How does Soil Swell and Shrink factor work in MiTS?
MiTS Earthwork user manual can refer here
Spreadsheet MiTS 1.11.1.1 vs MiTS 2.1.4.0 here
Grid Cluster information here
| Volume Needed Before Compact Fill:
(Before MiTS 2.0.40.0) Volume Needed Before Compacted Fill = Bank Fill * [1+ (1-Soil Shrink Factor)] (After MiTS 2.0.40.0) Volume Needed Before Compacted Fill=Bank Fill/Soil Shrink Factor |
Version used for testing; MiTS 1.11.6.1 & MiTS 2.1.32.0
Project file:
MiTS 1 here
MiTS 2 here
*using TIN as meshing method
*Grid size 25m2
*end area interval 10m
a) With Slope
| Method | MiTS 1.11.6.1 | MiTS 2.1.32.0 |
| DTM | 64 613.49 m3 | 63 298.38 m3 |
| Grid | 79 693.51 m3 | 64 151.88 m3 |
| End Area | 66 011.61 m3 | 62 104.68 m3 |
b) Without Slope
| Method | MiTS 1.11.6.1 | MiTS 2.1.32.0 |
| DTM | 75 021.05 m3 | 75 910.60 m3 |
| Grid | 79 693.51 m3 | 76 203.27 m3 |
| End Area | 76 627.53 m3 | 76 627.52 m3 |
c) With shrinkage or/and swell factor (with slope)
How to change shrink and swell factor
MiTS 1 here
MiTS 2 here
Shrink factor used = 0.9
| Method | MiTS 1.11.6.1 | MiTS 2.1.32.0 |
Volume needed before compacted fill, (a) = bank fill/soil shrink factor = 59323.65 m3 / 0.9 = 65915.17 m3 Export / import = Bank cut – (a) = (123937.14 – 65917.17) m3 = 58 021.97 m3 |
Volume needed before compacted fill, (a) = bank fill/soil shrink factor = 60824.50 m3 / 0.9 = 67582.77 m3 Export / import = Bank cut – (a) = (124122.88 – 67582.77) m3 = 56 540.10 m3 |
|
| Grid | 
Volume needed before compacted fill, (a) = bank fill/soil shrink factor = 51998.18 m3 / 0.9 = 57775.76 m3 Export / import = Bank cut – (a) = (131691.69 – 57775.76) m3 = 73 915.93 m3 |
Volume needed before compacted fill, (a) = bank fill/soil shrink factor = 61780.40 m3 / 0.9 = 68644.89 m3 Export / import = Bank cut – (a) = (125932.28 – 68644.89) m3 = 57 287.39 m3 |
| End Area | 
= 58 985.13 m3 |
Volume needed before compacted fill, (a) = bank fill/soil shrink factor = 62159.74 m3 / 0.9 = 69066.37 m3 Export / import = Bank cut – (a) = (124264.42 – 69066.37) m3 = 55 198.04 m3 |
Conclusion
- Generally , results between MiTS 1 and MiTS 2 may have little discrepancies ranging from 2% – 4%. And this is due to improvement on algorithm done in MiTS 2.
- In MiTS 1, there are some limitation when using Grid Method whereas the EW volume generated with slope or without slope will be the same.
- However, this limitation is improve in MiTS 2 Grid Method where the actual scenario will be reflected upon generating the EW volume with and without slope.