Solidified soil-riprap-solidified soil combined protection structure and construction method

Abstract

The invention relates to a solidified soil-riprap-solidified soil combined protection structure and a construction method. The protection structure is sequentially composed of a lower high-strength solidified soil layer, a middle grading riprap layer, an upper high-fluidity solidified soil layer and a detachable limiting mold surrounding the periphery of the high-strength solidified soil layer, the middle grading riprap layer and the upper high-fluidity solidified soil layer. During construction, the limiting mold and the slurry pumping hose are assembled on a construction ship and sink to a seabed around a pile foundation, and a lower solidified soil layer is formed through primary slurry pumping so as to stabilize the anti-impact foundation; then riprap is scattered to the middle in a layered mode, and a riprap layer is formed to disperse fluid impact; and finally, high-fluidity solidified soil is poured into the upper riprap layer, so that stone gaps are filled with the high-fluidity solidified soil, and a sealing layer is formed. The inner diameter of the limiting die and the thickness of the steel plate are precisely designed, it is guaranteed that the boundary of materials is precise and controllable in the construction process, and the materials can be recycled and reused. The structure is combined with the process, the retention rate of the solidified soil and the filling rate of riprap holes are increased, and the anti-scouring capacity and durability of the protective layer around the pile are remarkably enhanced.

Description

Technical Field

[0001] The present invention relates to the field of marine pile foundation / bridge pier foundation scour control, and in particular to a solidified soil-riprap-solidified soil combined protective structure and a construction method. Background Art

[0002] In the case of marine pile foundation scour protection, the limitations of single material protection have long been faced:

[0003] A. Pure riprap structure has the risk of pore scouring, which may lead to the instability of the protective layer;

[0004] B. Pure solidified soil protection is prone to edge breakage in a dynamic water environment, and the retention rate is insufficient under high flow conditions.

[0005] The patent application document with publication number CN118029386A discloses a high-loss-resistant formwork and casting method for solidified soil anti-scouring, including a high-loss-resistant formwork installation method, a construction method and a method for casting anti-scouring materials; the easy-to-assemble high-loss-resistant formwork is composed of a formwork platform and a splicing device; the formwork platform is composed of two shallow platforms with semi-circular tops and inclined sides with inclinations. The two semi-shallow platforms can be simply spliced ​​together to form a whole on a transport ship through locks and hinges; a water suction port (pumping port) is left on the top of the shallow platform, and a steel corbel is welded on the platform as a lifting point support.

[0006] However, existing combined protection technologies lack a layered design, failing to balance scour resistance with structural stability. Particularly in deepwater and high-tidal areas, traditional protective structures often fail due to water stripping. Furthermore, issues such as loose material interfaces and imprecise boundary control during layered construction further reduce the service life of the protection system. Summary of the Invention

[0007] The purpose of the present invention is to provide a solidified soil-riprap-solidified soil combined protective structure and a construction method to solve the problems existing in the prior art.

[0008] The object of the present invention is achieved as follows: a solidified soil-riprap-solidified soil combined protective structure, comprising:

[0009] A solidified soil limiting mold is placed on the seabed surface, wherein the solidified soil limiting mold is a cylindrical steel plate surrounding the pile foundation and coaxial with the pile foundation, and the interior space of the cylindrical steel plate is used as the cavity of the solidified soil limiting mold;

[0010] a lower solidified soil layer, the lower solidified soil layer being laid on the seabed surface at the bottom of the cavity of the solidified soil limiting mold;

[0011] A middle riprap layer formed by piling up a plurality of ripraps, the middle riprap layer covering the lower solidified soil layer and being located in the cavity of the solidified soil limiting mold;

[0012] an upper high-fluidity solidified soil layer, the upper high-fluidity solidified soil layer covering the middle riprap layer and penetrating downward under the influence of its own weight to fill the gaps in the middle riprap layer, thereby forming a sealing layer of a certain thickness for sealing the middle riprap layer;

[0013] The lower solidified soil layer, the middle riprap layer and the upper high-fluidity solidified soil layer are closely attached to the surface of the pile foundation.

