MEASURING DEVICE AND METHOD FOR MEASURING A HOLE IN THE GROUND

Abstract

A measuring device for measuring a hole in the ground having at least one measuring probe having at least one measurement signal transmitter to transmit a measurement signal, at least one measurement signal receiver to receive the measurement signal reflected on a wall area of the hole, and an evaluation unit for determining a wall distance between the measurement signal transmitter and the wall area of the hole, wherein a measuring distance based on an assignment rule can be assigned to the received, reflected measurement signal. A calibrating device having at least one calibration element. The measurement signal transmitter transmits a calibration signal, which can be reflected on the calibration element, wherein the measurement signal receiver receives the calibration signal reflected on the calibration element. The evaluation unit changes and calibrates the assignment rule based on the calibration signal reflected and received by the calibration element.

Claims

1. Measuring device for measuring a hole in the ground, having at least one measuring probe that can be lowered into the hole, having at least one measurement signal transmitter to transmit a measurement signal, at least one measurement signal receiver to receive a measurement signal from a wall area of the hole, a calibration signal transmitter to transmit a calibration signal to a calibration element and a calibration signal receiver to receive a calibration signal reflected on the calibration element, and an evaluation unit to determine a wall distance between the measurement signal transmitter and the wall area of the hole, wherein a measurement distance can be assigned to the received, reflected measurement signal based on an assignment rule, wherein by means of the evaluation unit the assignment rule can be changed and calibrated based on the calibration signal reflected and received by the calibration element, wherein the calibration element is rigidly attached to the side of the measuring probe with a defined calibration distance, the measurement signal transmitter is designed to transmit the measurement signal and the calibration signal transmitter to transmit the calibration signal laterally towards the wall area of the hole, the measurement signal transmitter and the calibration signal transmitter are designed to transmit ultrasound signals and the measurement signal receiver and the calibration signal receiver are designed to receive the reflected ultrasound signals.

2. Measuring device according to claim 1, wherein the measurement signal transmitter and the measurement signal receiver are designed in combination as at least one measurement signal transceiver, wherein the measurement signal transceiver is designed to transmit the measurement signal and to receive the measurement signal reflected on the wall area of the hole.

3. Measuring device according to claim 1, wherein a lowering means, in particular a winch means arranged above the hole, and at least one lowering rope attached to the lowering means and connected to the measuring probe are provided for lowering the measuring probe into the hole, wherein the lowering means is designed to receive and release the at least one lowering rope.

4. Measuring device according to claim 3, wherein the at least one lowering rope can be arranged parallel to a lowering axis in at least one lowering position of the measuring probe in the hole, wherein the lowering axis corresponds to a levelling axis of a underground engineering tool for creating the hole.

5. Measuring device according to claim 1, wherein the at least one measurement signal transmitter and the at least one measurement signal receiver are designed to transmit and receive measurement signals in a continuous way.

6. Measuring device according to claim 1, wherein the measuring probe and the calibrating means are surrounded by a housing frame that is open at least in part, the housing frame has a symmetry axis parallel to the lowering axis and the common centre of gravity of the measuring probe, the calibrating means and the housing frame lies on the lowering axis.

7. Measuring device according to claim 1, wherein the calibration element has a surface orientated orthogonally with respect to the measurement signal transmitter.

8. Measuring device according to claim 1, wherein to transmit the calibration signal to the calibration element a separate calibration signal transmitter is provided and/or to receive the calibration signal reflected on the calibration element a separate calibration signal receiver is provided.

9. Measuring device according to claim 1, wherein in each case a plurality of measurement signal transmitters and measurement signal receivers, in particular respectively two, three or four measurement signal transmitters and measurement signal receivers, are provided.

10. Measuring method for measuring a hole in the ground, in particular with a measuring device according to claim 1, wherein at least one measuring probe is lowered with a lowering means into at least one lowering position in the hole, at least one measurement signal transmitter of the measuring probe transmits a measurement signal towards a wall area of the hole, at least one measurement signal receiver of the measuring probe receives a measurement signal from a wall area of the hole and a calibration signal transmitter of the measuring probe transmits a calibration signal to a calibration element, a calibration signal receiver of the measuring probe receives a calibration signal reflected on the calibration element, an evaluation unit determines a wall distance between the measurement signal transmitter and the wall area of the hole, wherein a measuring distance is assigned to the received, reflected measurement signal based on an assignment rule and wherein the evaluation unit changes and calibrates the assignment rule based on the calibration signal reflected and received by the calibration element, wherein the calibration element is attached rigidly to the side of the measuring probe with a defined calibration distance, the measurement signal transmitter transmits the measurement signal and the calibration signal transmitter transmits the calibration signal laterally towards the wall area of the hole, the measurement signal transmitter and the calibration signal transmitter transmit ultrasound signals and the measurement signal receiver and the calibration signal receiver receive the reflected ultrasound signals.

