Agnieszka Stopkowicz

Urban parks, as shared public spaces, play a crucial role in fostering social integration, providing recreational opportunities, and enhancing residents’ quality of life. However, effective operation requires ensuring user safety, particularly in areas with elevated geological risk. This study assesses slope stability and rockfall risk in Bednarski Park in Kraków, established within a former limestone quarry—a site with unique natural and cultural value. The research used numerical modelling with the Finite Element Method (FEM) and rockfall trajectory analysis with the Rockfall Block Impact Model (RBIM) and Discrete Element Method (DEM), covering eight sectors of the park. The analysis focused on evaluating the Factor of Safety (FS), as well as displacement and rebound parameters of rock blocks, to identify zones with increased landslide susceptibility and local rockfall hazards. The results revealed significant spatial variability in stability conditions. The findings form the basis for developing design recommendations that reconcile geotechnical safety requirements with social expectations. Public consultations conducted alongside the scientific investigation enabled adaptation of planned mitigation measures to the park’s cultural and landscape values. The study underscores the need for a balanced approach to urban green space revitalisation, in which user safety is a fundamental prerequisite for maintaining the social functions and openness of public spaces. By integrating geotechnical risk assessment with community expectations and landscape conservation, the study supports a sustainable approach to the revitalisation and long-term management of post-extractive urban green spaces.

This article presents the results of a rockfall analysis conducted for the limestone walls of a former quarry that is now used as an urban park. The performed simulations (2D statistical analysis using Rigid Body Impact Mechanics—RBIM and Discrete Element Modelling—DEM) enabled the determination of the maximum displacement range during the ballistic phase and the maximum rebound height at the slope base, which facilitated the delineation of a safe land-use zone. A hazard zone was also identified, within which public access must be strictly prohibited due to the risk posed by flying debris. Based on slope stability assessments (safety factor values and rockfall trajectories), recommendations were formulated for slope reinforcement measures and appropriate management actions for designated sections to ensure safe operation of the site. Three mitigation strategies were proposed: (1) no protective measures, (2) no structural reinforcements but with installation of a rockfall barrier, and (3) full-scale stabilisation to allow unrestricted access to the quarry walls. The first option—leaving slopes unsecured with only designated safety buffers—is not recommended.

This study presents a stability assessment of rock slopes, considering the joint systems of the rock walls of Wojciech Bednarski Park. Special emphasis was placed on analysing the orientation and infill characteristics of the identified joint sets. Based on archival data and newly conducted geological surveys, stability calculations were performed for eight representative cross-sections corresponding to designated sectors. Numerical analyses were conducted using a finite element method (FEM) programme, based on the actual structure of the rock mass, specifically its discontinuities. This ensured a reliable reflection of the real conditions governing the slope instability mechanisms. Factors of safety were estimated with the Shear Strength Reduction Technique. The results indicate that slope failure is highly unlikely in Sectors 1 and 2 (FS > 1.50), unlikely but not fully meeting the safety criteria in Sector 3 (FS < 1.50), and highly probable in Sectors 4 and 6 (FS << 1.00), where unstable rock blocks and deeper structural slides are anticipated. In Sector 5, failure is considered probable (FS < 1.30) due to rockfalls, unstable blocks, and creeping weathered cover. For Sectors 7 and 8, assuming debris cover above the rock walls, failure is unlikely (FS > 1.50). In contrast, under the assumption of weathered material, it becomes probable in Sector 7 (FS < 1.30), and remains unlikely in Sector 8 (FS > 1.50). Due to the necessity of adopting several modelling assumptions, the results should be interpreted primarily in qualitative terms. The outcomes of this research provide a critical basis for assessing the stability of rock slopes within Wojciech Bednarski Park and support decision-making processes related to its planned revitalisation.

