Index: DamClients/DamUI/trunk/src/Dam/Forms/DamContext.cs
===================================================================
diff -u -r6436 -r6656
--- DamClients/DamUI/trunk/src/Dam/Forms/DamContext.cs	(.../DamContext.cs)	(revision 6436)
+++ DamClients/DamUI/trunk/src/Dam/Forms/DamContext.cs	(.../DamContext.cs)	(revision 6656)
@@ -49,6 +49,22 @@
         public bool Wti { get; set; } = true;
 
         /// <summary>
+        /// Returns a flag to indicate that this property must be validated
+        /// </summary>
+        /// <param name="source">The source </param>
+        /// <param name="member">The member </param>
+        /// <returns> the flag </returns>
+        public override bool? ShouldValidate(object source, string member)
+        {
+            if (source is Soil soil)
+            {
+                return ShouldValidateSoil(member, soil);
+            }
+
+            return base.ShouldValidate(source, member);
+        }
+
+        /// <summary>
         /// Method indicating a visibility override value for a given instance object.
         /// </summary>
         /// <param name="source">Object being evaluated.</param>
@@ -121,11 +137,6 @@
             }
 
             bool? isVisible = base.IsVisible(source, member);
-            if (member.Equals("Cohesion"))
-            {
-                return true;
-            }
-
             if (isVisible != null && isVisible.Value)
             {
                 return true;
@@ -189,6 +200,12 @@
                 {
                     return soil.ShearStrengthModel == ShearStrengthModel.CuCalculated;
                 }
+                
+                if (member == StaticReflection.GetMemberName<Soil>(s => s.Cohesion) ||
+                    member == StaticReflection.GetMemberName<Soil>(s => s.FrictionAngle))
+                {
+                    return soil.ShearStrengthModel == ShearStrengthModel.CPhi;
+                }
 
                 return true;
             }
@@ -266,6 +283,24 @@
             return base.GetFormat(type, source, member);
         }
 
+        private static bool ShouldValidateSoil(string member, Soil soil)
+        {
+            if (member == StaticReflection.GetMemberName<Soil>(s => s.POP) ||
+                member == StaticReflection.GetMemberName<Soil>(s => s.RatioCuPc) ||
+                member == StaticReflection.GetMemberName<Soil>(s => s.StrengthIncreaseExponent))
+            {
+                return soil.ShearStrengthModel == ShearStrengthModel.CuCalculated;
+            }
+            
+            if (member == StaticReflection.GetMemberName<Soil>(s => s.Cohesion) ||
+                member == StaticReflection.GetMemberName<Soil>(s => s.FrictionAngle))
+            {
+                return soil.ShearStrengthModel == ShearStrengthModel.CPhi;
+            }
+
+            return true;
+        }
+
         private bool? VisibleAccordingSoilUserFilter(string member)
         {
             if (alwaysVisibleProperties.Contains(member))