FI92506C - A method for forming a concrete structure in bulk material from the ground level and an apparatus for carrying out the method - Google Patents

Description

92506

The present invention relates to a process for forming a concrete structure in bulk from a ground level. a head provided with a drill bit, the type of which is described in more detail in the preamble of independent process claim 1, which will be presented later. The invention also relates to an apparatus for carrying out the process described above.

It is an object of the present invention to form permanent structural elements in bulk material without prior conventional excavation operations and temporary safety measures.

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Somewhat generally, it can be said that most of the processes currently in use for forming permanent structural elements into loose material provide relatively small improvements to the processes developed 40-50 years ago. The current technology is also based on a high processing rate, which leads to 25 high total costs due to e.g. digging, boarding and casting one section at a time. Expensive temporary structures such as grouting, earth reinforcements and supported protective walls must be erected before a permanent structure can be formed.

The advantages of the process of the present invention are due to the fact that it allows drilling in loose material from the ground level either indoors or outdoors depending on the type of soil. regardless of the level required to form watertight and permanent structures. Once the structure is finished in the ground, the only wounds in the terrain that 2 92506 are visible on the surface are slight "boreholes", i.e., holes with a diameter of about 15 cm.

The process and apparatus according to the invention make certain other conventional functions unnecessary, such as soil leveling measures, such as freezing, grouting, excavation, boarding, pouring as well as pumping wells, soil compensation and discomfort compensation. A reduction in construction time is also achieved.

The above is achieved according to the invention by means of the features set out in the characterizing part of independent process claim 1 below and in the following claims, and by means of the apparatus, the features of which are set out in the characterizing part of hardware claim 3 below and the following claims.

15 When a tunnel structure is built into the ground using currently known processes, the loose material remaining inside the tunnel is excavated. This means that a concrete shell must be laid, from which the loose material must be removed after hardening. With current technology, it is virtually impossible to build a tunnel into loose material without extensive excavation operations and stabilization measures for loose material.

The process and apparatus of the present invention are also well suited for the construction of tunnels (road drums) under existing railway tracks and roads without disturbing traffic on a level crossing or road line. In the context of the current methods 25, these are problems that could only be solved by temporary sidings or sidings, which are in themselves expensive arrangements.

The present invention will be described in more detail below with reference to the drawings, in which Figure 1 is a schematic front view of an apparatus for carrying out the process of the present invention shown in the position in which drilling has taken place and before erosion and post-casting operations have begun;

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Figure 2 is a schematic elevational view of the equipment arranged in the bulldozer drilling equipment;

Figures 3-5 show the principle of the process in three stages, comprising 5 initial borehole erosion, borehole expansion by erosion and further borehole expansion in its height direction, and simultaneous post-casting of the borehole with concrete in this sequence.

In Fig. 1, the apparatus is shown in the position reached during drilling in the ground 10 before the erosion of the drilled hole and the post-casting of the borehole, which hole is expanded by erosion.

The equipment comprises two units, i.e. for the post-casting of concrete in the erosion unit 2 and the post-casting unit 3.

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The erosion unit comprises an erosion head 2a, in which a bore 2b is arranged at the bottom. Below the latter, the erosion nozzle 2c is provided with a water nozzle and encloses it surrounded by an air nozzle for ejecting a radial jet stream of water and air. The erosion unit further comprises a guide tube 8 on which the above-mentioned 20 components are mounted and through which the water and air ducts pass through said; to feed the erosion nozzles 2c. The guide tube 8 is mounted on a bearing 8a which can be raised and lowered as well as rotated, and the rotating motor 8b is arranged in the frame 6a. The guide tube 8 is connected at its upper end to the air and water intake ducts 10 and 11 in this arrangement via the control members 10a.

The post-casting unit 3 as well as the post-casting head 3a and the drill bit 3b are mounted on a bearing 9a in a rotatable and liftable and lowering manner, and the rotating motor 9b is arranged in the frame 6b, and the unit 3 is connected to the upper end of the concrete

The frames 6a and 6b form a rack with adjusting members 7 for the mutual separation of the frames 6a, 6b. The purpose of the rack 6 is to be connected in an adjustable manner to the drilling rig F, e.g. the drilling rig of the work tractor, as shown in Fig. 2, by means Ft known per se, by means of which the rig can be raised and lowered by means of pressure cylinders 2. The erosion end 2a and the post-casting end 5 3a can thus be used independently for lowering, lifting and turning in this order. The bodies 6a, 6b can be moved towards and away from each other to adjust the center distance C between the erosion head 2a and the post-casting head 3a. As shown in the drawings, in Fig. 1, the adjusting member 7 consists of adjustable telescopic rods 7a connecting the frames 6a and 6b.

