Our daily life and economic activities are built on various social infrastructure. This infrastructure includes roads, railways, aircraft and watercraft, electricity, gas, waterworks, telecommunications, and the Internet. We take these social infrastructures for granted as we enjoy the convenient and comfortable lives they provide for us. Social infrastructure consists of public works and structures like tunnels, dams, and highways. We at Kumagai Gumi have been involved in creating numerous social infrastructure creation projects. Once completed people might take this work for granted, but we are strongly aware public nature and heavy responsibility of these projects and so we give our all to successfully completing them. Kumagai Gumi has technical ability that has been polished for over a century.

Pass Through
"Tunnel construction technology that 'passes through the earth.'" We strive for harmony with the natural environment while making life more convenient for people. Tunnel construction is one of our fortes to the extent that Kumagai Gumi has become the word for it.
  • Technological Points
    • "Pass Through" PointsTunnel construction technology consists mainly of mountain tunnel construction methods where relatively hard ground is tunneled through using blasting and excavation equipment and shielded tunnel construction methods where relatively soft ground is tunneled through using specialized equipment.

      Representative Technologies:4 Boom Drill Jumbo
  • Representative Technologies
    • 4 Boom Drill Jumbo
    • Middle-flow lamination concrete using on-site addition type fluidizing agent
    • Remote control technology for spray concrete
    • Suspension shield method
    • Sunrise bit method
    • Shield linear 3D simulation system
The history of human development is also the history of flood control and water utilization. Water cannot be used as a resource until it can be stored. Dam construction technology to dam water flows and store water.
  • Technological Points
    • "Store" PointsWe have experience building over 160 dams both in Japan and abroad to meet a variety of social requirements including flood control dams, irrigation dams, hydroelectric dams, multipurpose dams, and pumped-storage power generation dams.

      Representative Technologies:Particle size decision systems
  • Representative Technologies
    • Particle size decision systems
    • Precast gallery
    • Filler detection system
    • Rolling machine operation and management system
    • Automatic field permeability test system
    • Evaporative cooling method
Japan consists of over 6,853 large and small islands where two-thirds of the land area is mountainous. The islands are separated by the sea and people's travel is hampered by rivers and valleys. "Bridge technology" that links people's thoughts to the other side is also one of the technologies at which Kumagai Gumi excels.
  • Technological Points
    • "Bridge" PointsThe substructure for building the bridge's base consists of the foundation and bridge pier that support the bridge, and the superstructure consists of the work that places the bridge girders on the bridge pier.

      Representative Technologies:Cotter floor slab method for bridge
  • Representative Technologies
    • Cotter floor slab method for bridge
    • Cantilever method
    • Aseismic reinforcing method for plain concrete bridge pier
    • SENTAN pile method
    • Air cooling method combined water illing
Concrete is one of the main materials used to build buildings. At a glance concrete all looks the same, but concrete is a subtle thing that requires careful formula adjustment and pouring that differ depending on the construction environment, application, and purpose.
  • Technological Points
    • "Solidify" PointsWe are engaged in technological development that has accumulated a great deal of experience and knowledge not just for concrete technology including ultrahigh-strength concrete for super high-rise buildings, high-flow concrete to make construction easier, and concrete that can be poured underwater, but also for such things as drying shrinkage control technology and the development of restorative materials for repair work.

      Representative Technologies:Super performance concrete ~SP concrete~
  • Representative Technologies
    • Super performance concrete ~SP concrete~
    • Acrylic polymer concrete
    • Super Ecomax
    • Ecomax TypeP
    • AZ-Grout
    • Lining concrete curing method by thermal and wet protection carriage