RU212073U1 - Well element - Google Patents

Abstract

The utility model relates to the construction of underground engineering structures, namely to systems for water supply and sanitation networks, and can be used in the construction of systems that operate at a high level of groundwater, with a seasonal rise in groundwater in environments with varying degrees of aggressiveness from the outside. surrounding soil, as well as in plastic and mobile soils. Well element, including a wall part and a folded end surface made in the form of a tongue-and-groove, characterized in that it is made of concrete of a class of at least B30, and the ridge of the folded end surface is made of a reinforced rod of class AIII (A500) with a thickness of at least 8 mm. The technical result is an increase in the durability and tightness of the well by increasing the strength of the butt joint of the elements of the well.

Description

The utility model relates to the construction of underground engineering structures, namely to systems for water supply and sanitation networks, and can be used in the construction of systems that operate at a high level of groundwater, with a seasonal rise in groundwater in environments with varying degrees of aggressiveness from the outside. surrounding soil, as well as in plastic and mobile soils.

From the prior art, the use of reinforced concrete rings in the construction of wells is known (LLC Obninsk Plant of Composite Materials, https://ozkm40.ru/blog/armirovanie-betonnykh-kolets/, accessed 15.01.2022). The well ring is a cylindrical element, reinforced with a mesh of fiberglass rods, with end profiles (tongue-groove). This design eliminates the possibility of the ring being destroyed when it is lifted beyond 2 points, i.e. ensures safety during transportation and installation.

Such rings (well elements) do not ensure the durability of the well as a whole for the following reasons. The reinforcing mesh is placed in the mass of the ring (rings) only in the central, middle part of the ring (rings); the end parts (groove-ridge), which are the butt joint of the rings, do not contain a reinforcing mesh. Therefore, during long-term operation, as well as in the case of operation in aggressive conditions (plastic soils, significant temperature differences, etc.), the butt joint of the rings is destroyed, the rings are displaced relative to each other with the breakage of the groove and ridge elements and, accordingly, a violation of tightness with complete loss of functionality of the well as a whole. In addition, an attempt to reinforce the butt joint with fiberglass will also not provide high strength of the joint, since fiberglass reinforcement is brittle with slight bending loads that occur during well operation even in relatively stable soils.

The closest in technical essence is a lined sewer well (RU152410, publ. 05/27/2015). The well consists of a neck, a tray part and a working chamber. The elements of the prefabricated well are made of reinforced concrete and have a protective lining of the internal surfaces with a polyethylene liner made of polyethylene sheets with anchor ribs having T-shaped heads connected directly to the concrete in such a way that the inner surface of the lined well remains smooth, while the dimensions of the polyethylene sheets with anchor ribs are selected based on the dimensions of the reinforced concrete element. The tray part is made of concrete. The polyethylene liner is installed in the process of molding the reinforced concrete structure of the well during its manufacture under production conditions. The elements of the well are connected to each other by means of a tongue-and-groove butt joint, sealed with cement mortar.

The disadvantage of the known well, selected as a prototype, is the fragility. This is due to the fact that during operation, the cement mortar crumbles from adjacent elements of the well due to seasonal heaving of the soil and dynamic loads from transport, the tongue-and-groove butt joint is destroyed, and, consequently, the tightness of the well is violated, which leads to the impossibility of the well to fulfill its functional purpose ( for example, a well deforms, asphalt sinks, groundwater flows into the wastewater transportation system, etc.).

The technical problem is the creation of a durable and sealed well by increasing the strength of the butt joint of the well elements.

The technical result consists in increasing the strength of the locking edge of the well element (folded butt surfaces).

The technical result is achieved by the fact that the element of the well, including the wall part and the folded end surface, made in the form of a tongue-and-groove, according to the utility model, is made of class B30 concrete, and the ridge of the folded end surface is made of a reinforced rod of class AIII (A500) with a thickness of 8-10 mm .

