN
Wg = 15.735 kN/m3
[1x24x3]+[2.7x1x2.85]+[3x1x2.7]+[3.3x1x2.55]+[3.6x1x2.4]+[3.9x1x2.25]+[4.2x1x2.1]
dg =
23.1
dg = 57.645/23.1 = 2.4955m
Wg =[(4.2)(1)+(3.9)(1)+3.6(1)+3.3(1)+3(1)+2.7(1)+2.4(1)](15.735)
Wg = 363.4785 kN
Against Sliding
FSSL = µWg/Fa
FSSL = [0.55(363.4785)+185.441]/126.151+19.591
1 7 7
FSOT = 363.4785(2.4955)+185.441 (2.3) / 126.151 +18.597
3 3 2
x = RM-OM/Rv
x = [1049.232-359.421]/363.4785
x = 1.898m
Appendices 60
QMAX = 363.4785/4.2[1+6(0.593)/4.2]
QMIN = 363.4785/4.2[1-6(0.593)/4.2]
CAREER OBJECTIVE:
I am looking for an opportunity in a reputed engineering firm
where I can contribute my knowledge and integrated skills in
engineering.
QUALIFICATIONS:
EDUCATIONAL ATTAINMENT:
Tertiary Saint Louis College
Bachelor of Science in Civil Engineering
Lingsat, San Fernando City, La Union
June 2013 – October 2016
CHARACTER REFERENCES:
PERSONAL INFORMATION
Age: 26
Height: 168 cm
Weight: 60 kg
Birthday: July 7, 1992
Birthplace: Tarlac
Father’s Name: Francisco Sta. Marina
Mother’s Maiden Name: Leonidez Dela Cruz
Religion: Catholic
Civil Status: Single
CHARACTER REFERENCES:
CAREER OBJECTIVE:
Looking for positions of responsibility within Operations
area in construction industry that will greatly utilize my
skills and performance from my past experiences in school and in
the actual job training.
QUALIFICATIONS:
EDUCATIONAL ATTAINMENT:
Tertiary University of the Cordilleras
Bachelor of Science in Civil Engineering
Gov. Pack Road, Baguio City, Benguet
June 2012 – Present
OBJECTIVE:
Seeking an entry-level position as a civil engineer where I
can use my comprehensive, analytical, and calculative skills for
implementing construction plans and preparing accurate report
projects.
PERSONAL INFORMATION:
Age: 20
Height: 170 cm
Weight: 65 kg
Birthdate: May 12, 1998
Birthplace: Olongapo City, Zambales
Father’s Name: Leopoldo A. Tillo
Mother’s Maiden Name: Ailyn P. Villanueva
Religion: Roman Catholic
Civil Status: Single
Citizenship: Filipino
ORGANIZATIONS:
SKILLS:
AutoCAD
Knowledgeable in using Microsoft Office
Microsoft Word
Microsoft Excel
Microsoft PowerPoint
Has a good communication and interpersonal skill
Good Learner
EDUCATIONAL BACKGROUND: