ASSESSMENT OF THE VOLUME AND COST OF RESOURCES OF THE PREPARATORY STAGE OF THE FOUNDATION OF THE ROADBED IN THE FORESTED AREA

Abstract

The peculiarities of natural and climatic conditions and properties of territories determine the development of design solutions that ensure the required operational reliability of the projected highways. Ensuring the strength and durability of the pavement is largely achieved by the strength and immutability of the roadbed, the quality of excavation, rational (reasonable) placement of soils in the base of the roadbed, with the required physical and mechanical properties that minimize the process of transition to a state of unstable equilibrium, which is one of the reasons for the deformation of the roadbed on a weak foundation. The process of making a design decision that takes into account the removal and replacement (partial or complete) of weak soil, or the inclusion of measures to ensure the stability of the foundation and the layers of the roadbed, is carried out on the basis of a feasibility study and comparison of options. The determining criteria for making a sound technical decision are the quantitative and cost indicators of the volumes of preparatory and excavation work performed on the construction and strengthening of the foundation of the roadbed. Taking into account the absence of normative indicators that take into account the depth of soil development during the uprooting of stumps and the requirements for removing root systems during the passage of the route through forested terrain, an approach is proposed that allows us to assess the quantitative indicators of excavation and resource costs in the preparatory stage for construction. The essence of the approach consists in organizing, conducting and fixing trial uprooting of root systems of trees growing on a typical selected forest plot (with documentary photo and video confirmation, registration of inspection certificates and fixing of technical parameters), in order to identify the influence (functional dependence) of the types of growing trees, spatial distribution (occurrence) of the bulk of the root systems being removed, the means of mechanization used for the depth of development (stripping) of the soil layer and determining the scope of work on excavation and filling of the replaced soil at the base of the embankment of the roadbed.

Subject of research. The subject of research is the design solutions of the preparatory stage of the construction of a linear object, taking into account the features and specifics of the work, affecting the amount of excavation work on excavation and filling of the replaced soil at the base of the roadbed. The design solutions considered in the study relate to the preparatory stage of laying the route of a linear object in a wooded area.

Materials and methods. The conditions and factors influencing the process of developing and making design decisions of the preparatory stage of the construction of the roadbed of highways passing through forested terrain were studied. The research method is structural and functional analysis.

Results: The factors and conditions of construction production affecting the determination of quantitative parameters of the production of earthworks as part of design solutions for the construction of the embankment of the roadbed are considered. The properties (conditions) of the natural environment (forested area), the characteristics of the spatial distribution of the root systems of tree species, the normative indicators of the removal of the fertile layer depending on the types of soils, as well as the requirements for the organization of work on the preparation of the foundation of the roadbed, including clearing of tree and shrub vegetation, are analyzed.

Conclusions: The conditions are formulated for the adoption of sound technical decisions of design, working and organizational and technological documentation related to the quantitative indicators of excavation work to remove the root systems of trees and replace weak soil at the base of the roadbed during the passage of the highway route through the forested area. An approach is proposed that provides a basis for adjusting the technical solutions of the preparatory stage of the construction of the roadbed, including conducting a trial uprooting of trees growing in the nearest forest area with the identification and fixation of the depth of distribution of the main root systems.