FACTORS AFFECTING THE FAILURE/S OF ROAD SLIP PROTECTION: A CASE IN BRGY.MASAGAOSAO, KAWAYAN, BILIRAN

___________

A Thesis Presented to the College of Engineering

NAVAL STATE UNIVERSITY

Naval, Biliran

___________

In Partial Fulfilment for RES 513 CE Research Thesis

___________

SHARA JANE IGANO ABANGAN

October 2014

ii

ACKNOWLEDGMENT

The researcher wishes to extend her profound gratitude to the following

persons for without them this study would not have been realized:

Dr. Rossini B. Romero, Dean COE, her thesis adviser, for scholarly ideas

and support, which resulted in the completion of the manuscript;

Dr. Roland A. Niez, Dean CAS, who extended intellectual support and

encouragement for sloping and enriching the study;

The respondents of the study, for their cooperation and willingness to assist

her in data gathering and for providing much needed information;

Her family and friends for constantly inspiring her to continue with her studies

and for their love and understanding all the time; and most of all

The Lord Almighty, for His continued blessings and Divine Providence to her

and her family which meant a lot for the success in all her undertakings.

SHARA JANE I. ABANGAN

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TABLE OF CONTENTS

Page Title page………………………………………………………………..…..…….i

Acknowledgment……………………………………….………………….….…ii

Table of contents………………………………………………...………..….…iii

List of tables…………………………………………………………….…….….v

List of figures………………………………………………………..….……..…vi

List of appendices……………………………………………………....………vii

Abstract…………………………………………………………………..…...…viii

CHAPTER I- INTRODUCTION

Background of the Study……………………………………….………1

Objectives of the Study………………………………………..…..….. 4

Framework………………………………………………………….……5

Theoretical Framework………………………………….....…..5

Conceptual Framework………………………………….……..6

Importance of the Study………………………………………….…….8

Scope and Delimitation of the Study………………………….………8

Definition of Terms……………………………………………………...9

Review of Related Literature………………………………………….10

CHAPTER II- METHODOLOGY

Research Design……………………………………………………….14

Research Locale………………………………………………………..14

Research Subject…………………………………………….…………14

Research Instrument……………………………………..……..……...14

iv

Data Gathering Procedure……………………………………………..15

CHAPTER III- RESULTS AND DISCUSSION

Results and discussions……………………………………………..…16

CHAPTER IV- SUMMARY, CONCLUSION, AND RECOMMENDATION

Summary …………...………………………………………...................22

Conclusions…………………………………………………...................23

Recommendations…………………………………………..…………...24

Literature cited…………………………………………………...….…..……….26

Appendices…………………………………………………………….…..……..27

Curriculum vitae……………………………………………….……….……...…33

v

LIST OF TABLES

Table Page

1. Profile of Road Slip Protection…………………………………….……..16

2. Test/s Performed In the Road Slip Protection…………..…….………..18

3. Failures Encountered and Factors that Affects the Failures in Constructed

Road Slip Protection……………………………………………….………19

4. Maintenance Conducted.......................................................................20

5. Plans on the Failure/s of Constructed Road Slip Protection.................20

vi

LIST OF FIGURES

Figure Page

1. Conceptual Framework of the Study……………………………………..7

vii

LIST OF APPENDICES

Appendix Page

A. Letter Request to DPWH…………………………………………………..28

B. Survey Questionnaire……………………………………………….………29

viii

ABSTRACT

ABANGAN, SHARA JANE I., Naval State University, Naval, Biliran, Philippines.

October 2014. FACTORS AFFECTING THE FAILURE/S OF ROAD SLIP

PROTECTION: A CASE IN BRGY. MASAGAOSAO, KAWAYAN, BILIRAN, a

research study.

Adviser: Rossini B. Romero, Ph.D.

The goal of this research was to determine the factors affecting the failure/s

of road slip protection situated at Brgy. Masagaosao, Kawayan, Biliran. The

approach of this research has been to address the authorized personnel from the

Department of Public Works and Highways (DPWH), Biliran Engineering District.

The road slip protection only lasted 3 months after the completion of the

project, foundation lies on unstable soil/strata, and failed to perform all the tests

listed on the questionnare. Failures were encountered on the structure; these were

settlements of the structure happened months after the completion of the project.

However, the contractor was able to repair the said failure. Unfortunately, weeks

after the repair, due to heavy rains brought by typhoon Henry, the structure

collapsed. For now, there was no specific plans on the collapsed road slip

protection in the said station for it was still under investigation of who was

responsible to the failure happened in the structure.

The factor that affect the failure of the road slip protection was the soil where

the foundation of the structure lies.

