Test device and method for accurately evaluating the seabed disturbance effect of pile insertion and extraction

Abstract

The present invention discloses a test device and method for accurately evaluating the seabed disturbance effect of pile insertion and extraction, wherein the test device for accurately evaluating the seabed disturbance effect of pile insertion and extraction comprises: a support platform; a sounding penetration mechanism, which is arranged on the support platform; a test soil box, which is arranged on the support platform opposite to the sounding penetration mechanism; the sounding penetration mechanism comprises: a loading plate, which is slidably connected to the support platform; a sounding probe, which is connected to the loading plate, and a soil box through hole for the sounding probe to penetrate is provided on the side wall of the test soil box; a tension pressure sensor, which is connected between the loading plate and the sounding probe; a power mechanism, which is connected to the loading plate, and is used to make the loading plate drive the sounding probe away from or close to the test soil box. In the test device for accurately evaluating the seabed disturbance effect of pile insertion and extraction of the present application, multiple sounding probes are automatically penetrated into the test soil box at the same time, which improves the efficiency of the penetration resistance test and avoids the influence of human factors, time and other factors on the test results.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and in particular to a test device and method for accurately evaluating the seabed disturbance effect of pile insertion and extraction. Background Art

[0002] The jack-up platform is the main equipment for offshore oil and gas production. The transition between the floating and seabed support states of the platform is accompanied by the process of pile insertion and extraction. After each pile insertion and extraction, a sunken pile pit will be left on the seabed, and the surrounding soil will be disturbed. The physical and mechanical properties of the disturbed seabed soil are significantly different from those of the original undisturbed soil, which increases the unevenness of the seabed and has an adverse effect on the subsequent platform pile insertion operation. In severe cases, it may even lead to the failure of the platform pile insertion, resulting in serious engineering accidents. Therefore, quantitative evaluation of the scope and degree of seabed disturbance caused by pile insertion and extraction is of great significance to the safety and stability of marine engineering facilities.

[0003] At present, there are two main methods for evaluating the scope and degree of soil disturbance by indoor physical model tests. One is to pre-bury pore pressure, stress and strain sensors in the soil layer, and evaluate the scope and degree of soil disturbance by monitoring the changes in pore pressure, stress and strain during the disturbance. This method is limited by the buried position of the sensor, and the monitoring data can only reflect the state of a certain point inside the soil, and it is impossible to achieve an accurate evaluation of the scope and degree of soil disturbance; the other is to use a portable cross plate and a sounding probe to test point by point, and evaluate the soil disturbance by comparing it with the penetration resistance of the original undisturbed soil. The disadvantage of this method is that a single probe is tested separately, the test efficiency is low, and the comparability between multiple groups of test results is poor due to human and time factors. In addition, the probe is only penetrated vertically, and the continuous penetration resistance along the soil and the penetration resistance at the bottom of the pile pit cannot be obtained. There are great deficiencies in accurately identifying the scope and degree of soil disturbance. Summary of the invention

[0004] The present invention provides a convenient, fast and accurate test device and method for evaluating the seabed disturbance effect caused by inserting and removing piles.

[0005] To achieve the above-mentioned purpose, the present invention provides a test device for accurately evaluating the seabed disturbance effect caused by pile insertion and extraction, comprising:

[0006] A support platform, used to connect and support various components;

[0007] A sounding penetration mechanism is arranged on the support platform;

[0008] A test soil box is arranged on a support platform opposite to the penetration mechanism;

[0009] The probe penetration mechanism comprises:

[0010] A loading plate, slidably connected to the support platform;

[0011] A sounding probe is connected to the loading plate, and a soil box through hole for the sounding probe to penetrate is provided on the side wall of the test soil box;

[0012] A tension pressure sensor connected between the loading plate and the touch probe;

[0013] The power mechanism is connected to the loading plate and is used to enable the loading plate to drive the probe to move away from or close to the test soil box.

[0014] Preferably, the soil box through hole of the test soil box is connected to a drainage pipe, and the pipe opening of the drainage pipe is provided with a geotextile.

[0015] Preferably, the test soil box is cylindrical, the soil box through holes of the test soil box are evenly arranged along the circumference and axial direction of the test soil box, and the probing probes are arranged along a line parallel to the axis of the test soil box.