The authors of the utility model experimentally found that the high strength of the butt joint of the well elements is achieved with the optimal combination of the class of concrete and reinforcement used for casting the well elements. Thus, the authors carried out full-scale tests of wells of various sizes and materials used (concrete and reinforcement) in various operating conditions (well depth, type of surrounding soil and transported medium, influence of climatic conditions, etc.). The condition of the wells was assessed for 10 months. (every 2 months) by visual inspection of the internal cavity of the well and the surrounding space (for obvious seepage of groundwater into the well, as well as for the formation of holes (failures) near the hatches, which are formed due to washing out of the soil surrounding the well). The test results are shown in the table.

Table

Well diameter, mm Sample No. Well concrete grade Reinforcement class Rebar thickness, mm Well wall thickness, mm Butt joint dimensions (tongue and groove height), mm Result 1000 one IN 20 AI (A240) four 120 75 destruction of the butt joint, displacement of rings, formation of holes around the well 2 IN 20 AIII (A400) four 120 85 destruction of the butt joint, displacement of rings, formation of holes around the well 3 IN 20 AIII (A500) four 120 75 spalling of the butt joint, displacement of rings, formation of holes around the well four B30 AIII (A500) 6 120 85 spalling of the butt joint, displacement of rings, formation of holes around the well 5 B30 AIII (A500) eight 120 75 there is no destruction, maintaining the full functionality of the well 6 B40 AIII (A500) eight 120 85 there is no destruction, maintaining the full functionality of the well 7 B50 AIII (A500) eight 120 75 there is no destruction, maintaining the full functionality of the well 1200 eight IN 20 AI (A240) 6 135 75 destruction of the butt joint, displacement of rings, formation of holes around the well 9 IN 20 AIII (A400) ten 135 85 spalling of the butt joint, displacement of rings, formation of holes around the well ten B30 AIII (A500) 6 135 75 spalling of the butt joint, displacement of rings, formation of holes around the well eleven B30 AIII (A500) ten 135 75 there is no destruction, maintaining the full functionality of the well 12 B40 AIII (A500) 12 135 85 there is no destruction, maintaining the full functionality of the well 13 B50 AIII (A500) ten 135 75 there is no destruction, maintaining the full functionality of the well 1500 fourteen IN 20 AI (A240) 6 150 75 destruction of the butt joint, displacement of rings, formation of holes around the well fifteen IN 20 AIII (A400) ten 150 85 spalling of the butt joint, displacement of rings, formation of holes around the well 16 B30 AIII (A500) 6 150 85 spalling of the butt joint, displacement of rings, formation of holes around the well 17 B30 AIII (A500) ten 150 75 there is no destruction, maintaining the full functionality of the well eighteen B40 AIII (A500) 12 150 85 there is no destruction, maintaining the full functionality of the well 19 B50 AIII (A500) ten 150 75 there is no destruction, maintaining the full functionality of the well

Analysis of the table shows that in wells of various sizes, the use of low grades of concrete with reinforcement of small thickness (samples No. 1, 2, 3, 8, 9, 14 and 15) leads to the destruction of the well during operation (during periods of freezing and thawing of the soil) , i.e. butt joints are destroyed, the rings are shifted relative to each other, which leads to a violation of the tightness of the well, the flow of a large amount of groundwater into the sewerage network and the washing out of the contents of the well into the surrounding space. Such wells were subject to regular repair to restore the cement mortar sealing the joint, which, however, did not restore the original degree of tightness of the well and still led to an increase in the amount of drained water discharged to the treatment plant. The use of thicker reinforcement (samples Nos. 4, 10, 16) still did not ensure the long-term functioning of the well: there was local spalling of the butt joint and, accordingly, leakage, which, however, could be repaired without changing the well (by covering the chipped plots). Thus, the most optimal combination of the declared distinguishing features has been established, namely the use of concrete of a class of at least B30 and reinforcement of classes of class AIII (A500) with a thickness of at least 8 mm for various sizes of butt joints.

