Availability of the ground improvement work with Deep Mixing method by the dedicated machine in Indonesia

Infrastructure development like the Trans-Sumatra Toll Road, Jakarta-Bandung high-speed railway, Patimban Port, and Capital relocation are proceeding at a rapid pace. In large-scale infrastructures development and the need to complete the construction, it is necessary to overcome the soft ground and Ground Improvement work must be needed. Indonesia is a volcanic country, and unlike the deltaic land widespread in Southeast Asia, it has a wide variety of geology, including alluvial soil distributed in river deltas, soft soil deposited in valley bottoms formed by mountain building and erosion, and organic soil resulting from the jungle, all of which are layered in complex formations. In Indonesia, many of the soil improvement works for such complex ground use the Prefabricated Vertical Drains (PVD) method and Pile Slab method due to economic and technical matters. However, in the case of multi-layered ground, a construction method that can handle various geology is required, and a construction method specialized for the geology such as PVD construction is not suitable, and there are many cases where the results are different from what was expected. In addition, structural measures such as pile slab construction require a huge amount of maintenance in the future. Therefore, we planned the technology transfer of the Deep Mixing method, which has been widely used in Japan, a volcanic country where has many predominance of interlayered grounds. In specific, we attempted transfer the technology of Deep Mixing method as below: 1) To make it easier to introduce Deep Mixing construction method, cement produced locally will be used. 2) Introducing Deep Mixing dedicated machine to be able to start the work instantly, instead of the general-purpose construction machine which needs the attachment attached to do the work. 3) Introduce a construction system used in Japan (i.e. methods for determining the amount of cement to be mixed in/construction management methods/improved quality control methods, etc.). 4) Conducting demonstration construction and site tour at the local site. 5) For the demonstration construction, our team will prepare in accordance with the construction system together with local engineers to get them learn with practical training. We will focus on the results of demonstration construction (test construction) proceeded in Pekanbaru-Dumai section of the Trans Sumatera Toll Road Project in Indonesia.1)