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Note: During the different steps of the FORM analysis, the values of the four probabilistic parameters (D/H, c, cotan γ and cotan β) can lead to a damage profile outside the geometry limits. That's why the program extrapolate extrapolates the geometry at the both left and right sides by adding extending the surface line with an horizontal line (length is 1000 m) starting at the point situated at geometry limit as illustrated in figure below.
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