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h1. Table of Contents

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h1. 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.

h1. Overview of the benchmarks

The check result (i.e. Sufficient or Insufficient) is given in blue for {color:blue}{*}Legend:
(/) = Results of *D-Flow Slide* and results of the Benchmark are identical.
(x) = Results of *D-Flow Slide{*}{color} and inresults purple forof the {color:purple}{*}Benchmark{*}{color}Benchmark differ.

|| Group || File name || Input file \\
D-Flow Slide (*.fsx) || Input file \\
SLIQ2D 1.1.3.1 (*.slq) || Input file \\
SLIQ2D-Dos (*.sli) || Title || Global (VTV) || Simple (CUR-113) || Detailed (TR) || Advanced (SLIQ2D) ||
| 1 | bm1-1 | | | | Study Case described in "Technisch Rapport Voorland Zettingsvloeiing" | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) | | {color:blue}Sufficient{color} / {color:purple}Sufficient{color} => (/)  | | (/) | |
| 2 | bm2-1 | | | | Spui dike - hmp 63.9 (location Nieuw Beijerland) | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) | |
| | bm2-2 | | | | Spui dike - hmp 65.0 (between locations Oud Beijerland and Nieuw Beijerland) | {color:blue}Sufficient{color} / {color:purple}Sufficient{color} => (/)  (/) | | {color:blue}Sufficient{color} / {color:purple}Sufficient{color} => (/) | |
| | bm2-3 | | | | Spui dike - hmp 67.8 (location Oud Beijerland) | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) | | {color:blue}Insufficient{color} / {color:purple}Sufficient{color} => (x) | |
| 3 | bm3-(/) | | (x) {^}a^ | |
| 3 | bm3-1 | | | | Global check with traject: step 1 = no, step 3 = yes | | | | |
| | bm3-2 | | | | Global check with traject: step 1 = no, step 3 = no | | | | |
| | bm3-3 | | | | Global check with traject: | | | | |
| 4 | bm4-1 | | | | Test on the level indicator | | | | |
| | bm4-2a | | | | Test on the units (set 1) | | | | |
| | bm4-2b | | | | Test on the units (set 2) | | | | |
| | bm4-2c | | | | Test on the units (set 3) step 3 = yes | | | | |
| | bm4bm3-2d2 | | | | Test on the units (set 4) Global check with traject: step 1 = no, step 3 = no | | | | |
| | bm4bm3-2e3 | | | | TestGlobal oncheck thewith units (set 5) traject: | | | | |
| 4 | bm4-2f1 | | | | Test on the units (set 6)level indicator | | | | |
| | bm4-2g2 | | | | Test on the units (set 7)  | | | | |
| 5 | bm5-1a | | | | Comparison with SLIQ2D - Case LGZM1 | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => LGZM1 | | | | (/) |
| | bm5-1b | | | | Comparison with SLIQ2D - Case LGZM2 | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) |
| | bm5-1c | | | | Comparison with SLIQ2D - Case LGZM3 | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) |
| | bm5-1d | | | | Comparison with SLIQ2D - Case LGZM4 | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) |
| | bm5-1e | | | | Comparison with SLIQ2D - Case SIMPLETA | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) |
| | bm5-1f | | | | Comparison with SLIQ2D - Case LG1D5N5H | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) |
| | bm5-1g | | | | Comparison with SLIQ2D - Case HBPZBUI3 | | | | {color:blue}Insufficient{color} / {color:purple}Insufficient{color} => (/) |
| | bm5-2 | | | | Comparison with SLIQ2D-Windows - 2 layers partially saturated with fixed slope angle | | | {color:blue}Sufficient{color} / {color:purple}Sufficient{color} => | | (/) | |
| | bm5-3 | | | | Comparison with DZettingsVloeiing - Study Case described in "Technisch Rapport Voorland Zettingsvloeiing" | | | {color:blue}Sufficient{color} / {color:purple}Sufficient{color} => (/) | |(/) | |
{^}a^ = The detailed check with *D-Flow Slide* not succeeds wherease it should succeed acc. to the benchmark.

