Introduction
Deltares Systems commitment to quality control and quality assurance has leaded them to develop a formal and extensive procedure to verify the correct working of all of their geotechnical engineering tools. An extensive range of benchmark checks have been developed to check the correct functioning of each tool. During product development these checks are run on a regular basis to verify the improved product. These benchmark checks are provided in the following sections, to allow the users to overview the checking procedure and verify for themselves the correct functioning of D-FLOW SLIDE.
The benchmarks for Deltares Systems are subdivided into five separate groups as described below:
- Group 1 – Benchmarks from literature (exact solution)
Simple benchmarks for which an exact analytical result is available from literature. - Group 2 – Benchmarks from literature (approximate solution)
More complex benchmarks described in literature for which an approximate solution is known. - Group 3 – Benchmarks from spreadsheets
Benchmarks which test program features using Excel spreadsheets. - Group 4 – Benchmarks generated by the program itself
Benchmarks for which the reference results are generated using D-FLOW SLIDE. - Group 5 – Benchmarks compared with other programs
Benchmarks for which the results of D-FLOW SLIDE are compared with the results of other programs.
As much as software developers would wish they could, it is impossible to prove the correctness of any non-trivial program. Re-calculating all the benchmarks and making sure the results are as they should be will prove to some degree that the program works as it should. Nevertheless there will always be combinations of input values that will cause the program to crash or produce wrong results. Hopefully by using the verification procedure the number of times this occurs will be limited.
The benchmarks will all be described to such detail that reproduction is possible at any time. In some cases, when the geometry is too complex to describe, the input file of the benchmark is needed. The results are presented in text format with each benchmark description.
The input files belonging to the benchmarks can be downloaded from those pages.
Overview of the benchmarks
Legend:
= Results of D-Flow Slide and results of the Benchmark are identical.
= Results of D-Flow Slide and results of the Benchmark differ.
Group |
File name |
Input file |
Input file |
Input file |
Title |
Global (VTV) |
Simple (CUR-113) |
Detailed (TR) |
Advanced (SLIQ2D) |
|---|---|---|---|---|---|---|---|---|---|
1 |
bm1-1 |
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Study Case described in "Technisch Rapport Voorland Zettingsvloeiing" |
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2 |
bm2-1 |
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Spui dike - hmp 63.9 (location Nieuw Beijerland) |
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bm2-2 |
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Spui dike - hmp 65.0 (between locations Oud Beijerland and Nieuw Beijerland) |
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bm2-3 |
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Spui dike - hmp 67.8 (location Oud Beijerland) |
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3 |
bm3-1 |
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Global check with traject: step 1 = no, step 3 = yes |
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bm3-2 |
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Global check with traject: step 1 = no, step 3 = no |
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bm3-3 |
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Global check with traject: |
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4 |
bm4-1 |
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Test on the level indicator |
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bm4-2 |
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Test on the units |
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5 |
bm5-1a |
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Comparison with SLIQ2D - Case LGZM1 |
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bm5-1b |
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Comparison with SLIQ2D - Case LGZM2 |
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bm5-1c |
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Comparison with SLIQ2D - Case LGZM3 |
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bm5-1d |
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Comparison with SLIQ2D - Case LGZM4 |
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bm5-1e |
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Comparison with SLIQ2D - Case SIMPLETA |
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bm5-1f |
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Comparison with SLIQ2D - Case LG1D5N5H |
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bm5-1g |
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Comparison with SLIQ2D - Case HBPZBUI3 |
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bm5-2 |
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Comparison with SLIQ2D-Windows - 2 layers partially saturated with fixed slope angle |
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bm5-3 |
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Comparison with DZettingsVloeiing - Study Case described in "Technisch Rapport Voorland Zettingsvloeiing" |
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a The detailed check with D-Flow Slide not succeeds whereas it should succeed acc. to the benchmark.
Group 4: Benchmarks generated by the program itself
This section contains tests for which the reference results are generated with D-FLOW SLIDE.
4.1 Test on the level indicator
Description
To check that the level indicator is correctly inputted in D-FLOW SLIDE, the results of the two following calculations should lead to the same results:
- Benchmark 4-1a uses the same input as benchmark 1-1a, refer to paragraph 1.1 above.
- Benchmark 4-1b uses the same input as benchmark 4-1a except that the Y coordinates of the geometry are shifted by -20 m so that all points have a negative Y coordinate.
