RU2382846C1 - Retaining wall on rocky ground - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is related to hydraulic engineering and may find application in construction of retaining walls of various purpose. Retaining wall, according to invention, is intended for erection on rocky ground and comprises piles 2, which are arranged in a row and are concreted in sleeves-fixators that have been previously drilled rocky base, and closing thin-walled arc elements 4 arranged between them. Each pile 2 is equipped with two sheetpile joints, in which thickened side edges of arc elements 4 are placed as installed with support directly on rocky ground, without deepening. Sheetpile joints 6 are fixed on piles 2 in cavities passing via axis of pile 2 at angles accordingly plus a and minus a to plane, which is perpendicular to plane of retaining wall. Angle α is selected from 10 to 55 degrees, preferably equals 45 degrees. Retaining wall also comprises anchor device, including anchor traction rods, which are connected to piles, and anchor supports, which are preferably concreted into rocky base.

EFFECT: reduced material intensity, higher bearing capacity and soil impermeability.

4 cl, 6 dwg

Description

The invention relates to retaining walls for construction on a rocky base, made in the form of an anchored log house, and can be used in the construction of sea and river berths and shore protection structures, embankments, in road, industrial and civil engineering.

In hydraulic engineering, there is a problem of reducing the weight and material consumption of retaining wall structures intended for construction on hard rocky soils.

Traditionally on rocky soils, material-intensive constructions of the gravitational type are used.

For example, it is known that a berth structure is used on rocky soils, containing massive supports made mainly of concrete and installed between them, closing thin-walled arched elements resting on supports (SU No. 1134662 A, 1985).

In this well-known berth structure, efforts from the weight of the backfill and operational loads should be perceived by massive concrete stops installed directly on the surface of rocky soil, this is the reason for the high material consumption of the structure.

The closest in design features to the proposed technical solution (prototype) is a berth structure, including stops in the form of piles immersed in the ground with rigidly fixed to them from the back, i.e. on the backfill side, with tongue-and-groove locks, and immersed in the ground to almost the same depth as the piles that close the thin-walled arched elements in contact with the piles and abut against them with their side edges. Moreover, the lateral edges of each of their arched elements are thickened and placed in the internal cavities of the tongue-and-groove locks of two adjacent piles, and the curvature of the arched elements is made variable in height to ensure the perception of a variable in height effort from exposure to soil (RU No. 2010908, 1994).

The retaining wall structure of said known berth structure is not applicable for rocky soils. In addition, in this design, both bearing piles and thin-walled closing arch elements are immersed in the ground to a considerable depth, necessary to ensure pinching in the ground and thereby ensure the necessary strength of the structure when exposed to external operating loads. The need for deep immersion of the retaining wall elements leads to a significant consumption of both material of piles and thin-walled arched elements. The change in the curvature of the arch element in height, necessary for the perception of a variable load from the weight of the soil, leads to a loose fit of the thickened edges of the arch elements to the walls of the tongue-and-groove locks, and as a result to a deterioration of the soil-tightness properties of the retaining wall, to a decrease in the strength and reliability of the joint, as well as to increase metal consumption.

Another design disadvantage of the known sheet pile wall, leading to an increase in material consumption, is that the resultant from operational loads and soil weight is transferred completely to the piles, because paired tongue-and-groove locks are placed on the rear side of the pile practically in a plane perpendicular to the plane of the tongue wall, i.e. its longitudinal plane.

The objective of the invention is the creation of a light thin-walled retaining wall such as a bloodworm, which has low material consumption, good soil impermeability and reliability, and is applicable for erection on rocky ground.

The technical result is a reduction in material consumption while maintaining a given bearing capacity, increasing the strength and tightness of all nodes of the retaining wall.

The problem is solved due to the fact that in the retaining wall, including piles with tongue-and-groove locks fixed on their outer surfaces and arc-shaped planar locking thin-walled arched elements with thickened side edges placed in tongue-and-groove locks of adjacent piles, according to the invention, the piles are clamped into the rock base by concreting in pre-drilled fixing cups, and the arched elements are made of constant curvature in height and installed with support on a rocky base without deepening, while the tongue-and-groove locks of each pile are located in planes passing through the axis of the pile at angles α and minus α degrees, respectively, to a plane perpendicular to the longitudinal plane of the retaining wall in plan, with the possibility of perception and transmission of forces from the arch elements to the pile, the angle α can be equal to from 10 degrees to 55 degrees.

