## 2 Materials and Methods
### Tests on a Real Building
#### 2.1.1 Subsoil Examination
Loesses are transitional soils; therefore, determining \(OCR\) is not clear-cut, and the author was unable to find a credible interpretation determining \(OCR\) for these soils. Therefore, in order to present the nature of soil preconsolidation, the distribution of the \(K_{D}\) coefficient with depth is shown in Figure 6, because notwithstanding the exact \(OCR\) value, the \(K_{\rm D}\) coefficient very well reflects the history of the soil. On the basis of [PERSON]'s original formulas, it can be simplified that \(OCR=1\) for \(K_{D}=2\). \(K_{D}\) coefficients in Figure 6 indicate a slight preconsolidation of near-surface zones, which may be related to the temporary storage of soil from the neighbouring construction sites. It may also be the effect of \"quasi-preconsolidation\" associated with cementation of soil with calcium carbonate [39, 42]. A significant increase of \(K_{D}\) in the near-surface zone is a common phenomenon, often registered by the author in DMT tests on loess conducted in Lublin. In turn, deeper soil should be described as normally consolidated because \(K_{\rm D}\)-2. To sum up, the received \(K_{\rm D}\) charts show that the soil is normally consolidated, and the increase in \(OCR\) in the higher parts is typical for the near-surface zone [44, 45], so it was assumed in the calculations that the soil is normally consolidated. From three oedometric tests, the oedometric moduli \(E_{\rm oed}\) = 4.4 \(\div\) 6.0 MPa for the stress range of 126 \(\div\) 252 MPa, and \(E_{\rm oed}\) = 7.8 \(\div\) 10.1 MPa for the range of 252 \(\div\) 503 MPa were obtained. Unloading-reolading modulus assumed the value \(E_{\rm ur}\) = 48.5 \(\div\) 61.7 MPa. Effective internal friction angle \(\varphi\)\"-35\({}^{\circ}\) and effective cohesion \(c^{\prime}\)-5 kPa were obtained from TXCID triaxial tests. Selected laboratory tests results are presented in Figure 7. In addition,  
Figure 6: \(K_{\rm D}\) and \(M_{\rm DMT}\) distribution with depth (red line—foundation level). bulk density in the range of 1.75 \(\div\) 1.85 g/cm\({}^{3}\), natural moisture \(w_{\rm n}\) = 8.3 \(\div\) 16.4% and porosity index \(e\) = 0.55 \(\div\) 0.76 were obtained in the basic tests. Summing up, the subsoil in the area of the building is mainly composed of loess soils. Up to the depth of about 5 to 7 metres below the foundation level, there are loess silts of the aeolian facies, the so-called typical loess with a compact consistency and tip resistance \(q_{\rm c}\) = 4.6 \(\div\) 8.1 MPa (M\({}_{\rm CPT}\) = 27.6 \(\div\) 48.6), with an average of 5.3 MPa, and the constrained modulus \(M_{\rm DMT}\) = 30 \(\div\) 60 MPa (locally up to 80 MPa) with an average of approximately 40 MPa. These are relatively high values. Below the loess, there is a thin sandy interbedding and, locally, slightly plasticised clay loess which is deposited on residual soil and cracked limestone. Taking into account the thickness of the loess cover, the type of foundation and magnitude of loads, loess soils have fundamental importance for and impact on the building. It was the parameters of these soils that were the focus in the recognition of the subsoil. In relation to the results obtained from tests conducted in the Lublin area [46; 47; 48], soil conditions should be considered typical and representative of the Lublin area, and loess subsoil in this area can be considered as a good load-bearing substrate. A representative geotechnical cross-sections are shown in Figure 8.  
Figure 3:0 Geotechnical cross-sections. Figure 3:1 Laboratory test results (**a**) oedometric test—sample no. 1; (**b**) TXCID results on the \(p\)-\(q\) plane.