[0014] Furthermore, the lower solidified soil layer is evenly distributed above the seabed plane around the pile in the solidified soil limiting mold cavity, and its thickness d1 ranges from 1.5 to 2.5 times the median particle size d of the riprap. 50 .

[0015] Furthermore, the middle riprap layer is evenly distributed, and its thickness d2 ranges from 2 times the median particle size d of the riprap. 50 .

[0016] Furthermore, the upper solidified soil layer is evenly distributed, and its thickness d3 is in the range of 1.5 to 2.5 times the median particle size d of the riprap. 50 .

[0017] Furthermore, the solidified soil limiting mold is formed by welding steel plates, the radius R of which is in the range of 2 to 3 times the pile foundation diameter D, and the thickness d4 of the mold steel plate is in the range of 3 to 5 cm.

[0018] As another aspect of the present invention, a construction method is proposed, comprising the following steps:

[0019] S1. Preliminary preparation: Determine the customized size and protection range of the solidified soil limit mold according to the site conditions;

[0020] S2. Mould sinking: sink the solidified soil limiting mould as a whole to the seabed level around the pile to prepare for slurry pumping;

[0021] S3. One round of slurry pumping: Evenly pour the lower solidified soil layer above the seabed level around the pile to ensure that the fluidized solidified soil is evenly distributed and wait for it to solidify into shape;

[0022] S4. Riprap: Evenly scatter riprap on the solidified lower soil layer to fill the solidified soil limiting mold to form a middle riprap layer;

[0023] S5, two-wheel pump slurry: after the riprap is completed, the upper high-flowability solidified soil layer is used to fill the pores of the riprap body, and the upper high-flowability solidified soil layer is poured to a certain thickness above the top surface of the middle riprap layer;

[0024] S6. Demoulding: After the upper high-fluidity solidified soil layer is solidified and formed, the mould is lifted upwards to the construction vessel using a hinged starting mechanism for subsequent repeated use.

[0025] Furthermore, in step S2, the solidified soil limiting mold and the slurry pump hose are assembled into one on the construction vessel and sunk to the seabed around the pile foundation.

[0026] Furthermore, in step S3, a medium particle size d of 1.5 to 2.5 times the thickness of the riprap is formed by pumping the slurry once. 50 The lower soil layer is solidified to stabilize the anti-scouring foundation.

[0027] Furthermore, in step S4, riprap with a particle size of 80 to 150 mm is scattered into the mold cavity of the mold to a thickness twice the median particle size of the riprap, so as to form a middle riprap layer for dispersing fluid impact.

[0028] Furthermore, the solidified soil limiting mold is set as a cylindrical steel plate surrounding the pile foundation and coaxial with the pile foundation, the inner diameter R of which is 2D to 3D, where D is the diameter of the pile foundation, and the thickness of the steel plate is 3 to 5 cm.

[0029] The beneficial effects of the present invention are:

[0030] 1. The combined solidified soil-riprap-solidified soil protection structure proposed in this invention consists of two layers of solidified soil, upper and lower, and a middle layer of riprap. It offers excellent protection, significantly reducing pore scouring caused by riprap and edge breakage during solidified soil protection. It significantly enhances the scouring resistance of the seabed surrounding the piles, ensuring the integrity of the protective layer structure, especially the riprap layer, and the retention capacity of the solidified soil.

[0031] 2. During the construction process of the solidified soil-riprap-solidified soil combined protective structure of the present invention, the functions of each part are as follows: first, the lower solidified soil layer is constructed, which is used to closely adhere to the pile foundation seabed to build a stable anti-scour base; then the middle riprap layer is constructed, which can protect the lower solidified soil layer by dispersing the impact energy of the water flow and suppressing the vortex effect; finally, the upper solidified soil layer is poured, and the upper solidified soil layer fills the pores of the lower middle riprap layer with its fluidity and forms a sealing layer on the top surface of the riprap, which can resist the diffusion behavior under the continuous scouring of dynamic water. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is an overall schematic diagram of the present invention.

