RU2255168C2 - Granular-fill structure located under embankment - Google Patents

Abstract

FIELD: artificial motor and rail road structures, particularly granular-filled water-pass structures through waterways and tunnel underpasses.

SUBSTANCE: granular-fill structure includes floor panel rested upon supports and retaining walls fixedly jointed with floor panel and provided with cantilevers facing structure passing orifice and connected to retaining walls from below. Cantilevers are supported by foundation bearers and offset relative retaining wall plane.

EFFECT: increased structure reliability and service life, reduced material consumption.

5 cl, 4 dwg

Description

The invention relates to the construction of artificial structures of roads and railways and can be used in the construction of culvert backfill structures through waterways and overpasses of the tunnel type.

Known culvert construction, arranged in embankments of roads and railways for the removal of storm and flood waters and performed in the form of a culvert from prefabricated reinforced concrete elements and containing overlap (arch), side (retaining) walls and the lower face, which serves as the foundation [1] .

The known structure has a limited span (up to 4 m) and is not durable enough. It is characterized by insufficient bandwidth and operational reliability.

A culvert is known, including a foundation, side walls, a bottom, a block of overlap in the form of a vault, soil backfill, an inlet and outlet head made of gabions or “Reno” mattresses [2]. Known construction has a high throughput of the water stream.

The disadvantage of this structure is the complexity and complexity of its implementation, lack of operational reliability.

Closest to the proposed is a culvert under the embankment, including supports, a slab placed on them and retaining walls of a convex (from the longitudinal axis of the structure) outlines supported on foundations. From above, the ends of the retaining walls are supported on the console of the floor slab [3] (prototype).

Known backfill construction has an increased hole size and, accordingly, increased water throughput without increasing the speed of the water flow.

A disadvantage of the known technical solution is that the articulation of retaining walls with cantilever overhangs of the floor slab leads to increased deformability of this node. This leads to the fact that the embankment of the road in this place during operation can be damaged, and through the joint of the ceiling and retaining walls, water can be filtered from the embankment with the gradual destruction of the mating elements.

Thus, the well-known backfill structure is characterized by insufficient reliability and durability. The articulation of the plate and retaining walls does not allow to fully realize the redistribution of forces between these elements under load during operation and therefore the construction is unnecessarily material-intensive.

The proposed technical solution solves the problem of reducing the material consumption of the filling structure, increasing its reliability and durability.

To solve the problem in a filling structure under an embankment that includes supports, a slab placed on them and retaining walls, retaining walls are rigidly coupled to the slab. At the bottom, the retaining walls are equipped with consoles facing the inlet of the structure, and the consoles are supported on foundation pillows with eccentricity relative to the plane of the retaining walls.

At the same time, in the backfill structure, the consoles of the retaining walls with the base cushions can be pivotally rotated and pivotally movable with the possibility of rotation and horizontal displacement of the consoles relative to the supporting plane.

In addition, foundation pillows, retaining walls and floor slabs can be made of reinforced concrete.

In this case, the foundation pillows are made in the form of a pile grillage, the piles in which are arranged alternately with eccentricity on both sides of its longitudinal axis.

Comparative analysis with the prototype allows us to conclude that the claimed technical solution differs from the known new features:

1 - retaining walls are rigidly coupled to the floor slab;

2 - the bottom retaining walls are equipped with consoles facing the inside of the access opening of the structure;

3 - consoles are supported on foundation pillows with eccentricity relative to the plane of the retaining walls;

4 - conjugation of the consoles of the retaining walls with the base cushions is made hinged with the possibility of rotation of the consoles relative to the plane of support;

5 - the conjugation of the consoles of the retaining walls with the base cushions is pivotally movable with the possibility of rotation and horizontal displacement of the consoles relative to the plane of support;

6 - foundation pillows, retaining walls and floor slab made of monolithic reinforced concrete;

7 - foundation pillows are made in the form of a pile grillage;

8 - piles in the grillage are arranged alternately with eccentricity on both sides of its longitudinal axis.

