RU89538U1 - SOIL ANCHOR - Google Patents

Abstract

Soil anchor, including tubular thrust, consisting of a set of tubing, connected by a sleeve having a tapered thread, a protective sheath made of plastic, a hollow cutting tool, an adapter connecting the tubular thrust with a tensioner containing a stud on which placed a set of conical and spherical washers and a tension nut, as well as a cement stone, rigidly fixing the bottom of the tubular rod in the soil, characterized in that the anchor is rigidly fixed to the bottom of the tubular rod e-homogenizers elements of steel profile lengths disposed on its surface at least 2 in the radial direction, and the segments with a gap therebetween, and along the surface - in rows, staggered with respect to each other.

Description

The utility model relates to the field of foundation engineering, in particular to a device - soil anchor using tubular traction. It can be used for anchoring the structural elements of the foundation, attaching the walls of the pits, for prestressing the soil to increase the stability of structures due to the optimal distribution of the forces of pressing them to the base, as well as, if necessary, the application of an adjustable external load force, which prevents softening, collapse or overburden of the massif soil.

Known soil anchor (AS No. 1281635 MKI E02D 5/80 dated 01/06/84), [1] containing a rod rod with a tip and cement stone in the root part of the rod, draining the mixture in the form of a holder on the border of cement stone and soil. The rod is attached to the structure using a distribution plate and a tension locking device. The length of the freely extendable section of the thrust is made with a coating of anti-corrosion grease, enclosed in a plastic shell.

The device is complicated by basic and additional elements, costly, material-intensive, requires lubrication, a plasticizer, a draining composition, a casing and a multi-operation procedure for fixing cement stone and compaction of the hardening mortar.

Known soil anchor (AS No. 894073, IPC E02D 5/80 from 01.25.79) [2] containing a tubular rod in the form of a rod and an anchor head made in the form of rods, each of which has a bend to the side, opposite to the tubular rod and mounted on the tubular rod of the lower fixed and upper movable elements to which the ends of the rods are attached. The fixed and movable elements are made tubular, and the ends of the rods attached to them at a distance from the ends facing druk to each other.

The device has an expensive complex system of anchor heads, which must be applied with additional force and stored for a long time on the elements until the end of the formation of cement stone. In the case of untimely, unplanned removal of the pressing forces of the upper part to another, the disclosure is not realized and the anchor head does not fulfill its main function - the redistribution of the holding forces, and therefore will not provide the proper level of tubular traction in the cement stone. Tubular traction with anchor elements on it does not promote either effective mixing of the hardening mortar filling the borehole or collapse of cement bubbles in the solution. Heterogeneity and increased porosity of the composition leads to the fact that the cement stone has low strength, which significantly reduces its adhesive bonds with both soil and tubular traction. The bearing capacity of the device is reduced.

A well-known soil anchor [3] (see departmental building codes. BCN 506-88. Design and installation of soil anchors. (Section 3.0) M. 1989, the Ministry of installation and construction of the USSR), consisting of a rod, an insulating plastic shell, a cap, a seal (cement stone), retainers and heels. The tip consists of a base plate that transfers the load to the structure of the structure and fasteners (nut, washer, base plate, block, cone) that transfer the load from the rod to the plate.

The device is complicated by additional elements for producing cement stone by stage-by-stage injection of cement mortar through a stationary injection pipe or under pressure through casing pipes. To ensure an equal strength butt joint, a stud is additionally welded to the rod. The anchor rod is made entirely of thermally hardened bar steel with a screw profile or of bar reinforcement, which makes the structure more expensive. In addition, the use is limited in that it does not allow them to be used when installing a large length soil anchor into the soil at great depths due to insufficient rigidity of the anchor and the appearance of bending stresses in it. The clamp made of trapezoidal elements with a smooth surface is limited in action. Its main function is to increase the adhesion strength with cement stone, and for this, the wellbore is gradually cemented, which is not technologically advanced. With injection or during free pouring in a cement mortar, porosity is maintained until a cement stone is formed, its composition is heterogeneous, which significantly weakens the adhesion forces of the rod rod with cement stone and cement stone with soil. Therefore, the bearing capacity of the device is reduced.

