Soil recycling technology Bontelan method

A method for recycling pond bottom sediment and embankment excavation soil into high-performance ground materials.

<Overview of the Technology> The Bontelan method is a technology that repurposes bottom sediment accumulated in agricultural ponds or excavation soil from embankments, which are traditionally deemed unsuitable for use as fill, into high-performance ground materials for the renovation and reinforcement of embankments. <Purpose and Objectives of Development> Renovation of agricultural pond embankments requires high-quality soil with excellent strength and impermeability; however, it has become difficult to obtain such soil around these ponds. On the other hand, these ponds often have thick layers of bottom sediment, which contribute to a reduction in water storage capacity and deterioration of water quality, thereby hindering or degrading the functionality of the ponds. Bottom sediment typically contains a high proportion of clay and silt, and due to its generally high water content, it is not easy to dispose of. Therefore, there has been a demand for technology that actively repurposes this sediment into ground materials from environmental and economic perspectives. In response, we developed the Bontelan method by mixing fiber-based soil improvement materials called "Bonfiber" and solidifying agents into the bottom sediment of agricultural ponds, thereby adding functions such as excellent strength characteristics, high seismic resistance, and high durability. There was no earthquake damage to all embankment fill and pond embankment soil constructed using this method prior to the earthquake, and it was selected as one of six technologies recognized for their effectiveness during the Great East Japan Earthquake from a total of 165 submissions at the 2011 Construction Technology Forum.

basic information

**Features of the Bontelan Method** - Since the bottom sediment of the reservoir is used as raw material, there is no need to purchase high-quality soil or dispose of mud, which reduces environmental impact and improves cost-effectiveness. **Features of Bontelan Improved Soil** - No need to collect soil material from near the reservoir, eliminating the need to purchase high-quality clay. - Cost reduction in disposal fees by recycling mud. - Suppresses the occurrence of cracks and has high durability against repeated wetting and drying, as well as freeze-thaw cycles. - High seismic resistance, particularly effective in suppressing liquefaction. - Maintains high durability even with fluctuations in the water level of the reservoir. - Reduces deformation between existing embankments and improves adhesion. **External Evaluation** - Obtained a technical review certificate from the Advanced Construction Technology Center, No. 2203. - NETIS registration number TH-020042-V (registration period expired). - ARIC NNTD registration number 0245. - Received the "Minister of Land, Infrastructure, Transport and Tourism Award" at the 6th Industry-Academia-Government Collaboration Achievement Awards hosted by the Cabinet Office, Ministry of Internal Affairs and Communications, Ministry of Education, Culture, Sports, Science and Technology, and Ministry of Economy, Trade and Industry in 2008. - Received the "Minister of Economy, Trade and Industry Award" at the 6th Monozukuri Japan Awards hosted by the Ministry of Economy, Trade and Industry in 2015. - Selected for the "Twelve Civil Engineering Technologies" hosted by the Public Interest Incorporated Association of Civil Engineers in 2022, among others.