EP2730702A1 - Method and device for the production of parallel ground bodies using jet nozzle tools - Google Patents

Abstract

The method involves adjusting depth (T) of jet tools (8, 9) such that exhaust nozzles of the respective jet tools lie in a plane that is perpendicular to longitudinal axes of the jet tools. The jet tools are rotated around the respective longitudinal axes for applying injection medium into ground based on the depth of the jet tools. Angle position of one of the jet tools is controlled such that the exhaust nozzles of the respective jet tools are aligned simultaneously on an area of the ground, where the area lies between the jet tools. An independent claim is also included for a device for producing parallel ground bodies.

Description

The invention relates to a method for soil improvement by means of jet-jet technology. For this purpose, the pending in the field of the wellbore soil is cut or eroded using a jet of water or cement suspension, which can also be coated with air. The eroded soil is rearranged and mixed with cement slurry. With the nozzle jet process components of various geometric shapes can be produced. With the manufactured components, the load-bearing capacity of the soil can be improved, settlements avoided or ground can be solidified, for example in underpinning; likewise, the method can be used for sealing, for example under dams or excavation pits.

From the DE 199 60 023 A1 For example, a jet-blast method for soil improvement is known to increase its carrying capacity. For this purpose, binder suspension is injected from a plurality of distributed over a soil surface on a surface grid arranged holes in the upcoming soil. The injections are applied in the jet stream immediately after drilling from a suitably prepared drill string.

The so-called high-pressure injection process, which is also known under company names such as Soilcrete or Jet Grouting process, represents a further development of the injection process. For this purpose, a pipe is sunk under rinse aid. After reaching the final depth are located by located at the bottom of the tube side nozzles high-energy cutting jets from a suspension with high pressures pressed into the ground and pulled the tube with slow rotation or pivoting motion. This results in a columnar volume, which hardens by the introduced binder to a solid body. By different arrangement of nozzles or different movement patterns of the drilling tool, various geometric elements can be produced, such as half-columns or lamellae.

From the KR 10 2005 003 7911 A For example, a multiple nozzle jet method and apparatus is known. For this purpose, a double-walled linkage is provided, is injected from the cement from several laterally arranged nozzles simultaneously in the ground. To produce a watertight wall, several bodies are produced adjacent to one another in succession.

A known further development is the insertion of two parallel drilling tools on a carrier device. These have a defined distance from each other and are simultaneously driven and sunk. As a result, two bodies can be produced. In the paper "Jet grouting to construct a soilcrete wall" by K. Andromalos and H. Gazaway in 1989, this technology is described as a "Double Stem Method".

From the U.S. 5,589,775 For example, there is known a method for determining the distance and orientation of a first wellbore from a second wellbore. For this purpose, a rotating magnetic field is generated whose amplitude and phase is determined by means of sensors. A similar device is from the DE 102 25 518 B3 known.

In general, in the production of sealing walls or sealing soles by means of jet-jet processes, there is the problem that areas of the bottom remain unexposed between two jet-body radiators. These so-called "gussets" can reduce the bond between two adjacent jet streams and thus have an effect on the tightness, which is of particular importance when the Düsenstrahlkubatur is to act sealing against oppressive groundwater. There is therefore an interest in keeping this gusset as small as possible.

The present invention has for its object to provide a method for soil improvement, which provides a particularly high erosion performance in the production of the jet body or with the high tightness between two adjacent jet bodies can be achieved. The object is further to propose a corresponding device, can be produced with the nozzle jet body assemblies efficiently or with high density between the individual bodies.

• Abteufen und Einstellen der Tiefe der zumindest zwei Düsenstrahlwerkzeuge derart, dass eine Austrittsdüse eines ersten Düsenstrahlwerkzeugs und eine Austrittsdüse eines zweiten Düsenstrahlwerkzeugs zumindest etwa in einer zu den Düsenstrahlwerkzeugen senkrechten Ebene (E) liegen; und Drehen der zumindest zwei Düsenstrahlwerkzeuge um ihre jeweiligen Längsachse zum Einbringen von Injektionsmittel,
• wie Wasser bzw. einer Suspension, in den Boden, wobei die Winkelstellung zumindest eines der Düsenstrahlwerkzeuge derart geregelt wird, dass die Austrittsdüse des ersten Düsenstrahlwerkzeuges und die Austrittsdüse des zweiten Düsenstrahlwerkzeuges gleichzeitig auf einen zwischen den beiden Düsenstrahlwerkzeugen liegenden Bereich des Bodens gerichtet sind.

The solution consists in a method for the production of floor elements by means of at least two nozzle jet tools, with the method steps:

• Dumping and adjusting the depth of the at least two jet tools such that an exit nozzle of a first jet tool and an exit nozzle of a second jet tool are at least approximately in a plane (E) perpendicular to the jet tools; and rotating the at least two jet guns about their respective longitudinal axis for introduction of grout,
• such as water or a suspension, in the ground, wherein the angular position of at least one of the jet tools is controlled so that the outlet nozzle of the first jet nozzle and the outlet nozzle of the second jet tool are simultaneously directed to a lying between the two nozzle jet tools area of the soil.

