1
CHAPTER 1
INTRODUCTION
1.1
Background
Road infrastructure is very important because its presence would affect the
development of surrounding areas and contribute to economic growth. When the
government plans to construct a road in an area, the government hopes the road will
provide services in accordance with the road design life and with minimal
construction costs but can provide suitable functionality that is expected.
However, road constructing build in Indonesia will always be confronted with
the characteristics of the soil conditions that exist in Indonesia, some of the issues
soil problem that will face while construct roads like soft soil, peat and expansive
soil. Types of this soil would require a special approach when government/client
want construct the road, if the special treatment is not done the road will be damaged
prematurely.
One of the soil problem must be face when constructing road infrastructure is
expansive soil, in Indonesia especially in Java that place in lowland areas and of low
undulating hills that can be form with precipitated alluvium or volcanic deposits,
including the formation of alluvium (Qa), formation notopuro (Qpnv) and volcanic
deposits (Qav). Expansive soil is dominated by silty clay or clayey with grey to black
color. Expansive soil clay minerals generally consist of montmorillonite, illite,
kaolinite and quartz. The spread of expansive soil in Indonesia shown in Figure 1.1
2
Figure 1.1 Spread of Expansive soil in Indonesia
The area in west of Surabaya, Jatibarang area, east of Kudat between Cisaga
and Wanareja, and the area around Wirosari-Cepu, Semarang-Godong, and CarubanNgawi. The area around Cepu is the most famous and the most severe damage due to
expansive soil. In the other island expansive soil can be find in Timor island around
Kupang-Atambua road.
Expansive soils can caused damage to the pavement such as crack to the
pavement, heaving to the pavement, settlement to the pavement, and reduce bearing
capacity of soil. Pavement in expansive soil will damages prematurely if typical
construction not accommodate expansive soil factor.
There are many technique of construction when constructing pavement in
expansive soil to reduce bad impact cause by behavior of the expansive soil. To
chose what's best design that will be applied for construct pavement in expansive
soils by using value engineering method. This method selecting base on client
criteria wishes such as cost, time construction, workability and etc.
3
Value Engineering for road Construction began widely adopted due to see a
meaningful contribution in terms of budgeting (financial) and operational
improvements of the road.
Six stages of the study team activities multidiscipline (VE Team Study) for
the preparation of the concept of scientific manuscripts decision support system,
which can be described briefly as follows:
1.
Selection, the selection stage of the technology to be evaluated, in this case is
road Construction in expansive soil
2.
Information, is the stage of data collection and related information technology
implementation case study sites;
3.
Speculation, which is the creative thinking stage is to assess the benefits
obtained by the implementation of these technologies;
4.
Evaluation, an analysis and evaluation phase of the technology is technically
to be able to remove the estimated costs of each technology;
5.
Development, is the stage of preparation of the technical criteria such
technology
The exercise of value engineering can eventually affect the determination of
the distribution of cost, time construction, each effective of technology, that can help
for best alternative design with suitable with client want.
1.2
Issue
Various designs and cost of construction for solve road in expansive soil
problem are proposed by designer such as replace expansive soil with other material,
soil stabilize, membrane, and give load to a expansive soil. All design With variation
of cost of construction, time construction and other advantages of each technologies.
Saving cost is employer’s constraint, client always wants less cost, high quality,
timely project completion, and improved value of such design.
4
Value Engineering is one of technique to accommodate a client wishes
constrain with cost, and value of the project. Value Engineering can be defined as the
systematic application of technologies that have a standard by a multidisciplinary
team (multidiscipline team), to identify the functions of a product or service;
determine the value of the function; provides an alternative through the ideas
(creative thinking), and recommends a cost function the lowest total (WVDOH,
2004).
1.3
Problem statement
Budget of Infrastructure in Indonesia very limited, the portion never exceed 5
percent from total budget now is still less than 3 percent, no wonder if infrastructure
development in Indonesia did not improve. "In other countries, the share of the
budget for infrastructure is already in the top 5 percent," said Director Ahmad Erani
Yustika INDEF (Kompas, 2012). Besides that many local governments, which use
half the total local government budget to pay salaries of local officials, this resulted
low capacity for local government to finance infrastructure development in its area
(Kompas, 2012).
With this condition many examples that a construction project can suddenly
delayed the progress of work before reaching 100% due to the lack of development
funds, due to these strong effort is needed to cover lack of infrastructure
development fund.
In accordance with that, this an opportunity to apply Value Engineering so
government/client can maximize budget of infrastructure especially for the local
government that have a special soil problem in his area so must be consider in many
factor to make service life of the road not reduce drastically because impact of soil
problem. Maximize budget infrastructure by selecting best design from many
existing design that have been fulfill technique aspect and other impact will reduce
cost of maintenance.
5
For example constructed roads in expansive soils, to construct road above
this soil in design stage must accommodate behavior of soil characteristic, because
shrinkage and swelling of expansive soil accelerate damage to the pavement. One of
impact of expansive soil caused crack to the pavement and water will enter to the
crack when rainy season comes then will saturating the pavement material including
the sub grade, it will reduce the service life of pavement significantly. Many
approach design to solve road problem in expansive soil, with Value Engineering
method there opportunity to get suitable designs with expected by government/client
with more low initial cost without sacrifice value of design and finally will result
road construction that can give serviceability accordance with the design life and
reduce maintenance costs.
1.4
Objectives of study
To identify the best design for build road in expansive soil, base on criteria
related with cost, time construction, constructability, quality and safety of each
effective technology.
1.5
Scope of study
This study is taking place at Semarang-Godong link road Km 40+600 44+400 (3.8 km) and Purwodadi-Wirosari link road, Km 73+750 - 76+750 (3 km).
This location in expansive soil area base on prior study and have the same soil
characteristic with other area in Indonesia that have problem with expansive soil.
Evaluation phase is limited to quantifiable aspect (cost, time construction) and nonquantifiable aspects (quality, constructability, safety).
6
1.6
Significance of study
The importance of the study is would give an important information to the
client
the design option and comparative technology when construct road in
expansive soil by applying Value Engineering.
This study also can be used as basic guides if the government/client want to
construct a new road or rehabilitation existing road in expansive soil in the other area
must base on characteristic of local soil so will not give the problem in the future.
1.7
Methodology
Methodology of this study is provided in Chapter 3 of this study. Generally,
divides in 5 main stages: (1) study literature (2) data collection, (3) Value
Engineering in Expansive soils (4) and (5) conclusion and recommendation.
1.8
Thesis structure
Chapter 1 presents introduction of the study which contains background
studies, problem statement, objectives of the study, and scope of the study. Chapter 2
presents the literatures review of expansive soils and value engineering application in
construction. Chapter 3 presents methodology of the study. Chapter 4 will present
Value Engineering in Road Construction at Expansive Soil Problem and discussion.
Chapter 5 will present the conclusion of the result of Value Engineering in Road
Construction at Expansive Soil Problem and suggestion for the future study.