[0016] Preferably, a limiting block for limiting the position of the test soil box is provided on the supporting platform.

[0017] Preferably, the limit block is slidably connected to the support platform, a sliding groove is provided on the support platform, and a limit screw is penetrated through the limit block at a position relative to the sliding groove.

[0018] Preferably, the support platform comprises a first support portion and a second support portion;

[0019] The sounding penetrating mechanism is arranged on the first supporting part;

[0020] The test soil box, the limit block, the sliding groove and the limit screw are arranged on the second supporting part;

[0021] The first supporting portion and the second supporting portion are rotatably connected;

[0022] In addition, the present application also provides a test method for accurately evaluating the effect of pile insertion and extraction on the seabed disturbance, using any of the test devices for accurately evaluating the effect of pile insertion and extraction on the seabed disturbance described above. The method comprises the following steps:

[0023] S1: Place the test soil box on the support platform opposite to the penetration probe, connect the drainage pipe to the through hole of the soil box, prepare the seabed soil sample in the test soil box, observe the drainage conditions of each drainage pipe, and when no water is discharged from the drainage pipe 302, it indicates that the seabed consolidation is complete;

[0024] S2: Select one row of soil box through holes as the penetration hole for testing the penetration resistance of the seabed before pile insertion, remove the drainage pipe, start the power mechanism, move the penetration probe close to the soil box through hole, and stop the power mechanism when the penetration probe just touches the seabed soil, and clear the data of the tension pressure sensor through the computer-controlled data acquisition software;

[0025] S3: Start the power mechanism, penetrate the penetration probe into the test soil box along the soil box through hole at a constant rate, and the data acquisition software records the penetration depth and penetration resistance of each penetration probe in real time. After the penetration probe is completely penetrated into the soil box, the power mechanism is paused, and the power mechanism works in reverse to pull the penetration probe out of the test soil box;

[0026] S4: reconnect the drainage pipe to the through hole of the soil box, insert the model pile shoe vertically into the center of the test soil box, and pull out the model pile shoe after inserting to a predetermined depth, simulating the process of seabed disturbance caused by pile insertion and extraction. When no water is discharged from the drainage pipe, it indicates that the seabed has been reconsolidated after the disturbance caused by pile insertion and extraction. Rotate the soil box, repeat steps S2-S3, and test the penetration resistance of the seabed after pile extraction.

[0027] S5: Repeat steps S2-S4 to test the penetration resistance after repeated pile insertion and extraction to disturb the seabed. Take the penetration resistance of the seabed before pile insertion as a benchmark. By comparing the penetration resistance of the seabed at the same buried depth after the pile insertion and extraction, an accurate evaluation of the seabed disturbance effect of pile insertion and extraction can be achieved, including the disturbance range and degree.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) In the test device for accurately evaluating the seabed disturbance effect of pile insertion and extraction in the present application, multiple penetration probes are automatically penetrated into the test soil box at the same time, which improves the efficiency of penetration resistance testing and avoids the influence of human factors, time and other factors on the test results;

[0030] (2) The test device for accurately evaluating the seabed disturbance effect of pile insertion and extraction in the present application can obtain the continuous penetration resistance along the lateral direction of the soil, especially can continuously test the penetration resistance of the soil at the bottom of the pile pit, which has obvious advantages in accurately identifying the scope and degree of soil disturbance;

[0031] (3) This application unifies the probing area and the consolidation drainage circular hole, which not only ensures the test effect, but also greatly shortens the soil sample preparation time and improves the efficiency of the entire test. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of the test device for accurately evaluating the seabed disturbance effect caused by pile insertion and extraction according to the present invention;

[0033] Figure 2 It is a schematic diagram of the connection between the loading plate and the touch probe in the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of the present invention after removing the loading plate, the penetration probe and the test soil box;

[0035] Figure 4 It is a structural schematic diagram of the drainage pipe in the present invention;

[0036] Figure 5 The horizontal penetration resistance curve of the seabed before and after the pile is inserted and pulled out of the present invention.