As a prototype, the claimed utility model of the soil anchor device, the soil anchor device closest in technical essence and positive result was selected [4] (US Pat. No. 83517, IPC E02D 5/08, dated February 12, 09), including tubular thrust with a protective sheath made of plastic on the upper part of its lateral surface, cement stone is the root (the part of the anchor that transfers the load from the traction to the ground), rigidly fixing the lower part of the tubular traction. The device has a tension device in the form of an element - studs, on which a hinge from a set of washers is placed - conical (on the base plate), spherical (on the conical washer) and the tension nut - on the spherical washer. Between the tubular rod and the stud there is an adapter with a coupling connecting the tubular rod with a tapered thread adapter. The adapter and the stud are threaded. As tubular traction, a set of tubing was used, interconnected by a sleeve having a tapered thread. Centralizers in the form of disks are placed in the end parts of tubular traction pipes. At the end of the lower part of the tubular rod, a hollow cutting tool is rigidly fixed.

The device is easy to use due to the use of a set of smooth tubing as tubing. It has a high bearing capacity. But in the case of supplying an air-cement mixture, during drilling with the formation of a well, air microwells may form in pores and voids of the soil, which worsens the adhesion of the cement to the ground in the well during the period of solidification. Under these conditions, an air gap can also be maintained on the surface of the tubular rod, which helps to reduce the adhesion of the cement mortar to the tubular rod. Cement mortars supplied with various H / C through a hollow cutting tool into the formed wellbore are not sufficiently mixed both in their mass and soil, therefore, ultimately, the composition formed during solidification is heterogeneous, i.e. The cement stone formed then is not homogeneous in its composition, which negatively affects its operational properties. The bearing capacity decreases, especially in areas containing it in the cement stone, especially if it has plastic properties. An insufficient degree of mixing in the well leads to the preservation of a large number of air bubbles in the cement slurry with the soil itself, despite the existing pressure test, which should slam the resulting air cavities in the mass, but can keep them in the well soil. Centralizers in this case do not perform the function of cement mortar homogenizers.

The objective of the utility model, the soil anchor, is to increase the homogenization of the hardening mortar when filling it and increase the adhesion strength of the tubular traction to the cement stone, and the cement stone to the soil of the uncased wall of the wellbore by enhancing the effect of mixing the hardening mortar, increasing the reliability of collapse of air bubble homogenizing elements in hardening mortar and in the border areas in contact with cement stone in the soil and in tubular traction.

The technical result is achieved in that, like a well-known soil anchor, including tubular thrust from a set of tubing, connected by a sleeve having a tapered thread, a plastic sheath, a hollow cutting tool, an adapter connecting the tubular thrust a device containing a stud on which a set of washers are placed - conical on the base plate and spherical - on the conical washer and the tension nut - on the spherical washer, having a cement stone that is rigidly fixed to the groove nte the lower part of the tubular rod, according to the invention, in the lower part of the tubular rod there are homogenizing anchor elements, which can be used as sections of a steel profile, and as an option, segments of a reinforcing bar of a constant section having a relief surface in the form of two continuous protrusions along a segment of the rod and intermittent protrusions made between continuous protrusions at an angle to them, the segments of the reinforcing bar are rigidly connected to the surface of the tubing traction tubing part of which one of the continuous protrusions was used, another continuous protrusion was used as the front part, anchor elements - homogenizers are placed: on the surface of the tubular rod - in pairs in the radial direction with a gap between them, rows and in a checkerboard pattern - along the surface of the rod. The distance between the rows can be equal to twice the length L _{1 of the} anchor element-homogenizer, i.e. 2L ₁ .