The advantage lies in the regulation of the angular position, which makes it possible for the outlet nozzles of two adjacent nozzle jet tools to interact in a targeted manner during the introduction of the injection medium into the soil. By simultaneously injecting the injection agent into the bottom area located between the two nozzle tools, higher pore water overpressures and a greater water saturation are achieved here, which in turn leads to a higher erosion performance in the gusset area. The nozzle jets are preferably aligned against each other so that the pore water pressures of the individual jets add up, so that a base fracture of the soil occurs rather distant from the jet than when using only one jet or uncontrolled rotating jets. It can thus with a comparable center distance of the jet tools with the Invention, a higher degree of coverage of the column body can be achieved, or it can be set with a comparable degree of coverage of the column body to be produced, a greater distance of the jet stream tools.

By "at least approximately in one plane" with respect to the setting and regulation of a uniform depth of the cooperating exit nozzles of two jet tools, it is meant that measurement or process tolerances are taken into account. Preferably, adjusting and regulating the depth of two adjacent jet tools is such that, in a given depth position, a cutting jet of the first jet tool inserted into the ground has an at least partial overlap with a cutting jet of the second jet tool inserted into the ground in the longitudinal direction of the tool. In other words, even in the case of a maximum axial offset of the two opposite outlet nozzles, there is still a partial overlapping and mixing of the injection medium injected by the two jet-jet tools into the bottom between them. This offset can be up to one meter, depending on the depth of the holes.

The injection medium can be matched to the background conditions and the desired work result or selected accordingly. As injection means, for example, liquids, water, suspensions, cement paste, chemical agents in the form of solutions and / or emulsions can be used. For the solidification of the substrate, for example in underpinning or waterproofing, in particular a suspension of water and binder is used. As a binder, in particular mortar, cement, Utrafeinzemente, silicate gels or plastic solutions in question. To increase the erosion performance and thus the range of the jet can be encased via an annular nozzle in addition with compressed air. As the binder hardens, two semi-columnar, columnar, or lamellar floor improvement bodies are created which have an overlapping cut area. But it is also the use of pure water as injection conceivable.

By at least two jet tools it is meant that the apparatus may also comprise three, four or more jet guns which simultaneously inject grout into the soil. Each of the jet nozzles comprises at least one outlet nozzle, wherein two, three or more outlet nozzles per tool can be provided. The arrangement or distribution of the outlet nozzles is preferably identical for all jet-blasting tools. This ensures that when using a plurality of superposed outlet nozzles of a tool these can be brought into a depth position with corresponding outlet nozzles of the adjacent tool and interact with them.

The tools to be used can be selected according to the ground properties, geometric shape and required quality of the column body. The jet tools may have one or more injector jets alone. In particular, small to medium-sized column diameters can be produced with this method, which is also referred to as a single direct method. It is also possible to use tools for dispensing air-coated injection or suspension jets for cutting and mortaring the soil. To increase the erosion performance and thus the range, the injectant jet is additionally encased with compressed air via an annular nozzle. This process, also referred to as double direct method, is used in particular for lamellar walls, underpinsings and sealing soles. According to another option, tools for dispensing an additional water jet can also be used. This process, also known as the triple separation process, erodes the soil with an air-quenched high-speed water jet. The cement suspension is added at the same time via an additional nozzle below the water nozzle. A variant of the method can also work without air jacket. Crucial in the use of the last method is that two identical tools are used, so that both the suspension jets and the water jets of the two tools are in each matching depths.

According to a preferred process control, the injection agent is introduced into the soil while controlling the depth and the angular position of a first of the at least two jet tools depending on the depth and the angular position of a second of the at least two jet tools.

The method for regulating the depths of the two jet nozzles or the outlet nozzles preferably comprises the steps of: detecting a first depth size representing the depth position of the first jet tool by means of a first depth gauge; Detecting a second depth size representing the depth position of the second jet tool by means of a second depth gauge; Comparing the first and second depth sizes; and adjusting the drawing speed of the first jet tool to the drawing speed of the second jet tool.

The regulation of the angular position can preferably take place by the following method steps: detecting a first angular quantity representing the angular position of the first jet-jet tool by means of a first angle-detecting device; Detecting a second angular quantity representing the angular position of the second jet tool by means of a second angle detection device; Comparing the first and second angular sizes; and adjusting the angular position of the first jet tool to the angular position of the second jet tool.

By appropriate control loops, the depth or the angular position of a tool can be quickly tracked in occurring deviation from the depth or angular position of the other tool. In this way, it is advantageously ensured that the injection medium is injected into the ground at the same depth and in synchronized angular position of the two jet stream tools. The nozzle jets face each other simultaneously when passing through a full revolution (360 °) in a certain angular range, so that the pore water pressures of the individual jets add up and the injection medium can penetrate deeper into the soil.

