Marl, a transitional soft rock, exhibits complex geotechnical behavior due to its heterogeneous structure, parallel fissures, and variable cementation. The difficulty of obtaining undisturbed samples suitable for laboratory testing makes field-based calibration essential for realistic modeling of excavation performance. This paper presents field observations and numerical back-analysis of a strut-free excavation in marl rock supported by buttress pile walls. The study aims to calibrate the stiffness parameters of the Hardening Soil (HS) model to accurately reproduce the deformation behavior of the marl under actual excavation conditions. Field observations and a monitoring program, including systematic inclinometer measurements, were implemented to provide reliable reference data for model calibration and validation. The excavation was almost entirely in marl, ensuring consistent geotechnical conditions and eliminating the influence of other soil or rock layers that often complicate similar case studies. A three-dimensional finite-element back-analysis was conducted to evaluate the deformation behavior of the self-supporting buttress pile wall during staged excavation and to determine the stiffness parameters that best reproduce the observed field performance. Since both shear strength and stiffness govern wall displacements, shear strength values were fixed based on independent large-scale direct shear tests on intact marl and discontinuity samples from previous studies. Consequently, the analysis focused on identifying stiffness characteristics representative of marl rock under real excavation conditions. The calibrated parameters successfully captured the observed wall and ground deformations, providing a realistic representation of the excavation behavior. The findings offer valuable guidance for similar engineering problems, supporting more reliable prediction of system response in weak and transitional marl formations. Moreover, the results contribute to improved risk management and more informed geotechnical design decisions in future excavation projects under comparable geological and structural conditions.

Landmines and explosive remnants of war are still present in the Western Balkans and remain a deadly legacy of the hostilities at the end of the 20th century. Over the years, several incidents have occurred in Bosnia and Herzegovina, in Serbia, and in Croatia where intact ordnance has caused injuries and fatalities. Floods, torrential flows, and gravitational mass movements pose a particular threat. Landmines and explosive remnants of war are mobilized and displaced into previously uncontaminated areas. We first discuss the historical and technical background of this hazardous situation. We then show which hydro-morphological processes are responsible for the mobilization and displacement. We then illustrate how a prediction of the likely contaminated areas can be obtained. We show that the problem can only be tackled using a stochastic-deterministic model. However, for the eventual development of risk-hazard maps, preliminary work using laboratory experiments and field surveys is required. The article, therefore, proposes a novel approach to the problem in an international research project. The aim would be to produce risk-hazard maps that can be used by elected decision-makers, administrative authorities, and emergency personnel in affected municipalities.

The interaction between geogrid/wire fabric reinforcement and fill material in reinforced earth walls, as well as its quantification, is a complex problem that depends on a number of factors. This paper presents and discusses state of the art related to numerical simulations of pull-out tests used for investigation of interaction between cohesionless fill and reinforcement. In addition, the results of a specially designed group of numerical simulations are presented and compared with recommendations of American and European standards related to such experiments.

Abstract This paper presents the details of experimental and numerical analysis performed on three 0.8 m-high reinforced earth model walls with strip footing surcharge near the wall facing. The study investigates how wire mesh strength and geometry affect the failure mechanism. All three walls were nominally identical, except for reinforcement strength and geometry. The displacement field of the entire cross section was captured by high-resolution digital camera through transparent sidewall. The resulting images were analyzed using digital image correlation software. The results indicate that both reinforcement strength and aperture size influence the type of failure mechanism. Numerical modelling was also applied to assess the influence of sidewall friction (3D model) and reinforcement stiffness and strength (2D model) on the failure mechanism of the walls. The parameters for the numerical models were derived from independent tests and results, which were compared with the experimental observations. A good level of agreement with measurements was confirmed, even for the 2D model that excluded sidewall friction.

Institute for Materials and Structures of the Faculty of Civil Engineering in Sarajevo conducted static and dynamic testing of the RC track slab in the railway tunnel Ivan. Due to the tunnel age, traffic in the tunnel was impeded so that the reconstruction of the complete track bed structure was executed. A so-called integrated structure in which the prefabricated sleepers are connected to a stiff concrete slab by using reinforcement was applied for the first time in Bosnia and Herzegovina. The track slab was founded on heterogeneous material which includes weathered marl, granular material as well as amphibolite or schist rocks. The deflections measured under service load simulated by a locomotive and eigen frequencies indicate that the structure is quite rigid. Experimentally obtained data was used for numerical modelling of short-term settlement assuming Mohr-Coulomb material model in Plaxis and the results match quite well.