00317652

open access

Version of Record

ジバン ノ シントウ ハカイ ゲンショウ ニオケル スナ リュウシ ト スイリュウ ノ リキガクテキ ソウゴ サヨウ

Interaction between Soil Particles and Flow of Water in Seepage Failure Phenomena

Japanese (日本語)

神戸大学都市安全研究センター研究報告

6

379-395

神戸大学都市安全研究センター

2002-03

2007-04-13

In seepage failure of soil in an axisymmetric condition, after the onset of deformation, sand particles in circular wall arc in the floating state in upward seepage flow. In this paper, first, theory of particles floating in upward seepage flow or theory of equilibrium of fluid resistant force and weight of soil particles is investigated, and critical velocity required to move soil particles is discussed. Second, seepage failure tests of soil were conducted in one-dimensional condition with Lake-Biwa Sand 3. Relations between each of discharge velocity at 15 degrees v15, hydraulic gradient i and void ratio e were illustrated for test results, and equations relating these values V15-i-e are discussed. It is then proved that, for an axisymmetric condition, the flow within a circular wall is in one-dimensional state. The following results were then obtained: 1. Seepage failure of soil in one dimension (1) Some relationships between grain size d and critical velocity vc required to move soil particles were investigated systematically. (2) Relations between v15-i, e-i and e－v15 were illustrated for test results. (3) It was proved that, after collapse of soil layer, an individual soil particle is in an equilibrium state between upward seepage force and downward gravity force, and a unique relationship among v15, i and e is applied. (4) The relationship between d and vc by experiments is in good accordance with the formula by Ohno et al. The Shirai's formula and Sugii's formula are also applied. 2. Seepage failure of soil in an axisymmetric condition (5) For an axisymmetric condition, the soil within the circular wall is in an equilibrium state between an upward seepage force and a downward gravity force. The state is similar to that of the one-dimensional seepage failure test soil in the case of uniform flow condition.

紀要論文