GB2569661A

GB2569661A - Apparatus and method for pile head leveling

Info

Publication number: GB2569661A
Application number: GB1722048.4A
Authority: GB
Inventors: Huang Chun-Chia; Chung Feng-Yeang; Ou Chia-Chuan; Liao Ying-Chao; Liao Chi-Min
Original assignee: Ship and Ocean Industries R&D Center
Current assignee: Ship and Ocean Industries R&D Center
Priority date: 2017-12-22
Filing date: 2017-12-28
Publication date: 2019-06-26
Anticipated expiration: 2037-12-28
Also published as: GB2569661B; GB201722048D0; TWI669487B; TW201928292A

Abstract

An apparatus suitable for pile head levelling (guiding), having a pile guiding frame (1, Figure 1) having an inner surface 400 that surrounds a receiving space 403 and a level meter (500, Figure 1) on the inner surface 400. The level meter 500 may be received in a trench (401, Figure 4) and has an actuator 502 that has an extending portion 502b onto an ending position of which is configured a sensor 503, which may be a magnetic, optical or ultrasonic sensor. A displacement meter 501 is also connected to the actuator. There may be telescopic connection portion (404b, Figure 4) between the inner surface 400 and the level meter (500, Figure 1) that moves the level meter (500, Figure 1) horizontally to a measuring position. There is also a method for pile head levelling using the apparatus for calculating a pile head level difference using the sensor 503 and repeating the method until a pile basement (3, Figure 1) is drilled into a base for a predetermined depth.

Description

[0001] At least one embodiment of the present invention provides an apparatus and a method for pile head leveling, and more particularly to an apparatus and a method for underwater pile head leveling.

Description of the Related Art [0002] With respect to many major projects, both above and below water, the foundation of its seabed must be stabilized before the subsequent related works can be renewed. In recent years, with the increasing development of offshore constructions, such as offshore wind turbines or underwater piling operations, have become more and more important. Generally, piling may be adopted to settle the base, regardless offshore platforms or any constructions on the seabed.

[0003] For the piling operations, measurements of piling distances or elevation are necessary when performing the piling operations or evaluating effectiveness. When the piling operations need to be done underwater, the measurement of the elevation needs to be achieved by a special mechanism or process, which is different from the mechanism or process for the piling operation above the water.

[0004] One common underwater elevation measuring method is to set a measuring reference point by contacting a top of a pile. One solution relates to adopting a caliper measuring arm arranged outside the pile sleeve and to place the measuring surface on the top of the pile as the reference point. Sensors and displacement meters are adopted to measure the elevation of the piling operation, and signals may be detected and transmitted above the water.

[0005] Another common underwater elevation measurement is to hang a pressure sensor on the top of the pile, and to read value detected by the pressure sensor so as to obtain position information of the top of the pile.

[0006] However, the above-mentioned underwater elevation measurement requires the pile hammer to be removed from the top surface of the pile. As such, a measurement surface or sensing devices have to be placed on the top of the pile, and the measurement may be conducted. That is, the piling operations may be interrupted due to the elevation measurement process. As such, it may not only increase complexity of the operation, but also results in additional time-consuming, energy-consuming, and costs.

SUMMARY [0007] Some embodiments of the present invention provide an apparatus for pile head leveling. The apparatus includes a pile guiding frame including an inner surface. The inner surface is configured to be surrounded to form a receiving space.

[0008] The apparatus further includes a level meter configured on the inner surface. The level meter includes: an actuator including an extending portion, a sensor configured on an ending position of the extending portion, and a displacement meter connecting to the actuator.

[0009] Some embodiments of the present invention provide a method for pile head leveling. The method includes providing the apparatus for the pile head leveling, detecting the signal change, initiating the searching operation to activate the actuator to drive the extending portion to move downward, detecting a positioning flag by the sensor, terminating the actuator, reading the position information, and calculating a pile head level difference.

BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 is a cross-sectional view of an apparatus for pile head leveling in accordance with one embodiment of the present disclosure.

[0011] FIG. 2 is a partial, cross-sectional view of the apparatus for pile head leveling in accordance with another embodiment of the present disclosure.

[0012] FIG. 3(a), FIG. 3(b) and FIG. 3(c) show operations of a method for pile head leveling in accordance with one embodiment of the present disclosure.

[0013] FIG. 4 is a partial, enlarged view of the apparatus for pile head leveling in accordance with one embodiment of the present disclosure.

[0014] FIG. 5 is a partial, schematic view of the apparatus for pile head leveling in accordance with one embodiment of the present disclosure.

[0015] FIG. 6 is a flowchart illustrating the method for pile head leveling in accordance with one embodiment of the present disclosure.

[0016] FIG. 7 is a flowchart illustrating the method for pile head leveling in accordance with another embodiment of the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] To clarify the purpose, technical solutions, and the advantages of the disclosure, embodiments of the invention will now be described more fully hereinafter with reference to the accompanying drawings.

[0018] FIG. 1 is a cross-sectional view of an apparatus for pile head leveling in accordance with one embodiment of the present disclosure. Piling operations may be performed within a receiving space 403 of a pile guiding frame 1.

[0019] In one example, referring to FIG. 1, the pile guiding frame 1 is configured to be an annulus frame. The annulus frame may be formed by a plurality of pillars 402. The pillars 402 are configured to be surrounded to form the receiving space 403 inside of the surrounded pillars 402 and an external space located outside of the surrounded pillars 402. More specifically, the receiving space 403 is surrounded by inner surfaces 400 of the pillars 402. The pillars 402 may be configured in horizontal, vertical, or diagonal. It is noted that the pile guiding frame 1 shown in FIG. 1 is merely an example, the pile guiding frame and inner surface of the present disclosure are not limited to this.

[0020] In one example, a level meter 500 may connect to the inner surface 400 via a connection portion 404, or the level meter 500 may be configured on the inner surface 400. In another example, a trench 401 may be formed on the inner surface 400, and the level meter 500 may be arranged in the trench 401. Alternatively, the level meter 500 may be arranged in the trench 401 via the connection portion 404. In another example, the connection portion 404 may be a telescopic connection portion 404b capable of adjusting length, so as to adjust a horizontal position of the level meter 500 to a measuring position within the receiving space 403. The measuring position may provide an optimized measuring distance for a sensor 503, and may not impede operations of a pile basement 3 and a piling mechanism 6. For example, the sensor 503 may be an ultrasonic sensor, an optical sensor, or a magnetic sensor. When the sensor 503 is the magnetic sensor, magnetic threshold of the magnetic sensor may be in a range from 0.1 centimeter to 40 centimeters. The optimized measuring distance may be in the range of the magnetic threshold.

[0021] FIG. 2 is a partial, cross-sectional view of a portion of the apparatus for pile head leveling in accordance with one embodiment of the present disclosure. To clarify the mechanism of the present invention, a portion of a sleeve lb is omitted in FIG. 2.

[0022] In one example, referring to FIG. 2, the pile guiding frame 1 is configured to be the sleeve lb. The sleeve lb may include the inner surface 400. The inner surface 400 is configured to be surrounded to form a cylindrical and to form the receiving space 403. The piling operations are performed within the receiving space 403. It is noted that the sleeve lb shown in FIG. 2 is merely an example, which has the same functions as the pile guiding frame 1 shown in FIG. 1. However, structure of the pile guiding frame and the inner surface are not limited to FIGs. 1 or 2.

[0023] In one example, the level meter 500 may be configured on the inner surface 400. The level meter 500 may connect with the inner surface 400 via the connection portion 404 (shown in FIG. 1), the telescopic connection portion 404b, or mechanisms capable of connecting, but it’s not limited to.

[0024] Referring to FIG. 2, the level meter 500 may include an actuator 502. The actuator 502 may include an extending portion 502b. The sensor 503 may be configured on an ending positon of the extending portion 502b. A displacement meter 501 may connect to the actuator 502 to read displacement information of the actuator 502. When the actuator 502 is activated, the extending portion 502b may be extended and may move downward, and the sensor 503 configured on the ending positon of the extending portion 502b may be driven to move downward to detect an edge position of a head of the pile basement. As such, the displacement meter 501 may read the displacement information of the actuator 502 or the extending portion 502b. In one example, the displacement meter 501 is configured on a head of the actuator 502, but configuration of the displacement meter 501 is not limited to the figure. The displacement meter 501 may be any devices capable of reading the displacement information of the actuator 502. For example, the displacement meter 501 may be a digital device configured in the actuator 502. In one example, displacement accuracy of the displacement meter 501 may be in a range from -0.05 centimeter to +0.05 centimeter.