1

Chapter I

INTRODUCTION

Background of the Study

Road slip protection is a structure that has been used in several decades by

installing it at the roadside slope portion of a highway and is used to ensure the

vehicle driver’s safety and reduce the environmental degradation. At times,

materials in cut banks will slip downward onto the road, portions of high fills slide

outward and downward, often carrying portions of the roadway or shoulder along.

Such failures are often spectacular and gain considerable attention. The most

common failures in which slipping occurs is along a seam of wet or weak material. It

is influenced by a number of factors such as soil type, vegetation and landscape,

and it can occur on a specific field installation (Oglesby, 2005).

Road slip protection ensures the vehicles safety and reduce the

environmental degradation. However, if the construction is not well supervised,

materials used is not in good quality, design considerations were not followed

carefully, and inadequate maintenance and inspections were conducted, there’s a

possibility that failure/s to the structure will exist. Conditions of a road slip protection

can be easily deteriorated within a certain period of time thus continual observation

and maintenance should be carried out from time to time. Repairing a failed road

slope protection can be a costly business. Traditionally if the failure extends deeper

than superficial surface erosion, the repair involves excavating and removing the

failed fill material, to replace it with imported granular fill. Not only is it time

consuming and expensive (especially if it incurs landfill and aggregate taxation), it’s

also environmentally damaging (Kathmundo, 2007).

2

Road slip protections were installed to avoid soil erosion and provide safety

to public and vehicles passing on the site. However, there are some factors that

affects the functions of the structure that leads to failures. One of the case was in

Manhattan’s Castle Village (2005), during inspections the authorities discovered

failures occurred in their road slip, and these were, loose and displacement of

stones, deteriorating of the mortar, cracking and leaks.

A physical condition survey conducted by Antonucci and Lawless Architects

and Engineers (2005), reported twelve to eighteen inches of settlement in the park

area behind the wall. The settlement was caused either by the filling of voids left in

the backfill during the original construction, and/or by new or enlarged voids created

by the wall’s westward movement.

Four years later, Cutsogeorge & Tooman Architects (2009) indicated that

approximately six cubic feet of stone had spalled from the wall. Due to this failure, it

caused a great public distraction and wasted a lot of money for the constructed

structure that has failed. Another case was in South Pukekohe a town in the

Auckland Region of the North Island of New Zealand, consists of a steep slope

constructed using an unsuitable fill material which when combined with a build-up of

hydrostatic pressure after a heavy rainfall events resulted in slip failures and the

need for constant repair. The factors that affects the failure are using unsuitable

materials during construction and not enough maintenance for the structure.

Failures may occur during construction or at later date after the road is in service. It

may be better practice to risk some sliding or adjustments of large cut slopes than

to flatten them all and thus increase the pay yardage (Hicks, 2005).

The Philippine government funded different types of construction and

rehabilitation of roads for highway development and part of this is the construction

3

of road slip protections for critical sections along national roads. However, there are

common factors that affects the failures of road slip protection installed and these

were the improper installation, inappropriate materials used, the type of soil where

the structure was built and the weather. It is very important to consider these factors

when designing a roadside protection to prevent failure after the construction (Gue

& Tan, 2010).

The Department of Public Works and Highways focused for the road

improvement of the Biliran circumferential road last 2014. They allocated 420 million

pesos for the different road projects in Biliran Province, and 40 million of this was

allocated to road slip protection construction (2014 DPWH Infrastructure Program,

Based on GAA, Region VIII, 2014).

With this rapid development of highway and road slip construction, it was

very important to make sure that these structures functions well and if failures exist,

immediate actions must be made to ensure the public safety (Augdin, 2010).

In the Province of Biliran, the constructed road slip protections were along

Kawayan-Culaba section and in Cabucgayan-Biliran section (2014 DPWH

Infrastructure Program, Based on GAA, Region VIII, 2014).

Some portion of the constructed road slip protection in Brgy. Masagaosao,

Kawayan, Biliran has encountered failure. This failure caused the structure to settle

down. The road slip protection was just newly constructed but failure has already

occurred after months of completion of the project.

Hence, the study was conducted to determine the factors that affects the

failure of the road slip protection situated in Brgy. Masagaosao, Kawayan, Biliran.

4

Objectives of the Study

Generally, the study was conducted to determine the factors affecting the

failures in constructed road slip protection in Brgy. Masagaosao, Kawayan, Biliran.