This study investigates the wall thickness and specific surface area (S_BET) of ammonium nitrate(V) samples of varying provenance. The research focuses on both fertilizer-grade ammonium nitrate(V) and three porous prill samples obtained from different manufacturers. The samples were analyzed using tomography scanning and two distinct porosimetry methods. The wall thickness analysis revealed that fertilizer-grade ammonium nitrate(V) possesses thicker walls, ranging from 0.05 to 0.40 mm, compared to porous prill-type ammonium nitrate(V), which predominantly exhibited wall thicknesses between 0.05 and 0.025 mm, with occasional thicker regions up to 0.040 mm. These variations in wall thickness are likely attributable to differences in manufacturing processes and prilling conditions specific to the ammonium nitrate(V) porous prill-type samples. The specific surface area (S_BET), derived from nitrogen adsorption measurements, indicated that the samples exhibited surface areas ranging from 0.011 to 0.466 m²·g, suggesting that these samples do not exhibit particularly high absorption capacities. However, the S_BET values obtained from the mercury intrusion method suggested significantly higher absorption capacities, falling within the range of 4.87–18.29 m²·g. These findings suggest that mercury porosimetry may provide a more accurate assessment of the porosity and absorption potential of ammonium nitrate(V) samples.

Rock salt is a potential medium for underground storage of energy resources and radioactive substances due to its physical and mechanical properties, distinguishing it from other rock media. Designing storage facilities that ensure stability, tightness, and safety requires understanding the geomechanical properties of rock salt. Despite numerous research efforts on the behaviour of rock salt mass, many cases still show unfavourable phenomena occurring within it. Therefore, the formulation of strength criteria in a three-dimensional stress state and the prediction of deformation processes significantly impact the functionality of storage in salt caverns. This article presents rock salt’s mechanical properties from the Kłodawa salt dome and a statistical analysis of the determined geomechanical data. The analysis is divided into individual mining fields (Fields 1–6). The analysis of numerical parameter values obtained in uniaxial compression tests for rock salt from mining Fields 1–6 indicates an average variation in their strength and deformation properties. Upon comparing the results of Young’s modulus (E) with uniaxial compressive strength (UCS), its value was observed with a decrease in uniaxial compressive strength (E = 4.19968·UCS², R-square = −0.61). The tensile strength of rock salt from mining Fields 1–6 also exhibits moderate variability. An increasing trend in tensile strength was observed with increased bulk density (σ_t = 0.0027697·ρ − 4.5892, r = 0.60). However, the results of triaxial tests indicated that within the entire range of normal stresses, the process of increasing maximum shear stresses occurs linearly ((σ₁ − σ₃)/2 = ((σ₁ + σ₃)/2)·0.610676 + 2.28335, r = 0.92). A linear relationship was also obtained for failure stresses as a function of radial stresses (σ₁ = σ₃·2.51861 + 32.9488, r = 0.73). Based on the results, the most homogeneous rock salt was from Field 2 and Field 6, while the most variable rock salt was from Field 3.

Bentonite slurry trenches are becoming increasingly popular in the excavation of trenches, especially for diaphragm wall construction. The problem that needs to be addressed is the stability of bentonite slurry trenches. This paper presents a stability analysis of trenches with temporary support from bentonite slurry, with unit weights ranging from 10.5 to 12.0 kN/m³ in the realistic stratum, and C3 in the Hue city area. Our analysis employs the Shear Strength Reduction Technique (SSR) with Mohr–Coulomb materials to numerically evaluate the factor of safety (FS). The finite element method (FEM) software program (RS2 v. 121 and RS3 v. 4.0) and the finite difference method (FDM) FLAC v. 7.0 software were used. Additionally, the limit equilibrium method (LEM) of Bell–Washbourne and three-dimensional (3D) Bishop were used to calculate trench stability. The results of the analysis show a good agreement between RS2 and FLAC2D, and between RS3 and FLAC3D. Secondly, upon comparison, it was noted that the factor of safety of the 3D software programs (RS3 v. 4.0, FLAC v. 7.0) was higher than that of the 2D software programs (RS2 v. 11.0, FLAC v. 7.0), ranging from 52.3 to 63.0% for trench lengths of 6 m. However, for trench lengths of 54 m, the factor of safety values in 2D and 3D configurations were nearly equal. Thirdly, the factor of safety of the Bell–Washbourne method (LEM) was lower than that of the numerical analysis methods (FLAC and RS programs). Using the three-dimensional numerical method appears to be effective for estimating stability.

