著者

浅岡 顕 松尾 稔

出版者

The Japanese Geotechnical Society

雑誌

土質工学会論文報告集 (ISSN:03851621)

巻号頁・発行日

vol.20, no.4, pp.53-66, 1980-12-15 (Released:2008-02-29)

参考文献数

5

被引用文献数

8 16

---

This paper intends to give theoretical bases for observational settlement prediction methods which use autoregressive equations. The master differential equation derived is demonstrated to be effective even for a multilayered soil system under gradual load application. The technique for parameter identification of higher order autoregressive equations is also provided and numerical simulations show high applicability of the proposed method.

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

野田 利弘 浅岡 顕 中野 正樹 中井 健太郎 澤田 義博 大塚 悟 小高 猛司 高稲 敏浩 山田 正太郎 白石 岳 竹内 秀克 河井 正 田代 むつみ 酒井 崇之 河村 精一 福武 毅芳 濁川 直寛 野中 俊宏

出版者

名古屋大学

雑誌

基盤研究(S)

巻号頁・発行日

2009-05-11

---

日本の重要な社会資本は,沖積平野や海上埋立人工地盤といった地震被害が懸念される軟弱地盤上に多く蓄積されている.本研究では,特に沿岸域に立地する社会基盤施設を対象に,長周期成分を含み継続時間が数分にも及ぶ海溝型巨大地震が発生した際の耐震性再評価と耐震強化技術の再検討を実施した.既往の被害予測手法は地震時安定性評価に主眼が置かれ,地震後の長期継続する地盤変状を予測することはできない.「地盤に何が起こるかを教えてくれる」本解析技術による評価を既往手法と並行して実施することで,予測精度の向上とともに,被害の見落としを防ぐ役割を果たすことを示した.