The problem of improving the state of deformation of landmarks is an important aspect when performing civil services, because they have a historical interest and bring symbolisms which relate to an event of particular interest for the community. The engineering–geological surveys, technical evaluation and operational suitability of landmarks of national significance are performed to improve the state of deformation. The conducted analytical assessment of landslide hazard slope stability in the RocScience Slide computational complex shows that in the presence of landslide prevention works, and the stability coefficient is increased by a factor of 1.21–1.37. The regularities of deformation and strength parameters of the soil–cement obtained during the jet-grouting application indicated an increase in strength gain of amplifier elements by an average of 1.6–4.0 times. This proves the effectiveness of the jet-grouting application for improving the state of deformation of landmarks of national significance.

Purpose is to identify vertical displacements of the “soil basem strengthened with piles or micropiles based upon drilling-mixing technology” system relying upon parametric analysis of strain state of the mentioned system, and arrangement of the strengthening elements. Methods. Mathematical modeling took place for twelve finite-element models using the computing complex SCAD intended to analyze strength of structures by means of finite-element method. Numerical analysis was carried out with variation of elastic-strain modulus of vertical reinforcing elements and change in distance between them (3d and 6d of micropiles). Findings. Results of parametric analysis have been obtained for a model without a micropile (non reinforced soil base); a model with a single micropile; a model with two micropiles where distance between them is 1.5 m, i.e. 3d of micropiles; and a model with two micropiles where distance between them is 3.0 m, i.e. 6d of micropiles. The performed comparative analysis has made it possible to obtain the results proving the hypothesis by the authors as for the specific nature of vertical displacement formation of the “soil base strengthened with piles or micropiles based upon drill-mixing technology” system. Originality. It has been identified for the first time that basing upon the standardized document for the auger or displacement piles, it is impossible to decrease efficiently vertical displacements while approaching micropiles since distance between the micropiles is 3d for elements, developed on the basis of the drilling-mixing, is minimal. Practical implications. The obtained results of a strain state may become the keystone for the development of the genera-lized strain theory of the composite “soil base strengthened with piles or micropiles based upon drilling-mixing technology” system as a medium differing in minor changes of strain characteristics.

The paper deals with damages of transport constructions made of corrugated metal structures in the body of a railway track or a road during their operation. A constructive variant to restore the bearing capacity of structures was developed, which consists of installing an annular stiffening rib into the concave part of the corrugated metal profile. The main advantage of this method compared to the double corrugating method is the possibility of performing the reinforcement works during structure operation without interrupting the movement of transport vesicles. The study has proved that the reinforcement method significantly increases the carrying capacity of corrugated metal structures. A numerical finite element model was developed to determine the stress-strain state of structures made of corrugated metal structures reinforced with round stiffening ribs. The soil pressure on the corrugated shell in the model is taken into account with the application of radial and axial forces on the outer surface of the shell. It was determined that the most appropriate location of the ribs is in the centre of the building, where the reinforcement area corresponds to the width of the road or railway line. The advantage of this approach is the ability to more efficiently distribute the reinforcement material by selecting the ribs in the most loaded sections of corrugated metal structures.

Purpose. The study aims to optimize the design and reduce soil nail length in deep excavations with a soil nail system in fast-draining soils. Additionally, it investigates the parameters influencing slope stability in fast-draining soils. Methods. Integrating field and lab data with soil nail properties and advanced modeling, this study investigates how fixed nail length, inclination and spacing affect the stability of a 20 m-deep excavation in fast-draining soil. Findings. The study findings reveal that optimal parameters, such as nail spacing and inclination angle, have been identified for reinforcing deep excavation walls, ensuring stability with minimal nail length. Notably, the stability of excavation walls can be achieved without the need to increase the length of the soil nails. The recommended parameters are characteristic of an 8-meter-long soil nail system, a 30-degree inclination angle, and a spacing of 1.5×1.5 meters. Originality. This study presents a novel perspective on the structural characteristics of soil nails by determining emphasizing nail spacing, inclination angle, and fixed nail length. It offers a comprehensive framework for designing soil nail walls in fast-draining soils during deep excavations, contributing to advancements in open-cut excavation practices. Practical implications. The study offers practical implications for designers involved in deep slope earthworks, enabling the development of efficient and rational design solutions that ensure excavation stability and prevent displacement during excavation while reducing costs and project duration.