Abstract: A system for preventing seismic liquefaction of the ground in an urban area built on reclaimed land consisting of a loose fine grained layer vulnerable to liquefaction underlain with a soft cohesive layer liable to uneven settlement. The system includes a plurality of vertically-extending wells with submerged pumps which pump pore water out of the loose layer, creating pore voids therein. An air-tight tank pressurizes the pumped pore water and, using an air compressor, pushes the water into a deep layer below the cohesive layer. A regulating receptacle injects a tap water mixture to fill the pore voids in the loose layer, with the mixture reducing the degree of pore water saturation therein, preventing seismic liquefaction due to earthquake.

Abstract: A system for preventing seismic liquefaction of the ground in an urban area built on reclaimed land consisting of a loose fine grained layer vulnerable to liquefaction underlain with a soft cohesive layer liable to uneven settlement. The system includes a plurality of vertically-extending wells with submerged pumps which pump pore water out of the loose layer, creating pore voids therein. An air-tight tank pressurizes the pumped pore water and, using an air compressor, pushes the water into a deep layer below the cohesive layer. A regulating receptacle injects a tap water mixture to fill the pore voids in the loose layer, with the mixture reducing the degree of pore water saturation therein, preventing seismic liquefaction due to earthquake.

Abstract: A method of preventing seismic liquefaction of the ground in an urban area built on reclaimed land consisting of a loose fine grained layer vulnerable to liquefaction underlain with a soft cohesive layer liable to uneven settlement comprising pumping out pore water from the loose fine grained layer to lower the groundwater table to the bottom level of that layer, then injecting into the loose fine grained layer tap water saturated with air and containing micro particles of fly ash or another mineral serving as vehicles of the air into the loose fine grained layer so as to form countless tiny air bubbles and thereby reduce the degree of saturation of that layer to a level preventing seismic liquefaction.

Abstract: A method of preventing seismic liquefaction of the ground in an urban area built on reclaimed land consisting of a loose fine grained layer vulnerable to liquefaction underlain with a soft cohesive layer liable to uneven settlement comprising pumping out pore water from the loose fine grained layer to lower the groundwater table to the bottom level of that layer, then injecting into the loose fine grained layer tap water saturated with air and containing micro particles of fly ash or another mineral serving as vehicles of the air into the loose fine grained layer so as to form countless tiny air bubbles and thereby reduce the degree of saturation of that layer to a level preventing seismic liquefaction.

Abstract: In order to form an air-mixed zone containing tiny air bubbles in the ground with feeble cohesion or the cohesionless ground, an air-tight cover 1 covering the air-mixed zone is placed on the ground surface, along the outside periphery of the cover 1 an air-tight cut-off wall 2 extending down to the depth of ground water table is installed, the pipes 4 for blowing air are pushed from the ground surface penetrating through the air-tight cover 1 down into the ground, by blowing compressed air from the tip portion of the pipes 4 and collect the blown air through the pipes 5 for collecting air which are spaced at suitable distance from the pipes for blowing air and pushed into the ground in a simultaneous cycle of work with the pipes 4 for blowing air in repeated cycles so that the blown in air circulates and spreads uniformly in the air-mixed zone and splits into tiny air bubbles.