[0025] When force F is conducted on the pile basement 3 by a pile hammer 2, the pile basement 3 may be moved downward into a base. When the sensor 503 detects displacement of the pile basement 3, the actuator 502 may be activated to drive the extending portion 502b to move downward, and the sensor 503 configured on the ending positon of the extending portion 502b may be driven to move downward, so as to initiate an downward-edge-searching operation. When the sensor 503 is close to a bottom edge of the pile basement 3, the sensor 503 may detect positioning signals indicating the sensor 503 has reached the edge of the pile hammer 2. As such, pile head position may be obtained. The level meter 500 may terminate the operation of the actuator 502 to stop the downward-edge-searching operation upon the sensor 503 detects the positioning signals. The displacement meter 501 may obtain a pile head level difference of the piling operation by reading position information.

[0026] In one example, the sensor 503 may be the magnetic sensor. When force F is conducted on the pile basement 3 by the pile hammer 2, the pile basement 3 may be moved down into the base. Due to the pile basement 3 is made of metal material, a signal change may be detected by the magnetic sensor 503 when the pile basement 3 is moved downward. The actuator 502 may be activated to drive the extending portion 502b to move downward, and the sensor 503 configured on the ending positon of the extending portion 502b may be driven to move downward, so as to initiate the downward-edge-searching operation upon the sensor 503 detects the signal change. When the magnetic sensor 503 is close to the bottom edge of the pile basement 3, the magnetic sensor 503 may detect the positioning signals indicating the magnetic sensor 503 has obtained the pile head position. The level meter 500 may terminate the operation of the actuator 502 to stop the downward-edge-searching operation upon the magnetic sensor 503 detects the positioning signals. The displacement meter 501 may obtain the pile head level difference of the piling operation by reading the position information.

[0027] The positioning signals may be determined when correcting the pile head leveling apparatus. In one example, the positioning signals may be a characteristic wave pattern or signals indicating a position where data changes rapidly. It is noted that the positioning signals may be determined according to actual situation, and may not be limited.

[0028] FIG. 3(a), FIG. 3(b) and FIG. 3(c) show operations of a method for pile head leveling in accordance with one embodiment of the present disclosure. The level meter 500 is arranged on the inner surface 400 of the pile guiding frame 1. To clarify the method of the present invention, the pile guiding frame 1 and a connection mechanism are omitted in FIG. 3(a), FIG. 3(b) and FIG. 3(c).

[0029] Referring to FIG. 3(a), the level meter 500 is located at the measuring position within the receiving space 403 and is ready for a leveling process. The position of level meter 500 may be determined by an underwater position monitoring module. The underwater position monitoring module may include a camera, an underwater unmanned vehicle, or a detector. The level meter 500 may be fixed at the measuring position via the connection portion 404 or the telescopic connection portion 404b. The measuring position is determined by the underwater position monitoring module.

[0030] During an operational stage of the piling operation, the piling mechanism 6 is activated to drive the pile hammer 2 to conduct the force F on the pile basement 3 to push the pile basement 3 drilling down into the base. When the pile basement 3 drills into the base, the piling mechanism 6 keeps pushing the pile basement 3 to drive the pile basement 3 to continuously have a downward displacement. The pile hammer 2 tightly attaches to the head of the pile basement 3.

[0031] FIG. 3(b) illustrates a termination state of the operational stage of the piling operation. Referring to FIG. 3(b), the piling mechanism 6 stops pushing the pile basement 3. The pile basement 3 stands and the pile hammer 2 is located at a fixing position. The pile hammer 2 still tightly attaches to the head of the pile basement 3. States of the pile hammer 2 and pile basement 3 are changed from a down-moving state to a standing state. Such that, the signal change may be detected by the sensor 503 of the level meter 500.

[0032] Referring to FIG. 3(c), upon the sensor 503 detects the signal change, the level meter 500 may activate the actuator 502 to drive the extending portion 502b to move downward, and the sensor 503 configured on the ending positon of the extending portion 502b may be driven to move downward, so as to initiate the downward-edge-searching operation. Upon the sensor 503 reaches the edge of the pile hammer 2, the sensor 503 may detect a positioning flag, and the level meter 500 may terminate the actuator 502. The level meter 500 may obtain the pile head level difference of the piling operation by reading the position information via the displacement meter 501.