[0037] In the figure:

[0038] 100-supporting platform; 101-limiting block; 102-sliding slot; 103-limiting screw; 110-first supporting part; 120-second supporting part;

[0039] 200-probe penetration mechanism; 201- loading plate; 202-probe probe; 203- pull pressure sensor; 204- power mechanism; 2041- screw; 2042- guide rod;

[0040] 300-test soil box; 301-soil box through hole; 302-drainage pipe; 303-geotextile. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] See also Figure 1 As shown, the test device for accurately evaluating the seabed disturbance effect of pile insertion and extraction provided by the present application includes: a support platform 100, a sounding penetration mechanism 200 and a test soil box 300. Among them: the support platform 100 is used to connect and support various components; the sounding penetration mechanism 200 is arranged on the support platform 100; and the test soil box 300 is arranged on the support platform 100 opposite to the sounding penetration mechanism 200.

[0043] Specifically, Figure 2-3 As shown, the penetration mechanism 200 includes: a loading plate 201, a penetration probe 202, a tension and pressure sensor 203 and a power mechanism 204. Among them:

[0044] The loading plate 201 is slidably connected to the support platform 100. The slidable connection here may be a slider slot connection, or a roller slidably connected at the contact surface between the loading plate 201 and the support platform 100 through the loading plate 201;

[0045] The sounding probe 202 is connected to the loading plate 201. The side wall of the test soil box 300 is provided with a soil box through hole 301 for the sounding probe to penetrate. In this example, the sounding probe 202 is made of steel, a solid cylinder, a conical front end, and a threaded rear end.

[0046] The tension and pressure sensor 203 is connected between the loading plate 201 and the probe 202. The tension and pressure sensor 203 can test tension and pressure, and can be monitored and recorded in real time on a computer through data acquisition software. The front part is connected to the probe 202 by bolts, and the rear part is connected to the loading plate 201 by bolts.

[0047] like Figure 3 As shown, the power mechanism 204 is connected to the loading plate 201, and is used to make the loading plate 201 drive the probe 202 away from or close to the test soil box 300. In this embodiment, the power mechanism 204 is a servo motor, and the servo motor has a stepless speed change function, and different displacement loading rates can be set through the control system. When the power mechanism 204 adopts a servo motor, the driving end of the power mechanism 204 is connected to a screw rod 2041, and the screw rod 2041 is threadedly connected to the loading plate 201. In order to maintain the stability of the movement of the loading plate 201, at least one set of guide rods 2042 can be provided to make the loading plate 201 and the guide rods 2042 slidably connected.

[0048] As a further solution of this embodiment, Figure 1 , 4 As shown, the test soil box 300 is cylindrical, and the soil box through holes 301 of the test soil box 300 are evenly arranged along the circumference and axial direction of the test soil box 300. The probing probe 202 is arranged along the parallel line direction of the axis of the test soil box 300. The soil box through holes 301 of the test soil box 300 are connected to a drainage pipe 302, and the pipe mouth of the drainage pipe 302 is provided with a geotextile 303, which can achieve drainage while preventing soil particles from being discharged. The soil box through holes 301 have two functions. One is to serve as a drainage hole during soil sample preparation to accelerate soil sample consolidation, shorten consolidation time, and improve soil sample preparation efficiency; the other is to serve as a penetration hole for the probing probe 202 to facilitate conducting probing penetration tests from the horizontal direction.

[0049] As a further solution of this embodiment, a limit block 101 for limiting the test soil box 300 is provided on the support platform 100. The limit block 101 is slidably connected to the support platform 100. A sliding groove 102 is provided on the support platform 100. A limit screw 103 is provided through the position of the limit block 101 relative to the sliding groove 102. The position of the limit block 101 on the support platform 100 can be fixed by tightening the limit screw 103.

[0050] In order to enable the sounding penetration mechanism 200 to penetrate vertically downward, thereby achieving penetration in both vertical and horizontal directions, and more accurately evaluate the seabed disturbance effect of pile insertion and extraction, the support platform 100 is divided into two parts: a first support part 110 and a second support part 120. Among them, the sounding penetration mechanism 200 is arranged on the first support part 110, and the test soil box 300, the limit block 101, the sliding groove 102 and the limit screw 103 are arranged on the second support part 120. The first support part 110 and the second support part 120 are rotatably connected. When it is necessary to penetrate downward in the vertical direction, the first support part 110 can be rotated so that the first support part 110 and the second support part 120 form an angle of 90°.