Preferably, the angle α is 45 degrees.

The tongue-and-groove locks can be made of a rolling profile, while the mouth of each lock has a cross-sectional shape that repeats the cross-sectional shape of the thickened side edge of the arch element located in the lock, and is made covering the thickened edge with the possibility of their mutual rotation by an angle of plus or minus 20 degrees .

The retaining wall according to the invention can be equipped with an anchor device, including anchor rods connected to piles and anchor supports made pinched into the rock base by concreting in pre-drilled holes.

Due to the fact that the piles in the proposed retaining wall are concreted in retainer glasses previously drilled in the rock base, the jamming and, therefore, the strength and stiffness of the piles, equivalent to the technical solution of the prototype, is provided at a much shallower depth than in the case when the piles are immersed in ordinary soil, as is the case in the prototype. This leads to significant savings in pile material.

The reduction in material consumption is also due to the fact that the arched elements are installed without deepening and are made resting directly on prepared rocky soil, thereby significantly reducing their height compared to the prototype and, consequently, the material consumption of arched elements is reduced.

Due to the fact that the tongue-and-groove locks are located on piles in planes passing through the axis of the pile at angles respectively plus α and minus α degrees to the plane perpendicular to the longitudinal axis of the retaining wall in plan, the resultant from operational and soil loads is transferred to the pile respectively at an angle of α degrees on the one and the other. In this case, the normal component, i.e. the force acting on the pile perpendicular to the plane of the retaining wall decreases in proportion to the cosine of this angle. The larger the value of the angle α, the smaller the normal component acting on the pile, and the forces acting on each pile in the plane of the longitudinal wall, i.e. longitudinal components are mutually balanced, which also helps to reduce the metal consumption of piles and retaining wall as a whole.

Most preferred is an angle α of 45 degrees. In this case, the longitudinal and normal components of the external force are equal. The longitudinal components of the efforts of adjacent piles are directed towards each other and mutually balanced, and the normal component, reduced by about 1.4 times compared with the force from external loads per pile, is perceived by the anchor device.

The constant curvature of the arch element in height not only ensures a reliable tight fit of the thickened lateral edges of the arch element to the inner surface of the tongue-and-groove lock due to the pressing force from the external load, thereby improving the tightness of the joint, but also reduces the metal consumption of the arch element due to the rectangular shape of the scan of its workpiece .

The implementation of tongue-and-groove locks from a rolling profile with a throat having a cross-sectional shape that repeats the cross-sectional shape of the covered thickened edge of the arch element, provides a minimum clearance in the castle connection and, therefore, good soil tightness of the retaining wall. In addition, the rolling profile is more durable and reliable in the perception and transfer of loads on piles and the least metal-intensive. The possibility of mutual rotation within 20 degrees facilitates the assembly process and allows you to compensate for possible errors during installation.

The implementation of anchor supports pinched into rocky soil by concreting in pre-drilled holes also increases the reliability of the structure and provides material savings.

The invention is illustrated using the drawings, which depict:

figure 1 - retaining wall in cross section;

figure 2 is a section aa in figure 1;

figure 3 - scan arched element;

figure 4 is a section bB in figure 3;

figure 5 is a diagram of the loads acting on the pile;

figure 6 - anchor device of the present invention.

Retaining wall includes:

- the front wall 1, consisting of installed in a row of piles 2, mounted and concreted in glass-retainers 3 pre-drilled in the rock base and preventing the structure from shifting, and

- locking thin-walled arched elements 4 with thickened side edges 5 installed with the support directly on the rocky foundation without deepening into the rocky soil;

Each pile 2 is equipped with two tongue-and-groove locks 6, which are pre-welded to its outer surface. The locks 6 of each pile 2 are placed symmetrically in the planes passing through the longitudinal axis of the pile 2 at angles respectively plus α and minus α degrees to the plane perpendicular to the longitudinal plane of the retaining wall in the plan.

In the context of this application, the term “longitudinal plane” or simply “plane of the retaining wall” is a vertical plane passing through the longitudinal axis of all piles of the retaining wall.

Piles 2 may be made of pipes, preferably of circular cross section, but may have a cross section of any other shape. In the manufacture of piles 2, the tongue-and-groove locks 6 are welded to the pipe so that an angle 2α in cross section is formed between them.