Comparative analysis with the prototype shows that the inventive device increases the density, and, consequently, the strength of the cement stone due to the new functionality of the lower part of the tubular rod having anchor elements-homogenizers. Due to the fact that segments of the steel profile are used as homogenizing elements (angle sections, segments of finished reinforcing bars, polyhedron bars), the operational capabilities of tubing are expanding. So, in addition to possible and well-known functions - centering the device in the wellbore and fixing it (sealing) the location in the cement stone, it became possible to strengthen the mixing effect of the hardening mortar coming from the cavities of the tubular rod and the cutting tool from the bottom up along the formed wellbore, which helps to obtain in a cement stone of a homogenized composition of a cement mortar and a mixture of cement mortar with soil. Due to this, a composition with predictable properties along the entire length of the wellbore is formed. Thus, the use of segments of the steel profile can significantly increase the bearing capacity of the device. When using, for example, segments of a reinforcing bar, it is found that the relief surface of the homogenizing anchor elements, for example, in the form of continuous protrusions along the element and discrete protrusions at an angle to the continuous protrusions, allows you to create a system of intensive mixing of the components of the hardening mortar. In the horizontal plane, mixing occurs simultaneously round the “bodies” of the elements during rotation of the device, and down - when placing the homogenizing anchor elements on the surface of the tubular rod with discrete protrusions down from the continuous protrusion on the front surface of the element, when air bubbles in the hardening solution and soil need to collapse or enlarge them for subsequent more intense lifting and withdrawal to the surface.

Discrete protrusions from a continuous facial protrusion placed upward on the homogenizer anchor element utilize the acceleration of the exit of large sized bubbles from the solution. In this case, the homogenizing elements along the tubular rod are arranged in pairs in rows one below the other, and relative to each other in a checkerboard pattern and with a gap, the value of L _{2 of} which is equal to twice the length L ₁ 2L ₁ homogenizer anchor element. In this case, the following scheme of homogenization of the hardening mortar is implemented: from below, the cement hardening mortar flows along the tubular rod to the homogenizing anchor elements, which mix the solution “circularly” like blades, then the mortar falls into the gap between the rows and undergoes torsion, increasing the deformation of the treated mass of the hardening mortar. In this case, the air cavities in the mixed mechanical mixture degenerate into filamentary formations with the subsequent disappearance during the transition of the swirling mass in the gap to the anchor elements-homogenizers of the next row, which are pairwise radially placed symmetrically relative to each other in the horizontal plane. In this case, the distance of the anchor elements-homogenizers of one row to another was experimentally found. The gap between these rows was found to be optimal, equal to twice the length of the homogenizer anchor element, providing high-quality mixing accompanied by orientation of the structural components of the mixture in the solution, which ultimately leads to an additional increase in the strength of cement stone by 30-40%. A shorter distance, like a larger one, weakens the mixing effect. Since at least 2-3 rows of homogenizing anchor elements are placed along the tubular rod, the effect of hardening is strengthened and fixed many times. The placement of anchor elements-homogenizers in a checkerboard pattern along the tubular rod allows, rising up and filling the wellbore of a mixture of cement mortar with soil, to change continuously the direction of movement. First, along the elements-homogenizers at an angle and along them, depending on the action of a particular relief on the surface, then torsion in the gap between the rows along the surface of the tubular pull itself, then again at an angle and along the anchor-element of the homogenizer, etc.

The inventive soil anchor has a "novelty", has significant differences, is a technical solution and is industrially in demand. The utility model was tested on 20 models in real conditions while strengthening the walls of the pit. Not a single negative result was obtained, despite the fact that the tests were carried out in soils of various compositions. It is planned to introduce the device in Perm at LLC Construction Company InzhProektStroy and other construction organizations, as well as in the drilling equipment of the Russian Federation when using the device as an unrecoverable drilling tool.