4.2 Test on the units
Description
In the Units tab of D-FLOW SLIDE, it is possible to specify the unit of different parameters:
- Fraction: -, %, o/oo or ppm
- Length: m, mm, cm, inch, ft or km
- Tiny length: xxxm
- Angle: deg, rad, grad, tan or cot
- Weigth: kN/m3, N/m3, lb/in3, MN/m3, lb/ft3
- Pressure: kN/m2, N/m2, Pa, kPa, MPa, kN/cm2, psi
- Permeability: m/s, m/min, m/hr, m/day
To test the correctness of the convertion , 7 benchmarks are created using the following set of units:
Benchmark name |
Fraction unit |
Length unit |
Tiny length unit |
Angle unit |
Weigth unit |
Pressure unit |
Permeability unit |
|---|---|---|---|---|---|---|---|
bm4-2a |
m |
xxxm |
deg |
kN/m3 |
kN/m2 |
m/s |
|
bm4-2b |
% |
mm |
xxxm |
rad |
N/m3 |
N/m2 |
m/min |
bm4-2c |
o/oo |
cm |
xxxm |
grad |
lb/in3 |
Pa |
m/hr |
bm4-2d |
ppm |
inch |
xxxm |
tan |
MN/m3 |
kPa |
m/day |
bm4-2e |
ft |
xxxm |
cot |
lb/ft3 |
MPa |
m/s |
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bm4-2f |
km |
xxxm |
deg |
kN/m3 |
kN/cm2 |
m/s |
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bm4-2g |
m |
xxxm |
deg |
kN/m3 |
psi |
m/s |
D-FLOW SLIDE inputs
D-FLOW SLIDE results
Group 5: Benchmarks compared with other programs
5.1 Comparison with SLIQ2D (DOS and Windows) - One fully saturated layer with variable slope angle
Description
The benchmarks in this paragraph are intended to verify the advanced method by comparing D-FLOW SLIDE results with those from the older program SLIQ2D, using both DOS and Windows versions of this program.
Because of the limitations in the DOS version of SLIQ2D, only one fully saturated layer is inputted. The geometry and the material properties for each cases are given in the table below.
The original slope angle is 1:1.25 and is set to "variable" so that the program will search (for each point) for the most unfavorable slope.
Benchmark name |
Original file name (SLIQ2D-DOS) |
Soil type |
Slope height (m) |
Slope angle |
n (%) |
nmin (%) |
n max (%) |
Eps voldm0 |
m |
r |
s 2 |
s max |
v |
k so (kN/m 2) |
u |
Unit weight (kN/m 3) |
D r (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
bm5-1a |
LGZM1 |
Sand clay |
21.9 |
1:1.25 |
45.5 |
50 |
35 |
0.0025 |
1.7 |
7 |
1.28 |
1.7 |
1 |
50000 |
1 |
8.856 |
30 |
bm5-1b |
LGZM2 |
Sand clay |
21.9 |
1:1.25 |
45.5 |
50 |
35 |
0.0035 |
1.7 |
7 |
1.28 |
1.7 |
1 |
50000 |
1 |
8.856 |
30 |
bm5-1c |
LGZM3 |
Sand clay |
21.9 |
1:1.25 |
45.5 |
50 |
35 |
0.005 |
1.7 |
7 |
1.28 |
1.7 |
1 |
50000 |
1 |
8.856 |
30 |
bm5-1d |
LGZM4 |
Sand clay |
21.9 |
1:1.25 |
45.5 |
50 |
35 |
0.006 |
1.7 |
7 |
1.28 |
1.7 |
1 |
50000 |
1 |
8.856 |
30 |
bm5-1e |
SIMPLETA |
Sea sand |
10 |
1:1.25 |
47.4 |
50 |
37 |
0.0092 |
3 |
7 |
1.23 |
1.35 |
1 |
39460 |
1.33 |
8.547 |
20 |
bm5-1f |
LG1D5N5H |
Sand clay |
20.9 |
1:1.25 |
40.2 |
50 |
35 |
0.0022 |
1.7 |
7 |
1.18 |
1.4 |
1 |
85000 |
1 |
9.717 |
65.333 |
bm5-1g |
HBPZBUI3 |
Sea sand |
22 |
1:1.25 |
45.5 |
50 |
35 |
0.0054 |
2 |
7 |
1.25 |
1.4 |
1.25 |
50000 |
1 |
8.856 |
30 |
Benchmark results
In SLIQ2D-Windows only the value of the tangent angle is available in the output. The other parameters (such as Ko, the normal stress p and the deviatoric stress q) are not saved and can only be red on the screen, making the comparison difficult. Nota also that the automatic generation of the variable values of the slope angle used by SLIQ2D-DOS is not exactly the same as in SLIQ2D-Windows or D-FLOW SLIDE (which use 2 extra slopes compared to SLIQ2D-DOS: 1:1.4 and 1:1.3). The figures below show the critical slope angles, for each calculated points.