The above-listed features of the proposed technical solution during its implementation ensure the achievement of the goal of the total result and exceed the known, and in the above amount, the listed features are not known.

The essence of the proposed solution is illustrated by drawings. In Fig.1 presents the proposed filling structure, a cross section along the axis of the embankment, Fig.2 is the same, a longitudinal section along aa in Fig.1 along the axis of the structure, Fig.3 is the same, a section along BB figure 1, and figure 4 is a diagram of the structure under load.

The structure (Fig.1-3) is placed in the body of the embankment 1 and is filled. It includes a floor slab 2, retaining walls 3, provided with a lower consoles 4, facing the inside of the passage of the structure and supported on foundation pillows 5 with an eccentricity relative to the plane of the retaining walls. The retaining walls 3 are rigidly coupled to the floor slab 2.

The retaining walls 3 can be supported on the base pillows 5 by consoles 4 pivotally with the possibility of rotation and pivotally-movable with the possibility of rotation and horizontal displacement of the consoles 4 when loading the structure. In this case, only a compressive load can be transferred to the foundation pillow without transmitting bending moment and horizontal force (thrust).

Base pillows 5 can be made in the form of a pile grillage. Piles 6 are placed in the form of a “snake” with an eccentricity relative to the longitudinal axis of the grillage 5. Moreover, neighboring piles 6 are arranged alternately opposite to the specified axis.

In this case, the pile foundation is arranged in case of crossing a constant watercourse or in soils with insufficient bearing capacity.

The structure under consideration can be either single-span or multi-span. In the latter case, under the plate 2 parallel to the retaining walls can arrange single-row supports 7, allowing you to significantly increase the opening of the structure.

On dry ravines with small drains, as well as when using the structure as a cattle drive under an embankment or tunnel type viaducts with high-quality soils, pile foundations may not be arranged.

During operation, the filling structure located in the body of embankment 1 experiences the effect of a constant vertical load on the floor slab 2 from soil pressure and temporary load from a moving vehicle. Bending moments occurring in the sections of the plate 2 cause it to bend and due to its rigid conjugation with retaining walls 3, bending moments also occur in the sections of the latter, causing the walls 3 to bend towards the embankment 1 (Fig. 4).

The bending moments in the sections of the walls 3 and the slab 2 are reduced by the eccentric support of the walls 3 on the foundation pads by means of consoles 4. Moreover, the articulated or pivotally movable (depending on the height of the embankment) support of the consoles 4 on the foundation pads 5 provides high adaptive capabilities of the structure under loading.

It is advisable to use the hinge bearing when the height of the embankment (above the top of the structure) is more than 2 m. In this case, the retaining walls 3 are affected by significant horizontal pressure of the soil of embankment 1, for the perception of which the horizontal component of the reaction of the foundation pillows 5 is additionally used.

It is advisable to use the pivotally-movable bearing of the consoles 4 on the foundation cushions 5 when the embankment height is less than 2 m. When the wheel load P is located on the ceiling 2, the retaining walls 3 rotate (with displacement). In this case, the embankment soil 1 has an additional horizontal reactive rebound on the walls 3 , which leads to a decrease in the values of bending moments in the sections of the walls and floor slabs. This allows you to significantly reduce the magnitude of the internal forces in the sections of the bearing elements and reduce the material consumption of the structure.

With the proposed method of supporting the consoles 4 on the foundation pillows 5, under the sole of the pillows, almost uniform pressure on the ground is realized. This is especially effective for cattle rails and dry logs, where hydrological conditions do not require the installation of pile foundations from the erosion condition.

At constant streams, the foundation cushions 5 are made in the form of a pile grillage and are arranged according to local and general erosion. The support of the consoles 4 of the retaining walls 3 on the grillage can be carried out articulated and articulated-movable. In this case, only the vertical compressive force is transmitted to the grillage. Bending moment arising in the plane of the sole of the grillage (cushion) 5, due to the eccentric application of the vertical compression force, is perceived by piles 6 located in the form of a “snake” with eccentricity on both sides of its longitudinal axis. In this case, the bending moment on the piles 6 is not transmitted, and they work on compression of various sizes in each row.