The retaining wall also includes an anchor device 7, including anchor rods 8 connected to piles 2, and anchor supports 9, which can be concreted into the rock base.

The tongue-and-groove locks 6 serve to ensure the soil tightness of the retaining wall, in addition, through them from the arched elements 4 to the piles 2 there is a transfer of forces from soil and operational loads. In this design, tongue and groove locks work only on compression. The normal components of these efforts are transferred from the piles 2 further to the anchor rods 8 and anchor supports 9 of the anchor device 7.

To ensure the strength and tightness of the locking connection, as well as to save material, it is preferable if the tongue-and-groove locks 6 are made of a rolling profile and an internal cavity, i.e. The pharynx 10 of each lock 6 has a cross-sectional shape repeating the cross-sectional shape of the thickened side edge 5 of the arch element 4. The pharynx 10 of each tongue-and-groove lock 6 tightly covers the thickened edge 5 of the contacting arch element 4 with the possibility of rotation by a small angle, approximately plus or minus 15-20 degrees to compensate for pile installation errors 2.

Thickened side edges 5 of each arch element 4 are placed in the internal cavities of the tongue-and-groove locks 6 of adjacent piles and are supported on piles 2 through the corresponding tongue-and-groove lock.

Thin-walled arch element 4 in expanded form (Fig. 3) is a rectangle made of elastic sheet material, for example, metal, with bulges 5 on both side edges to ensure connection with tongue-and-groove locks 6 of two adjacent piles 2.

Installation of the proposed retaining wall is performed in the following sequence.

Through special guides, drill-holders 3 are drilled in the rocky base with a diameter slightly exceeding the diameter of piles 2. A retainer-glass 3 fixes the lower end of the pile 2 in the rocky base.

Through guides (not shown) lower the piles 2 lower ends in the glasses-retainers 3 and unfasten in the guides.

Reinforcing frames (not shown) are lowered into the cavity of the piles 2, which, if necessary, can be pinched in the rocky base into the bottom of the retainer 3.

Then, using the method of underwater or conventional concreting, fill the cavity of the piles with 2 concrete.

After at least 75% strength of concrete has been set, thin-walled arched elements 4 are lowered, placing their thickened edges 5 in the internal cavities of the tongue-and-groove locks 6 and adjusting the radius of curvature of the arched elements 4 with lanyards to compensate for minor deviations possible when drilling holes for fixing glasses and installing piles 2 .

Arched elements 4 are lowered to contact with the surface of the rock base and installed without being pinched, ensuring soil impermeability between the lower edge of the arch element 4 and the rock base due to the stone drainage-unloading prism 11 and the return filter 12. The tongue-and-groove locks 6 serve as stops for the thickened side edges 5 arched element 4, performing the function of mating elements of the castle connection.

Next, pour a stone drainage and unloading prism 11 with a crushed stone return filter 12 to prevent the removal of backfill soil through areas of loose contact of the arched elements 4 to the rocky base.

Then, the soil of the first stage 13 is poured into the body of the structure, the anchor supports 9 are installed and concreted, after which the tie rods are mounted 8. After they are tensioned, the soil of the second stage 14 is poured in the direction strictly from the anchor support 9 to the front wall 1.

After crimping all the structural elements, stabilizing the deformations of the front wall, they proceed to the device of the reinforced concrete head 15, which simultaneously serves as a distribution belt and rigidly pinches the upper faces of the arched elements 4.

To strengthen the design of the cavity, the piles 2 are filled with monolithic concrete and reinforcing frames (not shown). Through anchor rods 8, operational loads from the structure are transferred to anchor supports 9.

The joint work of piles 2 and arched elements 4 is provided by a monolithic reinforced concrete head 15 (figure 1).

The berthing facility according to the invention works as follows.

The pressure of the dead weight backfill of the stalled space, as well as operating loads, is transmitted from the arched elements 4 through the tongue-and-groove locks 6 to the piles 2 with the subsequent transfer of these forces to the anchor supports 9 by means of anchor rods 8. In this case, the main structural element of the structure - arch element 4, works for compression and self-sealing in sheet piles 6 piles 2 under the action of workloads.

