Wedge block measuring device and method suitable for pipe barrel pile open sea soil acting force

Abstract

The invention relates to a wedge block measuring device and method suitable for pipe barrel pile open sea soil acting force, the device comprises a sliding wedge block and a piezoelectric ceramic sensor fixed on the sliding wedge block, and the piezoelectric ceramic sensor is in communication connection with a controller of an offshore operation platform and is used for measuring the pressure value of the sliding wedge block; the multiple sliding wedge blocks are evenly arranged in the circumferential direction of the pipe barrel pile. The device is used for measuring the acting force of remolded sea soil outside a pipe barrel pile in the installation process, and then actual sea soil bearing performance data such as the soil weight and the static soil pressure coefficient are obtained through calculation.

Description

Technical Field

[0001] The invention relates to a wedge block measuring device and method suitable for sea soil force outside a tubular pile, belonging to the technical field of marine engineering. Background Art

[0002] Pipe piles such as offshore drilling guide pipes and positioning suction piles rely on the restraining force of the sea soil to provide anchoring. During the installation of pipe piles, the sea soil outside the piles is disturbed, and the anchoring force provided by the final reshaped sea soil is not easy to obtain in engineering. The calculation of this anchoring force using the soil pressure and bearing capacity coefficient of the soil layer obtained in the early exploration is not accurate enough because it does not include the changes in the bearing capacity of the sea soil during the pile installation process. There is still a lack of an effective method or device in the project to directly measure the reshaped bearing capacity of each layer of soil passed through during the installation of pipe piles. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a wedge block measurement device and method suitable for the sea soil force outside the tubular pile. The device is used to measure the force of the reshaped sea soil outside the tubular pile during installation, and then calculate the actual sea soil bearing performance data such as soil weight and static earth pressure coefficient.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A wedge block measuring device suitable for sea soil force outside a tubular pile, comprising: A sliding wedge and a piezoelectric ceramic sensor fixed on the sliding wedge, wherein the piezoelectric ceramic sensor is communicatively connected to a controller of an offshore operating platform and is used to measure a pressure value of the sliding wedge; The sliding wedges are in a plurality and are evenly arranged in the circumferential direction of the tubular pile.

[0005] A wedge block measurement method for the sea soil force outside a tubular pile, preferably using the above-mentioned wedge block measurement device for measurement, specifically comprising the following steps: The tubular pile carrying the wedge block measuring device is driven into the seabed. During the piling process, the piezoelectric ceramic sensor is used to measure the pressure value of the sliding wedge block in different soil layers, and then the static earth pressure coefficient of the soil layer in the soil elastic stage and the soil extrusion plastic failure stage is calculated according to the pressure value. and soil weight .

[0006] In the wedge block measurement method, preferably, the pressure value calculation formula of the sliding wedge block in different soil layers is as follows:

[0007] in, For At depth, the pressure value measured by the piezoelectric sensor above the wedge; is the circumferential stress of the soil; Vertical stress in soil; exist Coefficient of static earth pressure at depth; exist Soil weight at depth; The coefficient of friction between the wedge and the cylindrical pile; Angle of attack of the wedge.

[0008] The wedge measurement method, preferably, the static earth pressure coefficient of the soil layer in the soil elastic stage and soil weight The calculation formula is as follows:

[0009]

[0010] At the same depth, along the circumference of the circular pile, the wedges at different angles are measured to obtain the above two equations. The static earth pressure coefficient at this depth can be calculated by combining them: and soil weight .

[0011] The wedge measurement method is preferably used to measure the static earth pressure coefficient of the soil layer at the stage of plastic failure of soil extrusion. and soil weight The calculation formula is as follows:

[0012] In the formula, the wavy lines above each variable indicate that the soil is at the yield moment; is the friction coefficient of the inclined surface of the wedge at the time of limit failure, which can be regarded as a constant; is the shear stress on the inclined surface of the wedge at the ultimate failure; is the normal stress on the inclined surface of the wedge at the ultimate failure; is the soil cohesion; is the internal friction angle of soil.

