IT Construction Systems
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| Abstract |
The upper reservoir of the Omarugawa Project, which is under construction
by Kyushu Electric Power Co., Inc., will be one of the largest asphalt
faced reservoir in Japan, having impervious areas of approximately 0.3
million square meters.
Constructing the reservoir, there were many
excavation areas, and fill areas scattered around the confined project site.
Earthworks (completed in December, 2003) for the reservoir consisted of mainly
two activities: excavation of 6.7 million cubic meters of bedrock and fill of
4.5 million cubic meters of rock-fill materials obtained from the excavation areas.
In consideration of those features descried above,
the following construction system supported by information technology (IT) were
developed and introduced. At the stage of design, construction, maintenance,
this system is linked to Computer-Aided Design (CAD) data, and enabled the
owner to manage earthwork effectively.
Introducing these multiple systems supported by IT, the construction work
control and the progress control have proceeded successfully and efficiently
in terms of manpower and time saving. This paper
outlines these IT construction systems applied in the large-scale earthworks, and
their functionalities, performance and perceived benefits.
The following seven systems are utilized and the outline is shown below. |
Outline of the IT Construction Systems |
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Image of the IT Construction Systems |
| １．Dump Truck Navigation System |
This system enables real-time earth volume control at every excavation/fill
area, at every dump track according to the material classification. S-GPS
(Stand-alone Global Positioning System) was mounted on dump trucks, and
the material data input by
operators was transmitted to the base station in project site and the data was automatically processed.This system has been in operation since November,
2001. After one year of its operation, earth volume during the period
was compared to that obtained bysurveying. As a result, the difference
was within 3%. Besides, there was no trouble regarding operation
of the system during the period.Therefore, it was determined that the progress
control was supported by this system, and the interval of the progress
measurement executed by the owner every month was elongated to three months.
The merits of introducing this system were as follows:
(1) Real-time earth volume control was enabled.
(2) Automatic earth volume control at every dumptruck contributed
to manpower saving by eliminating integration of peration records from each operator.(Manpower saving;
0.5 person/day)
(3) Manpower saving on progress measurement was enabled. (50 person/year) |
| ２．Three Dimensional Machine Control System (3D-MC System) |
In this system, 3D positioning of a dozer
is tracked supported by RTK-GPS (Real
Time Kinematics Global Positioning System) or robotesque total station, and planned
3D positioning data stored
in a PC is transmitted to the
dozer. Then, the blade of the dozer is automatically controlled by control unit, and enables spreading
surface within centimeters of
accuracy.
This system is classified into two types according to each step of transition
layer: lower layer, upper layer.One is RTK-GPS
for lower layer and another is robotesque total
station for upper
layer.RTK-GPS is used for dozers of 38-ton class, and controls the spreading work of rock materials and transition materials of lower layer.The upper layer has more accuracy compared to the lower layer and robotesque total station is used for dozers of 15-ton class, and controls the spreading work of transition materials of upper layers underlie asphalt facing.
The merits of introducing this system are as follows:
(1) This system enabled “stringless construction” and manpower saving.(As
for spreading of transition; manpower savingis approximately 5 person/2,500
square meters)
(2) This
system enabled elevation control of the finished surface of the transition
layer including curved surfaces of slope areas with satisfactory accuracy.
(3) A decrease in dozer passes leads to an increase of efficiency and a decrease in excess material crushing of the surface. |
Outline of the 3D-MC System(TS) |
Spreading Work of the transition layer |
| ３．Compaction Work Management System |
In this system, RTK-GPS receiver is mounted on each vibratory compactor
in order to trace the compaction work.The amount of compaction conducted
to the objective area is displayed on the monitor in front of the cabin
of the roller. The objective area of compaction is divided into multiple
blocks on the monitor, the each block stands for 2m x 2m of actual area
of object, and the operator would know the places which need to be more
compacted by looking because the color of blocks are different depending
on the amount of compaction executed to each part.
The operation of this system began in November, 2001.After one year of
its operation, it was found that data reception became impossible in certain
areas depending on the topographical condition of the area or number of
satellites available to receive data.It was determined that if more than 90% of blocks among the objective
area satisfied the standard number of
compaction established in the
compaction work standard, the compaction
work of the area was regarded as completed.Checking on the control chart of compaction work obtained through
this system, the interval of in-situ
measurement of density by Radio Isotope (RI) was changed from
every one layer of spreading and compaction to once a day at
each fill area from March, 2003.
The merits of introducing this system are as follows:
(1) Real
time confirmation of the amount of compaction and compacted blocks is enabled,
so that helps to reduce the burden of the operator to count the number of
compaction, and that eliminates partially compacted areas.
(2)
Obtained data is integrated and 2D or 3D
management of compaction data is enabled, and integrated data is utilized in
other systems as progress measurement data.
(3) Less
approximately 20% of RI measurement was achieved by adoption of this system.
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Monitor equipped on the roller |
Compaction work of the transition layer
by self climbing roller on the slope |
| ４．Three Dimensional
Positioning Navigation
System (3D-Navi) |
In this system, one-man survey is enabled supported by RTK-GPS. Thus,
manpower saving and improvement of efficiency of surveying is achieved.
One-man survey system guided by RTK-GPS was developed for the constructor
from January, 2002.Because the accuracy of the survey measurements is within
centimeters, this system is used for progress measurement of the earthworks.
The
merits of introduction of this system are as follows:
(1) Only one person is required for surveying so that manpower is saved
approximately 50%
(2) Working hours are considerably saved. |
One-man survey supported by 3D-Navi System |
| ５．Three Dimensional
Scanning System (3D-Scan) |
In
this system, a 3D scanning camera supported to scan topographic information of
the finished surface, and the obtained data was combined with the CAD data.
Thus, topographic maps and bird’s eye view of the project were produced, and calculation of earth volume was executed.This system
was introduced as the progress control of working form for the owner from
May, 2001. And progress measurement supported by this system has
been conducted every month. Right figure shows the progress of earthworks
produced by this system.
The merits of introducing this system were as follows:
(1) Working hours
were considerably decreased compared to the conventional surveying method. (2
days for 0.5 million square meters)
(2) No need to stand with prism for surveying on slopes and safety measurement were enabled. |
| Changes of the surface of the reservoir as the progress of earthworks |
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| ６．３D-Dam Design Construction Supprt System |
This system is a system by which KAJIMA CORPORATION developed AutoCAD as
a base previously. It is in the design construction support system which
realized laborsaving and quality improvement of large work by huge 3-dimensional
figure processing of data accompanying a design and construction of a dam
while corresponding to change and an addition of a plan promptly.In the
system, it creates, implementation of creation of a 3-dimensional plan,
automatic drawing of the topographical map from a 3-dimensional survey
result, and a construction simulation, automatic drawing of Scene CG, and
3-dimensional construction system construction data are made, and automatic
drawing of a form drawing, quantity calculation, a list output, etc. are
carried out.
The earthwork plan figure and Scene CG (image view) by the construction
simulation created by this system are shown in the right figure. |
| Scene CG by the construction simulation |
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| ７．Construction Work Data Management System Based On GIS |
| This system was developed by the owner to unify construction management
data and save manpower.In the introduction of the system, it was determined
to develop GIS oriented system in consideration of efficiency of data processing,
availability for extension of function, and cost for introduction and operation.
Some databases have been developed such as survey, construction, monitoring
for GIS. An example of management based on GIS is progress control due
to comparison between elevation obtained by 3D-Scan and the planned
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| Monitor of tow-dimensional distribution of elevation differences between 3D-Scan and the planned based on GIS |
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