Mechanics and Stability of the Lookout Creek Earth Flow
Mechanics and Stability of the Lookout Creek Earth Flow
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Lookout Creek 土流的力学和稳定性
DOI：
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
G. Saunders
中科院分区：
文献类型：
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作者：
M. Pyles;K. Mills;G. Saunders
位于俄勒冈州西部喀斯喀特山脉的了望溪土流平均移动了约3.5英寸。(8.9 cm），在过去十年中。目前活跃的滑坡体至少在过去80年里一直在移动，覆盖在一个有40，000年历史的碎片存款上。自1975年以来，可测量的土流运动只发生在雨季;位于或靠近地面的测压水位在雨季和旱季之间仅变化约3英尺（0.9米）。地球流动的基础似乎是一个大约10英寸的剪切带。(25厘米）厚，位于21.5英尺（6.5米）的深度。虽然土流运动不直接相关的测压管水平，它与剪切带孔隙水压力计算的有限差分近似太沙基理论的一维固结;有限差分模型使用测压管压力测量的土流作为边界条件。剪切带中孔隙水压力上升约85 psf（4.1 kPa），或1.4 ft（0.4 m）的水，是计算的土流开始移动的阈值。然而，由于土流具有很强的排水能力，影响地下水状况的木材采伐不太可能引起大量的流动。
The Lookout Creek earth flow in the western Cascade Mountains of Oregon has moved an average of about 3.5 in. (8.9 cm) annually over the past decade. The currently active slide mass which has been moving for at least the past 80 years, overlies a 40,000-yr-old debris deposit. Monitored since 1975, measurable earth flow movement occurs only during the wet season; piezometric level, which is at or near the ground surface, varies only about 3 ft (0.9 m) between the wet and dry seasons. The base of the earth flow appears to be a shear zone about 10 in. (25 cm) thick located at a depth of 21.5 ft (6.5 m). Although earth flow movement does not correlate directly with piezometric levels, it does correlate with shear-zone pore-water pressures computed with a finite-difference approximation to the Terzaghi theory of one-dimensional consolidation; the finite-difference model uses piezometric pressure measured in the earth flow as a boundary condition. A rise in pore-water pressure in the shear zone of about 85 psf (4.1 kPa), or 1.4 ft (0.4 m) of water, is the calculated threshold value at which the earth flow begins to move. However, because the earth flow has a high drainage capacity, timber harvesting, which affects the ground-water regime, is unlikely to induce a large increase in movement.