[0013] The present invention adopts the above technical solution, which has the following advantages: The measuring device of the present invention is used to measure the force of reshaping the sea soil outside the tubular pile during installation, and then calculate and obtain actual sea soil bearing performance data such as soil weight and static earth pressure coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 An overall schematic diagram of a wedge block measuring device provided in one embodiment of the present invention; Figure 2 A schematic diagram of force analysis of wedges and soil units in the elastic stage of soil provided by this embodiment of the present invention; Figure 3 A schematic diagram of the force analysis of the wedge block provided in this embodiment of the present invention; Figure 4 A three-dimensional stress circle diagram of sea soil provided by this embodiment of the present invention; Figure 5 A schematic diagram of force analysis of a wedge block at the yield moment provided by this embodiment of the present invention; Figure 6 A schematic diagram of the force analysis of the soil unit at the moment of wedge yield provided in this embodiment of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are 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 persons in the art without creative work are within the scope of protection of the present invention.

[0016] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0017] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0018] Pipe piles such as offshore drilling guide pipes and positioning suction piles rely on the restraining force of the sea soil to provide anchoring. During the installation of pipe piles, the sea soil outside the piles is disturbed, and the anchoring force provided by the final reshaped sea soil is not easy to obtain in engineering. The calculation of this anchoring force using the soil layer bearing capacity coefficient obtained in the early exploration is not accurate enough because it does not include the changes in the bearing capacity of the sea soil during the pile installation process. There is still a lack of an effective method or device in the project to directly measure the reshaped bearing capacity of each layer of soil during the installation of pipe piles.

[0019] Based on the above technical problems, the present invention provides a wedge block measuring device suitable for the sea soil force outside the tubular pile, which is used to measure the force of the reshaped sea soil outside the tubular pile during installation, and then calculate the actual sea soil bearing performance data such as soil weight and static soil pressure coefficient.

[0020] like Figure 1 As shown, the wedge block measuring device suitable for the marine soil force outside the tubular pile involved in the present invention comprises: a sliding wedge block and a piezoelectric ceramic sensor fixed on the sliding wedge block, the piezoelectric ceramic sensor is communicatively connected to the controller of the offshore operating platform and is used to measure the pressure value of the sliding wedge block; there are a plurality of sliding wedge blocks, which are evenly arranged in the circumferential direction of the tubular pile.

[0021] like Figure 2 , 3 As shown, the force analysis of the sliding wedge and soil unit is as follows: The sliding wedge is subjected to the following forces:

[0022]

[0023]

[0024] The forces acting on the soil element are as follows:

[0025]

[0026]

[0027] In the formula, For At depth, the pressure value measured by the piezoelectric sensor above the wedge; is the friction between the wedge and the cylinder wall; is the total friction force on the inclined surface of the wedge; is the total pressure on the inclined surface of the wedge; is the squeezing force of the wedge on the cylindrical pile; is the normal stress on the surface perpendicular to the inclined surface of the wedge; is the normal stress on the inclined surface of the wedge; is the circumferential stress of the soil; Vertical stress in soil; is the shear stress on the inclined surface of the wedge; The coefficient of friction between the wedge and the cylindrical pile; Angle of attack of the wedge.

[0028] like Figure 4As shown, it is a three-dimensional stress circle diagram of sea soil. The pressure value received by the sliding wedge measured by the piezoelectric ceramic sensor is as follows:

[0029] Therefore:

[0030] In the formula, exist Coefficient of static earth pressure at depth; exist Soil mass at depth.

[0031] The technical solution of the present invention is described in detail below with reference to specific examples.

[0032] The bearing capacity of the wedge block outside the pile can be divided into two stages: the elastic deformation stage of the soil and the plastic failure stage of soil extrusion.

[0033] ① In the elastic stage of soil, the mutual compression between the wedge and the soil is not obvious, there is no relative slip between the wedge and the soil, and the load change will not cause positive pressure on the wedge-soil interface The change will only cause friction shear force The load is mainly borne by the friction shear stress between the wedge and the soil. At this stage, the mutual extrusion between the wedge and the soil is weak, and the maximum load is the critical plastic load of the wedge. The piezoelectric ceramics at the top of the wedge are compressed, and the corresponding pressure value is measured. .

[0034]

[0035]

[0036] At the same depth, along the circumference of the cylindrical pile, the wedges with different angles (for the sake of simple calculation, the inclined surface areas can be the same, that is, ) Two equations are obtained from the measurement, namely equation (1) and equation (2), which can be combined to calculate the static earth pressure coefficient at this depth and soil weight .

