A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
LIQUEFACTION COUNTERMEASURE METHOD
To improve a ground in a forced manner while reducing the cost regardless of site conditions.SOLUTION: A liquefaction countermeasure method according to the present invention comprises: inserting a rod 24' that is provided with an injection outlet 26 on the periphery near the tip from a ground surface ES into a sand ground SG for which liquefaction countermeasures were determined to be required; and, while injecting an injected material with high pressure, lifting the rod 24' while pivoting the rod 24' on its center axis as the rotation axis. This makes it possible to agitate the sand ground SG for which liquefaction countermeasures were determined to be required and the injected material in a forced manner. Furthermore, fine particle slurry that is made of fine particles of 75 μm or less in diameter and water is used as the injected material in order to add fine particles into the sand ground SG for which liquefaction countermeasures were determined to be required, in a forced manner. Because of this, it is possible to improve a ground to one that is unlikely to liquefy in a forced manner and effectively prevent the sand ground SG from liquefying by adjusting the concentration, particle size distribution, and injection amount for the injected fine particle slurry, and the rotation speed and lifting speed of the rod 24' so that the fine particle content of the sand ground SG is 35% or more in light of particle size distribution.SELECTED DRAWING: Figure 3
【課題】現場条件の如何に関わらず、コストを抑制しながら強制的に地盤を改質する。【解決手段】本液状化対策工法は、先端近傍の外周に噴射口２６が設けられたロッド２４´を、地表ＥＳから液状化対策が必要と判断された砂地盤ＳＧまで挿入し、噴射材を高圧で噴射しつつ、ロッド２４´をロッド２４´の中心軸を回転軸として回転させながら引き上げることで、液状化対策が必要と判断された砂地盤ＳＧと噴射材とを強制的に混合撹拌することができる。更に、噴射材として粒径が７５μｍ以下の細粒分に水を加えた細粒分スラリーを用い、液状化対策が必要と判断された砂地盤ＳＧ内に細粒分を強制的に添加するため、砂地盤ＳＧの粒度分布構成の細粒分含有率が３５％以上になるように、噴射する細粒分スラリーの濃度や粒度分布、噴射量、ロッド２４´の回転数や引き上げ速度等を調整することで、液状化しない地盤へと強制的に改質することができ、砂地盤ＳＧの液状化を効果的に抑制することができる。【選択図】図３
LIQUEFACTION COUNTERMEASURE METHOD
To improve a ground in a forced manner while reducing the cost regardless of site conditions.SOLUTION: A liquefaction countermeasure method according to the present invention comprises: inserting a rod 24' that is provided with an injection outlet 26 on the periphery near the tip from a ground surface ES into a sand ground SG for which liquefaction countermeasures were determined to be required; and, while injecting an injected material with high pressure, lifting the rod 24' while pivoting the rod 24' on its center axis as the rotation axis. This makes it possible to agitate the sand ground SG for which liquefaction countermeasures were determined to be required and the injected material in a forced manner. Furthermore, fine particle slurry that is made of fine particles of 75 μm or less in diameter and water is used as the injected material in order to add fine particles into the sand ground SG for which liquefaction countermeasures were determined to be required, in a forced manner. Because of this, it is possible to improve a ground to one that is unlikely to liquefy in a forced manner and effectively prevent the sand ground SG from liquefying by adjusting the concentration, particle size distribution, and injection amount for the injected fine particle slurry, and the rotation speed and lifting speed of the rod 24' so that the fine particle content of the sand ground SG is 35% or more in light of particle size distribution.SELECTED DRAWING: Figure 3
【課題】現場条件の如何に関わらず、コストを抑制しながら強制的に地盤を改質する。【解決手段】本液状化対策工法は、先端近傍の外周に噴射口２６が設けられたロッド２４´を、地表ＥＳから液状化対策が必要と判断された砂地盤ＳＧまで挿入し、噴射材を高圧で噴射しつつ、ロッド２４´をロッド２４´の中心軸を回転軸として回転させながら引き上げることで、液状化対策が必要と判断された砂地盤ＳＧと噴射材とを強制的に混合撹拌することができる。更に、噴射材として粒径が７５μｍ以下の細粒分に水を加えた細粒分スラリーを用い、液状化対策が必要と判断された砂地盤ＳＧ内に細粒分を強制的に添加するため、砂地盤ＳＧの粒度分布構成の細粒分含有率が３５％以上になるように、噴射する細粒分スラリーの濃度や粒度分布、噴射量、ロッド２４´の回転数や引き上げ速度等を調整することで、液状化しない地盤へと強制的に改質することができ、砂地盤ＳＧの液状化を効果的に抑制することができる。【選択図】図３
LIQUEFACTION COUNTERMEASURE METHOD
液状化対策工法
KANEKO HIROAKI (author) / AKAGAWA SUNAO (author)
2020-04-09
Patent
Electronic Resource
Japanese
IPC:
E02D
FOUNDATIONS
,
Gründungen
LIQUEFACTION COUNTERMEASURE STRUCTURE AND LIQUEFACTION COUNTERMEASURE METHOD
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