It is understood that the method can be used as needed for the production of any cubes. For generating columns or cylinders, the jet nozzles are continuously rotated about their respective axis of rotation. Similarly, semi-columnar bodies can be created by pivoting the jet tools about their axis of rotation during drilling or pulling. Slats can be produced by partial introduction of injection medium or suspension by means of the jet-jet tool at different depths.

According to a favorable procedure, it is provided that the first jet tool and the second jet tool are driven so that they rotate at the same angular speed and / or that they are driven synchronously and / or that the first jet tool and the second jet tool are driven so that they turn in opposite directions of rotation.

The ejection of the injection medium is preferably carried out by drawing the nozzle jet tools so that columnar cubatures are produced, or stepwise so that column sections are produced, or even only in a depth position in a predetermined grid, to produce a sealing sole. During the drawing, the depths and the angular positions of the at least two jet nozzles are continuously detected and controlled.

According to a preferred method, the control of the angular position of the at least two jet tools is such that the outlet nozzle of the first jet tool and the outlet nozzle of the second jet nozzle viewed in a cross-sectional plane through the tools, at least about mirror symmetry in each rotational position during the injection of injection agent into the ground are aligned to a running between the two tools center plane.

The rotational movement of the first jet tool may be defined by a first phase angle (φ1) over time (t) and the rotational movement of the second jet tool may be defined by a second phase angle (φ2) over time (t). Preferably, the angular position of the at least two jet guns is controlled such that the sine of the first and second phase angles (φ1, (φ2) is in phase (phase offset of 0 °) and the cosine of the first and second phase angles (φ1, (φ2) is a phase offset of A tolerance-related offset for the sine and the cosine deviating from these phases is preferably within a range of at most ± 10 °, in particular at most ± 5 °, or even at most ± 2.5 °.

The solution of the above-mentioned object further consists in an apparatus for the production of floor elements, comprising: at least two nozzle jet tools, which are rotationally drivable by a drive unit; each jet tool a depth gauge for determining the depth of the jet tool; each nozzle jet tool an angle detection device for determining an angular size representing the angular position of the jet tool; and an actuator, with the depth and angular position of at least one of the two jet tools being adjustable such that an exit nozzle of the first jet tool and an exit nozzle of the second jet tool are at least approximately in a plane perpendicular to the axes of rotation of the jet tools and simultaneously to one between the two Jet jet tools are directed lying floor area.

With the device according to the invention with depth gauges, angle gauges and adjusting unit for regulating or adjusting the depth and angular position of the two tools, the advantages mentioned above in connection with the proposed method result, to which reference is made in this respect. As a result, the device advantageously allows a targeted interaction of the nozzle jets of the two adjacent tools in a floor area, so that in this area a stronger water saturation and thus a higher erosion performance is given. For an automated process it is particularly favorable when a control unit is provided, which independently regulates the depth and the angular position of a first jet tool in dependence on the depth and the angular position of a second of the at least two jet guns.

According to a preferred embodiment, a single drive unit is provided for rotationally driving the at least two jet stream tools. Preferably, a distributor unit is arranged in the drive train between the drive unit and the at least two nozzle jet tools, which distributes an initiated drive torque to the at least two nozzle jet tools and which can drive at least two nozzle jet rods or tools in opposite directions of rotation. This provides a simple and inexpensive solution for driving both jet stream tools. It is particularly favorable if the setting unit is arranged in the drive train between the drive unit and the at least two jet-jet tools, with which the angular position of at least one of the jet-jet tools can be individually changed.

The detection of the angular position of the two jet stream tools by means of a corresponding angle detection device. This can have a rotation angle sensor per jet tool, which cooperates with a magnet on the other jet tool. The magnet generates a magnetic moment perpendicular to the longitudinal axis of the tool, which is detected by the rotation angle sensor of the parallel jet tool. For this purpose, the rotation angle sensor has a receiver which can detect three time-dependent magnetic field components Hx (t), Hy (t) and Hz (t).

Figur 1

ein Bohrgerät mit einer erfindungsgemäßen Vorrichtung zur Herstellung von Bodenelementen zur Baugrundverbesserung in Frontalansicht vor dem Abteufen;

Figur 2

das Bohrgerät nach Figur 1 während des Ziehens der Düsenstrahlwerkzeuge und unter gleichzeitigem Einbringen eines Injektionsmittels in den Boden;

Figur 3

die erfindungsgemäße Vorrichtung nach Figur 2 im Querschnitt durch die Düsenstrahlwerkzeuge während der Durchführung des erfindungsgemäßen Verfahrens