Results of SLIQ2D-Windows - Overview of the unstable points:
bm5-1a: |
bm5-1b: |
bm5-1c: |
bm5-1d: |
bm5-1e: |
bm5-1f: |
bm5-1g: |
Results of SLIQ2D-Windows - Values of the critical slope angle for each calculated point:
bm5-1a: |
bm5-1b: |
bm5-1c: |
bm5-1d: |
bm5-1e: |
bm5-1f: |
bm5-1g: |
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D-FLOW SLIDE results
Maximum relative error between SLIQ2D-DOS and D-FLOW SLIDE:
Case |
Slope angle at which instability occurs (Tan Alpha) |
Tan Alpha_p |
Ko_p |
Normal stress p |
Deviatoric stress q |
|---|---|---|---|---|---|
bm5-1a |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
bm5-1b |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
bm5-1c |
0.00 |
0.54 |
0.13 |
0.00 |
0.00 |
bm5-1d |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
bm5-1e |
0.00 |
0.00 |
0.15 |
0.00 |
0.02 |
bm5-1f |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
bm5-1g |
0.00 |
0.00 |
0.12 |
0.00 |
0.02 |
Results between SLIQ2D-Windows and D-FLOW SLIDE are exactly the same for the tangent angle, as show in the table below.
Maximum relative error between SLIQ2D-Windows and D-FLOW SLIDE for the tangent angle:
Case |
Tan Alpha |
|---|---|
bm5-1a |
0.00 % |
bm5-1b |
0.00 % |
bm5-1c |
0.00 % |
bm5-1d |
0.00 % |
bm5-1e |
0.00 % |
bm5-1f |
0.00 % |
bm5-1g |
0.00 % |
5.2 Comparison with SLIQ2D-Windows - 2 layers partially saturated with fixed slope angle
Description
This benchmark is intended to verify the advanced method by comparing D-FLOW SLIDE results with those from the older program SLIQ2D-Windows, for a 21 m height channel composed of 2 layers where the top layer is partially saturated. The slope of the channel is fixed to 1:3.333 (i.e. Tan Alpha = 0.3).
Layer |
Height (m) |
Soil type |
n (%) |
n min (%) |
n max (%) |
Eps voldm0 |
m |
r |
s 2 |
s max |
v |
k so (kN/m 2) |
u |
Unit weight (kN/m 3) |
D r (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Top sand |
12 |
Sand clay |
45.5 |
50 |
35 |
0.006 |
1.7 |
7 |
1.28 |
1.7 |
1 |
50000 |
1 |
8.856 |
30 |
Bottom sand |
9 |
Sand clay |
47.4 |
50 |
37 |
0.0092 |
3 |
5 |
1.23 |
1.35 |
1.25 |
39460 |
1.33 |
6.312 |
20 |
Benchmark results
Results of SLIQ2D-Windows for bm5-2 - Overview of the unstable points:
Unable to render embedded object: File (Embankment SLIQ2D - bm5-2.bmp) not found.
D-FLOW SLIDE results
Unable to render embedded object: File (Results D-FLOW SLIDE - bm5-2.bmp) not found.
Results between SLIQ2D-Windows and D-FLOW SLIDE are exactly the same for all calculated parameters, as shown in the table below.
Maximum relative error between SLIQ2D-Windows and D-FLOW SLIDE:
Parameter |
Max. relative error (%) |
|---|---|
Tan Alpha_p |
0.00 |
Ko_p |
0.00 |
Normal stress p |
0.00 |
Deviatoric stress q |
0.00 |
5.3 Comparison with DZettingsVloeiing - Study Case described in "Technisch Rapport Voorland Zettingsvloeiing"
Description
This benchmark is intended to verify the detailed method by comparing D-FLOW SLIDE results with those from the program DZettingsVloeiing. The same input as in benchmark 1-1 is used.
DZettingsVloeiing results
Input and Results of DZettingsVloeiing for bm5-3 (= bm1-1):
Unable to render embedded object: File (Voorland zettingvloeing - Benchmark 1.bmp) not found.
D-FLOW SLIDE results
Results between DZettingsVloeiing and D-FLOW SLIDE are exactly the same for all calculated parameters, as shown in the table below.
xxx