Known devices [1-3] have anchor elements for centering the anchor during installation in the well bore or to increase adhesion to the cement stone after cement mortar has hardened, for the first time tubing pipes are used as a mixer when installing soil anchor due to the elements available on their surface homogenizers. As an anchor-homogenizer element, it is possible to use different metals (mainly steel) with a profile that creates a relief contact surface with a mixed solution of cement with soil. These can be pieces of corners, multifaceted rods, etc., the strength of which allows mixing the mass without deformation.

Soil anchor contains tubular thrust, consisting of a set of tubing 1 ^I , 1 ^II , 1 ^III , etc., interconnected by couplings 2 ^I , 2 ^II , 2 ^III . On top of the tubular rod 1 ^III, free of anchoring elements, homogenizers, previously placed protective sheath 3 made of plastic with a clearance to the tube surface. Anchor elements are welded on pipes 1 ^I and 1 ^II - homogenizers from segments of the reinforcing bar, for example, 4 ^I and 4 ^II , 5 ^I and 5 ^II , 6 ^I and 6 ^II , 7 ^I and 7 ^II , 8 ^I and 8 ^II , 9 ^I and 9 ^II , 10 ^I and 10 ^II , 11 ^I and 11 ^II (Fig. 1, Fig. 2a). Continuous protrusions along the stiffening element 12, 13, protrusions 14, 15 - at an angle to the protrusions 12, 13. In the lower end part of the pipe 1 ^I , a hollow cutting tool 16 is rigidly fixed, for which a drill bit is used. An adapter 17 is fixed in the upper part of the tubular rod with a tapered thread of the coupling 18. A tension device is connected to the adapter, consisting of a tubular element - a stud 19, on which there is a base plate 20, a conical washer 21, a spherical washer 22 and a tension nut 23. On the surface of the lower pipes The tubing is welded in a row in pairs by anchor elements - homogenizers 4 ^I and 4 ^II , and under each other (in rows): 4 ^I and 4 ^II , 5 ^I and 5 ^II , etc., and along the rows from bottom to top - in a checkerboard pattern, with, for example, a gap (L ₂₎ between the rows equal to twice the length L ₁ (2L ₁₎ ankernog Homogenizer element. An anchor element - a homogenizer from a segment of a reinforcing bar has a cylindrical shape, on the surface of which there is a relief in the form of protrusions of "stiffeners" on the "front" surface and on the back side, as well as side protrusions 12, 13, respectively, which are made at an angle to the ribs stiffnesses 12, 13. But there are also possible options: homogenizing elements are welded to the pipe surface with lateral protrusions from a continuous central, front protrusion 12 up 14 or down 15 (Fig. 3), depending on the mode of supply of the cement hardening mortar ora from the cutting tool 16 to the anchor elements-homogenizers, the functions of which are reduced mainly to thoroughly mixing the solution itself and the mixture of the hardening solution with the soil, compacting the mixture, while removing air cavities, voids from it (Fig. 3), increasing the strength clutch with cement stone 24 (figure 4) and soil 25 of the wall open hole.

Figure 1 shows the device in the transport position, a General view with a cut.

On figa shows the placement of the same anchor elements relative to each other on their surfaces, General view.

On figb - schematically shows a system of directions of the forces of mass displacement, a General view.

Figure 3 shows the anchor element-homogenizer - a segment of the reinforcing bar, welded to the surface of the tubular rod with a "stiffener" (continuous protrusion on the surface of the segment of the reinforcing bar) - the back, general view.

Figure 4 shows the lower part of the tubular rod (tubing) with anchor elements-homogenizers from segments of the reinforcing bar on it in a cement stone, General view.

Figure 5 schematically shows a variant of tubular traction with anchor elements - homogenizers from 4 radially directed segments of a multifaceted rod, General view.

Figure 6 schematically shows a variant of tubular traction with 4 anchor elements-homogenizers in a row of segments of an isosceles corner, general view.