• a) zu einem ersten Zeitpunkt (t1) mit ersten Winkelstellungen der Düsenstrahlwerkzeuge;
• b) zu einem zweiten Zeitpunkt (t2) mit zweiten Winkelstellungen der Düsenstrahlwerkzeuge;
• c) zu einem dritten Zeitpunkt (t3) mit dritten Winkelstellungen der Düsenstrahlwerkzeuge;
• d) zu einem vierten Zeitpunkt (t4) mit vierten Winkelstellungen der Düsenstrahlwerkzeuge;

Figur 4

ein Ablaufschema zur Tiefenregelung

• a) vor Herstellungsbeginn einer Kubatur;
• b) während der Herstellung einer Kubatur;

Figur 5

ein Ablaufschema zur Winkelstellungsregelung

• a) vor Herstellungsbeginn einer Kubatur;
• b) während der Herstellung einer Kubatur;

Figur 6

schematisch den Verlauf des Porenwasserüberdrucks bei einem Düsenstrahl eines Düsenstrahlwerkzeugs;

Figur 7

schematisch den Verlauf der Porenwasserüberdrücke bei gegengleich ausgerichteten Düsenstrahlen gemäß dem erfindungsgemäßen Verfahren; und

Figur 8

ein Düsenstrahlraster für eine Dichtsohle einer Baugrube hergestellt nach dem erfindungsgemäßen Verfahren in Draufsicht.

Preferred embodiments of the invention are explained below with reference to the drawing figures. Hereby shows:

FIG. 1

a drill with a device according to the invention for the production of soil elements for ground improvement in frontal view before the sinking;

FIG. 2

the drill after FIG. 1 during the pulling of the jet stream tools while simultaneously injecting an injection agent into the soil;

FIG. 3

the device according to the invention FIG. 2 in cross-section through the nozzle jet tools during the implementation of the method according to the invention

• a) at a first time (t1) with first angular positions of the jet nozzles;
• b) at a second time (t2) with second angular positions of the jet nozzles;
• c) at a third time (t3) with third angular positions of the jet nozzles;
• d) at a fourth time (t4) with fourth angular positions of the jet nozzles;

FIG. 4

a flow chart for depth control

• a) before the start of production of a volume;
• b) during the production of a cubature;

FIG. 5

a flow chart for angular position control

• a) before the start of production of a volume;
• b) during the production of a cubature;

FIG. 6

schematically the course of the pore water overpressure in a jet of a jet tool;

FIG. 7

schematically the course of the pore water overpressures with counter-aligned nozzle jets according to the method of the invention; and

FIG. 8

a nozzle jet grid for a sealing sole of a pit produced by the inventive method in plan view.

The Figures 1 and 2 , which will be described together below, show a drill 2 with a device 11 according to the invention in a first embodiment. The drill 2 stands on a floor surface 3 and faces the viewer. Attached to the drilling apparatus 2 is a Mäklermast 4, which vertically movable support means 5 for supporting two nozzle beam linkages 6, 7 for each jet nozzle 8, 9. The jet tools 8, 9 each comprise one or more outlet nozzles 15, 16 via an injection means, as a suspension, and / or water and / or compressed air can be discharged through the nozzle jet linkage 6, 7 in the upcoming soil, and a drill bit 12, 13 which is arranged at the end of the respective jet beam linkage 6, 7. The jet nozzles 8, 9 are each guided by a through-boring turret 23, by means of which the respective nozzle jet linkage 6, 7 about a rotational axis A1, A2 is rotationally driven. The jet nozzles 8, 9 are parts of the device 11 according to the invention for the production of soil elements for ground improvement in the ground.

The nozzle beam linkage 6, 7 are connected via corresponding brackets or carriage with the broker 4 and movable relative to this. At the upper end of the nozzle jet linkage 6, 7, a rotary drive 14 and a flushing head 22 are provided, which can both be moved vertically on the broker 4. The rotary drive 14 is used for rotatable, respectively pivotable driving of the nozzle beam linkage 6, 7. The flushing head 22, which is also referred to as a swivel, is used to connect lines for introducing suspension or water, possibly also air, the lines are not shown. To sink a borehole into a subsoil, the respective rotary head 14 is lowered with the nozzle jet linkage 6, 7.

There are two nozzle beam linkages 6, 7 provided with rotary actuators 14 for corresponding jet tools 8, 9. The two jet stream tools 8, 9 are lowered together via the respective drill pipes 6, 7 and the associated rotary drives 14 in order to call off two boreholes 20, 21 which are parallel to one another. The advantage of the present device 11 with two nozzle jet tools 8, 9 is that two bottom bodies 29, 30 can be produced simultaneously.

In the following, the inventive method is based on the FIGS. 1, 2 and 3a to 3d explained. FIG. 1 shows the drill 2 in the starting position. It can be seen that the bottom layers 26, 27 below the railing top edge 3 have a different nature. By way of example, the condition is such that the upper bottom layer 26 is softer and should be improved by the addition of a binder, such as cement or Betonit, by means of jet-blasting. The underlying lower soil layer 27 is a load-bearing or water-impermeable bottom, which is to serve as a lower edge for the soil element to be created.

