On the effect of reducing preparation during foundation discretisation

When designing and operating overhead power line pylons in challenging geological conditions, such as permafrost (perennially frozen) soils, particular attention must be paid to the design of the foundations. Most foundations constructed in areas with permafrost are built using standard driven reinforced concrete piles. In frozen soils, this design is characterized by relatively low material costs and greater load-bearing capacity for horizontal loads and uplift loads, however, this type of structure is most susceptible to the effects of frost heave. A wide range of structural and technical measures has been developed to counteract heave. The authors’ analysis of the proposed solutions has shown that most of the measures implemented in domestic practice require further research.

The aim of this study was to justify the use of shallow strip foundations, to confirm their effectiveness, and to identify the most rational structural solutions (configurations of foundation elements). The aim of this study was to justify the use of shallow strip foundations, to confirm their effectiveness, and to identify the most appropriate structural solutions (configurations of foundation elements).

To analyse vertical deformations and overall behaviour. For strip foundations of various configurations, analytical calculation methods were selected, such as the layer-by-layer summation method and the linearly deformable layer method, as well as numerical methods, using a specialized geotechnical software package implementing the finite element method. Quantitative data were obtained on the settlements of continuous slab and element foundations, as well as their influence on the surrounding soil mass. The effectiveness of using element foundations was established in terms of a reduction in vertical deformations of up to 30–40% compared to a standard continuous slab foundation. Graphical materials illustrating the behaviour of the soil mass are presented for each foundation configuration.

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