This study was conducted with the following specific objectives:

1. Ascertain the profile of the constructed road slip protection in terms of:

1. location;

2. construction;

3. year/s of service;

4. type of road slip protection installed;

5. height;

6. thickness;

7. foundation depth;

8. length of structure;

9. slope;

10. soil quality in terms of:

1.10.1 type of soil;

1.10.2 soil strength; and

11. materials used;

2. Ascertain the soil and material test/s performed in the road slip protection;

3. Identify the existing failure/s in the constructed road slip protection;

4. Assess the road slip protection maintenance conducted; and

5. Determine the plans of Department of Public works and Highways (DPWH)

with regards to the existing failures in the constructed road slip protection.

5

Framework of the Study

This study took hold on the following theoretical and conceptual frameworks

as its main and solid foundation in the due course of its proceedings.

Theoretical framework. The theoretical framework of the study was anchored

on the theory propounded by different authorities. The theory formulated by Charles

Coulomb and Christian Otto Mohr (19th century) points out that a material fails

because of a critical combination of normal stress and shear stress, and not from

their either maximum normal or shear stress alone.

According to the Mohr-Coulomb theory, understanding shear strength is the

basis to analyse soil stability problems like: lateral pressure on earth retaining

structures, slope stability, and bearing capacity. The safety of any geotechnical

structure is dependent on the strength of the soil, if the soil fails, the structure

founded on it can collapse. The shear strength of a soil is its resistance to shearing

stresses. It is a measure of the soil resistance to deformation by continuous

displacement of its individual soil particles. Shear strength in soils depends primarily

on interactions between particles. Shear failure occurs when the stresses between

the particles are such that they slide or roll past each other. If the forces available to

resist movement are greater than the forces driving movement, the slope is

considered stable.

Another theory that is anchored in the study was formulated by Karl Terzaghi

(a mechanical engineer and geologist) who developed the framework for theories of

bearing capacity of foundations, and the theory for prediction of the rate of

settlement of clay layers due to consolidation. In his 1948 book, Donald Taylor

recognized that interlocking and dilation of densely packed particles contributed to

the peak strength of a soil.

6

The theory of Terzaghi on evaluation of the ultimate bearing capacity of

rough shallow foundations states that a foundation is shallow if its depth is less than

or equal to its width. The bearing capacity of soil is the maximum average contact

pressure between the foundation and the soil which should not produce shear

failure in the soil. Ultimate bearing capacity is the theoretical maximum pressure

which can be supported without failure; allowable bearing capacity is the ultimate

bearing capacity divided by a factor of safety. Sometimes, on soft soil sites, large

settlements may occur under loaded foundations without actual shear failure

occurring; in such cases, the allowable bearing capacity is based on the maximum

allowable settlement.

The theory of Mohr-Coulomb and Terzaghi provide the foundation for this

study that geared towards slope failures theories and have a great impact on the

conduct of the study.

Conceptual framework. Figure 1 shows the schematic diagram of the flow of

the study. As shown on the diagram, the design, soil quality and materials used

might be the factors affecting failure of constructed road slip protection which affects

the year of service and condition of the structure. The factors that affects the failure

of the road slip protection will be the bases for the plans of DPWH for alternative

solution to the problem and for the improvement of the construction of road slip

protections.

7

FACTORS AFFECTING THE

FAILURE/S IN ROAD SLIP

PROTECTION

Profile of Road Slip Protection

Design In Terms Of:

1. location;

2. construction;

3. year/s of service;

4. type of road slip

protection installed;

5. height;

6. thickness;

7. foundation depth;

8. length of structure;

9. slope;

10. soil quality in terms of:

1.10.1 type of soil;

1.10.2 soil strength;

and

11. materials used;

MAINTENANCE CONDUCTED IN

ROAD SLIP

PROTECTION

THE PLANS OF

DPWH FOR

ALTERNATIVE

SOLUTION TO THE

PROBLEM

IMPROVED

ROAD SLIP

PROTECTION

SOIL AND MATERIAL

TEST/S CONDUCTED

Figure 1. Conceptual Framework of the Study

8

Importance of the Study

This study provides information on the factors that affect the failures of the

road slip protection and identify the plans that should be conducted in the failure/s

of the structure. Thus, the study was addressed to:

Civil Engineering students. This study is important to civil engineering

students for this will give insights on what factors affects the failure/s of road slip

protections.

Contractors. This study is important to contractors because if failure exists to

their constructed road structures, they will be responsible for the renewal of the

failed structure.

Department of Public Works and Highway. This study is important to DPWH

because they are the most responsible agency in public construction. The identified

factors that affects the failure of the constructed road slip protection can be further

studied for the awareness that needs to consider in designing and constructing road

slip protection in the future.