In the first step, which is not shown separately, the two juxtaposed jet stream tools 8, 9 are respectively sunk by their respective axis A1, A2 through the upper bottom layer 26, namely up to the intended final depth T, in the present case approximately through the boundary the adjacent layers 26, 27 is defined.

After the nozzle jet tools 8, 9 have reached the desired final depth T and the bores 20, 21 have been sunk down to the lowest soil layer 27, two bottom bodies 29, 30 are produced simultaneously by means of the jet nozzles 8, 9. This second process step is in FIG. 2 shown. The production of the two bottom bodies 29, 30, which may also be referred to as jet blasting bodies or cubatures, are accomplished by pulling the jet blasting tools 8, 9 upwards while rotating, or using one or more nozzles 15, 16 water or suspension escapes under high pressure and erodes the pending soil. Simultaneously with the erosion or cutting of the soil cement suspension is supplied under pressure and mixed by the process-related turbulence. In FIG. 2 are schematically the nozzle jets S1, S2 and lower parts of the already produced cubature recognizable. This consists of two mutually centrally intersecting column bodies 29, 30. The process is carried out from bottom to top through the upper bottom layer 26, starting from a lying slightly below the depth T depth until reaching the desired height of the jet body 29, 30th After the preparation of the jet body 29, 30 are in the subsequent step, which is not shown separately, the nozzle jet tools 6, 7 pulled upwards.

The peculiarity of the present method and the device is that in addition to the adjustment and control of the depth of the nozzle jet tools 8, 9 and the outlet nozzles 15, 16 and a regulation of the angular position of the jet tools is done, in such a way that the outlet nozzle 15 of the a nozzle jet tool 8 and the outlet nozzle 16 of the other jet tool 9 are simultaneously directed to a lying between these area of the soil. This adjustment or regulation of the angular positions of the jet nozzles 8, 9 is in the FIGS. 3a to 3d which will be described together below.

It can be seen that the two nozzle jet tools 8, 9 are brought at least approximately into an angular position, such that the radial orientation of the outlet nozzle 15 of one nozzle jet tool 8 with respect to a center plane EM lying between the two tools is mirror-symmetrical to the radial orientation of the outlet nozzle 16 the other nozzle jet tool 9 is located. Before the start of the jet-blasting process, the two outlet nozzles 15, 16 are aligned in the same direction. The drive of the two jet stream tools 8, 9 takes place synchronously with the same angular velocity. In this case, the two jet stream tools are driven in opposite directions of rotation, that is, one of the two tools is rotated in the one and the other counterclockwise. During the execution of the jet-blasting process, the angular position of the two jet-blasting tools 8, 9 is continuously controlled so as to ensure that the jet streams S1, S2 are simultaneously directed to the ground between the two tools and in the injection means, such as a suspension or water. The rotational movement of the first jet tool can be defined by a first phase angle φ1 over time t and the rotational movement of the second jet tool can be defined by a second phase angle φ2 over time t. The angular position of the jet nozzles 8, 9 is controlled so that the sine of the first and second phase angles φ1, φ2 is in phase and the cosine of the first and second phase angles φ1, φ2 has a phase offset of 180 °. A tolerance-related offset for the sine and the cosine deviating from these phases is preferably within a range of at most ± 10 °, in particular at most ± 5 °, or even at most ± 2.5 °.

FIG. 3a shows the outlet nozzles 15, 16 and the nozzle jets S1, S2 of the first and second jet tool 8, 9, which are rotated from a starting position (0 °) by a phase angle φ1, φ2 of magnitude about 115 °. Furthermore, the radius R1, R2 of the nozzle jets S1, S2 can be seen. Radially outside the jet zone ZS detected by the jet front, whose boundary is represented by the radius R, there is an adjacent water saturation zone. The water contained in the water saturation zone can be contained in the soil from the outset, for example, by a layer below the groundwater level, or it is introduced by the jet itself into the soil. In the latter case, the water saturation zone precedes the nozzle jet or the nozzle jet front. In the rotational position shown, both jet streams S1, S2 jointly act on the ground area 24 lying outside the jet zone ZS in the region of the center plane EM. In this floor area 24, which in FIG. 3a hatched, the pore water overpressures of the two jet streams S1 and S2 add up, since these act simultaneously, which leads to a particularly high erosion performance. The erosion effects associated with pore water overpressures in the water saturation zone will be discussed in greater detail below.

In FIG. 3b are the outlet nozzles 15, 16 and the nozzle jets S1, S2 of the first and second jet tool 8, 9 further rotated, by a phase angle φ1, φ2 of about 155 ° from the starting position (0 °). In this angular position, the two jet streams S1, S2 lie approximately in a plane defined by the longitudinal axes of the tools plane EW. The two cutting beams S1, S2 of the two jet nozzles 8, 9 meet each other; It comes to the so-called "bullet" through the soil between the two rays, and to the connection of the two cubatures together to a cubature.