The device operates as follows. A tubular draft of the soil anchor is assembled on the soil surface. To do this, use tubing (tubing) (figure 1) - 1 ^I , 1 ^II , 1 ^III , the length of each is 3 meters. They are interconnected by couplings 2 ^I , 2 ^II , 2 ^III , respectively. Pre-placed on the pipe 1 ^III protective sheath 3 of plastic.

Pipes with couplings are fixed with a tapered thread, forming a tubular draft of a soil anchor of a given length. On the surfaces of pipes 1 ^I and 1 ^II, preliminary anchor elements-homogenizers 4 ^I , 4 ^{II are} welded; 5 ^I , 5 ^II ; 6 ^I , 6 ^II ; 7 ^I , 7 ^II ; 8 ^I , 8 ^II ; 9 ^I , 9 ^II ; 10 ^I , 10 ^II ; 11 ^I , 11 ^{II in} pairs or more than 2 (Figs. 5 and 6) in horizontal planes, symmetrically relative to each other. Between the rows of elements are placed in a checkerboard pattern (Fig.1, 2, 5, 6). On the front and back parts of all elements-homogenizers from segments of the reinforcing bar there are longitudinal continuous protrusions 12, 13 (figure 3). And the side surfaces of the same anchor elements-homogenizers have protrusions at an angle to the protrusion 12 up 14 or down 15, respectively (figure 3). The protrusion 13 is in contact with the surface of the tubular rod and welded to it. In the lower part, a hollow cutting tool 16, a chisel, is rigidly fixed. At the end of the upper part 1 of the ^III tubular rod, the adapter 17 is fixed with the coupling 18 on the thread. A crimping unit (not shown) is connected to the adapter and a Drill 830 BB type drill rig (not shown) is connected. The hollow cutting tool 16 with tubular thrust 1 ^I , 1 ^II , 1 ^{III is} rigidly connected to each other. A well is drilled with simultaneous installation of an anchor in soil 25. First, drilling is carried out when a weak cement mortar with W / C = 1 is supplied through a tubular rod 1 ^I , 1 ^II , 1 ^III and a hollow cutting tool 16. Anchor elements-homogenizers 4 ^I -11 ^II (Fig. 1), (Fig. 2a), (Figs. 5, 6) are placed in three rows on each 3-meter pipe (tubing). The rotation of the tubular traction with homogenizing anchor elements promotes intensive impregnation of the walls of the well with cement, effectively mixing it in the well before then injecting the cement into it at W / C = 0.6-0.4. after installation in the soil to a predetermined level of tubular draft of the anchor with a cutting tool, cement mortar is fed into it into the formed well with B / C = 1. The solution fills the well and rising from the bottom, the top passes a difficult path between the anchor elements-homogenizers (fig.2b), constantly changing directions from the translational between the elements in a pair in the horizontal plane, translational up - along the protrusions 14, return - along the side protrusions down 15 (Fig. .2b and 3), in the case of using segments of the reinforcing bar, before torsion, between the rows of anchor elements-homogenizers in the gap (as in FIGS. 5 and 6). The distance L ₂ from the element to the element along the tubular rod may be equal to twice the length L ₁ (2L ₁ = L ₂ ) of the homogenizer anchor element (Figs. 1 and 2), identified as optimal for high-quality mixing of the cement mortar and cement mortar with soil accompanied by lengthening of the air cavities in the direction of torsion with their subsequent complete disappearance, as well as for the orientation of structural elements, their deformation in the mass. Ultimately, this leads to a significant hardening of the cement stone in comparison with the strength of the cement stone obtained by the prototype. When filling the well, the solution also impregnates the soil in the border zone. Then it flows out through the wellhead. At the same time, due to the presence of the proposed design of anchor elements-homogenizers, pores and voids in the soil are more intensively filled with a solution, soil is better wetted by it, and a well is prepared to fill it with a working homogeneous hardening solution with specified properties. Then, cement slurry with W / C = 0.6-0.4 is fed into the well in the same way. however, he goes the same difficult path in the well along the barrel of tubular traction (figb).