[0033] Figure 2 It is a layered schematic diagram of the present invention.

[0034] Explanation of the accompanying figures: 1-lower solidified soil layer; 2-middle riprap layer; 3-upper high-fluidity solidified soil layer; 4-solidified soil limiting mold. DETAILED DESCRIPTION

[0035] The following is a combination of the embodiments of the present invention Figure 1-2 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] like Figure 1-2 As shown in the figure, a combined protective structure of stabilized soil, riprap and stabilized soil is proposed, including:

[0037] A solidified soil limiting mold 4 is placed on the seabed surface. The solidified soil limiting mold 4 is configured as a cylindrical steel plate surrounding the pile foundation and coaxial with the pile foundation. The interior space of the cylindrical steel plate is configured as a cavity of the solidified soil limiting mold 4.

[0038] The lower solidified soil layer 1 is laid on the seabed surface at the bottom of the cavity of the solidified soil limiting mold 4;

[0039] A middle riprap layer 2 formed by a plurality of riprap piles, the middle riprap layer 2 covers the lower solidified soil layer 1 and is located in the cavity of the solidified soil limiting mold 4;

[0040] The upper high-fluidity solidified soil layer 3 covers the middle riprap layer 2 and penetrates downward under the influence of its own weight and fills the gaps in the middle riprap layer 2 to form a sealing layer of a certain thickness for sealing the middle riprap layer 2;

[0041] Among them, the lower solidified soil layer 1, the middle riprap layer 2 and the upper high-fluidity solidified soil layer 3 are closely attached to the surface of the pile foundation.

[0042] The lower solidified soil layer 1 is evenly distributed above the seabed plane around the pile in the cavity of the solidified soil limiting mold 4, and its thickness d1 ranges from 1.5 to 2.5 times the median particle size d of the riprap. 50 (preferably 2 times), ensuring that its slump is between 250 and 330 mm, and its 28d compressive strength is between 0.5 kPa and 1 MPa, so as to adhere closely to the pile foundation seabed and build a stable anti-impact base.

[0043] The middle riprap layer 2 is evenly distributed, and its thickness d2 is in the range of 2 times the median particle size d of the riprap. 50 The specific parameters of the middle riprap layer 2 are: the middle riprap layer 2 is filled with graded granite blocks with a particle size of 80 to 150 mm and a test porosity of ≤35%, and the thickness is controlled to be the median particle size d 50The depth of the soil layer is twice as large as that of the water flow (i.e. 160-300 mm), which protects the lower solidified soil layer 1 by dispersing the impact energy of the water flow and suppressing the vortex effect.

[0044] The upper solidified soil layer 3 is evenly distributed, and its thickness d3 is in the range of 1.5 to 2.5 times the median particle size d of the riprap. 50 The thickness of the upper solidified soil layer 3 is also 12 to 37.5 cm (preferably 15 cm), so that it has a slump of ≥250 mm, an initial setting time of 4 to 6 hours, and a 28-day compressive strength of 0.5 kPa-1 MPa. Its fluidity fills the pores of the lower middle riprap layer 2 and forms a sealing layer on the top surface of the riprap.

[0045] The solidified soil limit mold 4 is welded from steel plates. Its radius R ranges from 3 to 5 times the pile foundation diameter D, and its mold steel plate thickness d4 ranges from 3 to 5 cm. The solidified soil limit mold 4 is made of four 90° arc plates welded or bolted together, with an inner diameter of 2D to 3D (preferably 2.5D) and a steel plate thickness of 30 to 50 mm (preferably 40 mm). Both ends of the mold are equipped with φ8 mm concave and convex connection structures with a spacing of 30 to 40 mm. Eight to twelve φ50 mm hose clips are evenly arranged in the circumference to secure the slurry pump hose.

