Figure 10.2: Isochrone example at specified time In practice, the use of Taylor series adopts the first few terms omitting the higher order derivatives and the error due to truncate the series can be reduced to minimum when β = 1/6. Seeing this condition, n and m can be then directly determined to satisfy a fixed β = 1/6 for both layer conditions. If m is an input data, then Equation 10.3 and 10.4 can be re‐ written to determine n as follows:
im = Cells(4, 2) 'no. of layer m = 10 * im h = Cells(3, 2) 'height of layer t = Cells(5, 5) 'time cv = Cells(5, 2) 'coef. of consolidation FDCCase = Cells(3, 5) 'Case of calculation 'open layered Tv = cv * t / (h / 2) ^ 2 n = 1.5 * m ^ 2 * Tv
'half closed layered Tv = cv * t / h ^ 2 n = 6 * m ^ 2 * Tv
An Introduction to Excel for Civil Engineers
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