Figure 3c shows the nozzle jet tools in a further rotated position in which the two jet streams S1, S2 just meet to produce a common cubature in the center plane EM. Starting from the 0 ° output position, the tools or the nozzle jets S1, S2 are rotated by phase angles φ1, φ2 of approximately 190 °, which corresponds to a rotation relative to the tool plane EW of approximately 210 °. In the rotational position shown, both jets S1 act , S2 in the region of the center plane EM to the outside of the jet zone ZS lying water saturation zone 25, which in Figure 3c hatched. Here, the pore water overpressures add up due to the joint action of the two jet streams S1 and S2, which leads to a particularly high erosion performance.

In 3d figure the nozzle jet tools 8, 9 are shown schematically after again reaching the starting position of the nozzle jets S1, S2, that is, after exactly one complete revolution (360 °). It can be seen the two cubatures 29, 30, which are connected to one another in the region of the median plane EM with the formation of constrictions 28 to one another. These constrictions 28 in the transition region of the two cubatures are also referred to as gussets. The inventive method or device with synchronously rotating in a common depth and oppositely directed outlet nozzles 15, 16 is achieved in an advantageous manner that the constrictions 28 are particularly small or that the connection area between the two cubatures 29, 30 is particularly large.

The preferred regulatory steps for carrying out the method are in the FIGS. 4a, 4b . 5a and 5b and are described below.

In FIG. 4a is shown a control scheme for the depth control before production of cubatures. To set a uniform depth of several jet tools, the depths of the two jet tools 8, 9 are first determined in step V1, which can be done by measuring the insertion of the linkage 6, 7. Subsequently, the determined depth of the two jet stream tools 8, 9 are compared with each other (step V2). If the two nozzle jet tools 8, 9 or the outlet nozzles 15, 16, taking into account tolerances of up to a maximum of one meter, are at the same depth (step V3: position equal), the release for the production of the cubatures takes place in step V4. If, however, it is determined that the tools are not at a depth (step V5: position different), the lower nozzle jet linkage in step V6 is subtracted by the determined difference, and the depth position is determined again (step V1).

The regulation of the depth position during the production of a cubature is in FIG. 5 shown. This takes place analogously to the depth control before the start of production, so that with regard to the common steps to the above description FIG. 4 Reference is made. The same steps are provided with the same reference numerals as in FIG. 4 , One difference is that when a different position is detected (step V5) in the subsequent method step V6 ', an adjustment of the drawing speeds of the two jet-blasting tools is carried out. This can be done, as shown, by reducing the pull rate of the higher boom for a certain period of time, but also by increasing the pull rate of the lower boom.

In FIG. 5a is shown a flow chart for the alignment of the jets before production of the cubature. This is similar to the setting of the depth before the start of production, so in this regard to the description figure 4a Reference is made. To set the desired mirror-symmetrical alignment of the jet tools 8, 9, the angular positions of the two jet tools are first determined in step V1, which can be done by appropriate markings on the linkage or angular position sensors. Subsequently, the determined angular positions of the two jet stream tools are compared with each other (step V2). If the two nozzle jet tools or the outlet nozzles are in mirror-symmetrical alignment with one another taking into account tolerances of up to ± 5 ° (step V3: position OK), the release for the production of the cubature takes place in step V4. However, if it is determined that the tools are not in the desired angular position (step V5: alignment not OK), one of the jet tools will be skewed in step V6 and the orientation will be reestablished (step V1) until the alignment is mirror symmetric to the median plane EM. Then the production of the cubatures can begin with mirror-symmetrical alignment of the outlet nozzles with the same angular velocity in opposite directions of rotation.

The regulation of the angular position during the production of a cubature is in FIG. 5b shown. This takes place analogously to the angle adjustment before production, so that reference is made to the above description with regard to the common steps. The same or corresponding steps are provided with the same reference numerals, as in FIG. 5a , One difference is that upon detection of a different angular position (step V5) in the subsequent method step V6, an adjustment of the rotational speeds of the two jet stream tools is carried out. This can, as shown, by reducing the rotational speed of the leading tool for a certain period of time, but also by increasing the rotational speed of the trailing tool.

The nozzle jet process begins only when both a matching depth (loop according to FIG. 4a ) as well as the desired angular position (loop according to FIG. 5a ) of the two jet tools abuts. The regulation of the depth and angular position during the production of the cubature, that is during the introduction of the injection agent in the soil, is carried out continuously over time or at defined intervals until reaching the desired end position.

Hereinafter, the peculiarity and the advantage of the method or device according to the invention with reference to FIGS. 6 and 7 explained.

