کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6426727 | 1634444 | 2015 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Using 2Â m Extended Column Tests to assess slope stability
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم زمین و سیاره ای (عمومی)
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چکیده انگلیسی
Extended Column Tests (ECTs) are used to assess crack initiation and propagation. Previous research shows that tests 90Â cm in length may propagate, suggesting instability, while tests 2Â m in length may not propagate, suggesting stability, for identical snowpacks. A practical question is: are 90Â cm ECTs optimal for assessing stability? To test the added value of 2Â m ECTs for stability evaluation, we collected data on 220 ECTs, with 136 side-by-side standard length ECTPs (full propagation indicating instability) followed by 2Â m ECTs. We only performed 2Â m ECTs after a standard ECT propagated because we assumed 2Â m ECTs would not propagate if standard length tests did not. These tests were preceded by an a priori stability assessment. Our results show imbalances for both tests. The ECT had a similar probability of detection (0.88-0.92, POD), i.e. the ability to detect unstable conditions, as in previous studies, but a much lower probability of null events (0.54-0.75, PON), i.e. the ability to detect stable conditions, with variation due to the binary classification of “Fair” stability as stable or unstable. Adding a 2Â m test after an ECTP result lowered the POD (0.49-0.58), but substantially raised the PON (0.88-0.98) of the combined tests. The proportion of tests in agreement, i.e. ECTP and 2Â m ECTP, increases with decreasing stability. We conclude that an ECTP followed by a 2Â m ECTP is a clear red flag, indicating instability. The interpretation of an ECTP followed by a 2Â m ECTN/X (no propagation) is not clear. Though this result suggests stability, a high potential for a false stable result means we cannot recommend the 2Â m ECT for binary stability assessments.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cold Regions Science and Technology - Volume 120, December 2015, Pages 191-196
Journal: Cold Regions Science and Technology - Volume 120, December 2015, Pages 191-196
نویسندگان
Edward H. Bair, Ron Simenhois, Alec van Herwijnen, Karl W. Birkeland,