RU2765770C1 - Variable-pitch geogrid for reinforcing slopes and adjacent ground surfaces - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the field of construction and can be used to strengthen the slopes, cones of bridges, inclined foundations of highways, industrial and construction sites, as well as coastlines, water courses. A geogrid with a variable pitch for reinforcing slopes and slopes is made of strips of thermoplastic polymer material, preferably of low- or high-pressure polyethylene strips, interconnected in parallel rows with a pitch along the length of the strip and with a staggered offset. The geogrid is made in sections connected into a single block along the slope length, while the step in each subsequent geogrid section is different along the slope length - from the minimum value at the top of the slope to the maximum value in its lower part. The number of cells in each section of the geogrid is doubled in the next section relative to the previous one, while the number of cells with the same pitch in the geogrid block depends on the length and angle of the slope.

EFFECT: ensuring the possibility of obtaining a geogrid, divided into sections, with a variable pitch of each section, which allows evenly distributing the load over the entire surface of the slope, which contributes to increasing the reliability of the geogrid, increasing its strength.

1 cl, 3 dwg

Description

The invention relates to the field of construction. The geogrid is intended for reinforcing both slopes and surfaces adjacent to them. The proposed geogrid can be used in the construction of pavements, and for strengthening railway tracks and slopes. And also in many other use cases, in the transport, hydraulic engineering industries of construction, where high and stable indicators of strength and durability of the structures being built are required.

Various devices are known from the prior art (patent RU 2358063, published on 06/10/2009 and patent RU 2152480, published on 07/10/2000), in which spatial polymer gratings, in particular the so-called "geo-grids", are used to fix the slope surface layer.

Geogrids are made from flexible and durable polymer tapes, by cutting the tapes into measured strips and fastening them together in a checkerboard pattern with transverse seams, cellular structures are obtained that can fix and hold the soil masses loaded into the cells from displacement.

The material for the manufacture of these tapes is usually used polyethylene of various grades. Polyethylene strips are flexible, durable, resistant to adverse natural factors.

However, when this type of geogrid is placed on slopes, the load on it increases with an increase in the angle of slope, which reduces its strength, compared with the horizontal arrangement of the same geogrids, due to an increase in the rupture force.

The problem solved by the invention is to increase the bearing capacity of the reinforced soil surfaces by equalizing the specific loads over the entire surface of the slope.

The closest in technical essence to the present invention is a lattice with a cellular structure and a method for its manufacture (see patent RU 2129189, published 20.04.1999).

Grid with a honeycomb structure for stabilizing and fixing the ground surface, made of flexible polymer strips. They are mounted on ribs and interconnected by welded seams in a checkerboard pattern. The welds are located vertically or obliquely with respect to the ribs of the strips, which are made from a composition containing a mixture of high pressure polyethylene and low pressure polyethylene. At the same time, the size of the cells, according to the height of their location on the slope, is made increasing from the beginning to the base of the slope

However, the resulting effect is reduced due to the greater weight of the soil held by the geogrid.

The greater the angle of inclination of the slope or slope, the greater the force acting on the break of the geogrid and, in particular, on its weak element, the connection of the horizontal and inclined blocks. As a result, the strength at the joints of the blocks is violated, which can lead to the destruction of the geogrid and, in turn, the collapse of the reinforced soil.

The claimed invention is aimed at eliminating the indicated drawback of this type of geogrid by solving the problem of increasing the strength and stability of the geometric parameters of the geogrid during operation under load on slopes and slopes.

The technical result of the invention is to divide a single geogrid block into sections with a variable pitch of each section. The step size varies from the minimum at the top of the slope to the maximum at the bottom. In the section at the top of the slope, in the most loaded area, the geogrid spacing is minimal, and in the section at the bottom of the slope, the maximum. Reducing the step and, accordingly, the size of the geogrid cell leads to an increase in its strength due to an increase in the number of welds. As you move down the slope, the load on the geogrid decreases and, therefore, you can increase the cell size and, accordingly, the geogrid spacing.

The use of a geogrid with a variable pitch makes it possible to evenly distribute the load over the entire surface of the slope, which contributes to an increase in the reliability of its operation.

Also, the use of this type of geogrid makes it possible to increase the strength of the weakest point - the transition zone, where the maximum soil shedding occurs due to a decrease in the specific load on the upper section of the slope.

In addition, the claimed geogrid, with its simplicity, opens up the possibility of its use in new areas that require increased strength and stability of structures, for example, in the slopes of the embankment of railways, as well as directly under the railroad and highway bed during long ascents and descents. To achieve the specified technical result, a spatial polymer lattice is proposed.

Figure 1 shows a section of a slope with inclined and horizontal geogrid blocks located on it.

The figure 2 shows a drawing of a geogrid sweep on a slope or slope.

The figure 3 shows a drawing of the connection of sections with different steps between them.

All strips of geogrid sections are made of the same width. Section 1, located at the top of the slope, has a minimum pitch (Fig. 2). Section 2 has a pitch and the number of cells twice that of section 1. Section 3 has a pitch and the number of cells twice that of section 2, and so on until the end of the slope.

Empirically, the relationship between the length of the slope L _otk , geogrid cell pitch, L _{i i} , D _cell , depending on the angle of inclination of the slope α.

The advantage of the claimed geogrid is the ability to achieve uniform load distribution over the entire area of the slope. An increase in the geogrid spacing in each section relative to the previous section leads to a decrease in the specific load on the geogrid in the most loaded areas of the slope surface.

The connection of the sections to each other (Fig. 3) in the zone of connection of the strips 4 of the geogrid with different cell pitches makes it possible to strengthen the connection of the sections with additional welds 5 of the geogrid. This allows you to create an additional reinforcement of the geogrid block at the junction of the sections.

Thus, the technical result of the claimed invention is achieved in terms of increasing the strength and stability of the geometric parameters of the geogrid structure, as well as increasing the bearing capacity of the reinforced soils.

Claims (1)

Variable pitch geogrid for strengthening slopes and slopes, made of strips of thermoplastic polymeric material, preferably of low or high pressure polyethylene strips, interconnected in parallel rows with a step along the length of the strip and with a checkerboard offset, characterized in that the geogrid is made sections connected into a single block along the length of the slope, while the step in each subsequent section of the geogrid is different along the length of the slope - from the minimum value at the top of the slope to the maximum value in its lower part, and the number of cells of each section of the geogrid doubles in the next section relative to the previous one, at the same time, the number of cells with the same step in the geogrid block depends on the length and angle of the slope.

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