Introduction. Protecting the underground parts of industrial and civil buildings and structures from the effects of water of various origins, including groundwater, infiltration water, man-made leaks, and other sources, is a key objective in increasing their durability. To protect underground and buried structures from flooding, primary and secondary protection of the concrete enclosing structure is provided. Primary protection encompasses all necessary measures to create a watertight structure (concrete composition design, placement and compaction technology, etc.). Secondary protection measures include the installation of waterproofing and anticorrosive coatings, as well as the construction of water drainage systems (wall, bed, and ring drains). As a rule, secondary protection is achieved using waterproofing coatings, roll, and sheet coatings, while backfill made of graded sand or gravel serves as wall drainage. This paper is devoted to the problem of protecting underground buildings and structures from the harmful effects of surface and groundwater. Materials and methods. The study focused on two-layer composite materials. The base layer for all types was a profiled sheet of virgin low-density polyethylene (HDPE) with rounded, volumetric protrusions 8-10 mm high and a filter geotextile. Two types of rolled composite materials designed for wall drainage were selected. Studies were conducted to determine the effect of the degree of compression of composite drainage materials with different geotextiles from the backfill soil on its water permeability. To calculate the lateral soil pressure on the drainage material, the following factors were taken into account: the depth of the underground structure and the soil type. Results: Various methods of waterproofing underground structures and drainage systems are analyzed. The effectiveness of the materials used is assessed. Roll-type composite drainage systems consisting of a base layer of profiled polyethylene sheeting and nonwoven geotextile materials are considered. The results of studies of the water permeability of two types of drainage systems with different base layer and geotextile shell configurations are presented. A comparative analysis of the water permeability of these materials under the pressure of various backfill soils at different underground structure installation depths is provided. The results of suffusion studies of these systems when operating in the most hazardous soils (fine and silty sands) are also presented. Conclusions: Based on the obtained results, it was concluded that the water permeability of profiled sheets and the pore structure of nonwoven geotextiles allow their use in drainage systems at depths of up to 15 meters, depending on the backfill soil type. The use of rolled composite drainage materials will significantly improve the quality of protection for underground structures and reduce labor intensity compared to other drainage systems.
Olga Lyapidevskaya (Fri,) studied this question.