The nozzle jet S of a nozzle jet tool is shown schematically as an arrow, wherein the arrowhead represents the nozzle jet front or the radius to which the injection medium penetrates into the soil. Adjacent thereto radially outside is a water-saturated zone, which is in direct communication with the jet. The pressure level of the water contained in the pores between individual grains extends from a maximum value directly at the nozzle jet front to about zero at the edge between the water saturation zone and the upcoming dry soil. This pore water pressure in the water saturation zone is therefore higher, the smaller the distance to the jet S is. Due to the localized energy input of the nozzle jet S, a disproportionate pressure increase in the water, which can also be referred to as pore water overpressure P, arises in the vicinity of the jet tip. Soil grains in close proximity lose contact with each other, which reduces the shear strength and erodes the soil. In this respect, this described effect of friction reduction in the soil by increasing the pressure of the pore water in the vicinity of the nozzle jet tip for the erosion performance of a jet is essential.

FIG. 6 shows qualitatively the course of the pore water pressure P at a nozzle jet S over the distance A to the nozzle jet front. In this case, the distance A to the nozzle jet front is plotted on the X axis, while the Y axis indicates the pore water overpressure P. The nozzle jet S is shown schematically as an arrow. It can be seen that the pore water overpressure P in the region of the nozzle jet tip (X = 0) is maximum and decreases exponentially with increasing distance from the nozzle jet tip (X> 0).

Due to the symmetrical alignment of the nozzle jets against each other and the synchronous rotational movement of the two jets in the opposite direction of rotation, the pore water pressures P1, P2 of the nozzle jets S1, S2 facing each other are added, so that an erosion of the ground is rather distant from the respective jet S1, S2 occurs, as when using only one jet or time-shifted action of two jets.

This situation is in FIG. 7 which qualitatively shows the course of the pore water overpressure P (Y axis) over the distance A to the nozzle jet front (X axis). A nozzle jet S1 acting from the left is shown schematically with a first arrow, a nozzle jet S2 acting from the right with a second arrow. A first solid curve shows the pore water pressure P1 (A) caused by the first jet S1. A second solid curve shows the pore water pressure P2 (A), which is caused by the oppositely directed second jet S2.

It can be seen that the pore water pressures P1 (A), P2 (A) in the soil add up to a resulting pore water pressure Pges (A), which is shown by a dashed line. In the present case, the two jet streams S1, S2 are directed exactly opposite. It is understood, however, that these can also run at an angle to each other. The two jet streams S1, S2 do not have to touch each other directly to achieve a higher separation efficiency. Rather, the addition of the pore water overpressures P1, P2 in the area adjoining the nozzle jet zone bottom area here causes an increased soil discharge by reducing the shear strength between the soil grains. This effect occurs by the method or device according to the invention, in particular in the so-called gusset area between two full columns simultaneously produced in overcut. The gusset area is the area of constriction between the two overlapping bodies.

FIG. 8 shows an example of a jet stream grid for a produced from individual cubes seal bottom of a pit.

By the above-described effect of increasing the range by adding the pore water pressures P1, P2 of two jets S1, S2 and the associated greater separation power in the gusset region of two jet bodies 29, 30, in the gusset area a larger cutting performance compared to the production with only one jet or two arbitrarily rotating Jet jets reached. In the same manufacturing parameters such as nozzle pressure, rotational speed and pulling speed can be increased in the double process according to the invention, the axial distance of a nozzle jet body 29, 30 simultaneously produced without jeopardizing the tightness of the nozzle jet. Because especially in the gusset areas, the cutting performance is increased, so that despite larger center distance of the body, the same gusset coverage, as in the conventional method is achieved. As a result, in total over the entire sealing sole less jet blast bodies are needed, so that the costs of the entire production are reduced.

LIST OF REFERENCE NUMBERS

2

drill

3

ground surface

4

Mäklermast

5

carrying device

6

Jet linkage

7

Jet linkage

8th

Jet tool

9

Jet tool

10 11

contraption

12

drill bit

13

drill bit

14

rotary drive

15

exhaust nozzle

16

Outlet nozzle 17 18 19

20

well

21

well

22

flushing head

23

By fitting rotation head

24

floor area

25

floor area

26

soil layer

27

soil layer

28 29

sediment

30

sediment

A

axis

e

level

R

radius

S

cutting jet

T

depth

V

step

Z

Zone

φ

angle

Claims (15)