The proposed design of the grillage 5 and the arrangement of piles 6 allows us to approximately halve the number of piles, compared with their usual two-row arrangement and to provide the required high bearing capacity of the foundations of the structure.

The implementation of the foundation cushions 5, retaining walls 3 and floor slab 2 made of reinforced concrete allows you to simply and reliably provide the required pairing of the building elements and the redistribution of forces between them during loading, which allows you to create a reliable and durable backfill structure.

Thus, in comparison with the analogs [1, 2] and the prototype [3] in the proposed structure, with the above signs, it was possible to fully reduce the efforts in the design sections of the elements of the backfill structure due to their effective redistribution, to include reactive soil rejection embankments behind retaining walls. In addition, in the proposed backfill structure, in contrast to the known ones [1-3], the joints between the elements are completely excluded and the continuity of the overlap and retaining walls is ensured.

As a result, not only the material consumption of the structure is reduced, but also operational reliability and durability are significantly increased, water filtration from the embankment, silicification and thawing of concrete structures are completely excluded. The proposed filling facility can be used over a wide range of overlapping spans - from 4 to 18 meters.

The proposed filling structure is erected in the same sequence as the prototype [3]. First, foundation pillows 5 are laid, or piles 6 are hammered and a pile grillage is made. Intermediate supports 7 are arranged, reinforcing cages (not shown) of the consoles 4 and retaining walls 3 are installed, the formwork of these elements is installed and concreted, providing upward releases of the reinforcement. Then, supporting devices (scaffolds) are installed for the formwork of the floor slab 2. The reinforcement of the slab 2 is placed on the deck and the rebar releases from the supports 7 and the retaining walls 3.

After concreting the slab 2, a reinforced concrete structure closed at the top is formed that is rigidly connected to the reinforced concrete walls 3 and supported by consoles 4 on the foundation pads 5.

After waterproofing on the outer surfaces of the slab 2 and walls 3, an embankment 1 is filled in with a layer-by-layer compaction at the walls 3. In some cases, a cushion of crushed stone or sand-gravel mixtures can be arranged behind the walls 3.

Thus, the technology of erecting the backfill structure is traditional and does not require additional labor costs.

The proposed technical solution will be implemented in road construction both in the Republic of Belarus and in the Russian Federation. Its use will undoubtedly improve the operational reliability of roads both in the general network and in local and agricultural ones.

Sources of information

1. OST 35-27.0-85 Reinforced concrete links of round and rectangular culverts for railways and roads. - M., Mintransstroy, 1986.

2. RF patent No. 2181812. Culvert construction. IPC E 01 F 5/00, E 01 D 4/00, BIPM, No. 12, 04/27/2002.

3. USSR copyright certificate No. 1579944. Culvert under the embankment, MKI ⁵ 01 F 5/00, BI No. 27, 07.23.90.

Claims (5)

1. The filling structure under the embankment, including the floor slab and retaining walls placed on the supports, characterized in that the retaining walls are rigidly coupled to the floor slab, and provided with consoles below, facing the structure’s through-hole, while the consoles are supported on foundation pillows with an eccentricity relative to planes of retaining walls. 2. The backfill structure according to claim 1, characterized in that the coupling of the consoles of the retaining walls with the base cushions is hinged with the possibility of rotation of the consoles relative to the plane of support. 3. The backfill structure according to claim 1, characterized in that the conjugation of the consoles of the retaining walls with the foundation cushions is pivotally movable with the possibility of rotation and horizontal displacement of the consoles relative to the plane of support. 4. The filling structure according to claims 1 to 3, characterized in that the base cushions, retaining walls and floor slab are made of reinforced concrete. 5. The filling structure according to claims 1-3, characterized in that the foundation cushions are made in the form of a pile grillage, the piles of which are arranged alternately with eccentricity on both sides of its longitudinal axis.

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