METHOD FOR MONITORING OVERBURDEN WHEN ADVANCE WORKING IN THE GROUND, AND ADVANCE- WORKING DEVICE

Abstract

A method for monitoring overburden during excavation in soil, in which the soil pressure exerted by the soil (10) on an excavation device driven through the soil (10) is monitored by means of a pressure control element (5) extended from the circumference (3) of the driving device. An excavation device for carrying out the method has a pressure control element (5) which is arranged on the circumference (3) of the excavation device and can be extended beyond the circumference (3) of the excavation device.

Claims

1-9. (canceled)

10. Method for drilling a hole in the soil for the installation of pipes, comprising; driving an excavation device with a rotating drill head and a peripheral wall into the soil from a starting pit, transporting the overburden released from the drill head away in the direction of the starting pit, providing a pressure control element for controlling the removal quantity of the overburden during driving in the soil, by monitoring the soil pressure exerted by the soil on the excavation device, wherein the pressure control element is arranged in a box-shaped receptacle pivotable about a pivot axis, wherein the pressure control element is wedge-shaped and has a contact surface, and wherein the pressure control element is articulated to a piston of a hydraulic cylinder, pivoting the pressure control element into an extended position projecting from the peripheral wall with the hydraulic cylinder, and bringing the pressure control element into an extended position after the penetration of the excavation device into the soil whereby the contact surface comes into contact with the surrounding soil.

11. Method according to claim 10, wherein the pressure control element is moved at least one of hydraulically or pneumatically.

12. Method according to claim 11, further comprising detecting a change in the soil pressure by at least one of measuring the pressure in a pressure medium used in at least one of the pneumatic or hydraulic system, or measuring a change in position of the pressure control element.

13. Method according to claim 10, wherein the pressure medium is subjected to a fraction, at least one of at most 20%, at most 10%, or at most 5% of the passive earth pressure of the surrounding earth.

14. Method according to claim 10, further comprising adjusting the pressure of a pressure medium acting in the hydraulic cylinder to maintain the extended position.

15. Method according to claim 14, wherein when at least one of the pressure falls below a limit value or a pressure change occurs at least one of a signal is automatically emitted, or an action is triggered in order to at least one of reduce the rate of advance or the amount of overburden conveyed per unit of time.

16. Method according to claim 10, further comprising; presetting an output pressure of the pressure medium, and detecting a change in the position of the pressure control element.

17. Excavation device, comprising: a drill head, a motor unit for driving the drill head a peripheral wall, having a pressure control element which is arranged on the peripheral wall, which can be extended beyond the circumferential wall of the excavation device and is arranged in the region of the crown of the excavation device, wherein; the pressure control element is arranged in a box-shaped receptacle to be pivotable about a pivot axis, the pressure control element is wedge-shaped and has a contact surface, the pressure control element is articulated to a piston of a hydraulic cylinder, via which the pressure control element can be brought into an extended position, and the contact surface projects at least partially beyond the circumference of the peripheral wall in the extended position of the pressure control element, wherein the excavation device is configured to; drive the drill head and the peripheral wall into the soil from a starting pit, transport the overburden released from the drill head away in the direction of the starting pit, wherein the pressure control element is configured to control the removal quantity of the overburden during driving in the soil by monitoring the soil pressure exerted by the soil on the excavation device, articulate the pressure control element to a piston of a hydraulic cylinder, pivot the pressure control element into an extended position projecting from the peripheral wall by the hydraulic cylinder, and bring the pressure control element into an extended position whereby the contact surface comes into contact with the surrounding soil after the penetration of the jacking device into the soil.

18. Excavation device according to claim 17, wherein the pressure control element is at least one of pneumatically or hydraulically operated.

19. Excavation device according to claim 18, further comprising a pressure measuring element configured to measure a pressure medium in the pneumatic or hydraulic system.

20. Excavation device according to claim 17, further comprising a position measuring element configured to measure the position or a change in position of the pressure control element.

21. Excavation device according claim 17, wherein the contact surface of the pressure control element is flush with the peripheral wall in the retracted state.

22. Excavation device according claim 17, wherein the contact surface of the pressure control element projects into the soil.

Description

[0020] It shows

[0021] FIG. 1: Lateral cross-section of the front end of an excavation device with pressure control element,

[0022] FIG. 2: in an enlarged section of the excavation device according to FIG. 1 the pressure control element in the retracted state,

[0023] FIG. 3: the pressure control element according to FIG. 2 in the retracted state in axial cross-section, and

[0024] FIG. 4: Lateral cross-section of the pressure control element according to FIG. 2 in the extended state.