[0033] The pile head leveling method of the present disclosure may repeat the operations shown from FIG. 3(a) to FIG. 3(c) to measure the pile head level difference with respect to each of the operational stage of the piling operation until the pile basement is drilled into the base for a predetermined depth. The positioning signals may be determined when correcting the pile head leveling apparatus. In one example, the positioning signals may be the characteristic wave pattern or the signals indicating the position where data changes rapidly. It is noted that the positioning signals may be determined according to the actual situation, and may not be limited.

[0034] The method for pile head leveling of the present disclosure may include a preparing operation configured to determine the horizontal position of the level meter 500 via the underwater position monitoring module. When the level meter 500 has been located at the measuring position within the receiving space 403 inside the pile guiding frame 1, the leveling process shown in FIG. 3(a) to FIG. 3(c) may be performed. When the level meter 500 moves away from the pile guiding frame 1, the horizontal position of the level meter 500 may continue to be adjusted until the level meter 500 has been located at the measuring position within the receiving space 403 inside the pile guiding frame 1. The level position may be determined via the underwater position monitoring module. The preparing operation may be terminated upon the level meter 500 reaches the measuring position, and the leveling process (as shown in FIG.3(a) to FIG. 3(c)) may be initiated.

[0035] The apparatus for pile head leveling of the present disclosure may further include a timer configured to provide time information to the actuator 502 as a parameter for the actuator 502 to perform the downward-edge-searching operation command.

[0036] FIG. 4 is a partial, enlarged view of the pile head leveling apparatus in accordance with one embodiment of the present disclosure. In one example, the pile guiding frame 1 is configured to be the sleeve lb. The sleeve lb may include the inner surface 400. The inner surface 400 is configured to be surrounded to form a cylindrical and to form the receiving space 403. The piling operations are performed within the receiving space 403. It is noted that the sleeve lb shown in FIG. 2 is merely an example, which has the same functions as the pile guiding frame 1 shown in FIG. 1. However, the structure of the pile guiding frame and the inner surface are not limited to FIGs. 1 or 2.

[0037] In one example, the trench 401 may be formed on the inner surface 400 of the sleeve lb and is configured to place or receive the level meter 500. Alternatively, the level meter 500 may be arranged in the trench 401 via the connection portion 404, the telescopic connection portion 404b, or other mechanism capable of adjusting length. When the level meter 500 is arranged on the inner surface 400 via the telescopic connection portion 404b, the level meter 500 may move horizontally to the measuring position via the telescopic connection portion 404b. The measuring position may provide the optimized measuring distance for the sensor 503. In another example, the measuring position may be located in the trench 401.

[0038] FIG. 5 is a partial, schematic view of the pile head leveling apparatus in accordance with one embodiment of the present disclosure. In one example, the pile guiding frame 1 is configured to be the annulus frame. The annulus frame may be formed by a plurality of the pillars 402 configured to be surrounded. The pillars 402 may be configured in horizontal, vertical, or diagonal. The inner surface 400 is an assembly of the inner surfaces of the pillars 402. In one example, the inner surface 400 is a discontinuous surface. The receiving space 403 may be formed within the inner surface 400. The piling operation may be performed in the receiving space 403.

[0039] In one example, the level meter 500 is arranged on the inner surface 400 via the telescopic connection portion 404b, the level meter 500 may move horizontally to the measuring position by a shrinking motion of the telescopic connection portion 404b to perform the leveling process. As shown in FIG. 5, the measuring position may provide the optimized measuring distance for the sensor

503, and may not impede the operations of the pile basement 3 and the piling mechanism 6.

[0040] In one example, the sensor 503 may be the magnetic sensor. The magnetic threshold of the magnetic sensor may be in a range from 0.1 centimeter to 40 centimeters. The optimized measuring distance may be in the range of the magnetic threshold.

[0041] In another example, the underwater position monitoring module may include the camera, the underwater unmanned vehicle, or the detector. The underwater position monitoring module is configured to monitor a position of the level meter 500 to ensure the level meter to be at the correct measuring position.

