RU2729103C1 - Method to prevent collapse of steep river banks - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to hydraulic engineering and nature protection construction and can be used for protection of coastal zones from landslides and caving of soil massifs. Purpose of the invention is to increase productivity of works on hydraulic washing of soils that form a steep shore without damage to safety of these works and use of hydraulic transportation of removed soil without damage to its further use when backing up the water-guiding shaft. Soil washing and formation of terraces begins with upper soil layers. For this purpose a dredge is installed on the surface of the shore and two inclined wells are drilled from the shore surface to the river water rim for water supply to soil washing-out and removal of the obtained pulp for back-filling of the water-guiding shaft. To receive pulp, flexible containers of water-permeable geomaterial are used.

EFFECT: disclosed method makes it possible to use not only hydraulic but also mechanical action at soil washing, without damage to safety of works, and also to use the obtained pulp for formation of water-guiding shaft.

1 cl, 3 dwg

Description

The invention relates to hydraulic engineering and environmental construction and can be used to protect coastal zones from landslides and collapse of soil massifs. Such collapses are most likely at a large slope angle and its excessive height [1]. The collapse of the banks leads to the shallowing of the reservoir, damage and even destruction of buildings located on the shore or near the shore. The slope angle can be reduced by its preliminary, stage-by-stage, partial destruction with the creation of additional terraces from the destroyed soil.

For example, a method of forming terraces on a slope is known [2], including:

- sampling of soil from a horizontal gap at the base of a steep slope;

- filling from this soil a water guide shaft, which isolates the bottom section adjacent to the steep slope from the main water flow;

- self-collapse of the soil canopy, formed after sampling the horizontal slot;

- leveling the self-collapsed soil canopy on an isolated area of the bottom so that the mark of the ridge of the water guide shaft exceeds the mark of the terrace canvas.

The main disadvantage of this method is the great danger of carrying out excavation work associated with sampling a horizontal slot at the base of a steep slope. With a high bank height and moisture saturation of its base (undermining from the river), sudden collapses of large soil masses (landslides) are possible. The use of hydraulic monitors for the formation of horizontal slits [3], destroying the soil with a stream of river water from a safe distance, is hampered by the following contradiction:

- to increase the performance of the water monitor, it should be as close as possible to the destroyed land mass;

- to improve the safety of the water monitor, it should be as far away from the destroyed land mass as possible (due to the inevitable collapse of the overlying soil layers).

This contradiction can be overcome with the help of the “transition to another dimension” technique, when the jet monitor starts its work from the upper layer of the soil massif.

Therefore, it is necessary to deliver the jet and water to the very top of the steep bank. Such an arrangement will completely protect it from the effects of landslides and will allow it to come into direct contact with the eroded soil and supplement the hydraulic effect with a mechanical one. That is, we will be able to use a dredger with a cutter to erode the soil massif [4]. This will increase the productivity of work on soil sampling by two orders of magnitude (instead of a point effect, linear and tangential). The dredger is delivered to the place of work by automobile equipment and is placed by crane equipment in a previously dug initial pool.

To deliver river water to the dredger and drain the pulp from the shore to the river water level, two inclined wells are drilled. To fill the initial basin, river water is supplied from below by a pressure pump. The dredger begins to work by eroding the upper tier of the steep bank and feeding the resulting slurry down to form a water guide shaft. Having finished removing soil from the first tier, the dredger makes an initial pool for itself in the next tier, and the finished tier is drained.

Another controversy that interferes with the use of hydraulic wash is as follows:

- for ease of transportation, the soil removed from the body of the steep bank should be liquid (pulp);

- for filling the water guide shaft, the soil must be dry (difficult to wash off by the river flow).

This contradiction can be overcome by using “flexible shells and thin films”, when the resulting pulp is fed not into a river flow, but into flexible containers from permeable geo-shells [5]. With this supply, water passes through the shell into the river, and the soil remains inside it.

The purpose of the invention: increasing the productivity of works on hydraulic washing of soils composing a steep bank, without compromising the safety of these works and the use of hydraulic transport of the removed soil without prejudice to its further use when filling the water guide shaft.

This goal is achieved by the fact that soil erosion and the formation of terraces begins from the upper layers of the soil, for which a dredger is installed on the shore surface and two inclined wells are drilled from the shore surface to the river water edge to supply water for soil erosion and remove the resulting pulp for filling the water guide shaft. At the same time, flexible containers made of water-permeable geomaterial are used to receive pulp.