Future researchers. Information obtained from the study will serve as guide

and provide data for other similar future studies. This may serve as a reference for

future researchers in developing their research problems and in conceptualizing

their research paper diagram using the same variables or research locale.

Scope and Delimitation of the Study

This study focused mainly on determining the factors affecting the failure/s of

constructed road slip protection in Brgy. Masagaosao, Kawayan, Biliran. The profile

of the structure will be limited to its design, the materials used during construction,

the type of soil, year of service and the condition of the constructed road slip

9

protection. A more précised information of the study will be gathered by identifying

the existing failures in the constructed road slip protection and ascertain the

inspection and maintenance conducted.

Definition of Terms

To have a clear and vivid understanding about the concept of the research,

the following terms were defined operationally and conceptually:

Department of Public Works and Highways. Is the executive department of

the Philippine government responsible for all safety of projects in the field of public

works. It is also responsible for the maintenance of the Philippine road network and

irrigation system.

Failure. Is the load refusal, breakage, or separation of component parts. Load

refusal is the point where the ultimate strength is exceeded. Is the state or condition

of not meeting a desirable or intended objective, and may be viewed as the

opposite of success in the construction of road slip protection.

Foundation depth. Is the depth of foundation in a structure that must meet

the designed depth to avoid unexpected accidents.

Maintenance. The process of maintaining or preserving the road slip

protection, to determine if the structure is still in good condition and to identify the

existing damage in the structure.

Road slip protection. Is a structure constructed at the roadside of a highway,

its purpose is to ensure the safety of vehicles passing on and decreases

environmental degradation, it usually have a concrete barrier on the upper portion

that also serves as a guardrail for the vehicles.

10

Slope. A surface of which one end or side is at a higher level than another; a

rising or falling surface. The term is used in the study as a slope of soil in a highway

that needs to be protected.

Soil quality. Is a measure of the condition of soil relative to the requirements

of one or more biotic species and or to any human need or purpose and it has a

great impact on the geotechnical works. Soil quality is one of the factor that an in-

charge engineer should consider when designing a road slip protection and must

perform soil tests to determine whether the soil meet the required strength for the

construction of the structure.

Structure. Is to construct or arrange according to a plan, if failed to perform

the plans, a possible failure of the constructed structure might exist.

Review of Related Literature

This part of the manuscript presents a review of the concepts and principles

that are related to the study. These concepts are condensed from books, articles

and research studies which serve as the guide in the development of the framework

of the study, the methods and the survey instrument that were used. Furthermore,

these concepts were used as the basis for comparison of results, benchmarking

and recommendations.

Good planning for and management of a geotechnical site investigation is the

key to obtaining sufficient and correct site information for designing a structure in a

timely manner and with minimum cost for the effort needed. A geotechnical site

investigation is the process of collecting information and evaluating the conditions of

the site for the purpose of designing and constructing the foundation for a structure.

(I.Holubec Consulting Inc., 2010).

11

The importance of proper selection and investigation of sites and routes in

permafrost areas cannot be overemphasized. Reconnaissance and detailed site

and route studies must be made, and environmental considerations and the

availability of construction materials must be taken into account. Increased costs of

construction, operation and maintenance, as well as unsatisfactory performance of

engineering structures, inevitably result when there is a lack of information on

conditions and other terrain factors (Johnston, 1981).

Civilization’s earliest attempts at construction probably involved soil;

however, the understanding of the role of soil as a foundation or building material

developed by trial and error. Since the early 20th century, an improved

understanding of soil behaviour has been achieved by applying the principles of

physics, solid mechanics, fluid mechanics, strength of materials, and structural

engineering to define soil behaviour. The body of knowledge developed by

analysing soil behaviour on a theoretically sound basis is called "soil mechanics"

and its application to solution of actual problems is called “geotechnical

engineering.” Soil is a complex three-phase medium that contains various amounts

of water and/or air surrounding the solid particles. It is not a solid mass, i.e., a

continuum, as many of the theories of solid mechanics require. Therefore, an

entirely theoretical solution of the most commonly encountered soil problems is not

practical (Topolnicki, 2004).

Throughout the 1990’s interest in soil quality and understanding its

importance has come to the forefront of environmental sustainability (Wallace &

Terry, 1998).

Many feel that soil quality cannot be defined for a complex system as diverse

and dynamic as soils. "Quality" and "soil quality" are seen by some to have infinite

12

meanings and basically are indefinable (Sojka & Upchurch, 1999). Others, however,

have taken on the challenge of converting asubjective term such as "soil quality"

into an objective characterize able term. The difficulty in establishing a definition

comes from the variety of land uses, locations, environments, types of soils and

general lack of understanding between the interactions of a multitude of processes

occurring within the soil (Kennedy & Papendick, 1995).