[0051] In addition, the present application also provides a test method for accurately evaluating the effects of pile insertion and extraction on the seabed disturbance.

[0052] The test is based on the following:

[0053] Pile insertion and extraction refers to the behavior of vertically penetrating the pile shoe into the soil to a certain depth and then pulling it out of the soil. Therefore, pile insertion and extraction will cause disturbance of the soil within a certain range around the pile shoe. Taking the penetration resistance of the seabed before pile insertion as a benchmark, the penetration resistance of the seabed at the same burial depth after pile insertion and extraction is compared, and the seabed disturbance effect of pile insertion and extraction can be quantitatively evaluated.

[0054] The test method includes the following steps:

[0055] S1: Place the test soil box 300 on the support platform 100 opposite to the penetration probe 202, connect the drainage pipe 302 with the geotextile 303 on the pipe mouth to the soil box through hole 301, prepare the soil sample by mud method, fill the mud soil sample into the test soil box 300, prepare the seabed soil sample in the test soil box 300, open the drainage pipe 302, observe the drainage conditions of each drainage pipe 302, when no water is discharged from the drainage pipe, it means that the seabed is consolidated and the sample preparation is completed. In addition, the load can be added on the top of the soil sample as needed to improve the density of the soil;

[0056] S2: Select one of the soil box holes 301 as the penetration hole for testing the seabed penetration resistance before pile insertion, remove the drainage pipe 302, start the power mechanism, slowly move the penetration probe 202 close to the soil box hole 301, and pause the power mechanism when the penetration probe 202 just touches the seabed soil, and clear the data of the tension pressure sensor 203 through the computer-controlled data acquisition software;

[0057] S3: Set the power mechanism 204 to the rate control mode, start the power mechanism 204, penetrate the sounding probe 202 into the test soil box 300 along the soil box through hole 301 at a constant rate, and the data acquisition software records the penetration depth and penetration resistance of each sounding probe 202 in real time. After the sounding probe 202 is completely penetrated into the soil box, the power mechanism 204 is paused, and the power mechanism 204 works in reverse to pull the sounding probe 202 out of the test soil box 300, clean the sounding probe 202 and prepare for the next penetration;

[0058] S4: Reconnect the drainage pipe 302 at the soil box through hole 301, insert the model pile shoe vertically into the center of the test soil box 300, and pull out the model pile shoe after inserting to a predetermined depth, simulating the process of disturbing the seabed by inserting and pulling piles. When no water is discharged from the drainage pipe 302, it means that the seabed has been re-consolidated after the disturbance by inserting and pulling piles. Rotate the soil box and repeat steps S2-S3 to test the penetration resistance of the seabed after the piles are pulled out.

[0059] S5: Repeat steps S2-S4 to test the penetration resistance after repeatedly inserting and pulling out piles to disturb the seabed. Take the penetration resistance of the seabed before inserting piles as the benchmark, and compare the penetration resistance of the seabed at the same buried depth after the disturbance of the piles (such as Figure 5 As shown in Figure 1), the seabed disturbance degree is calculated (Formula I), which can realize the accurate evaluation of the seabed disturbance effect of pile insertion and extraction, including the disturbance range and disturbance degree.

[0060] (Formula I)

[0061] Where: D represents the seabed disturbance degree, and its value is usually between 0 and 1, 0 represents undisturbed, and 1 represents fully disturbed; R0 represents the penetration resistance before pile insertion, unit: N; R i Represents the penetration resistance after pile extraction, unit: N.