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A shoulder 12 is arranged around the guide tube 8 for collecting and guiding the eroded loose material from the borehole in an adjustable manner by means of a mass and density meter in order to calculate the volume of the eroded opening, i.e. the expanded opening. The average distance between the erosion head 2a and the post-casting head 3a can be adjusted by means of adjustable separating members 7a according to the designed diameter of the expanded bore 4a.

After casting unit 3, the casting tubes 9 are extended.

When said process is carried out by means of the above-mentioned equipment, the erosion unit 2 and the post-casting unit 3 are drilled into the rock or supporting soil at a predetermined center distance C between the units 2 and 3. During the erosion of the rock surface, the erosion head 2a and the guide pipe 25 8 are pulled upwards by means of lifting means (not shown). Pulling out takes place slowly during continuous rotation and simultaneous ejection of highly compressed water and air at a high pressure of 100-1000 bar from the water and air nozzle 2c. Said water jet surrounding the air breaks the particle structure and dissolves the soil in the borehole 4, which hole is drilled in the drill bit 2b of the erosion head 2a.

Thus, an expanded bore 4a is formed having a desired diameter, which can be measured with equipment known per se, which will not be described in detail in this connection. In this way, a cylindrical eroded opening is formed which forms said

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5 92506 expanded bore 4a. By means of the overpressure generated by the nozzle 2c of the high-pressure jet 5a, the material flushed down is forced towards the surface through the bore 4 and said shoulder 12. Simultaneously with the formation of the opening 4a, the high-quality concrete D is pumped through the post-pouring pipe 9 provided with the post-casting head 3a to fill the opening 4a, which also causes pushing upwards through the bore of the material E, which was broken by rinsing. The concrete D can be provided with additives which make it water-repellent so that the flows caused by the erosion jet 5a to the opening 4a cause a minimum amount of binder to detach from the concrete D.

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When the guide tube 8 as well as the erosion end 2a and the post-casting tube 9 and the post-casting end 3a are pulled up, the post-casting head 3a should preferably be located at least 0.5 m below the erosion jet nozzle 2c.

The borehole is eroded by means of an air and water jet 5c to the desired level H when the erosion head 2a is pulled upwards, after which the erosion is stopped. The post-casting of the opening 4a with the concrete D is continued during the simultaneous pull-out 20 of the post-casting pipe 9 until the opening 4a is filled, which is checked by means of eroded material,. which is forced upwards through the bore 4. When the opening 4a is completely filled, such a material is replaced by an extruded concrete cementitious binder D.

Figure 3 thus shows the erosion head 2a and the after-casting head 3a drilled to the desired depth in the ground A and the finishing downward erosion jet 5b coming from the erosion head 2a to clean the bedrock. When said erosion jet 5b is completed, the erosion beam 5a of the nozzle 2c is started to widen the bore 4 and to provide an expanded bore 4a and thus a desired opening as shown in Fig. 4, with the desired height H in Fig. 4 and has been presented.

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Figure 4 shows the onset of expansion of the borehole during the rotation and pull-out of the erosion head 2a, while the feed pipe 9 provided with the post-casting head 3a is at rest in the circumferential position at the bottom of the expanded borehole 4a.

Fig. 5 shows the next step, in which the erosion head 2a is pulled up to approximately the desired height H of the expanded borehole, and in which concrete D is fed through the feed pipe 9 to fill the expanded borehole 4a. This operation is continued until the expanded bore 4a is filled.

Figures 4 and 5 show expanded boreholes 4a with a substantially circular cross-section and a desired diameter B leading to a cylindrical structure of concrete D.

In order to obtain an erosion jet, i.e. to carry the air and water jet 5a forward and backwards across the sector by means of a corresponding rotation of the erosion head 2a, a concrete structure having a corresponding cross-section can be arranged.

When the erosion end 2a is completely rotated during the simultaneous adjustment of the erosion pressure of the air-water jet 5, it is possible, for example, to provide concrete structures with oval cross-sections, such as oval stacks depending on the rotation angle of the rotation head 2a.

The process of this invention can be implemented in any type of country. This process is thus suitable for clay, mud and gravel, as well as most aggregates, moraine and peatland.