Method for producing floor elements by means of a device (11) with at least two nozzle jet tools (8, 9), with the method steps: Dumping and adjusting the depth (T) of the at least two jet tools (8, 9) such that an outlet nozzle (15) of a first jet tool (8) and an outlet nozzle (16) of a second jet tool (9) at least approximately in one of the longitudinal axes (A1, A2) of the nozzle jet tools (8, 9) are vertical plane (ED), Rotating the at least two nozzle jet tools (8, 9) about their respective longitudinal axis (A1, A2) for introducing an injection agent into the ground, wherein the angular position (φ1, φ2) of at least one of the nozzle jet tools (8, 9) is controlled such that the outlet nozzle (15) of the first jet tool (8) and the outlet nozzle (16) of the second jet tool (9) simultaneously to one between the two nozzle jet tools (8, 9) are directed lying area of the soil. Method according to claim 1,
characterized,
that an injection means in the ground under control of the depth and angular position of a first jet tool (8, 9) in dependence on the Depth (T) and the angular position (φ) of a second jet tool (9, 8) is introduced. Method according to claim 1 or 2,
characterized,
that are provided as further method steps: Pulling the at least two nozzle jet tools (8, 9) from the ground with the introduction of injection means into the soil, wherein the depth (T) and the angular position (φ) of the at least two jet tools (8, 9) is detected and controlled while pulling. Method according to one of claims 1 to 3,
characterized
Controlling the depth (T) of the at least two jet tools (8, 9) such that, in a given depth position of the first and second jet tools (8, 9), a cutting jet (S1, S2) of the first jet tool ( 8, 9) in the longitudinal direction of the jet tool at least partially an overlap with an introduced into the ground cutting jet (S2, S1) of the second jet tool (9, 8). Method according to one of claims 1 to 4,
characterized
Controlling the angular position (φ) of the at least two jet tools (8, 9) such that the outlet nozzle (15) of the first jet tool (8) and the outlet nozzle (16) of the second jet tool (9), in a cross-sectional plane viewed through the jet tools (8, 9) are aligned in each rotational position during the injection of injection medium into the ground at least approximately mirror-symmetrical to a between the two longitudinal axes (A1, A2) extending center plane (EM). Method according to one of claims 1 to 5,
characterized,
that the rotational movement of the first jet tool (8) by a first phase angle (φ1) over time (t) is defined, and the rotational movement of the second jet tool (9) by a second phase angle (φ2) over time (t) is defined,
wherein the angular position (φ) of the at least two jet tools (8, 9) is controlled such that the sine of the first and second phase angles (φ1, φ2) has a phase offset of 0 ° ± 10 ° and the cosine of the first and second phase angles (φ1 , φ2) has a phase offset of 180 ° ± 10 °. Method according to one of claims 1 to 6,
characterized,
in that the first and second jet stream tools (8, 9) are driven to rotate at the same angular velocity. Method according to one of claims 1 to 7,
characterized,
in that the first and second jet stream tools (8, 9) are driven to rotate in opposite directions of rotation. Method according to one of claims 1 to 8,
characterized,
in that the first and second jet stream tools (8, 9) are driven synchronously. Method according to one of claims 1 to 9,
characterized,
that is provided as a further method step: Detecting a depth dimension (T1) of the first jet tool (8) representing the first depth by means of a first depth measuring means, Detecting the second depth size representing the depth position (T2) of the second jet tool (9) by means of a second depth measuring device, Comparing the first and second depths, Adjusting the drawing speed of the first jet tool (8, 9) to the drawing speed of the second jet tool (9, 8). Method according to one of claims 1 to 10,
characterized,
that is provided as a further method step: Detecting a first angular quantity representing the angular position (φ1) of the first jet tool (8) by means of a first angle detection device, Detecting a second angular quantity representing the angular position (φ2) of the second jet-jet tool (9) by means of a second angle-detecting device, Comparing the first and second angle sizes, Adjusting the angular position (φ1) of the first jet tool (8) to the angular position (φ2) of the second jet tool (9). Device for producing floor elements, comprising: a first jet tool (8) and a second jet tool (9), which are rotationally driven by at least one drive unit (14); each jet tool (8, 9) has a depth measuring device for determining the depth of the jet tool, each jet nozzle (8, 9) an angle detection device for determining an angular size representing the angular position of the jet tool, an adjusting unit with which the depth (T1, T2) and the angular position (φ1, φ2) of at least one of the two jet-cutting tools (8, 9) can be set in such a manner, an outlet nozzle (15) of the first jet nozzle (8) and an outlet nozzle (16) of the second jet nozzle (9) lie at least approximately in a plane (ED) perpendicular to the axes of rotation (A1, A2) of the nozzle jet tools (8, 9) and are simultaneously directed to a lying between the two nozzle jet tools (8, 9) bottom area. Device according to claim 12,
characterized,
that a control unit is provided which is designed such that the depth (T1) and the angular position (φ1) of the first jet tool (8) depending on the depth (T2) and the angular position (φ2) of the second jet tool (9) can be adjusted is. Device according to claim 12 or 13,
characterized,
in that at least one drive unit (14) is provided for rotationally driving the two jet-blasting tools (8, 9),
wherein in the drive train between the drive unit (14) and the nozzle jet tools (8, 9) a distributor unit is arranged, which divides an introduced drive torque on the at least two jet tools (8, 9) and drives the two jet stream tools (8, 9) in opposite directions of rotation , Device according to one of claims 12 to 14,
characterized,
in that the adjusting unit for adjusting the angular position of at least one of the jet-jet tools (8, 9) is arranged in the drive train between the drive unit (14) and the jet-jet tools.

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