The bentonite slurry trenches are becoming increasingly popular in the excavation process of trenches, especially for diaphragm wall construction. The problem that needs to be addressed is the stability of bentonite slurry trenches. This paper presents a stability analysis of trenches with temporary support of bentonite slurry, with unit weights ranging from 10.5 to 12.0 kN/m3, in the realistic stratum: C3 in the Hue city area. The analysis employs the shear strength reduction technique (SSR) with Mohr-Coulomb materials for the numerical method to evaluate the factor of safety (FS). The finite element method (FEM) software program (RS) and the finite difference method (FDM) FLAC software were applied. Additionally, the limit equilibrium method (LEM) of Bell-Washbourne and three-dimensional (3D) Bishop are used for calculating trench stability. The analysis results show a good agreement between RS2 and FLAC2D and RS3 and FLAC3D. Secondly, upon comparison, it is noted that the safety factors of the 3D software programs (RS3, FLAC3D) are higher than those of the 2D software programs (RS2, FLAC2D), ranging from 52.3 to 63.0% for trench lengths of 6m. However, for trench lengths of 54m, the safety factor values in 2D and 3D are nearly equal. Thirdly, the safety factor of the Bell-Washbourne method (LEM) is lower than the numerical analysis methods (FLAC and RS programs). Using the three-dimensional numerical method appears to be effective for estimating stability.

The surface of Phobos is an intriguing subject of research for many scientists. This is associated, among other things, with the fact that it is perceived as a potential launch site for future human Mars exploration. Additionally, measurements conducted on its surface would not only deepen our knowledge about Phobos but also provide insights into geochemical processes occurring on similar small bodies in the Solar System. Therefore, understanding the physical–mechanical properties of regolith is a crucial aspect of planetary exploration. These properties are key factors needed for both planning safe landings and establishing future bases on celestial bodies. In this paper, information is compiled regarding hypotheses about its origin, the probable composition of Phobos’ surface (spectral properties and HiRISE data), as well as its morphology. The article also presents the process of regolith formation covering Phobos’ surface and its presumed physical properties. It has been established that the estimated bulk density of Phobos, compared to the densities of other asteroids and meteorites, is most similar to C-type asteroids. It was also found that C-type asteroids, in terms of total porosity, best reflect Phobos. However, determining the surface composition of Phobos and its detailed physical properties requires additional information, which could be obtained through in situ studies or sample return missions.

The hazards of gaseous geodynamic phenomena and rockbursts are among the most challenging to assess and classify. This perception arises from both a review of the literature and an examination of available instructions and regulations in underground mining facilities. The hazard of gaseous geodynamic phenomena in Polish copper ore mines only appeared in 2009, whereas these phenomena occur and are commonly described in other mining countries. In Polish copper ore mines, due to the room and pillar system in fields with lengths of about 460 m, very often parallel to neighboring fields, which together give a length of about 900 m, it is difficult to identify the location of gas traps due to the large size of the area. This paper presents an analysis of the influence of the velocity of the excavation on the possibility of escalating or reducing the described mining hazards. An analysis of the impact of excavation velocity on the state of gaseous geodynamic and roof fall hazards was conducted for two mining fields. For the considered mining fields, the hypothesis was formulated that an excavation velocity greater than or equal to 17 m/month positively influences a reduction in both gaseous geodynamic and roof fall hazards.

The article presents the results of the third research stage on the potential microstructured charcoal additives in ANFO. The charcoal powder was liquid adsorption-treated with Fe in various ratios. Adding MC-Fe to ANFO changed the exothermic peak’s position from ca. 280 °C to 250 °C due to lower activation energy, which influenced the kinetics of the reaction. Bruceton’s test indicated that the MC-Fe addition to ANFO resulted in ca. 10% lower initiation energy in comparison with pure ANFO. However, the energy level did not influence the potential applicability of the additives. The fumes analysis indicated a lower concentration of CO for all tested samples; however, the concentration of NO_x rose. The thermodynamic calculations confirmed the experimental results, which could be explained by the increased positive oxygen balance. Moreover, all analyses showed that the most promising blasting properties referred to the ANFO sample containing the microstructured charcoal additive of a C:Fe ratio of 4:1. Therefore, further research will be dedicated to advanced studies between the chemical composition of this specific ANFO sample and its physicochemical and blasting properties.