[0042] In one example, the actuator 502 may be a linear motor or a hydraulic actuator. When the actuator 502 is the hydraulic actuator, an actuation distance of the actuator 502 is in a range from 0.1 centimeter to 3000 centimeters. The level meter 500 may further include the displacement meter 501 configured to read the displacement information of the actuator 502. For example, the displacement meter 501 may be the digital device configured in the actuator 502. The person skill in the art may understand configurations of the displacement meter 501 in the embodiment are merely an example, and the displacement meter 501 may not be limited. In another example, the displacement accuracy of the displacement meter 501 is in a range from -0.05 centimeter to +0.05 centimeter.

[0043] FIG. 6 is a flowchart of the method for pile head leveling in accordance with one embodiment of the present disclosure. Referring to FIG. 2 and FIG. 6, the preparing operation is performed. The position of the level meter 500 is determined by the underwater position monitoring module. When the level meter 500 is close to the pile guiding frame 1 or the sleeve lb, and the level meter 500 is located at measuring position within the receiving space 403 inside the pile guiding frame 1, the leveling process may be activated. When the level meter 500 moves away from the pile guiding frame 1 or the sleeve lb, the position of the level meter 500 may continue to be adjusted until the level meter 500 has been located at the measuring position within the receiving space 403 inside the pile guiding frame 1. The level position may be determined by the underwater position monitoring module. The preparing operation may be terminated upon the level meter 500 reaches the measuring position.

[0044] After performing the leveling process, the timer may be activated and the actuator 502 may be driven to perform the flange/edge-searching operation upon the sensor 503 of the level meter 500 detects the signal change. The timer is configured to provide a predetermined value to the actuator 502 as the parameter for the actuator 502 to perform operational commands. The timer and the actuator may not be activated, and the follow-up operations may not be performed until the sensor 503 of the level meter 500 detects the signal change.

[0045] During the flange/edge-searching operation, the flange/edge-searching operation may be terminated upon the sensor 503 detects the positioning signals. The current position information may be obtained, and elevation of the pile head may be calculated. The flange/edge-searching operation may continue until the sensor 503 detects the positioning signals. As such, the current position information may be obtained, and the elevation of the pile head may be calculated.

[0046] After one stage of the piling operation and calculation of the elevation of the pile head are completed, the leveling process may be re-activated to perform the calculation of the elevation of the pile head for the piling operation in next stage.

[0047] FIG. 7 is a flowchart illustrating the method for pile head leveling in accordance with one embodiment of the present disclosure. As shown in FIG. 7, the method for pile head leveling may include steps (a) to (g). The method may be performed by the apparatus shown in FIG. 1 to FIG. 5.

[0048] In step (a), providing the apparatus for the pile head leveling. In step (b), detecting the signal change by the sensor. In step (c), initiating the searching 5 operation, including activating the actuator to drive the extending portion to move downward until detecting the positioning flag by the sensor in step (d). In step (e), terminating the actuator. In step (f), reading the position information by the displacement meter. In step (g), calculating the pile head level difference. The steps (a) to (g) are repeated until the pile basement drills to the base for the 10 predetermined depth. The pile hammer tightly attaches to the head of the pile basement during the leveling process.

Claims

1. An apparatus for pile head leveling, comprising:

a pile guiding frame comprising an inner surface, wherein the inner surface is configured to be surrounded to form a receiving space; and a level meter configured on the inner surface, wherein the level meter comprises:

an actuator comprising an extending portion;

a sensor configured on an ending position of the extending portion; and a displacement meter connecting to the actuator.

2. The apparatus for pile head leveling as claimed in claim 1, wherein the apparatus further comprises:

a telescopic connection portion configured between the inner surface and the level meter;

wherein the level meter moves horizontally to a measuring position via the telescopic connection portion.

3. The apparatus for pile head leveling as claimed in claim 2, wherein the inner surface further comprises a trench configured to receive the level meter.

4. The apparatus for pile head leveling as claimed in claim 1, wherein the sensor is a magnetic sensor, an optical sensor, or an ultrasonic sensor.

5. The apparatus for pile head leveling as claimed in claim 1, wherein the apparatus further comprises an underwater position monitoring module comprising a camera, an underwater unmanned vehicle, or a detector.

6. The apparatus for pile head leveling as claimed in claim 4, wherein a magnetic threshold of the magnetic sensor is in a range from 0.1 centimeter to 40 centimeters.

7. The apparatus for pile head leveling as claimed in claim 1, wherein the actuator is a linear motor or a hydraulic actuator.