[0046] Through the above-mentioned combined protective structure, the solidified soil retention rate can reach more than 90%, and the riprap pore filling rate can reach more than 95%. The overall protective layer's ability to resist scouring is significantly improved, while significantly suppressing the negative effects of scouring.

[0047] Based on the above-mentioned combined protective structure, a construction method is proposed, which includes the following steps:

[0048] S1. Preliminary preparation: Determine the customized size and protection range of the solidified soil limiting mold 4 according to the site conditions and specific process requirements;

[0049] S2. Mold sinking: The solidified soil limit mold 4 and the slurry pump hose are assembled into one piece on the construction vessel and sunk to the seabed around the pile foundation. The solidified soil limit mold 4 is completely sunk to the seabed plane around the pile to prepare for slurry pumping. During this process, the ship-mounted crane sinks the solidified soil limit mold 4 as a whole to the seabed around the pile at a rate of ≤0.2m / s. Underwater video and buoy positioning are used to ensure that the contact gap between the bottom surface of the mold and the seabed does not exceed 5cm, and that the deviation between the geometric center of the solidified soil limit mold 4 and the pile foundation axis is less than 2%;

[0050] S3, one round of slurry pumping: evenly pour the lower solidified soil layer 1 above the seabed plane around the pile to ensure that the fluidized solidified soil is evenly distributed. After solidification, a 10-20 cm thick lower solidified soil layer 1 is formed by one round of slurry pumping to stabilize the anti-scour foundation. More specifically, a multi-tube pump is used with a 20-30 m 3Pour the lower solidified soil slurry to d1 = 5 cm above the seabed at a flow rate of / h and a pressure of 0.8-1.2 MPa, and let it stand for 48 hours;

[0051] S4, riprap: After the lower solidified soil layer 1 is initially solidified, riprap is evenly scattered above the solidified lower solidified soil layer 1 to fill the solidified soil limiting mold 4. Riprap with a particle size of 80 to 150 mm is scattered into the mold cavity. The thickness is twice the median particle size of the riprap to form a middle riprap layer 2 for dispersing fluid impact. The riprap ship is at a speed of 50m 3 / h rate of layered scattering, each layer thickness does not exceed 40cm, until d2 = 2d 50 and confirm the uniformity and flatness of the middle riprap layer 2 through underwater photography;

[0052] S5, two-wheel pump slurry: After the riprap is completed, the upper high-flowability solidified soil layer 3 is used to fill the pores of the riprap body, and the upper high-flowability solidified soil layer 3 is poured to a thickness of 15 cm above the top surface of the middle riprap layer 2, and the 28-day strength is between 0.5 kPa and 1 MPa;

[0053] S6. Demoulding: After the upper high-fluidity solidified soil layer 3 is solidified and formed, the solidified soil limiting mould 4 is lifted upward onto the construction vessel by using a hinge starting mechanism for subsequent repeated use. The solidified soil limiting mould 4 is lifted and recovered at a speed of ≤0.1m / s by using a hydraulic hinge device. After removal, it is cleaned and repaired, and the solidified soil limiting mould 4 can be reused for no less than 10 times.

[0054] The solidified soil limiting mold 4 is set as a cylindrical steel plate surrounding the pile foundation and coaxial with the pile foundation. The inner diameter R is 2D to 3D, where D is the diameter of the pile foundation, and the thickness of the steel plate is 3 to 5 cm.

[0055] This application case proposes a structural design and construction method for combined solidified soil, riprap, and solidified soil protection to mitigate scour of solidified soil in marine pile foundation structures. The structure consists of two layers of solidified soil, upper and lower, and a central layer of riprap. It offers excellent protection, significantly reducing pore scouring caused by riprap and edge breakage associated with solidified soil protection. It significantly enhances the scour resistance of the seabed surrounding the piles, ensuring the integrity of the protective layer structure, particularly the riprap layer, and the retention of the solidified soil.

