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For case G, the same input as benchmark 1-1 (see group 1) is used except for the state parameter which is equal to -0.06 instead of -0.03 and except for the diameters D50 and D15 which are equal to 250 μm and 150 μm resp. for sand layers.For the Detailed check, the required probability of failure is 1 per 40000 years instead of 1 per 4000 years and the migration velocity is 0.5m/year instead of 10 mm /year.
Benchmarks results
For each cases, the Global and Detailed checks are worked out in an Excel spreadsheet.
Hereafter, the main results are given per case,
NOTE: For the Detailed check, the reliability index (β) can't be easily calculated by an analytical solution, as the four stochastics (cotan(β), cotan(γ), D/H and c) have a LogNormal distribution. Therefore, the value of the reliability index (β) calculated by D-Flow Slide (using a FORM analysis, invoked from a probabilistic library largely tested) is used in the spreadsheetHereafter are given the analytical results per case.
Case A:
Global check - Step 1:
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XSsign > XSzv => Flow slide would not lead to damage on levee => Global check passes.
Detailed check: (see table below : for intermediary results) Probability of flood damage by liquefaction liquefaction (= 8.10 × 10-110.00) < Allowable probability of failure (2.50 × 10-6) => Detailed check passes.
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Global check - Step 3: The foreland is artificial => Global and Detailed check fail, an Advanced check is needed.
Detailed check: (see table below for intermediary results: ) Probability of flood damage by liquefaction < Allowable probability of failure => Detailed check passes.
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Global check - Step 6: The average diameters over a thickness of 5m are D50 = 180 μm and D15 = 130 μm. So layers are present with D50 < 200 μm and D15 < 100 μm => Global check fails and Detailed check needed.
Detailed check: (see table below for intermediary results: ) Probability of flood damage by liquefaction < Allowable probability of failure => Detailed check passes.
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Global check - Step 7: The slope channel is 1:2, so the slope is steeper than the critical (local) slope from the CUR table => Global check fails and Detailed check needed.
Detailed check: (see table below for intermediary results: ) Probability of flood damage by liquefaction > Allowable probability of failure => Detailed check fails.
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Global check - Step 7: The slope channel is 1:6, so the slope is softer than the critical (local) slope from the CUR table => Global check passes.
Detailed check: (see table below for intermediary results: ) Probability of flood damage by liquefaction > Allowable probability of failure => Detailed check fails.
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