The claimed utility model is illustrated by drawings, where in Fig. 1 shows a schematic representation of one of the embodiments of the well (size), assembled from the elements of the well with the stated design features, in Fig. 2 is an enlarged view of the butt joint of adjacent elements of the well, in Fig. 3 - view of the butt joint of adjacent elements of the well, with a sealing ring.

The utility model is described using the most common well design as an example. The well contains the following elements: a bottom 1, several wall rings 2, a neck ring 3, a support ring 4 and a hatch 5 (a storm water inlet). Depending on the needs of operation, the well may contain other elements, for example, a floor slab, a transition slab, a bottom plate, a ring neck, etc. (not shown in the figures).

Elements of the well 1-4 in general form include a wall part and a folded end surface made in the form of a tongue-and-groove, and are made of concrete of a class of at least B30. Between themselves, the elements of the well 1-4 are connected by mating the folded end surfaces, i.e. using a butt joint 6 "groove-comb" (Fig. 2).

The crest of the folded end surface (butt joint 6 "groove-groove") of each element of the well is made of a reinforced rod of class AIII (A500) with a thickness of at least 8 mm. Rings 7 made of steel rods of class AIII (A500) with a thickness of at least 8 mm were used as reinforcement, located in the mating elements of the butt joint, i.e. in tongue and groove, as shown in Fig. 2. The rods used have a profile with crescent-shaped protrusions that do not intersect with longitudinal ribs, which ensures high plastic and strength characteristics, and are characterized by high corrosion resistance.

Class AIII (A500) rebar is manufactured in accordance with GOST R 52544-2006 from low-carbon steel grades 35G2S and 35GS in two ways: hot-rolled in the production of rod reinforcement and cold-drawn in the manufacture of rolled and wire rods. Class A500 steel has a profile with crescent-shaped protrusions that do not intersect with longitudinal ribs, which provides higher plastic and strength characteristics. The alloy contains less carbon than A400 steel and fewer alloying elements, which significantly reduces the cost of the final product. In terms of strength, it is somewhat inferior to class A400 reinforcement, but it has increased resistance to corrosion, which allows the use of welding when assembling the reinforcing frame, and also reduces the time for its installation.

Inside each butt joint 6 there is a rubber sealing ring 8 (in Fig. 3). The sealing ring 8 is made of an elastic material (for example, rubber, rubber), while the cross section of the ring can be of any geometric shape, for example, in the form of a right triangle, as shown in Fig. 3, in such a way that the protruding part, on the one hand, increases the tightness of the butt joint, and, on the other hand, dampens shear loads and increases resistance to deformation.

The use of concrete grade no less than B30 made it possible to abandon a large amount of steel reinforcement, which reduced the likelihood of gas corrosion, leading to concrete spalling and a violation of the strength of the butt joint. In addition, such concrete (over B30) makes it possible to produce well elements with high geometrical accuracy, as well as with a smooth surface (minimum roughness), which makes it possible to use the sealing ring for a long time (it does not wear out over time). At the same time, the increased thickness of the well element (from 150 mm), compared to the traditionally used ones (standard thickness 100 mm), allows the formation of a strong seam end surface in the form of a tongue-and-groove with a height greater than that of wells available on the market (75-85 mm), reinforce it with sufficiently thick reinforcement (AIII (A500) with a thickness of at least 8 mm), as well as exclude the use of steel reinforcement in the wall part of the well element. All this ensures the safety of the elements of the well during transportation, installation, operation.

Thus, the claimed utility model increases the durability and tightness of the well by increasing the strength of the butt joint of the well elements.

Claims (1)

Well element, including a wall part and a folded end surface made in the form of a tongue-and-groove, characterized in that it is made of class B30 concrete, and the ridge of the folded end surface is made of a reinforced rod of class AIII (A500) 8-10 mm thick.

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