8. The apparatus for pile head leveling as claimed in claim 1, wherein an actuation distance of the actuator is in a range from 0.1 centimeter to 3000 centimeters.

9. The apparatus for pile head leveling as claimed in claim 1, wherein displacement accuracy of the displacement meter is in a range from -0.05 centimeter to +0.05 centimeter.

10. The apparatus for pile head leveling as claimed in claim 1, wherein the apparatus further comprises a timer.

11. A method for pile head leveling, comprising:

step (a), providing the apparatus for pile head leveling as claimed in claim 1; step (b), detecting a signal change by the sensor;

step (c), initiating an edge-searching operation comprising activating an actuator to drive an extending portion of the actuator to move downward;

step (d), detecting a positioning flag by the sensor;

step (e), terminating the actuator;

step (f), obtaining position information from a displacement meter; and step (g), calculating a pile head level difference.

12. The method for pile head leveling as claimed in claim 11, wherein the steps (a) to (g) are repeated until a pile basement is drilled into a base for a predetermined depth.

13. The method for pile head leveling as claimed in claim 11, wherein the method further comprises a preparing operation comprising:

step (Pl), determining a position of the level meter by an underwater position monitoring module;

step (P2), performing the steps (a) to (g) when determining the level meter is close to a pile guiding frame; and adjusting the position of the level meter when the level meter moves away from the pile guiding frame.

14. The method for pile head leveling as claimed in claim 11, wherein the activating step further comprises:

5 step (Cl), providing time information to the actuator by a timer; and step (C2), activating the actuator to drive to the extending portion to move downward.

15. The method for pile head leveling as claimed in claim 12, wherein a pile hammer tightly attaches to a head of the pile basement when performing steps (a)

10 to (g).

24 01 19

Amendments to the claims have been filed as follows

1. An apparatus for pile head guiding, comprising:

a pile guiding frame comprising a receiving space; and a level meter configured on the pile guiding frame, wherein the level meter

5 comprises:

an actuator comprising an extending portion, wherein the actuator is drivable to move the extending portion downwards;

10 2. The apparatus for pile head guiding as claimed in claim 1, wherein the apparatus further comprises:

a telescopic connection portion configured to connect the pile guiding frame and the level meter;

wherein the level meter moves horizontally to a measuring position via the

15 telescopic connection portion.

3. The apparatus for pile head guiding as claimed in claim 2, wherein the pile guiding frame has a trench configured to receive the level meter.

20 5. The apparatus for pile head guiding as claimed in claim 1, wherein the apparatus further comprises an underwater position monitoring module comprising a camera, an underwater unmanned vehicle, or a detector.

6. The apparatus for pile head guiding as claimed in claim 4, wherein the sensor is the magnetic sensor and a magnetic threshold of the magnetic sensor is in a range from 0.1 centimeter to 40 centimeters.

7. The apparatus for pile head guiding as claimed in claim 1, wherein the actuator is

24 01 19 a linear motor or a hydraulic actuator.

8. The apparatus for pile head guiding as claimed in claim 1, wherein an actuation distance of the actuator is in a range from 0.1 centimeter to 3000 centimeters.

9. The apparatus for pile head guiding as claimed in claim 1, wherein displacement

5 accuracy of the displacement meter is in a range from -0.05 centimeter to +0.05 centimeter.

10. The apparatus for pile head guiding as claimed in claim 1, wherein the apparatus further comprises a timer.

11. A method for pile head guiding, comprising:

10 step (a), providing the apparatus for pile head guiding as claimed in claim 1;

step (b), detecting a signal change by the sensor;

step (d), detecting a positioning flag by the sensor;

15. The method for pile head guiding as claimed in claim 12, wherein a pile hammer tightly attaches to a head of the pile basement when performing steps (a) to (g).

15 step (e), terminating the actuator;

12. The method for pile head guiding as claimed in claim 11, wherein the steps (a) to (g) are repeated until a pile basement is drilled into a base for a predetermined

20 depth.

13. The method for pile head guiding as claimed in claim 11, wherein the method further comprises a preparing operation comprising:

25 step (P2), performing the steps (a) to (g) when determining the level meter is close to a pile guiding frame; and adjusting the position of the level meter when the level meter moves away from the pile guiding frame.

14. The method for pile head guiding as claimed in claim 11, wherein the activating step further comprises: