## 1 Introduction  
This article contains an analysis of the correlation of selected geotechnical parameters of waste soils determined in the laboratory and \"in situ\" in the \"White Seas\" area in Cracow. The correlations of the strength parameters obtained from laboratory tests and in situ CPTUs have been widely studied and reported by many researchers for various soils. Correlation formulas were created from scientific research for various soils in order to quickly assess their properties for construction purposes. This saves on the time and costs that are needed to perform laboratory tests. Correlation formulas usually concern natural soils. It is rare to find waste in such a large area where there are large construction investments (buildings, roads, tunnels, bridges). The novelty of this article is to obtain such a correlation for the tested waste. There is no such relationship reported so far, and it is important from the point of view of construction investments on these anthropogenic soils. There are many correlation formulas and relationships in the literature which have been established for a specific soil, but these can also be applied to soils with the same parameters and mineral composition. It may be in a different location, but the soil must be the same in terms of geotechnical parameters. The premise for choosing the research topic of the work was due to the number of construction investments in the area of the \"White Seas\" in Cracow in recent years and the difficulties that have been encountered with regard to determining the geotechnical parameters of this soil [1, 2]. The research was conducted on anthropogenic soil in the \"White Seas\" area, which is located in the southern part of Cracow, Poland (Figure 1). Anthropogenic soil landfill is an alkaline calcareous sludge flotation waste disposal product that was formed during the production of industrial s Plant in Cracow. The soil is an alkaline waste residue and primarily consists of suspended particles such as CaCO\({}_{3}\), CaCO\({}_{4}\), and soluble chloride salts (CaCl\({}_{2}\), NaCl) [3; 4; 5]. Flotation waste is a white-coloured, fine-grained material commonly stored in landfills or settling ponds [6; 7]. The unusual soil condition and lack of correlation between the geotechnical parameters and the results of the cone penetration test with pore water pressure measurement (CPTU) have been problems for engineers in the structural design process of future buildings [3]. One of the most popular in situ soil testing methods is the cone penetration test with pore water pressure measurement (CPTU). Advantages such as speed, accuracy and the repeatability of test results are the reasons why the CPTU is the most widely used in geotechnical investigation. CPTUs provide information about soil condition in the tested profile of the subsoil at a relatively low cost. Soil testing and obtaining material strength parameters in the tested soil are important elements in the correct assessment of subsoil for planned investments. There are many publications in both the international and Polish literature on the possibility of using the results from the CPTU method to assess the properties of subsoil [8; 9; 10; 11]. Using in situ soil investigations, it is possible to survey a significantly larger area in a short amount of time. All investigations are conducted on the site of the future investment in natural conditions in situ, meaning within the current state of stress, saturation level, and temperature. These probes are minimally invasive and are sometimes the only method for determining soil parameters when terrain conditions do not enable the collection of samples. Despite their benefits, in situ investigations also have certain limitations [12]. The most significant limitations include the inability to determine parameters under different stress conditions, high rates of soil deformation during the investigation, and the inability to control drainage conditions.