| 講演要旨(和文) | | 薬液注入による地盤改良において，薬液の注入範囲を把握することは重要である。筆者らは弾性波の振幅減衰を用いた薬液注入範囲の把握方法を高度化するために，円筒形の小型供試体試験と模型土槽試験を行った。小型供試体試験の結果から，薬液の注入後約300分で振幅は減衰し始め，また減衰量は薬液濃度に比例することを確認した。一方，速度はわずかに減少した。模型土槽実験の結果から，薬液を注入した範囲で振幅が減衰すること，また，部分的に飽和度が低下していた場所では振幅が増加することを確認した。 |
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| | 講演要旨(英文) | | It is desirable to verify a chemical grout injection area for earthquake liquefaction countermeasure by chemical grout injection method. We have carried out two tests, a cylindrical specimen test and a laboratory soil model test, for the purpose of improving a verification method for chemical grout injection area by P-wave attenuation tomography. The cylindrical specimen test results showed that P-wave attenuation started increasing about 300 minutes after chemical grout was injected into the specimen and increased in proportion to silica concentration. On the other hand, P-wave velocity did not change clearly. The laboratory soil model test results showed that P-wave attenuation increased at the injection area but decreases in partially unsaturated area. In conclusion, it is believed that P-wave attenuation tomography can be useful to verify a chemical grout injection area in saturated ground. |
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