The shortage of construction workers is one of the biggest issues in construction industry. Therefore, MLIT¹⁾ is promoting “i-Construction” for productivity improvement of construction site. As examples of “i-Construction” of CRDB²⁾, we introduce full scale use of ICT and promotion of using three-dimensional data.

1) Ministry of Land, Infrastructure and Transport

2) Chugoku Regional Development Bureau

Prestressed ground anchors are broadly used for stabilizing slopes around reservoir. Appropriate inspection and timely maintenance of them is required against deterioration due to aging and severe field condition such as fluctuating reservoir and ground water level. In general, numerous anchors are placed in a slope which is very steep and large area. This field condition made the inspection work difficult and requiring great effort. In order to reduce this effort, primary screening to extract certain anchors which need further diagnosis was tried using a popular-price multicopter. Through this study, the optimal way of observation was identified such as a newly developed form for recording an inspection result and appropriate distance for shooting pictures of a target structure. Roughly, 70% of work load could be reduced by this method.

Terrestrial laser scanners are used by surveying companies as devices that perform three-dimensional measurement. UAV mounted laser scanner is the latest measurement instrument realized by UAV ability innovation and laser miniaturization, and it is expected to expand in the future.

By using two types of instruments in combination, we can verified the method for improving efficiency of measurement work.

“i-Construction” means the effort toward productivity improvement on construction work sites by full utilization of information and communication technology (ICT), with a view to optimize the whole construction production processes. And The Ministry of Land, Infrastructure, Transport and Tourism aims for including improvement of the business environment and working conditions, and the realization of a safe construction site in the construction industry. Kanatsu Engineering Construction Co., Ltd. thinks that it is indispensable for a local construction company to works energetically for promoting “i-Construction”, and the company attempt strenuously on it.

At actual construction sites, the company is mainly focused on ICT earthworks, and take a process of trial and error of introduction and utilization of ICT equipment, creation and utilization of 3-dimensional data, etc. in various situations from construction preparation to completion, with repeated trial and error, and works not only acquisition of know-how but also verification of effectiveness and added value.

A crop classification method using satellite data is proposed as an alternative to the existing ground survey. In this study, crop types were classified using two kinds of SAR data (i.e., TerraSAR-X X-band dual-polarization data and Radarsat-2 C-band fully-polarization data) and Random Forests. Sigma naught polarimetric parameters were calculated from SAR data and classifications were conducted using the following four different datasets ; Case 1 : all parameters calculated from Radarsat-2, Case 2 : all parameters calculated from Radarsat-2 and sigma naught calculated from TerraSAR-X data, Case 3 : all parameters calculated from Radarsat-2 and polarimetric parameters calculated from TerraSAR-X data, and Case 4 : all parameters calculated from Radarsat-2 and both sigma naught and polarimetric parameters calculated from TerraSAR-X. The highest overall accuracy of 0.934 was achieved by Case 4, and there were significant differences with the other classification results (p>0.05, based on Z-test). These results reveal that combining two kinds of SAR data can be improved classification accuracy.