О расчете размывающих скоростей при проектировании фильтрующих сооружений в связных грунтах

Abstract

Objective: To develop a method for calculating erosion rates in the place of contact of filtering structures with cohesive soils. Methods: Previously at the VNIIG n. a. B. E. Vedeneev, hydrodynamic and strength criteria of contact suffusion were established concerning hydraulic structures. However, there were no calculated dependencies for determining the critical Reynolds number and, accordingly, the critical velocity for coarse-grained materials. Through special processing of experimental data on filtration in non-cavity drain fillers of various grades, it was possible to integrate numerous curves into a single one, making it possible to isolate the transient regime boundaries and obtain a formula for the critical Reynolds number. This made it possible to calculate the critical rate. As a result, a formula was obtained for calculating the erosion rate. Results: The calculated dependencies made it possible to determine the critical rate for the filler material and the erosion rate at the contact boundary between the filtering structure and the soil, based on the initial data of the coarse-grained material from which the filtering structures are made, and the characteristics of the soils in which they are built. Practical importance: The proposed calculation method made it possible to: 1) establish whether the manifestations of erosion by the filtration flow are possible in the place of contact of the filtering structure with the soil; 2) develop measures to eliminate erosion. Geotextile material can be laid along the border of the contact of the filtering structure with the soil, or a finer material can be used as a filler in the filtering structure, the actual filtration flow rates in which will be less than the erosional rates. In this case, the erosion rates in the place of contact with the finer material will increase.