[0037] ② As the load continues to increase, the friction between the wedge and the soil cannot fully bear the external load, and the wedge moves downward, so the wedge and the soil squeeze each other, causing the positive pressure and friction shear force between the wedge and the soil to change, and the wedge and the soil enter the plastic failure stage of squeezing the soil. At this time, the increased load is borne by the positive stress and shear stress on the wedge-soil interface until the soil on the wedge-soil interface is sheared and the piezoelectric ceramic measurement value on the top of the wedge reaches the limit.

[0038] like Figure 5As shown, the force analysis of the wedge and its equilibrium equation are as follows:

[0039]

[0040]

[0041]

[0042]

[0043] The soil on the wedge slope is in a shear failure state, with:

[0044] There are also limit equilibrium conditions for clay soil:

[0045] In the formula, It is the pressure measured by the piezoelectric ceramic at the ultimate failure; is the shear force on the inclined surface of the wedge at the ultimate failure; is the pressure on the inclined surface of the wedge at the ultimate failure; is the circumferential stress of the soil at the ultimate failure; is the vertical stress of the soil at ultimate failure. is the friction coefficient of the inclined surface of the wedge at the time of limit failure, which can be regarded as a constant; is the shear stress on the inclined surface of the wedge at the ultimate failure; is the normal stress on the inclined surface of the wedge at the ultimate failure; is the soil cohesion; is the internal friction angle of soil.

[0046] The stress analysis of soil unit is as follows:

[0047]

[0048]

[0049] In the formula, It is the normal stress of the surface perpendicular to the inclined surface of the wedge at the time of ultimate failure.

[0050] From formula (3):

[0051] In the above formula, the wavy line above the variable indicates that the soil is at the yield moment.

[0052] Substituting (4) into (5), we have:

[0053] According to the process of ①, two wedges at different angles can measure the static earth pressure coefficient at the yield moment at a certain depth. and soil weight .Will and , substituting into (6), we can also get and The relational expression (7):

[0054] and The relational expression (7) can provide a reference for the design of inclined piles and wedge piles in local sea areas.

[0055] ③ For the continuously penetrated cylindrical pile, the wedge has passed through multiple layers of soil, and the measured values ​​corresponding to different depths are , the static earth pressure coefficient of each remolded soil layer can be solved and soil weight (It is necessary to install two wedges at different angles along the circumference of the cylindrical pile).

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wedge block measuring device suitable for measuring the sea soil force outside a tubular pile, characterized in that: include: A sliding wedge and a piezoelectric ceramic sensor fixed on the sliding wedge, wherein the piezoelectric ceramic sensor is communicatively connected to a controller of an offshore operating platform and is used to measure a pressure value of the sliding wedge; The sliding wedges are in a plurality and are evenly arranged in the circumferential direction of the tubular pile.

2. A wedge block measurement method suitable for sea soil forces outside tubular piles, characterized in that: The measurement is performed using the wedge measuring device according to claim 1, specifically comprising the following steps: The tubular pile carrying the wedge block measuring device is driven into the seabed. During the piling process, the piezoelectric ceramic sensor is used to measure the pressure value of the sliding wedge block in different soil layers, and then the static earth pressure coefficient of the soil layer in the soil elastic stage and the soil extrusion plastic failure stage is calculated according to the pressure value. and soil weight .

3. The wedge measurement method according to claim 2, characterized in that: The calculation formula of the pressure value of the sliding wedge in different soil layers is as follows: in, For At depth, the pressure value measured by the piezoelectric sensor above the wedge; is the circumferential stress of the soil; Vertical stress in soil; exist Coefficient of static earth pressure at depth; exist Soil weight at depth; The coefficient of friction between the wedge and the cylindrical pile; Angle of attack of the wedge.

4. The wedge measurement method according to claim 2, characterized in that: Static earth pressure coefficient of soil layer in the elastic stage of soil and soil weight The calculation formula is as follows: At the same depth, along the circumference of the circular pile, the wedges at different angles are measured to obtain the above two equations. The static earth pressure coefficient at this depth can be calculated by combining them: and soil weight .

5. The wedge measurement method according to claim 2, characterized in that: When the cylindrical pile is continuously pressed into the soil, the static earth pressure coefficient of each soil layer is plastically destroyed in turn and soil weight The calculation formula is as follows: In the formula, the wavy lines above each variable indicate that the soil is at the yield moment; is the friction coefficient of the inclined surface of the wedge at the time of limit failure, which can be regarded as a constant; is the shear stress on the inclined surface of the wedge at the ultimate failure; is the normal stress on the inclined surface of the wedge at the ultimate failure; is the soil cohesion; is the internal friction angle of soil.

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