Depending on the magnitude of the loads and the distance between the piles 2, the radius of curvature and the wall thickness of the arched elements 4 are selected for the various materials used (steel sheet, glass, plastic or composite materials).

When the tongue-and-groove locks 6 according to the present invention are located (FIG. 2) on the outer surfaces of the piles 2 in planes passing through the centers of the piles 2 at angles respectively plus α and minus α degrees to the plane perpendicular to the longitudinal plane of the retaining wall in plan, the normal component of the force, acting on each pile 2 is reduced. As can be seen in figure 5, the resultant 2 R from the impact of operational loads and soil weight is distributed on two adjacent piles. The force per one tongue-and-groove lock is R. This force at the point of contact with the pile is decomposed into two components, namely: the force passing through the axis of the pile in a plane parallel to the plane of the face wall, equal to Rsin α (longitudinal component), and the force acting perpendicular to the plane of the retaining wall and perceived directly by the pile equal to Rcos α. Under equal conditions, this force is less than in the prototype, where all the force from the loads is transferred entirely to the pile.

The longitudinal components resulting from external and ground loads are mutually balanced, with the exception of the final piles, which can be further strengthened (not shown).

The constant curvature of the arched elements in height ensures an even tight fit of the thickened edges to the inner cavity, i.e. to the throat 10 of the tongue and groove lock, which ensures the tightness of the connection.

The stability of the structure is ensured by pinching piles 2 in the cups-retainers 3, made in the rocky base, and due to the anchor supports 9 located outside the prism of the collapse of the soil backfill.

An embodiment of the invention, in which the anchor supports 9 are also concreted into rocky soil, is preferable from the point of view of achieving the technical result of the invention.

The main objective of the invention, i.e. the creation of a lightweight retaining wall structure such as a cage working on rocky soil with low material consumption and good soil permeability at a given bearing capacity is carried out by abandoning the gravity type structures traditionally used on rocky soils and switching to a thin-walled structure with minimal pinching in the rock base is not on the entire front of the structure, but at individual points, i.e. at the locations of the piles 2.

Thanks to the implementation of the load-bearing elements in the form of piles pinched in the ground with locks on the outer surfaces offset by an angle of 10 to 55 degrees along the outer surface of the pipe in the direction of the axis of the retaining wall symmetrically with respect to the plane perpendicular to the plane of the retaining wall, less material-intensive lightweight a bolster type construction with good load-bearing characteristics, and the pressure of external forces and soil weight acting on the arched elements is only partially transmitted to the piles, and gave it through anchor rods - to anchor supports made in the form of anchor plates or anchor piles, driven into the ground of the first stage of filling the structure, or, according to an embodiment of the invention, concreted into rocky soil.

Due to the proposed arrangement of tongue-and-groove locks on the outer surfaces of the piles, the elastic properties of the arch element, the spacer forces in each arch element directed to the centers of adjacent piles contribute to greater compaction inside the castle space and exclude the filling of the backfill.

The proposed design of the retaining wall for rocky soil has a low material consumption, is economical and has a high bearing capacity.

Claims (4)

1. Retaining wall, mainly for erection on rocky soil, including piles with tongue-and-groove locks fixed to them and locking thin-walled arched elements with thickened lateral edges placed in tongue-and-groove locks of adjacent piles, characterized in that the piles are pinched into the rock base by concreting into pre-drilled cups-clamps, and the above-mentioned arched elements are made of constant curvature in height and installed with support on a rocky base, while the tongue-and-groove locks each pile is located in planes passing through the axis of the pile at angles α and minus α °, respectively, relative to a plane perpendicular to the longitudinal plane of the retaining wall in the plan, and is configured to receive and transmit forces from the arch elements to the pile, while the angle α is from 10 up to 55 °. 2. The retaining wall according to claim 1, characterized in that the angle o is equal to 45 °. 3. The retaining wall according to claim 1, characterized in that the tongue-and-groove locks are made of a rolling profile, while the mouth of each lock has a cross-sectional shape that repeats the cross-sectional shape of the thickened side edge of the arch element located in the said castle, and is made covering the thickened edge with the possibility of their mutual rotation by an angle of plus or minus 20 °. 4. The retaining wall according to claim 1 or 2, characterized in that it is equipped with an anchor device, including anchor rods connected to piles and anchor supports made pinched into the rock base by concreting in pre-drilled holes.

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