Erosion is unavoidable during construction. However, the severity of erosion

can be mitigated by the consistent application of the principles of soil erosion control

(JETTEN et. al., 2003). The natural characteristics of a site should be analysed

during the design of a project. Fitting a project to a site can include aligning roads

along contours and locating building pads on the flatter portions of the site. Roads

running straight up and down a hill have a long slope length and very high flow

velocities, both of which greatly increase the potential for erosion (EuroSoilStab,

2002).

Construction activities should be timed to reduce the exposure of soil to

erosion. This can be accomplished in two ways. First, construction should be staged

so that the size of exposed areas is reduced. This includes the prompt installation of

erosion control measures in disturbed areas. Second, if possible, construction

should be performed during times of the year when the erosion potential is least

(EuroSoilStab, 2002).

Design methods for slope erosion control are not well developed. In the

absence of design procedures, the principles of erosion control are very important.

They provide the designer with rules of thumb for making design decisions. The

design should be based in the philosophy of diverting and controlling runoff:

13

managing concentrated flows, and establishing vegetation on slopes (Topolnicki,

2004).

The success or failure of a geotechnical feature is often decided in the early

stages of a project. Geotechnical engineering is a specialized field. Therefore, to

assure success of a project, the input of a qualified and experienced geotechnical

specialist should begin at project inception and continue until completion of

construction (Maher et al., 2006; Jelisic and Lappen, 1999; Hayward baker Inc,

Garbin et al., 2011, Andersson et al., 2000).

Hence, the study was conducted to determine the factors that affects the

failure of the road slip protection situated in Brgy. Masagaosao, Kawayan, Biliran.

14

Chapter II

METHODOLOGY

This chapter elaborates the different processes and methods on how this

research was undertaken. This comprises the description of research design,

locale, respondents, data gathering procedure, data scoring, and statistical

treatment as a mean of developing and evaluating the research.

Research Design

This study used the descriptive-survey method classification of research

which correlates to the suggested plans given by the respondents during the

conduct of the study. This is a descriptive research classified as a cross-sectional

survey type for it involved the collection of data from selected respondents in a

single period of time.

Research Locale

This study was conducted at Brgy. Masagaosao, Kawayan, Biliran.

Research Subject

The respondents of this study were the authorized personnel from the

Department of Public Works and Highways, Biliran Engineering District, Naval,

Biliran.

Research Instrument

This study is operationally designed to conduct interviews regarding to the

existing failure/s to the constructed road slip protection situated in Brgy.

Masagaosao, Kawayan,Biliran with the aid of personalized questionnaire that based

15

on the objectives of the study and on the researcher’s knowledge about the course.

The contents of the questionnaire were divided into five parts. Part I covers the data

of the profile of the constructed road slip protection in terms of its location,

construction, year/s of service, design, type of road slip protection installed, height,

thickness, foundation depth, length, slope, soil quality, and materials used. Part II

covers soil and material test/s conducted in the road slip protection. Part III covers

the identified existing failures of road slip protection. Part IV covers the

maintenance/s conducted to the structure and Part V covers the plans of the DPWH

with regards to the existing failure.

Data Gathering Procedures

Before the implementation of the study, the research secured an approval

letter or permission form the head of the DPWH to conduct a research study on the

road slip protection situated at Brgy. Masagaosao, Kawayan, Biliran. After the

approval, a personalized survey questionnaire was distributed to the respondents

personally by the researcher. Instruction and personal interview were all conducted

during the distribution. The researcher noted the corresponding answers to the

questionnaires. Data were collected, analysed and interpreted based on the

variable of the study.

16

Chapter III

RESULTS AND DISCUSSIONS

This chapter presents the results of the study conducted. The data derived

from the survey questionnaire responded by the authorized personnel from the

Department of Public Works and Highways (DPWH), Biliran Engineering District

were arranged and presented into five sections based on arrangement of the

objectives of the study.

Table 1 below shows the tabulated results on the profile of road slip

protection.

Table 1 Profile of Road Slip Protection

Location Left side of the road.

Construction:

Started

Ended

January 30, 2014

April 25, 2014

Year/s of service 3 months

Type of Road Slip Protection

installed

Riprap and stone masonry.

