Hiroaki Tezuka

Development of Rational Soil Liquefaction Countermeasure Consisting of Lattice-Shaped Soil Improvement by Jet Grouting for Existing Housing Estates

The lattice-shaped soil improvement by means of jet grouting is one of the promising methods for soil liquefaction countermeasures. In order to develop a more effective construction method for residential houses, a series of centrifuge model tests and numerical analyses are conducted to see if there would be any more rational shapes of underground soil improvement structures to counter against soil liquefaction. It is found that the ordinary lattice walls with a surface cover would be more effective. The field verification tests are also conducted to examine if the micro machine developed in the present study can be practically used in residential areas.

Development of a New In-place Cement-Mixing Method by High-Pressure Injection

Jet grouting technology is examined and developed as one of soil liquefaction countermeasure methods. The examination of the mechanism of jetting is performed to increase the diameter of stabilized soil columns and also to produce arbitrary shapes of improved soil structures. The in situ performance verification are also performed to verify arbitrary shapes and large diameters of stabilized soil columns, mechanical properties of stabilized soil columns, and real-time construction management.