[0025] FIG. 1 shows schematically in lateral cross-section the front part of a tubular excavation device having a peripheral wall 3 with a drill head 1 and a motor unit 2 for driving the drill head 1. The peripheral wall 3 can be formed by a cutting shoe in a controlled bore. A wedge-shaped pressure control element 5 is arranged in a box-shaped receptacle 4 fixed to the peripheral wall 3 so that it can pivot about a pivot axis 6. The pressure control element 5 is articulated to a piston 7 of a hydraulic cylinder 8. Via the hydraulic cylinder 8 and the piston 7, in their entirety referred to below as hydraulic system 11, the pressure control element 5 can be brought into an extended position in which an upper contact surface 9 of the pressure control element 5 projects at least partially beyond the circumference of the peripheral wall 3.

[0026] FIG. 2 shows an enlarged section of the excavation device with the box-shaped receptacle 4, the pressure control element 5, the piston 7 and the hydraulic cylinder 8 together with the soil 10 surrounding the excavation device. In the retracted state, the contact surface 9 of the pressure control element 5 is essentially flush with the circumference of the peripheral wall 3. FIG. 3 shows the situation according to FIG. 2 in axial cross-section. FIG. 4 shows the pressure control element 5 in an extended position corresponding to FIG. 2, in which the contact surface 9 of the pressure control element 5 protrudes into the soil 10.

[0027] The exemplary procedure is as follows: From a starting pit not shown here, the excavation device is driven into the soil 10, for example with a rotating drill head 1. The drill head 1 has a slight overcut in relation to the circumference of the peripheral wall 3 of the excavation device. For example, lubricating material 12, for example bentonite, can be introduced into an intermediate space created by the overcut via lines not shown here and openings in the circumferential wall 3, which reduces the friction of the peripheral wall 3 against the soil 10.

[0028] Excavated soil 10, i.e. the overburden, can be removed towards the starting pit with the addition of a liquid, for example water, via hoses not shown here. Alternative types of removal are also possible, for example via a screw or bucket conveyor arranged inside the excavation device, which is also not shown here. When the excavation device penetrates the soil 10 or shortly thereafter, the pressure control element 5 is brought into an extended position by means of the hydraulic system 11 (see FIG. 1 and FIG. 4) so that the contact surface 9, which is preferably flat but can also take on other shapes, comes into contact with the surrounding soil 10.

[0029] When the pressure control element 5 is extended, the pressure of a pressure medium in the hydraulic system 11 is set so that there is a balance between the torques that are exerted on the pressure control element 5 via the pressure of the soil 10 on the one hand and via the piston 7 on the other. If the pressure of the soil 10 decreases, the pressure in the hydraulic system 11 must be reduced accordingly to maintain the position of the pressure control element 5, so that the reduction in soil pressure can be determined via the pressure in the hydraulic system 11. Such a reduction in the soil pressure indicates that an over-extraction of soil 10 has occurred, so that as a countermeasure, for example, the delivery rate of the excavated material can be reduced and/or the advance of the excavation device can be increased in order to prevent subsidence or undesired loosening of the soil 10.

[0030] As an alternative to measuring the pressure in the hydraulic system 11 or parallel to this, the extension length of the piston 7 or the position of the pressure control element 5 relative to other parts of the excavation device, e.g. to the circumferential wall 3, can also be measured using suitable methods in order to determine a change in the earth pressure exerted on the pressure control element 5 by the soil 10. For this purpose, an initial pressure can be set in the hydraulic system to which a fraction of, for example, 10% of the passive earth pressure of the surrounding soil 10 is applied. From an initial position of the pressure control element 5, in which the pressure control element 5 protrudes with its contact surface 9 from the peripheral wall 3 of the excavation device, e.g. by a maximum of 30 mm, the pressure control element 5 is then pressed outwards when the soil pressure is less than 10% of the passive soil pressure. This movement can be used to detect over-extraction of overburden in the soil 10.

[0031] In order to prevent soil 10 from entering the receptacle 4, the receptacle 4 can be filled with a material, for example bentonite, which does not hinder the functions of the hydraulic system 11. This is preferably under a pressure at least substantially corresponding to the pressure of the lubricating material 12 in order to prevent the ingress of the lubricating material 12, which may be mixed with soil 10.

[0032] It is also possible to move the pressure control element 5 with a translational movement rather than just pivoting it.

[0033] The features of the device and of the method illustrated in the embodiment examples shown can be replaced or supplemented in the sense of the invention by alternative or further features, such as those shown in the general part of the description or which are apparent to a person skilled in the art.

LIST OF REFERENCE SYMBOLS

[0034] 1 drill head [0035] 2 motor unit [0036] 3 peripheral wall [0037] 4 receptacle [0038] 5 pressure control element [0039] 6 pivot axis [0040] 7 piston [0041] 8 hydraulic cylinder [0042] 9 contact surface [0043] 10 soil [0044] 11 hydraulic system [0045] 12 lubricating material