Height More or less 9 meters

Thickness 0.30 meter for riprap, and

0.60 - 1 meter for stone masonry

Foundation depth More or less 1 meter but not less than 0.60 meter

17

Length 16.7 meters

Slope 5:1

Soil quality:

Type of soil

Soil strength

Clay

Soft

Material/s Used Boulders (6-8 inches)

The profile of the road slip protection was according to the location,

construction, year/s of service, type of road slip protection installed, height,

thickness, foundation depth, length, slope, soil quality in terms of type of soil and

soil strength, and material/s used. The structure was located at the left side of the

road. The construction started on January 30, 2014 and ended on April 25, 2014. It

only lasted for 3 months. There were two types of road slip protection that were

installed, these were, riprap and stone masonry. Its height was more or less 9

meters. Since there were two types of road slip protection installed, the thickness

for riprap was 0.30 meter while 0.60-1.00 meter for the stone masonry. The depth of

road slip protection’s foundation was more or less 1 meter but not less than 0.60

meter, it was based on the soil. It has a length of 16.7 meters and has a slope of

5:1. The soil quality was classified into two, these were: type of soil and soil

strength; the type of soil the road slip protection has underneath is clay and its soil

strenght is soft. The material used was boulders (6-8 inches).

18

Table 2 below shows the tabulated results of test/s performed in the road slip

protection.

Table 2 Test/s Performed In the Road Slip Protection

Soil Tests Material Testing

Atterberg limits

California bearing ratio

Compaction test

Water content test

Test for resistance to degradation of small-size coarse aggregate

Test for soundness of aggregates

Quality test for Portland cement

Organic impurifier and mortar strength of fine-aggregates

Specific gravity and absorption of boulders

There were test/s performed in road slip protection before construction.

These were classified into two: soil test/s (for embankment materials) and material

testing (for FA, cement, and boulders). The DPWH were able to perform four soil

tests, these were: Atterberg limits, California bearing ratio, Compaction test, and

Water content test. There were three material tests listed on the questionnaire of

the researcher, the DPWH was able to perform test for resistance to degradation of

small-size coarse aggregate, and test for soundness of aggregates, however, the

respondent specified other tests such as, quality test for Portland cement, organic

impurifier and mortar strength of fine-aggregates, and specific gravity and

absorption of boulders.

19

Table 3 below shows the tabulated results of the failures encountered and

factors that affect the failures in constructed road slip protection.

Table 3 Failures Encountered and Factors that Affects the Failures in Constructed

Road Slip Protection

Failures Encountered

Factors that Affect the Failure

Settlement of the structure.

The structure collapsed.

Foundation of the structure lies on unstable soil/strata in which the project engineer overlooked.

No coordination of contractor’s Project Engineer to DPWH Materials Engineer during the excavation and preparation of road slip protection foundation.

During heavy rains brought by typhoon Henry, saturated mass caused the failure of the structure.

There were failures encountered in the road slip protection such as,

settlement, and the collapsed of the structure. The respondent of the study stated

the factors that affects the failures, such as, foundation of the structure lies on

unstable soil/strata in which the project engineer overlooked, no coordination of

contractor’s Project Engineer to DPWH Materials Engineer during the excavation

and preparation of road slip protection foundation, and during heavy rains brought

by typhoon Henry, saturated mass caused the failure of the structure

20

Table 4 below shows the tabulated result on the maintenance conducted.

Table 4 Maintenance Conducted

Maintenance Conducted None

Every national highway structures has maintenance made by DPWH after 1

year of completion of the project. However, since the road slip protection was newly

constructed, it was still on the contractor’s responsiblities to conduct maintenance

on the structure, while the DPWH only conducted inspection wether the road slip

protection is still in good condition.

Table 5 below shows the tabulated results of plans on the failure/s of

constructed road slip protection.

Table 5 Plans on the Failure/s of Constructed Road Slip Protection

Type of Agency Plans on the Failures

DPWH- Construction Section

As of now, they don’t have specific plans

on the said failure, they were still

investigating of who was responsible for

the collapsed structure. If it failed due to

technical error, the contractor will be the

one who’s responsible for the

reconstruction of the structure. However,

since it collapsed during typhoon Henry,

if the failure was caused by it, the DPWH

will wait for the next budget that will be

allocated for the reconstruction of the

structure.

21

According to the respondent of the study, for now, the DPWH was still

investigating for who was responsible of the collapsed road slip protection situated

in Brgy. Masagaosao, Kawayan, Biliran. If it failed due to technical error, the

contractor will be the one who’s responsible for the reconstruction of the structure.

However, since it collapsed during typhoon Henry, if the failure was caused by it,

the DPWH will wait for the next budget that will be allocated for the reconstruction of

the structure.

22

Chapter IV

SUMMARY, CONCLUSION, AND RECOMMENDATION

This chapter presents the summary of findings based on the results and the

objectives being presented, conclusion made by the researcher based on the

summary of findings and the recommendations drawn based on the conclusion.