The erosion and post-casting process can be carried out in the cohesion country in two stages if desired, because the transition stresses in the cohesion countries usually prevent the eroded opening from collapsing if it is filled with water. If the erosion and post-casting-30 process is carried out in two stages, several advantages are achieved:

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7 92506 1. Local loose material is prevented from mixing with the concrete, as post-casting is carried out under water, like normal casting of an opening (planking).

2. Concrete in the return material is avoided through the borehole 4, which consists of eroded material 5 and added water from the erosion jet 5a. If the volume and density of the return material are continuously measured by a mass and density meter 12 connected to a shoulder 12 in the borehole 4, it is later possible to calculate the volume of the eroded opening 4a. Since the height H of the opening 4a - possibly the length if the borehole 4 is oblique or horizontal - is always known, its mean diameter C 10 can also be calculated.

3. It is possible to perform an accurate mapping of the amount of the opening 4a by means of an acoustic probe which can be lowered into the opening. By systematically rotating the probe while pulling it up, the entire width, usually diameter B, can be mapped.

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Both operations, i.e. erosion and post-casting, have to be performed in the friction soil as one operation, because the stacked opening 4a usually collapses before the post-casting with concrete D is completed. However, the opening, i.e. the extended bore 4a, can be stabilized if a heavy stabilizing fluid, e.g. 20 bentonite, is fed into the opening. However, said liquid tends to mix with the return material, i.e. soil and rinsing water, so that the amount, i.e. the width B of the structure / stack, can only be measured by means of an acoustic probe or by measuring the volume of concrete D poured into the opening 4a.

It was mentioned above that the distance between the erosion head 2a and the post-casting head 3a can be. adjusted by means of telescopic rods 7a in the rack 6. It is thus possible to ensure that the post-casting head 3a and the erosion head 2a have the desired mutual center distance when drilled in the ground A, whereby the post-casting head 3a is arranged on the circumference of the eroded / expanded bore 4a, as shown in Figs. Concrete D, which is thus injected through a relatively thick .. feed pipe 9, fills the expanded borehole 4a from the location in the wall 8 92506 and thus expels any eroded material and water upwards through the borehole 4.

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Claims (5)

A method for forming a concrete structure in loose masses, from ground level, using a rotatable erosion head (2a) and a casting head (3a) provided with a drill bit for downhole drilling to desired depth in the ground (A) in solid ground, and then the drilled hole (4) is expanded by erosion by means of air-water jets (5a) to the desired width (B) and height (H) during simultaneous erection of the erosion head (2a), eroding the mass and water of the erosion flows up and out through the borehole (4), and simultaneously or thereafter, the expanded borehole (4a) is molded by supply of molded material (D) under pressure with the aid of the casting head (3a) while simultaneously displacing the eroded pulp (E) characterized in that the erosion head (2a) with the drill bit (2b) and the casting head (3a) with the drill bit (3b) comprising components of an erosion unit (2) and a casting unit (3) are drilled simultaneously and parallel to each other in the ground. (A) m ed, center distance (C) is inserted, whereupon the erosion head (2a) rotates and is raised during simultaneous erosion of the borehole (4) walls and the casting head (4a) is raised simultaneously but slightly offset in relation to the erosion head (2a), while providing the casting material. years eg concrete (D). 2. A method according to claim 1, characterized in that the center distance (C) between the erosion head (2a) and the casting head (3a) for downpouring in the soil (A) is adjusted to the desired center radius for the erosion of the enlarged borehole (4a). Installation for using the method according to any one of claims 1 or 2, characterized in that it comprises an erosion unit (2) and a casting unit (3) arranged in a frame (6) with inboard distance control (7), which frame is intended for use. to be adjustable fixed to a rig (F) by means of per se known means (Fj), wherein the erosion head (2a) and the casting head (3a) of the erosion unit (2) and the casting unit (3) are arranged independently maneuverable for lowering and raising, and possibly rotation. 92506 12 Installation according to claim 3, characterized in that the frame (6) comprises two frames (6a, 6b) with bearings (8a, 9a) and drive motors (8b, 9b) for the erosion heads (8a) and the casting heads (3a) ) guide and molding tubes (9), which tubes (8,9), which are perforated, are provided with rotatable connections 5 (10a, 11) for connection of its upper portions to supply lines (10,11) for water / air and concrete, which two bodies (6a, 6b) are moved in and out of each other for installation of the center spacing (C) of the erosion head (2a) and the casting head (3a). Installation according to claim 4, characterized in that the bodies (6a, 6b) are connected with the aid of adjustable telescopic rods (7a). • · II