5.2 DETERMINATION OF THE LOAD ON THE ARCH GALLERY FROM THE IMPACT OF A SINGLE STONE

Abstract

The load magnitude and penetration depth of an arched gallery structure from a single stone determined theoretically and experimentally. When using antiseismic structures, it is necessary to consider the degree of risk from the proposed changes in the structure, since it is possible that an economically developed structure in case of a possible earthquake will lead to negative end results.

Кeywords: arch gallery, earthquake, rockfall, rockfall load

Introduction

Due to sharply increased volumes of transportation, especially in mountainous areas, more stringent requirements to traffic safety in our country and the vital need for uninterrupted traffic at any time of the year, avalanche-protective and kmneprotective galleries on railroads are becoming more and more widespread despite the high estimated cost and difficult conditions of construction. The analysis of the design of these structures shows that the design has a number of deficiencies in the rational consumption of materials and in the technology of construction of the structure. Studies of already built structures show the inaccuracy of existing calculations

Avalanche protection galleries, retaining walls, and massive foundations are engineering structures for which the stiffness parameters in various directions are many times greater than those of the foundation [1,2]. In these cases, the motion of the system under dynamic actions is determined by the deformations of the foundation [3]. Such structures can be modeled by a system of non-deformable bodies, and the soil base can be modeled by distributed elastic bonds.

Research methodology

In the process of theoretical and experimental studies, the depth of immersion of the stone in the ground was obtained and the load transferred to the gallery slab, which works in bending and is the most vulnerable part of the structure, was determined. The gallery overlap is supported by a retaining wall and supporting columns, which are in slightly better conditions for the performance of their functions, but all these parts have different dynamic stiffness, which complicates the conditions of joint operation under the influence of earthquakes. The gallery of the arch structure is a single system in terms of stiffness, and its structural elements work mainly in compression, which makes it possible to fully utilize the strength properties of concrete and reduce the percentage of reinforcement [4].

It is necessary to specify the depth of penetration of a single stone into the soil of the gallery backfill, as well as the impact force of the stone on the structure of the arch stone protection gallery, the working conditions of which differ significantly from the gallery of rectangular outline. In addition, calculations and experimental studies of stone impact loads on the gallery should reveal the influence of the properties of the backfill soils and the degree of their moisture content, which will allow recommending certain soils to improve the working conditions of the gallery during an earthquake, activate the descent and weaken the impact of stones.