Introduction to our construction technologies
CSG (Cemented Sand and Gravel) refers to the mixture of locally sourced construction materials (Sand and Gravel), with Cement and water. A trapezoidal CSG dam uses these CSG materials to create a trapezoidal shape that allows for an identical slope incline on both the upstream and downstream surfaces. It is a new dam model that fully meets the strict quality standards required to be qualified as a permanent structure while also being made up of low-cost materials that have a reduced environmental impact. Kajima previously used this construction method to build the world’s first trapezoidal CSG Dam, Tobetsu Dam, in Hokkaido.
Characteristic 1Reduced Environmental Impact
Effective Use of Local Materials (stones and gravel)
CSG is a material that uses stones, sand, and gravel which can be extracted from near the construction site, that is then mixed with cement and water. Since this method effectively uses materials generated during the foundation construction work, large-scale topographical changes near the site are minimized.
Characteristic 2Quality Guarantee
Assurance of permanent structure-certified quality through its trapezoidal shape, strength testing, and quality control
Thanks to its trapezoidal shape, the impact from stress when a large-scale earthquake occurs can be suppressed, and in comparison with conventional right-angle shaped dams, the structure requires less strength to stand and to withstand such stress factors. In addition, the trapezoidal CSG dam model has developed and established its own strength definition, strength testing method, and quality control method to ensure sufficient quality as a permanent structure. It is a highly reliable structure that has been proven to be as safe as other existing conventional dams.
Characteristic 3Short Construction Period and Low Cost
Significant reduction in construction period and cost due to rationalization of materials
This method effectively utilizes local materials and basically eliminates the need for certain labor tasks such as classification and adjustment of aggregate material particle size and cleaning. In addition, there is no need for a large-scale aggregate material plant, so construction equipment can be simplified. Also, mechanized and rapid construction with general-purpose machines is made possible. By improving the efficiency of such materials and construction methods, construction can be carried out at a low cost and in a short period of time.
The dam body of Naruse Dam is being constructed using the CSG method.
This method is also being implemented in buidling surrounding structures such as temporary cofferdams, ancillary structures, and landslide prevention structures.