h1. Group 1: Benchmarks from literature (exact solution)

This section describes a number of benchmarks for which an exact analytical solution can be found in the literature.

h2. 1.1. Study Case described in "Technisch Rapport Voorland Zettingsvloeiing"

h5. Description

The example given in "Annex A - Case Study" of the Deltares report 1200503-001-GEO-0004 "Concept Technisch Rapport Voorland Zettingsvloeiing" of G.A. van den Ham & Co is used.
In this example, both global and detailed checks are completed on the basis of a (fictitious) dike section, which with regard to geometry and soil structure is typical of the Southwest Delta.
The dike has a height of NAP+5 m, a crest width of 3 m and a slope of 1:3.
The foreshore begins to imaginary toe of the dike at an elevation of NAP and is 60 m wide. The toe of the trench is NAP-15 m and has a slope of 1:6. The dike section is 800 m long. The phreatic level is at NAP-2 m.
The soil profile is as follows:
* from NAP+3.5 m to NAP+1 m: peat
* from NAP+1 m to NAP-5 m: silty clay
* from NAP-5 m to NAP-18 m: moderately to loosely compacted sand (Calais)
* from NAP-18 m to NAP-30 m: densely compacted sand

h5. Benchmarks results

The details of the calculation can be found in annex A of the report. The main results are given in the table below. The global check fails but the detailed check passes.

h5. *D-Flow Slide* results

Results of benchmark 1-1 for the Global Check
|| Results || Benchmark || D-Flow Slide || Relative error [%|%] ||
| Step 1 | xxx | xxx | xxx |

h1. Group 2: Benchmarks from literature (approximate solution)

This section uses the results of a by-hand calculation performed for three profiles of the Spui dike project (see figure below):
* km 63.9 (Nieuw Beijerland)
* km 65.0 (between Oud Beijerland and Nieuw Beijerland)
* km 67.8 (Oud Beijerland)

!Dwarsprofielen Spui.bmp|width=1000!

As the details of the calculation performed by hand are not available, those benchmarks are set in group 2.

h2. 2.1. Spui dike at km 63.9 (Nieuw Beijerland)

h5. Description

The dike profile at hmp 63.9 is given in the figure below.
!Profile km 63-9.bmp|width=1000!

The soil profile and the material properties are given in the following table:
|| Level top layer (m NAP) || Material || Formation || Material sensitive to liquefaction || D{~}r~ (%) || n (%) || n{~}min~ (%) || n{~}max~ (%) || Gamma ~unsat~ (kN/m{^}3^) || Gamma{~}sat~ (kN/m{^}3^) || Gamma ~grains~ (kN/m{^}3^) || D{~}50~ (mm) || D{~}15~ (mm) || Phi (deg) || c (kPa) || Eps{~}voldm0~ || s{~}max~ || s{~}2~ || k{~}so~ (kN/m{^}2^) || m || r || u || v ||
| Grond level | Clay | Dunkirk / anthropogenic | No | | | | | 18 | 18 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-0.5 | Clay/Sand | Dunkirk | No | | | | | 18 | 18 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-6.5 | Peat | Holland | No | | | | | 10 | 10 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-7.5 | Clay | Calais | No | | | | | 18 | 18 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-8.5 | Sand clayey/Sand | Calais | Yes | 35 | 45 | 36.5 | 49.5 | 19 | 19 | 26.5 | 0.160 | 0.080 | 25 | 0 | 0.000444 | 1.575 | 1.2 | 43.2 | 3 | 7 | 1.2 | 1 |
| \-9.5 | Sand | Calais | Yes | 30 | 45.6 | 36.5 | 49.5 | 20 | 20 | 26.5 | 0.160 | 0.080 | 30 | 0 | 0.000325 | 1.55 | 1.2 | 41.6 | 3 | 7 | 1.2 | 1 |
| \-12.5 | Sand | Calais | Yes | 25 | 46.3 | 36.5 | 49.5 | 20 | 20 | 26.5 | 0.160 | 0.080 | 30 | 0 | 0.000238 | 1.525 | 1.2 | 40 | 3 | 7 | 1.2 | 1 |
| \-18 | Sand | Pleistocene | Yes | 60 | 41.7 | 36.5 | 49.5 | 20 | 20 | 26.5 | 0.160 | 0.080 | 35 | 0 | 0.00212 | 1.7 | 1.2 | 51.2 | 3 | 7 | 1.2 | 1 |

The other calculation parameters used are:
* Water level: 0.9 m
* Required probability of failure of the dike: 1:4000
* Percentage probability of failure byliquefaction: 1 %
* Model factor: 1
* Area ratio (c = A2/A1): 1.4
* Standard deviation cot(gamma): 4.6
* Considered dike length: 100 m

h5. Benchmark results

According to the by hand calculation, both Global and Advanced checks fail.

h5. *D-FLOW SLIDE* results

*D-FLOW SLIDE* results are in accordance with the results by hand as show in the table below.
|| Method || Benchmark || D-FLOW SLIDE || Relative error ||
| Global check | Failed | Failed | (+) |
| Detailed check | Failed | Failed | (+) |

h2. 2.2. Spui dike at km 65.0 (between Oud Beijerland and Nieuw Beijerland)

h5. Description

The dike profile at km 65.0 is given in the figure below.
!Profile km 65-0.bmp|width=1000!

The soil profile and the material properties are the same as for the profile at km 63.9 (see paragraph 2.1).

h5. Benchmark results

According to the by hand calculation, both Global and Advanced checks pass.

h5. *D-FLOW SLIDE* results

*D-FLOW SLIDE* results are in accordance with the results by hand as show in the table below.
|| Method || Benchmark || D-FLOW SLIDE || Relative error ||
| Global check | Passed | Passed | (+) |
| Detailed check | Passed | Passed | (+) |


h2. 2.3. Spui dike at km 67.8 (oud Beijerland)

h5. Description

The dike profile at km 67.8 is given in the figure below.
!Profile km 67-8.bmp|width=1000!
The soil profile and the material properties are given in the following table:
|| Level top layer (m NAP) || Material || Formation || Material sensitive to liquefaction || D{~}r~ (%) || n (%) || n{~}min~ (%) || n{~}max~ (%) || Gamma{~}unsat~ (kN/m{^}3^) || Gamma{~}sat~ (kN/m{^}3^) || Gamma{~}grains~ (kN/m{^}3^) || D{~}50~ (mm) || D{~}15~ (mm) || Phi (deg) || c (kPa) || Eps{~}voldm0~ || s{~}max~ || s{~}2~ || k{~}so~ (kN/m{^}2^) || m || r || u || v ||
| Grond level | Clay | Dunkirk / anthropogenic | No | | | | | 18 | 18 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-0.5 | Clay/Sand | Dunkirk | No | | | | | 18 | 18 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-4 | Peat | Holland | No | | | | | 10 | 10 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-5 | Clay | Calais | No | | | | | 18 | 18 | 26.5 | | | 25 | 0 | | | | | | | | |
| \-6 | Sand | Calais | Yes | 20 | 46.9 | 36.5 | 49.5 | 20 | 20 | 26.5 | 0.160 | 0.080 | 30 | 0 | 0.000174 | 1.5 | 1.2 | 38.4 | 3 | 7 | 1.2 | 1 |
| \-20 | Sand | Pleistocene | Yes | 60 | 41.7 | 36.5 | 49.5 | 20 | 20 | 26.5 | 0.160 | 0.080 | 35 | 0 | 0.00212 | 1.7 | 1.2 | 51.2 | 3 | 7 | 1.2 | 1 |

h5. Benchmark results

According to the by hand calculation, the Global check fails and the Advanced check passes.

h5. *D-FLOW SLIDE* results

*D-FLOW SLIDE* results differ from the results by hand for the Detailed check, as show in the table below.
|| Method || Benchmark || D-FLOW SLIDE || Relative error ||
| Global check | Failed | Failed | (+) |
| Detailed check | Passed | Failed | (-) |


h1. Group 3: Benchmarks from spreadsheets

This section contains tests that are missing in the other groups, for example for the CUR-113 method.

