- 著者
- 嘉門 雅史 張 虎元 勝見 武 澤 直樹
- 出版者
- The Japanese Geotechnical Society
- 雑誌
- 地盤工学会論文報告集 (ISSN:13417452)
- 巻号頁・発行日
- vol.42, no.6, pp.79-91, 2002-12-15 (Released:2008-02-29)
- 参考文献数
- 37
- 被引用文献数
- 1 12
Microbial activities can be enhanced by organic rich leachate occurring in solid waste landfills, which possesses the potential to alter the barrier capacity of clay liners. Flexible-wall hydraulic conductivity tests are conducted to investigate the effect of the microbial activities on the hydraulic conductivity of Osaka marine clay used for clay liners of offshore solid waste landfill sites in Japan. Permeants with different redox potentials are employed to investigate the redox effect; and, permeants with high nutrients are used to check the effect of the microbial production in soil specimens. Test results indicate that there are no obvious changes in the free swell index, the liquid limit, or the hydraulic conductivity of the marine clay when a strong reducing agent is used. When nutrients are applied for the growth of microorganisms, however, a decrease in hydraulic conductivity, ranging from greater than two orders of magnitude to less than one order of magnitude, is observed. The formation of biofilm and anaerobic inorganic precipitation on the surface of the soil particles is considered to be responsible for this reduction in hydraulic conductivity. Test results reveal that microbial activities, enhanced by landfill leachate, may not cause an increase in the hydraulic conductivity of natural clay liners of offshore landfill sites.
- 著者
- 野田 利弘 中野 正樹 水野 和憲 竹内 秀克
- 出版者
- 公益社団法人地盤工学会
- 雑誌
- 地盤工学会論文報告集 (ISSN:13417452)
- 巻号頁・発行日
- vol.41, no.4, pp.113-123, 2001-08-15
- 被引用文献数
- 1 1
- 著者
- 浅岡 顕 野田 利弘 山田 英司 金田 一広 中野 正樹
- 出版者
- 公益社団法人地盤工学会
- 雑誌
- 地盤工学会論文報告集 (ISSN:13417452)
- 巻号頁・発行日
- vol.42, no.5, pp.47-57, 2002-10-15
- 参考文献数
- 16
- 被引用文献数
- 16
In critical state soil mechanics, the volume change behavior of soils has typically been analyzed based upon conventional "e-logp' relationships". However, compaction/densification of loose sand, for example, can sometimes occur even without any significant increase of mean effective stresses. This study presents a model which considers the fact that volume change can occur due to decay/collapse of the structure of soils. Taking into consideration the differences between clay and sand, this study models super-subloading surfaces together with rotational hardening using the modified Cam-clay model. The effects of decay of the soil structure, loss of overconsolidation and evolution of anisotropy are mutually discussed concerning their relationship with ongoing plastic deformation. Fundamental constitutive model responses are illustrated in the present study particularly for "compaction" of sand. Repeated application of low-level shear stress upon loose sand yields a huge amount of volume compression, which is due to the rapid collapse of the initial soil structure. Repetition of the loading also results in a rapid increase of the overconsolidation ratio. Drained and undrained shear behavior of the sand naturally changes remarkably along this densification/compaction procedure, which is also consistently predicted using a single set of soil parameters. Elasto-plastic behavior of the same sand at various densities is thus totally described in the present study in a single the-oretical framework based on soil parameters independent of density.
- 著者
- 土田 孝
- 出版者
- 公益社団法人地盤工学会
- 雑誌
- 地盤工学会論文報告集 (ISSN:13417452)
- 巻号頁・発行日
- vol.41, no.1, pp.127-143, 2001-02-15
- 被引用文献数
- 6 10