Summary of Findings

This study generally aimed to determine the factors affecting the failures of

the constructed road slip protection.

The following were the findings of the study:

Profile of the road slip protection. The structure was located at the left side of the

road. The construction started on January 30, 2014 and ended on April 25, 2014. It

only lasted for 3 months. There were two types of road slip protection that were

installed, these were, riprap and stone masonry. Its height was more or less 9

meters. Since there were two types of road slip protection installed, the thickness

for riprap was 0.30 meter while 0.60-1.00 meter for the stone masonry. The depth of

road slip protection’s foundation was more or less 1 meter but not less than 0.60

meter, it was based on the soil. It has a length of 16.7 meters and has a slope of

5:1. The soil quality was classified into two, these were: type of soil and soil

strength; the type of soil the road slip protection has underneath is clay and its soil

strenght is soft. The material used was boulders (6-8 inches).

Tests performed. There were test/s performed in road slip protection before

construction. These were classified into two: soil test/s (for embankment materials)

and material testing (for FA, cement, and boulders). The DPWH were able to

perform four soil tests, these were: Atterberg limits, California bearing ratio,

23

Compaction test, and Water content test. There were three material tests listed on

the questionnaire of the researcher, the DPWH were able to perform test for

resistance to degradation of small-size coarse aggregate, and test for soundness of

aggregates, however, the respondent specified other tests such as, quality test for

Portland cement, organic impurifier and mortar strength of fine-aggregates, and

specific gravity and absorption of boulders.

Failure/s encountered. The failures encountered in the road slip protection

were settlement, and the collapsed of the structure.

Factors that affects the failures. The factors that affects the failures were: the

foundation of the structure lies on unstable soil/strata in which the project engineer

overlooked, no coordination of contractor’s Project Engineer to DPWH Materials

Engineer during the excavation and preparation of road slip protection foundation,

and during heavy rains brought by typhoon Henry, saturated mass caused the

failure of the structure.

Maintenance conducted. The DPWH haven’t conducted maintenance on the

road slip protection yet.

Plans on the failure/s of constructed road slip protection. As of now, no

specific plan was implemented, because the structure was still under investigation.

Conclusions

The following assumptions were the gathered facts taken from the survey

conducted:

1. The road slip protection at Brgy Masagaosao, Kawayan, Biliran only

served 3 months.

2. The DPWH were able to perform four soil tests, and five material testing.

24

3. The failures encountered in the road slip protection were settlement, and

the collapsed of the structure.

4. The factors that affects the failure of the structure were: the foundation of

the structure lies on unstable soil/strata in which the project engineer

overlooked, no coordination of contractor’s Project Engineer to DPWH

Materials Engineer during the excavation and preparation of road slip

protection foundation, and during heavy rains brought by typhoon Henry,

saturated mass caused the failure of the structure.

5. The DPWH haven’t conducted maintenance on the road slip protection

yet.

6. As of now, the structure was still under investigation and no plans were

drawn yet.

Recommendations

Based on the conclusion the following recommendations are highly

forwarded.

1. In constructing a road slip protection, a good design, planning, and

adequate supervision must be consider to achieve a functional structure.

2. Engineers must comply all the tests required in the design of the structure

to avoid failures in the future and contractors must coordinate to

authorized personnel of DPWH when constructing national road

structures.

3. Every project engineers must conduct thorough soil investigation to

determine the designed depth of foundation and the type of structure to

be constructed enough to hold the stiffness of road side slope.

25

4. For a sustainable road slip protection there is a need for adequate

maintenance to make sure that the structure is still in good condition and

functions well.

26

LITERATURE CITED

Reference Books:

1. Clarkson H. Oglesby ang R. Gary Hicks: “Highway Engineering” p.547

2. C. Donald (2001), Foundation Design, Prentice-Hall, ISBN 0-13-589706-8

3. Das, Braja (2007). Principles of Foundation Engineering (6th edition), p.45

4. Kathmundo, (2007). “Road Maintenance and Development Project, institutional Strengthening Component: Roadside Geotechnical Problems”

Internet:

1. http://www.geotechlinks.com, retrieved on July 20,2014

2. http://en.wikipedia.org/wiki/Slope_stability, retrieved on August 5, 2014

3. http://www.dpwh.gov.ph/pdf/2011_GAA/2014_GAA/Region%20VIII_FY%202014.pdf, retrieved on August 5, 2014

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APPENDICES

28

Appendix A

LETTER REQUEST TO DPWH

October 2, 2014 ENGR. SUPREMO VICTOR D. SABITSANA Engineer II, Construction Section DPWH, Biliran Engineering District Naval, Biliran

Sir:

Greetings!