The proposed method for preventing the collapse of a steep river bank consists of the following stages:

- drilling from the surface of the coast to the river water edge of two inclined wells for water supply for soil erosion and removal of the resulting slurry for filling the water guide shaft;

- creation of an initial pool by filling it with river water supplied from below along an inclined well and placing a dredger in the pool;

- the work of the dredger to remove soil from the developed tier and remove the resulting pulp along an inclined well down to dumping, filling containers from flexible geomaterial with pulp, forming a water guide shaft from containers, filling the area between the bank and the formed water guide shaft with pulp, displacing water into the river

- repetition of the previous two stages on each successive tier until the coast height is completely exhausted.

The proposed method allows:

- to use not only hydraulic but also mechanical action during soil erosion without compromising the safety of work;

- use the resulting slurry to form a water guide shaft.

The inventive method with its inherent essential features can be repeatedly and in various versions, using various devices and materials, successfully implemented in practice with obtaining the above result.

Example. The method for preventing the collapse of steep river banks is illustrated by the drawing in FIG. 1. The dredger (1) is delivered by road to the river bank. To deliver river water (2) to the dredger, an inclined well (3) is drilled from the shore to the river water level. At the same time, in order for it to be involved in the technological process of erosion, the angle of its inclination must constantly coincide with the design angle of the slope.

Since the water level in the river is not constant for its intake, it will be necessary to use a float water intake device (4) equipped with a pump (5) to supply water to the required height, and a flexible water conduit (6) to connect to the well outlet

The water-soil mixture (7) leaving the dredger (slurry) will need to be removed. To do this, next to the first water supply inclined well (3), we drill the second one (8) at the same angle to remove the slurry from the dredger. To unload the slurry, we use a special float device (9) and a flexible slurry pipeline (10). The pulp is discharged into a flexible container made of water-permeable geomaterial (11) For the convenience of setting, such a container can be designed as a seine net with floats on the top pick and weights on the bottom, with the possibility of pulling the bottom and top picks.

When the pulp enters the container, the water will go into the river and the soil (12) will remain in the shell, filling it. When the shell is completely filled and connected in a line, a water-guide shaft or "retaining wall" is formed. The space between the shaft and the underwater part of the steep bank (13) can also be filled with slurry or bulkhead material (14) separating the erosion zone (2) from the edge of the coast.

After the completion of the development and drainage of the first tier, this cofferdam can be brought down from a safe distance into the mentioned space using a water monitor installed on the dredger (1). In the opposite cofferdam of a part of the drained layer, the upper sections of the wells (3) (8) will be exposed, which will make it possible to shorten them during the development of the next layer (Fig. 2) When developing the second and subsequent layers of the coast, the bulk of the pulp will be directed into the space between the water guide shaft and the underwater part of the shore, for which the float device for unloading the pulp (9) will be moved from the loop of the flexible water-permeable shell (11) into this space.

After the development and drainage of all levels (Fig. 3), a system of terraces with a projected river slope angle is obtained. In this case, all the soil worked out by the dredger was used to construct a new border of contact between the coast and moving river waters (2): water - geotextile (11) and filling (liquidation) of the former border of contact: water - soil (13). Terraces can be used for planting bank-strengthening plants (14).

Sources of information:

[1] Electronic pecypc: https://studfile.net/preview/8153987/

[2] A.S. USSR N 1752208 IPC А01В 13/16. A way of forming terraces on a slope. V.M. Ivonin, Sh.T. Mukayev. Publ. 08/07/92. Bul. N 32.

[3] A.S. USSR N 1604991 IPC E21C 45/00. Hydromonitor. G.P. Stepanov, F.I. Koziin. Publ. 07.11.90. Bul. N 41.

[4] A.S. USSR N 848542 IPC E02F 3/90. Plunger cutter of a dredger. D.V. Roshchupkin, F.T. Pimenov, Yu.M. Kuznetsov, A.A. Cernant. Publ. 07/23/81. Bul. N27.

[5] Electronic resource: https://remstd.ru/archives/sovremennyie-tehnologii-beregoukrepleniya/

Claims (1)

A method of preventing the collapse of steep river banks with the formation of terraces and a water guide shaft by hydraulic washing, characterized in that in order to increase the productivity of works on hydraulic washing of soils composing a steep bank, without prejudice to the safety of these works and the use of hydraulic transport of the removed soil without prejudice to its further use during filling water guide shaft, soil erosion and the formation of terraces begins from the upper soil layers, for which a dredger is installed on the shore surface and two inclined wells are drilled from the shore surface to the river water edge to supply water for soil erosion and remove the resulting pulp for filling the water guide shaft, while for receiving the pulp, flexible containers made of permeable geomaterial are used.

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