[0062] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0063] In the test device for accurately evaluating the effect of seabed disturbance caused by driving and pulling piles of the present invention, multiple sounding probes are automatically penetrated into the test soil box at the same time, which improves the efficiency of penetration resistance testing and avoids the influence of human factors, time and other factors on the test results; the penetration resistance can be obtained continuously along the transverse direction of the soil body, especially the penetration resistance of the soil body at the bottom of the pile pit can be tested, which has obvious advantages in accurately identifying the scope and degree of soil disturbance; the test device for accurately evaluating the effect of seabed disturbance caused by driving and pulling piles of the present invention unifies the sounding area and the consolidation drainage circular hole, which ensures the test effect while greatly shortening the soil sample preparation time and improving the efficiency of the entire test.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A test device for accurately evaluating the effect of pile insertion and extraction on the seabed disturbance, characterized in that: include: A support platform (100) is used to connect and support various components; A sounding penetration mechanism (200) is arranged on the support platform (100); A test soil box (300) is disposed on a support platform (100) opposite to the penetration mechanism (200); The sounding penetration mechanism (200) comprises: A loading plate (201) is slidably connected to the support platform (100); A sounding probe (202) is connected to the loading plate (201), and a soil box through hole (301) for the sounding probe to penetrate is provided on the side wall of the test soil box (300); A tension pressure sensor (203) connected between the loading plate (201) and the contact probe (202); A power mechanism (204) is connected to the loading plate (201) and is used to enable the loading plate (201) to drive the penetration probe (202) away from or close to the test soil box (300); The support platform (100) is provided with a limiting block (101) for limiting the position of the test soil box (300); The limit block (101) is slidably connected to the support platform (100); a sliding groove (102) is provided on the support platform (100); and a limit screw (103) is provided through the limit block (101) at a position relative to the sliding groove (102); The support platform (100) comprises a first support portion (110) and a second support portion (120); The sounding penetration mechanism (200) is arranged on the first supporting part (110); The test soil box (300), the limiting block (101), the sliding groove (102) and the limiting screw (103) are arranged on the second supporting part (120); The first supporting portion (110) and the second supporting portion (120) are rotatably connected.

2. The test device for accurately evaluating the seabed disturbance effect caused by pile insertion and extraction according to claim 1 is characterized in that: The soil box through hole (301) of the test soil box (300) is connected to a drainage pipe (302), and a geotextile (303) is provided at the pipe opening of the drainage pipe (302).

3. The test device for accurately evaluating the seabed disturbance effect caused by pile insertion and extraction according to claim 2 is characterized in that: The test soil box (300) is cylindrical, the soil box through holes (301) of the test soil box (300) are evenly arranged along the circumference and axis direction of the test soil box (300), and the penetration probes (202) are arranged along a line parallel to the axis of the test soil box (300).

4. A test method for accurately evaluating the effect of pile insertion and extraction on the seabed disturbance, characterized in that: The test device for accurately evaluating the seabed disturbance effect of pile insertion and extraction as described in any one of claims 1 to 3 comprises the following steps: S1: placing the test soil box (300) on the support platform (100) opposite to the penetration probe (202), connecting the drainage pipe (302) to the soil box through hole (301), preparing a seabed soil sample in the test soil box (300), observing the drainage conditions of each drainage pipe (302), and when no water is discharged from the drainage pipe (302), it indicates that the seabed consolidation is complete; S2: selecting one row of soil box through holes (301) as a penetration hole for testing the penetration resistance of the seabed before pile insertion, removing the drainage pipe (302), starting the power mechanism, and moving the penetration probe (202) close to the soil box through hole (301). When the penetration probe (202) just touches the seabed soil, the power mechanism is stopped, and the data of the tension pressure sensor (203) is cleared by computer-controlled data acquisition software; S3: starting the power mechanism (204), penetrating the sounding probe (202) into the test soil box (300) along the soil box through hole (301) at a constant rate, and the data acquisition software records the penetration depth and penetration resistance of each sounding probe (202) in real time. After the sounding probe (202) is completely penetrated into the soil box, the power mechanism (204) is paused, and the power mechanism (204) works in reverse to pull the sounding probe (202) out of the test soil box (300); S4: reconnect the drainage pipe (302) to the soil box through hole (301), insert the model pile shoe vertically into the center of the test soil box (300), and pull out the model pile shoe after inserting to a predetermined depth, simulating the process of disturbing the seabed by inserting and pulling piles. When no water is discharged from the drainage pipe (302), it means that the seabed has been reconsolidated after the disturbance by inserting and pulling piles. Rotate the soil box and repeat steps S2-S3 to test the penetration resistance of the seabed after the piles are pulled out. S5: Repeat steps S2-S4 to test the penetration resistance after repeated pile insertion and extraction to disturb the seabed. Take the penetration resistance of the seabed before pile insertion as a benchmark. By comparing the penetration resistance of the seabed at the same buried depth after the pile insertion and extraction, an accurate evaluation of the seabed disturbance effect of pile insertion and extraction can be achieved, including the disturbance range and degree.

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