Index: DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporterSigmaTauCurves.cs
===================================================================
diff -u
--- DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporterSigmaTauCurves.cs	(revision 0)
+++ DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporterSigmaTauCurves.cs	(revision 4544)
@@ -0,0 +1,117 @@
+// Copyright (C) Stichting Deltares 2024. All rights reserved.
+// 
+// This file is part of the application DAM - UI.
+// 
+// DAM - UI is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+// 
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Threading;
+using Deltares.Dam.Data.Importers;
+using Deltares.Standard.IO;
+using Deltares.Standard.Language;
+using LumenWorks.Framework.IO.Csv;
+
+namespace Deltares.Dam.Data.CsvImporters;
+
+public class CsvImporterSigmaTauCurvesException(string message) : ApplicationException(message);
+
+public class CsvImporterSigmaTauCurves
+{
+    private readonly int currentColIndex = -1; // Keep track of column for error message
+
+    public CsvImporterSigmaTauCurves(string fileName)
+    {
+        ErrorMessages.Clear();
+        ThrowHelper.ThrowIfStringArgumentNullOrEmpty(fileName, StringResourceNames.CsvFileNotValid);
+        ThrowHelper.ThrowIfFileNotExist(fileName, StringResourceNames.CsvFileNotFound);
+        CultureInfo oldCultureInfo = Thread.CurrentThread.CurrentCulture;
+        try
+        {
+            Thread.CurrentThread.CurrentCulture = CsvReaderUtilities.DetermineCultureForFile(fileName);
+            using (var csv = new CsvReader(new StreamReader(fileName), true, ';'))
+            {
+                string[] headers = CsvImporterHelper.GetFieldHeaders(this, csv);
+                if (headers.Length < 2)
+                {
+                    string csvHeaderError = LocalizationManager.GetTranslatedText(GetType(), "csvHeaderError");
+                    throw new CsvImporterSoilsException($"{fileName} : {csvHeaderError}");
+                }
+
+                int colIndexSigmaTauCurveName = CsvReaderUtilities.GetHeaderIndexByString(headers, CsvColumnNames.SigmaTauCurveNameColumnName);
+                CheckColumn(colIndexSigmaTauCurveName, fileName, CsvColumnNames.SoilNameColumnName);
+
+                int colIndexSigma = CsvReaderUtilities.GetHeaderIndexByString(headers, CsvColumnNames.SigmaColumnName);
+                CheckColumn(colIndexSigma, fileName, CsvColumnNames.SigmaColumnName);
+
+                int colIndexTau = CsvReaderUtilities.GetHeaderIndexByString(headers, CsvColumnNames.TauColumnName);
+                CheckColumn(colIndexTau, fileName, CsvColumnNames.TauColumnName);
+
+                while (csv.ReadNextRecord())
+                {
+                    var sigmaTauCurveRecord = new SigmaTauCurveRecord();
+                    try
+                    {
+                        // Required columns
+                        currentColIndex = colIndexSigmaTauCurveName;
+                        sigmaTauCurveRecord.SigmaTauCurveName = csv[currentColIndex];
+
+                        currentColIndex = colIndexSigma;
+                        sigmaTauCurveRecord.Sigma = Convert.ToDouble(csv[currentColIndex]);
+
+                        currentColIndex = colIndexTau;
+                        sigmaTauCurveRecord.Tau = Convert.ToDouble(csv[currentColIndex]);
+
+                        ImportedItems.Add(sigmaTauCurveRecord);
+                    }
+                    catch (Exception e)
+                    {
+                        string csvSigmaTauCurveError = string.Format(LocalizationManager.GetTranslatedText(GetType(), "csvSigmaTauCurveError"),
+                                                                     sigmaTauCurveRecord.SigmaTauCurveName, currentColIndex + 1);
+                        ErrorMessages.Add(csvSigmaTauCurveError + e.Message);
+                    }
+                }
+            }
+        }
+        finally
+        {
+            Thread.CurrentThread.CurrentCulture = oldCultureInfo;
+        }
+    }
+
+    public List<string> ErrorMessages { get; } = new();
+    public List<SigmaTauCurveRecord> ImportedItems { get; } = new();
+
+    private void CheckColumn(int index, string fileName, string fieldName)
+    {
+        if (index < 0)
+        {
+            string csvHeaderFieldError = LocalizationManager.GetTranslatedText(GetType(), "csvHeaderFieldError");
+            throw new CsvImporterSigmaTauCurvesException($"{fileName} : {csvHeaderFieldError} {fieldName}");
+        }
+    }
+
+    public class SigmaTauCurveRecord
+    {
+        public string SigmaTauCurveName { get; set; }
+        public double Sigma { get; set; }
+        public double Tau { get; set; }
+    }
+}
\ No newline at end of file
Index: DamClients/DamUI/trunk/src/Dam/Deltares.Dam.Tests/CsvImporterTestsNew.cs
===================================================================
diff -u -r4539 -r4544
--- DamClients/DamUI/trunk/src/Dam/Deltares.Dam.Tests/CsvImporterTestsNew.cs	(.../CsvImporterTestsNew.cs)	(revision 4539)
+++ DamClients/DamUI/trunk/src/Dam/Deltares.Dam.Tests/CsvImporterTestsNew.cs	(.../CsvImporterTestsNew.cs)	(revision 4544)
@@ -818,7 +818,7 @@
 
         CreateSoilProfilesFileWithIllegalHeader(testFilePath);
         Assert.That(() => new CsvImporterSoils(testFilePath),
-                    Throws.InstanceOf<CsvImporterSoilsException>().With.Message.Contains("The header misses the field:  soil_type"));
+                    Throws.InstanceOf<CsvImporterSoilsException>().With.Message.Contains("The header misses the field:  soil_color"));
     }
 
     [Test]
@@ -838,6 +838,58 @@
         Assert.AreEqual(3, csvImporterSoils.ErrorMessages.Count);
     }
 
+    [Test]
+    public void SigmaTauCurvesCorrectFileTest()
+    {
+        const string importFile = "sigmataucurves.csv";
+        string testFilePath = Path.Combine(importFolder, importFile);
+        if (File.Exists(testFilePath))
+        {
+            File.Delete(testFilePath);
+        }
+
+        CreateSigmaTauCurvesFile(testFilePath);
+        var csvImporterSigmaTauCurves = new CsvImporterSigmaTauCurves(testFilePath);
+        IList<CsvImporterSigmaTauCurves.SigmaTauCurveRecord> sigmaTauCurveRecords = csvImporterSigmaTauCurves.ImportedItems;
+
+        Assert.AreEqual("CurveKlei", sigmaTauCurveRecords[0].SigmaTauCurveName);
+        Assert.AreEqual(0.0, sigmaTauCurveRecords[0].Sigma);
+        Assert.AreEqual(2.05, sigmaTauCurveRecords[0].Tau);
+        Assert.AreEqual("CurveKlei", sigmaTauCurveRecords[1].SigmaTauCurveName);
+        Assert.AreEqual(13.0, sigmaTauCurveRecords[1].Sigma);
+        Assert.AreEqual(8.05, sigmaTauCurveRecords[1].Tau);
+        Assert.AreEqual("CurveKlei", sigmaTauCurveRecords[2].SigmaTauCurveName);
+        Assert.AreEqual(26.0, sigmaTauCurveRecords[2].Sigma);
+        Assert.AreEqual(13.79, sigmaTauCurveRecords[2].Tau);
+        Assert.AreEqual("CurveKlei", sigmaTauCurveRecords[3].SigmaTauCurveName);
+        Assert.AreEqual(65.0, sigmaTauCurveRecords[3].Sigma);
+        Assert.AreEqual(28.1, sigmaTauCurveRecords[3].Tau);
+        Assert.AreEqual("CurveKlei", sigmaTauCurveRecords[4].SigmaTauCurveName);
+        Assert.AreEqual(110.5, sigmaTauCurveRecords[4].Sigma);
+        Assert.AreEqual(44.6, sigmaTauCurveRecords[4].Tau);
+        Assert.AreEqual("CurveZand", sigmaTauCurveRecords[5].SigmaTauCurveName);
+        Assert.AreEqual(0.0, sigmaTauCurveRecords[5].Sigma);
+        Assert.AreEqual(0.0, sigmaTauCurveRecords[5].Tau);
+        Assert.AreEqual("CurveZand", sigmaTauCurveRecords[6].SigmaTauCurveName);
+        Assert.AreEqual(200.0, sigmaTauCurveRecords[6].Sigma);
+        Assert.AreEqual(129.88, sigmaTauCurveRecords[6].Tau);
+    }
+
+    [Test]
+    public void SigmaTauCurvesMissingColumnFileTest()
+    {
+        const string importFile = "sigmataucurves_missing_column.csv";
+        string testFilePath = Path.Combine(importFolder, importFile);
+        if (File.Exists(testFilePath))
+        {
+            File.Delete(testFilePath);
+        }
+
+        CreateSigmaTauCurvesMissingColumngFile(testFilePath);
+        Assert.That(() => new CsvImporterSigmaTauCurves(testFilePath),
+                    Throws.InstanceOf<CsvImporterSigmaTauCurvesException>().With.Message.Contains("The header misses the field:  sigma"));
+    }
+
     /// <summary>
     ///     Create csv file with segments containing 1d soilprofiles
     /// </summary>
@@ -939,6 +991,30 @@
         writer.WriteLine("Veen;#A4FFA6;Peat;11.000;11.000;2.000;20.500;210.00;0.001;None;;;0;10.000");
     }
 
+    private static void CreateSigmaTauCurvesFile(string filePath)
+    {
+        using StreamWriter writer = File.CreateText(filePath);
+        writer.WriteLine("sigma_tau_curve_name;sigma;tau");
+        writer.WriteLine("CurveKlei;0.0;2.05");
+        writer.WriteLine("CurveKlei;13.0;8.05");
+        writer.WriteLine("CurveKlei;26.0;13.79");
+        writer.WriteLine("CurveKlei;65.0;28.10");
+        writer.WriteLine("CurveKlei;110.5;44.60");
+        writer.WriteLine("CurveZand;0.0;0.0");
+        writer.WriteLine("CurveZand;200.0;129.88");
+    }
+
+    private static void CreateSigmaTauCurvesMissingColumngFile(string filePath)
+    {
+        using StreamWriter writer = File.CreateText(filePath);
+        writer.WriteLine("sigma_tau_curve_name;tau");
+        writer.WriteLine("CurveKlei;2.05");
+        writer.WriteLine("CurveKlei;8.05");
+        writer.WriteLine("CurveKlei;13.79");
+        writer.WriteLine("CurveKlei;28.10");
+        writer.WriteLine("CurveKlei;44.60");
+    }
+
     private static void CreateSoilProfilesFileWithIllegalHeader(string filePath)
     {
         using StreamWriter writer = File.CreateText(filePath);
Index: DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporter.cs
===================================================================
diff -u -r4539 -r4544
--- DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporter.cs	(.../CsvImporter.cs)	(revision 4539)
+++ DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporter.cs	(.../CsvImporter.cs)	(revision 4544)
@@ -39,6 +39,7 @@
     private const string characteristicPointFileNamePart = "characteristicpoints";
     private const string scenariosFileNamePart = "scenarios";
     private const string soilsFileNamePart = "soils";
+    private const string sigmaTauCurvesFileNamePart = "sigma_tau_curves";
     private string folderName;
 
     public List<LogMessage> ErrorMessages { get; } = new();
@@ -57,6 +58,8 @@
 
     public List<CsvImporterSoils.SoilRecord> SoilsRecords { get; private set; } = new();
 
+    public List<CsvImporterSigmaTauCurves.SigmaTauCurveRecord> SigmaTauCurvesRecords { get; private set; } = new();
+
     /// <summary>
     ///     Imports the CSV data from directory.
     /// </summary>
@@ -108,6 +111,12 @@
                 ImportSoils(SoilsFileName);
             }
 
+            if (File.Exists(SigmaTauCurvesFileName))
+            {
+                progress?.Invoke(0.29);
+                ImportSigmaTauCurves(SigmaTauCurvesFileName);
+            }
+
             progress?.Invoke(0.30);
         }
     }
@@ -133,6 +142,8 @@
 
     private string SoilsFileName => string.Format(filePattern, ImportFolderLocation, soilsFileNamePart);
 
+    private string SigmaTauCurvesFileName => string.Format(filePattern, ImportFolderLocation, sigmaTauCurvesFileNamePart);
+
     /// <summary>
     ///     Imports the locations.
     /// </summary>
@@ -152,7 +163,7 @@
                     ErrorMessages.Add(logMessage);
                 }
             }
-            catch (CsvImporterSegmentsException e)
+            catch (Exception e)
             {
                 var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
                 ErrorMessages.Add(logMessage);
@@ -176,7 +187,7 @@
                 ErrorMessages.Add(logMessage);
             }
         }
-        catch (CsvImporterSegmentsException e)
+        catch (Exception e)
         {
             var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
             ErrorMessages.Add(logMessage);
@@ -199,7 +210,7 @@
                 ErrorMessages.Add(logMessage);
             }
         }
-        catch (CsvImporterCharacteristicPointsException e)
+        catch (Exception e)
         {
             var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
             ErrorMessages.Add(logMessage);
@@ -212,7 +223,7 @@
     /// <param name="fileName">Name of the file.</param>
     private void ImportSoilProfiles(string fileName)
     {
-        // 1D Soilprofiles are not mandatory. The project can use 2D-geometries
+        // 1D SoilProfiles are not mandatory. The project can use 2D-geometries
         if (File.Exists(fileName))
         {
             try
@@ -225,7 +236,7 @@
                     ErrorMessages.Add(logMessage);
                 }
             }
-            catch (CsvImporterSoilProfilesException e)
+            catch (Exception e)
             {
                 var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
                 ErrorMessages.Add(logMessage);
@@ -249,7 +260,7 @@
                 ErrorMessages.Add(logMessage);
             }
         }
-        catch (CsvImporterSurfaceLinesException e)
+        catch (Exception e)
         {
             var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
             ErrorMessages.Add(logMessage);
@@ -272,11 +283,6 @@
                 ErrorMessages.Add(logMessage);
             }
         }
-        catch (CsvImporterScenariosException e)
-        {
-            var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
-            ErrorMessages.Add(logMessage);
-        }
         catch (Exception e)
         {
             var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
@@ -300,11 +306,29 @@
                 ErrorMessages.Add(logMessage);
             }
         }
-        catch (CsvImporterSoilsException e)
+        catch (Exception e)
         {
             var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
             ErrorMessages.Add(logMessage);
         }
+    }
+
+    /// <summary>
+    /// Import the Sigma Tau Curves 
+    /// </summary>
+    /// <param name="fileName">The filename of the file to read</param>
+    private void ImportSigmaTauCurves(string fileName)
+    {
+        try
+        {
+            var csvImporterSigmaTauCurves = new CsvImporterSigmaTauCurves(fileName);
+            SigmaTauCurvesRecords = csvImporterSigmaTauCurves.ImportedItems;
+            foreach (string errorMessage in csvImporterSigmaTauCurves.ErrorMessages)
+            {
+                var logMessage = new LogMessage(LogMessageType.Error, this, errorMessage);
+                ErrorMessages.Add(logMessage);
+            }
+        }
         catch (Exception e)
         {
             var logMessage = new LogMessage(LogMessageType.FatalError, this, e.Message);
Index: DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/Importers/CsvColumnNames.cs
===================================================================
diff -u -r4539 -r4544
--- DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/Importers/CsvColumnNames.cs	(.../CsvColumnNames.cs)	(revision 4539)
+++ DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/Importers/CsvColumnNames.cs	(.../CsvColumnNames.cs)	(revision 4544)
@@ -431,6 +431,16 @@
     public const string SigmaTauCurveNameColumnName = "sigma_tau_curve_name";
 
     /// <summary>
+    /// Normal effective stress
+    /// </summary>
+    public const string SigmaColumnName = "sigma";
+
+    /// <summary>
+    /// Shear strength
+    /// </summary>
+    public const string TauColumnName = "tau";
+
+    /// <summary>
     ///     strength_increase_exponent
     /// </summary>
     public const string StrengthIncreaseExponentColumnName = "strength_increase_exponent";
Index: DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/Translations.xml
===================================================================
diff -u -r4539 -r4544
--- DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/Translations.xml	(.../Translations.xml)	(revision 4539)
+++ DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/Translations.xml	(.../Translations.xml)	(revision 4544)
@@ -376,6 +376,9 @@
     <Translation ID="csvSoilError"
                  en-US="Next error occured whilst reading soil {0} column {1} from csv: "
                  nl-NL="Tijdens het lezen van materiaal {0} in kolom {1} uit de csv trad de volgende fout op: "/>
+    <Translation ID="csvSigmaTauCurveError"
+                 en-US="Next error occured whilst reading sigma tau curve {0} column {1} from csv: "
+                 nl-NL="Tijdens het lezen van sigma tau tabel {0} in kolom {1} uit de csv trad de volgende fout op: "/>
     <Translation ID="noIdOrSoilForSoilProfileRecordError" en-US="This soil profile record has no id and/or soilname."
                  nl-NL="Dit record met grondprofiel data bevat geen Id en/of Soilname."/>
     <Translation ID="noIdSurfaceLineRecordError" en-US="This surface line record has no id."
Index: DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporterSoils.cs
===================================================================
diff -u -r4539 -r4544
--- DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporterSoils.cs	(.../CsvImporterSoils.cs)	(revision 4539)
+++ DamClients/DamUI/trunk/src/DamClientsLibrary/Deltares.Dam.Data/CsvImporters/CsvImporterSoils.cs	(.../CsvImporterSoils.cs)	(revision 4544)
@@ -66,7 +66,7 @@
                 CheckColumn(colIndexSoilName, fileName, CsvColumnNames.SoilNameColumnName);
 
                 int colIndexSoilColor = CsvReaderUtilities.GetHeaderIndexByString(headers, CsvColumnNames.SoilColorColumnName);
-                CheckColumn(colIndexSoilName, fileName, CsvColumnNames.SoilColorColumnName);
+                CheckColumn(colIndexSoilColor, fileName, CsvColumnNames.SoilColorColumnName);
 
                 int colIndexSoilType = CsvReaderUtilities.GetHeaderIndexByString(headers, CsvColumnNames.SoilTypeColumnName);
                 CheckColumn(colIndexSoilType, fileName, CsvColumnNames.SoilTypeColumnName);