@article{oai:nagoya.repo.nii.ac.jp:00006963, author = {金田, 一広 and KANEDA, Kazuhiro and 山田, 正太郎 and YAMADA, Shotaro and 浅岡, 顕 and ASAOKA, Akira}, issue = {III-64}, journal = {土木学会論文集}, month = {Sep}, note = {地下水揚水に起因する自然体積粘土地盤の圧密沈下の諸特徴を調べた。自然堆積の粘土地盤は、つねに若干過圧密で、しかもたいていは「構造」が発達している。弾塑性構成式には、カムクレイモデルに下負荷面・上負荷面を導入したものを用い、塑性変形の進展に伴う過圧密の喪失と構造の劣化を表現できるようにした。一連の圧密計算によれば、地下水位低下がある閾値を越えて長く持続するときは、粘土の骨格構造の劣化によって塑性圧縮にもかかわらず軟化が起こり、これが原因となって時間遅れで大沈下が現れることが分かった。また多層系地盤のときは、地下水位低下の影響が下層の粘土に及ぶのに時間がかかり、このため現在かりに地盤低下が沈静化していても、将来遅れて大沈下の可能性があることも示した。, One-dimensional numerical simulations of land subsidence due to dewatering were preformed based on the soil-water coupled finite deformation analysis. Naturally deposited soils are usually at overconsolidated state and those soils are mostly at structured state. In order to express loss of overconsolidation and decay of soil structure with loading, the super-subloading surfaces were introduced to the Cam-clay model. The following findings were obtained : (1) when dewatering exceeds a certain level, delayed consolidation with huge settlement is observed, which is concluded as the results of plastic softening of soils with plastic volume compression. (2) When multi-layered system is the case, delayed compression/consolidation of lower layers may occur even after the finish of the settlement of upper layers. This is due to the delay of propagation of the increase of effective stress that occurs due to dewatering.}, pages = {89--103}, title = {地下水位低下に起因する地盤の遅れ圧密沈下のメカニズム}, volume = {743}, year = {2003} }