11. Measuring method according to claim 10, wherein the calibration signal is transmitted simultaneously or temporally offset with respect to the measurement signal.

12. Measuring method according to claim 10, wherein the assignment rule is changed and calibrated in the determination of a plurality of wall distances at a plurality of lowering positions in the hole.

13. Measuring method according to claim 10, wherein measurement signals are transmitted and received during lowering and raising back again to the surface of the measuring probe, wherein the wall distances determined by the evaluation unit during raising back again to the surface of the measuring probe are used to control the wall distances detected during lowering.

14. Method for producing a wall in the ground, in particular a bored pile wall or diaphragm wall, which is formed from a plurality of wall elements adjacent to each other, wherein a hole is created for each wall element, the hole is measured and the hole is filled with a settable mass to form the wall element, wherein a measuring method according to claim 10 is used to measure at least one hole.

Description

[0035] The invention will be described below by reference to a preferred embodiment, which is shown schematically in the attached drawing, in which:

[0036] The FIGURE shows a perspective view of a measuring device according to the invention in a hole in the ground.

[0037] One embodiment of a measuring device 1 according to the invention will be explained below in association with the FIGURE. The measurement environment for the measuring device 1 is composed, inter alia, of a hole 3 in the ground. The hole 3 is not provided with pipework and is filled with a liquid medium, here bentonite suspension. The measuring probe 10 is located within the hole 3 and is surrounded by the bentonite suspension. The hole 3 was deepened by means of underground engineering equipment. A levelling axis 36 of the underground engineering equipment is present, which corresponds to the lowering axis 36 of the measuring device 1. These axes are vertical and do not correspond, at least in portions, to the centre axis of the hole 3, which is not shown.

[0038] To lower the measuring probe 10 in the hole 3, a lowering means 30 is arranged above the hole 3. The lowering means 30 has in particular a winch means 32, on the drum of which the lowering rope 34, which is connected to the measuring probe 10, is wound. The winch means 32 can thereby be locked in any desired lowering position of the measuring probe 10 in the hole 3. Alternatively the measuring probe 10 can be continuously lowered with constant lowering speed into the hole 3. The winch means 32 is also able to raise the measuring probe 10 back to the surface again after reaching the full lowering depth in a lower area of the hole 3, wherein this is also realised along the lowering axis 36.

[0039] The measuring probe 10, which is shown in this exemplary embodiment schematically as a cube, has three measurement signal transmitters 12 and three measurement signal receivers 14, one of which each can be seen in the perspective view. The measurement signal transmitters 12 and measurement signal receivers 14 are thereby located centrally on three of the vertical cube surfaces. The measuring probe 10 is designed to be watertight, wherein in particular the measurement signal transmitters 12 and measurement signal receivers 14 are protected against entry of the bentonite suspension. The measuring probe 10 further has a calibration signal transmitter 16 and a calibration signal receiver 18, which are located centrally on the fourth vertical cube surface. On the measuring probe 10 a calibrating means 20 is arranged on the side of the fourth cube surface, the calibrating means 20 being composed of a plurality of struts and a calibration element 22 held on them. The distance between the calibration signal transmitter 16 and calibration element 22 in this exemplary embodiment is between 10 cm and 50 cm. The calibrating means 20, which holds the calibration element 22, is rigidly and securely connected to the measuring probe 10. While corresponding wall distances 7 extend between the measurement signal transmitters 12 and measurement signal receivers 14 and the corresponding wall areas 5 of the hole 3, a calibration distance to the calibration element 22 is formed between the calibration signal transmitter 16 which is located on the same cube side as the calibration element 22. This arrangement serves for the correction of all measurement distances by means of a calibration of the assignment rule. In the exemplary embodiment, it can also optionally be provided to use the calibration signal transmitter 16 also as an additional fourth measurement signal transmitter 12, wherein the calibration element is located in part in the signal path between the calibration signal transmitter 16 and a corresponding wall area 5 to be measured, wherein a signal response is reflected, with a time offset, by the calibration element 22 and the wall area 5.