The compacted composite is kept from a homogeneous hardening cement mortar with soil for 0.5 hours, then pressure testing is carried out by connecting a crimping unit (not shown) to the adapter. Pressure testing is carried out under a pressure of 10 atmospheres. A hardening solution is left under pressure for 10-14 days to harden the cement and form a cement stone 24 (Fig. 4) on the lower part of the tubular rod 1 ^I , 1 ^II and to obtain a strong adhesive bond between the cement and the ground. After 10-14 days, the crimping unit is removed and the tensioner is fixed in the upper end face with the thread. For this, a pin 19 is fixed in the adapter through a yoke fixed to the pit wall (not shown). A support plate 20, a hinge made of conical 21 and spherical 22 washers, and also a tension nut 23 are freely placed on the hairpin. The anchor is tensioned with a controlled force 1.5 times the rated load. The anchor is kept under load for 0.5 hours, then fixed with a tension nut 23 on the wall. Due to the hinge, possible deformation of the stud in the gap between the elements of the tensioner does not create problems when fixing the anchor with the washer in the tensioner. Due to the anchor elements - homogenizers, the adhesive bond with the cement stone of tubular traction made of tubing pipes is enhanced. The tubing pipes are made of K.L. (GOST 633-80) with a length of 3 m. Anchor elements-homogenizers can be made from sections of a finished reinforcing bar (GOST 5781-82, class A-3 reinforcement) 200-300 mm long (0.2-0.3 m) with the declared relief on the surface or from other segments of the steel profile (corner, rod, etc.). The device compared with the prototype allows to increase the productivity by 2-3 times and the quality of mixing the cement mortar with the soil due to the rotation of the tubular traction during the drilling of the wellbore and the simultaneous supply of cement mortar into the well and the presence of the claimed anchor homogenizing elements on it, initiating the process mixing. The number of anchor elements in the radial direction on the tubular rod depends on the diameter of the pipes used (tubing) and the drilling mode, which ensures the intensification of the homogenization process. The device allows 2-3 times to increase the adhesive strength, i.e. adhesion between the wall of the well and the cement stone, between the cement stone and the surfaces of the tubular traction, including the surfaces of the anchor elements-homogenizers, by improving the quality of mixing and collapse of air bubbles in the mixture filling the wellbore.

Therefore, it guarantees the absence of cavity voids in the hardening mortar, the reduction of porosity in the cement stone, thus, the homogenizing anchor elements can be simultaneously centralizers, mixers, dispersants, sealants, accelerators for removing air bubbles from the solution and from the pores, cavities in the borehole wall (soil) hardeners of cement stone. At the same time, the bearing capacity of the device increases by 1.5-2 times. Homogenizing elements can be cuts (cuts from building structures), for example, from corners of various profiles (GOST 13737-80), rods of high-strength steel with thread along the entire length. And if this is a waste, then the manufacture of the device is significantly cheaper.

List of information taken into account

1. A.S. No. 1281635, IPC E02D 5/80, dated June 1, 84 (analogue)

2. A.S. No. 894073, IPC E02D 5/80, dated January 25, 79 (analogue)

3. Departmental building codes. BCH 506-88. Design and installation of soil anchors, (section 3.0), M. 1989. Minmontazhspetsstroy. USSR), (analogue)

4. pat. No. 83517, IPC E02D 5/08, dated 12.02.09, (prototype)

Claims (1)

Soil anchor, including tubular rod, consisting of a set of tubing, connected by a sleeve having a tapered thread, a protective sheath of plastic, a hollow cutting tool, an adapter connecting the tubular rod with a tensioner containing a stud on which placed a set of conical and spherical washers and a tension nut, as well as a cement stone, rigidly fixing the bottom of the tubular rod in the soil, characterized in that the anchor is rigidly fixed to the bottom of the tubular rod e-homogenizers elements of steel profile lengths disposed on its surface at least 2 in the radial direction, and the segments with a gap therebetween, and along the surface - in rows, staggered with respect to each other.