Build a Social Infrastructure
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.
"Pass Through" Points
Tunnel 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
Four-boom drill jumbo
Medium-fluidity lining concrete based on onsite dosing superplasticizer
Remote control technologies for shotcrete spraying
Suspension shield method
Sunrise Bit method
Shield linear 3D simulation system
Store
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.
"Store" Points
We 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
Aggregate particle size determination system using stereo camera
Precast corridor
Filler detection system
Rolling machine operation management system
Automatic field permeability test system
Evaporative cooling method
Bridge
Japan consists of over 14,125※ 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.
- Survey by Geospatial Information Authority of Japan, January 2022
"Bridge" Points
The 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 bridges
Cantilever method
Seismic reinforcement for unreinforced bridge piers
SENTAN pile method
Air cooling system with water injection
Solidify
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.
"Solidify" Points
We 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
SP concrete: Super performance concrete
Acrylic polymer concrete
Super Ecomax
Ecomax Type P (premix-type cement-based plastic injection material)
AZ-Grout
Lining concrete curing method using heat and wet carriage