h1. Group 4: Benchmarks generated by the program itself

This section contains test for which the reference results are generated with *D-FLOW SLIDE*.

h2. 4.1 Test on the level indicator

h5. 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.


h2. 4.2 Test on the units

h5. Description

In the Units tab of *D-FLOW SLIDE*, it is possible to specify the unit of different parameters:
* Fraction: \-, %, {^}o^/{~}oo~^o^/~oo~ or ppm
* Length: m, mm, cm, inch, ft or km
* Tiny length: xxxm
* Angle: deg, rad, grad, tan or cot
* Weigth: kN/m{^}3^, N/m{^}3^, lb/in{^}3^, MN/m{^}3^, lb/ft{^}3^
* Pressure: kN/m{^}2^, N/m{^}2^, Pa, kPa, MPa, kN/cm{^}2^, 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/m{^}3^ | kN/m{^}2^ | m/s |
| bm4-2b | % | mm | xxxm | rad | N/m{^}3^ | N/m{^}2^ | m/min |
| bm4-2c | {^}o^/{~}oo~^o^/~oo~ | cm | xxxm | grad | lb/in{^}3^ | Pa | m/hr |
| bm4-2d | ppm | inch | xxxm | tan | MN/m{^}3^ | kPa | m/day |
| bm4-2e | -  | ft | xxxm | cot | lb/ft{^}3^ | MPa | m/s |
| bm4-2f | -  | km | xxxm | deg | kN/m{^}3^ | kN/cm{^}2^ | m/s |
| bm4-2g | -  | m | xxxm | deg | kN/m{^}3^ | psi | m/s |


h5. *D-FLOW SLIDE* inputs

h5. *D-FLOW SLIDE* results

h1. Group 5: Benchmarks compared with other programs

h2. 5.1 Comparison with SLIQ2D (DOS and Windows) - One fully saturated layer with variable slope angle

h5. 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 (%) || 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~ (%) ||
| 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 |

h5. 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: \\ !Embankment SLIQ2D - bm5-1a.bmp|width=400! | bm5-1b: \\ !Embankment SLIQ2D - bm5-1b.bmp|width=400! | bm5-1c: \\ !Embankment SLIQ2D - bm5-1c.bmp|width=400! |
| bm5-1d: \\ !Embankment SLIQ2D - bm5-1d.bmp|width=400! | bm5-1e: \\ !Embankment SLIQ2D - bm5-1e.bmp|width=400! | bm5-1f: \\ !Embankment SLIQ2D - bm5-1f.bmp|width=400! |
| bm5-1g: \\ !Embankment SLIQ2D - bm5-1g.bmp|width=400! |


Results of *SLIQ2D-Windows* \- Values of the critical slope angle for each calculated point:
| bm5-1a: \\ !Results SLIQ2D - bm5-1a.bmp|width=800! | bm5-1b: \\ !Results SLIQ2D - bm5-1b.bmp|width=800! |
| bm5-1c: \\ !Results SLIQ2D - bm5-1c.bmp|width=800! | bm5-1d: \\ !Results SLIQ2D - bm5-1d.bmp|width=800! |
| bm5-1e: \\ !Results SLIQ2D - bm5-1e.bmp|width=800! | bm5-1f: \\ !Results SLIQ2D - bm5-1f.bmp|width=800! |
| bm5-1g: \\ !Results SLIQ2D - bm5-1g.bmp|width=800! | |

h5. *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 % |

h2. 5.2 Comparison with SLIQ2D-Windows - 2 layers partially saturated with fixed slope angle

h5. 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 |

h5. Benchmark results

Results of *SLIQ2D-Windows* for bm5-2 - Overview of the unstable points:
!Embankment SLIQ2D - bm5-2.bmp|width=800!

h5. *D-FLOW SLIDE* results

!Results D-FLOW SLIDE - bm5-2.bmp|width=800!

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 |