## 3 Results  
### Dilatometer Tests Results  
The test results obtained for selected sites are presented in Figures 7 and 8. They were taken into account in the construction of a new classification system for organic soils presented in the following chapter. values to determine the soil type, its bulk weight, and undrained shear strength. Based on the \(u_{o}\), \(p_{0}\) and \(p_{1}\) values, the soil states were separated (Table 1); they were established on the undrained shear strength \(\tau_{fu}\), using the division proposed by [PERSON] together with co-workers [24;32]. Analysis of the traced points on Marchetti's nomogram by inserting the dilatometer modulus \(E_{D}\) (MPa) on the vertical axis and the index \(I_{D}\) (-) value on the horizontal axis shows that only this part of the non-cohesive soil area (\(I_{D}>1.8\)) gives clear discrimination of this group. However, the remaining soils of these divisions are not visible. Therefore, an action was undertaken to determine the boundaries of the division of a particular group of soils (residual mineral soils and organic soils); presented in Figure 10.  
In order to create a mechanism for sub-dividing the area for each soil, a new interpretation of dilatometer results was proposed as follows by introducing the values \(p_{1}\) (MPa) and \(S_{IDMT}=(p_{0}-u_{o})/p_{1}\). Namely, it was necessary to enter \(p_{1}\) (MPa) values on the vertical axis and \(S_{IDMT}=(p_{0}-u_{o})/p_{1}\) values on the horizontal axis. On the basis of this technique, it can be noticed that in the case of non-cohesive soils, results similar as in Marchetti's nomogram will be obtained. However, for both cohesive soils and organic soils, this new approach gives a clear subdivision of the area for a specific  
Figure 7: Profiles of \(p_{0}\), \(p_{1}\) and \(p_{2}\) from dilatometer (DMT) and hydrostatic pressure \(u_{o}\) tests: (**a**) for the Antoniny site; (**b**)—for the Nielisz subsoil; (**c**)—for the Stegny subsoil; (**d**)—for the SGGW Campus subsoil [30;31]. soil. As shown in Figure 10, seven areas may currently be distinguished. The areas are depicted by variously coloured dashed lines: the line in black represents non-cohesive soils, the line in blue stands for silt soils, the line in brown represents clay soils, the line in violet is the transition area, the line in red is gyttja, the line in green is mud and organic mud, and the line in grey represents peat. To recognize the residual mineral soils and organic soils in a more detailed manner compared to [PERSON] and Crapps [2], the proposed diagram shows the relationship between the second reading \(p_{1}\) and the soil type index I\({}_{\text{SDMT}}\) (Equation (11)). The I\({}_{\text{SDMT}}\) soil type index values can be calculated using Equation (11). Subsoils are classified as organic soils when the soil type index \(0.40<\text{I}_{\text{SDMT}}\leq 1.0\) and the second pressure dilatometer reading \(p_{1}\) is in the range of \(0.01\) MPa \(<p_{1}\leq 1.0\) MPa (Tables 4 and 5). The new diagram contains 10 areas: \(1\div 4\)--non-cohesive soils, \(5\)--silt, \(6\)--clay, \(7\)--gyttja, \(8\)--mud/organic mud, and \(9\div 10\)--peat (Figure 11a-c). For a more precise subdivision of organic soils, an additional nomogram chart was developed for areas \(7,8,9\) and \(10\). The detailed form and the use of this nomogram chart is shown in Figure 11b,c. Soil type index:  
\[I_{SDMT}=\frac{p_{0}-u_{o}}{p_{1}} \tag{11}\]  
Figure 8: Profiles of material indexes \(I_{D}\) from the DMT tests carried out for the subsoil of the Nielisz, Stegny and the SGGW Campus sites: (**a**)—before loading, (**b**)—after loading for Nielisz site; \(1\)—measured values, \(2\)—average values \(\pm\) one standard deviation. Figure 9: Chart for estimating soil type and unit weight (normalized to \(\gamma_{w}\)) [2].