The undersigned is a 5th year Bachelor of Science in Civil Engineering

(BSCE) student of Naval State University who is presently proposing a research

study entitled “FACTORS AFFECTING THE FAILURE/S OF ROAD SLIP

PROTECTION: A CASE IN BRGY. MASAGAOSAO, KAWAYAN, BILIRAN”.

In connection with this, I would like to request from your good Office some

necessary data for my study regarding the construction of road slip protection.

Your full assistance and genuine support in this particular research will be

very much appreciated and would help me a lot in my endeavour.

Thank you very much for your help. God bless.

Respectfully yours,

SGD. SHARA JANE I. ABANGAN

Researcher

Noted:

SGD. ROSSINI B. ROMERO, Ph.D.

Ass0. Prof. 4

Approved:

SGD. ENGR. SUPREMO VICTOR D. SABITSANA

Engineer II, Construction Section

29

Appendix B

SURVEY QUESTIONNAIRE

FACTORS AFFECTING THE FAILURE/S OF ROAD SLIP PROTECTION: A

CASE IN BRGY. MASAGAOSAO, KAWAYAN, BILIRAN

Instructions: Please feel free in answering this questionnaire. Never leave any

question unanswered. In accordance with the “ethics of research”, your answer will

be treated very confidentially.

Please supply the needed data by filling up the line or checking the box provided for

your choice. Thank you!

Date of survey conducted: ______________

Name of Respondent: ______________________________ (Optional)

Rank/Position: ____________________________________

PART I: Profile of the Constructed Road Slip Protection

1. Side of road

Left Right

2. Construction of road slip protection

Date Started: ______________________

Date Ended: _______________________

3. Year/s of Service: ___________________

4. Type of road slip protection installed

Riprap

Wire enclosed rock

Grouted boulders

Others (kindly specify):__________________________

5. Height of road slip protection ____________m.

6. Thickness of road slip protection ____________m.

30

7. Foundation depth ____________m.

8. Length of road slip protection ____________m.

9. Slope ____________

10. Soil quality

10.1 Type of soil

Clay

Silt

Sand

Loam

Others (kindly specify): ___________________

10.2 Soil Strength

Very soft

Soft

Very Stiff

Stiff

Firm

Hard

11. Materials used

Stones/rocks (kindly specify the size) __________in.

Rounded

Angular

Boulders (kindly specify the size) __________in.

RSB (kindly specify the dia.) __________mm.

Drain pipe (kindly specify the dia.) __________mm.

Others (kindly specify):

__________________________________________________________

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PART II: Test/s Performed

1. Soil test/s

Atterberg limits

California bearing ratio

Direct shear test

Compaction test

Hydraulic conductivity test

Water content test

Cone penetration test

Standard penetration test

None

Others (kindly specify): ____________________________________

2. Material testing

Test for specific gravity and

absorption of coarse aggregate Test for resistance to degradation

of small-size coarse aggregate

Test for soundness of aggregates

None

Others (kindly specify): _____________________________________

PART III: Failure/s Encountered

1. Kindly state the failure/s encountered in the road slip protection.

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

32

2. What might be the factors that affects the failure/s of the structure?

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

PART IV: Maintenance Conducted

1. Have you conducted maintenance in constructed road slip protection situated

at Brgy. Masagaosao, Kawayan, Biliran?

Yes No

2. How often you conducted maintenance on road slip protection?

Monthly Bi-annual

Annually Others kindly specify: _____________

3. In the maintenance conducted, have you encountered failure/s in the road

slip protection situated at Brgy. Masagaosao, Kawayan, Biliran?

Yes No

PART V: Plans on the Failure/s of Constructed Road Slip Protection

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

Thank you!

33

CURRICULUM VITAE

34

SHARA JANE IGANO ABANGAN Calumpang, Naval ,Biliran

sharajane_abangan@yahoo.com Mobile No: 0930-852-7709

CURRICULUM VITAE

DATE OF BIRTH : June 5, 1994

PLACE OF BIRTH : Naval, Biliran

AGE : 20

RELIGION : Roman Catholic

MOTHER’S NAME : Arsenia I. Abangan

OCCUPATION : House wife

FATHER’S NAME : Felicisimo A. Abangan (Deceased)

EDUCATIONAL ATTAINMENT

College : Naval State University

Bachelor of Science in Civil Engineering

Under Graduate

Secondary : Naval National High School

Larrazabal, Naval, Biliran

Elementary : Calumpang Elementary School

Calumpang, Naval, Biliran

ORGANIZATION

Philippine Institute of Civil Engineers – Student Chapters