[0056] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "front", "back", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in the present invention, it should also be noted that the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integrally formed connection, a mechanical connection, or an indirect connection through an intermediate connecting component, and the specific meaning of the terms in this utility model can be understood according to the specific circumstances.

[0057] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be embraced herein, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0058] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A solidified soil-riprap-solidified soil combined protection structure, characterized in that: include: A solidified soil limiting mold (4) is placed on the seabed surface, wherein the solidified soil limiting mold (4) is configured as a cylindrical steel plate surrounding the pile foundation and coaxial with the pile foundation, and the interior space of the cylindrical steel plate is configured as a cavity of the solidified soil limiting mold (4); A lower solidified soil layer (1), the lower solidified soil layer (1) being laid on the seabed surface at the bottom of the cavity of the solidified soil limiting mold (4); A middle riprap layer (2) formed by piling up a plurality of ripraps, the middle riprap layer (2) covering the lower solidified soil layer (1) and being located in the cavity of the solidified soil limiting mold (4); An upper high-fluidity solidified soil layer (3), the upper high-fluidity solidified soil layer (3) covering the middle riprap layer (2) and permeating downward under the influence of its own weight and filling the gaps in the middle riprap layer (2) to form a sealing layer of a certain thickness for sealing the middle riprap layer (2); The lower solidified soil layer (1), the middle riprap layer (2) and the upper high-fluidity solidified soil layer (3) are closely attached to the surface of the pile foundation.

2. The solidified soil-riprap-solidified soil combined protection structure according to claim 1, characterized in that: The lower solidified soil layer (1) is evenly distributed above the seabed plane around the pile in the cavity of the solidified soil limiting mold (4), and its thickness d1 is in the range of 1.5 to 2.5 times the median particle size d of the riprap. 50 .

3. The solidified soil-riprap-solidified soil combined protection structure according to claim 2, characterized in that: The middle riprap layer (2) is evenly distributed, and its thickness d2 is in the range of 2 times the median particle size d of the riprap. 50 .

4. The solidified soil-riprap-solidified soil combined protection structure according to claim 3, characterized in that: The upper solidified soil layer (3) is evenly distributed, and its thickness d3 is in the range of 1.5 to 2.5 times the median particle size d of the riprap. 50 .

5. The solidified soil-riprap-solidified soil combined protective structure according to claim 4, characterized in that: The solidified soil limiting mold (4) is formed by welding steel plates, the radius R of which is in the range of 2 to 3 times the pile foundation diameter D, and the thickness d4 of the mold steel plate is in the range of 3 to 5 cm.

6. A construction method based on a combined protective structure of solidified soil, riprap and solidified soil, characterized in that: The following steps are involved: S1. Preliminary preparation: Determine the customized size and protection range of the solidified soil limiting mold (4) according to the on-site conditions; S2, mold sinking: sink the solidified soil limiting mold (4) as a whole to the seabed plane around the pile, and prepare for slurry pumping; S3, one round of pumping slurry construction: evenly pour the lower solidified soil layer (1) above the seabed plane around the pile to ensure that the fluidized solidified soil is evenly distributed and wait for it to solidify into shape; S4, riprap: evenly scatter riprap above the solidified lower solidified soil layer (1) to fill the solidified soil limiting mold (4) to form a middle riprap layer (2); S5, two-wheel pump slurry: after the riprap is completed, the upper high-fluidity solidified soil layer (3) is used to fill the pores of the riprap body, and the upper high-fluidity solidified soil layer (3) is poured to a certain thickness above the top surface of the middle riprap layer (2); S6. Demolding: After the upper high-fluidity solidified soil layer (3) is solidified and formed, the mold is lifted upward onto the construction vessel using a hinged starting mechanism for subsequent repeated use.

7. A construction method according to claim 6, characterized in that: In step S2, the solidified soil limiting mold (4) and the slurry pump hose are assembled into one on the construction vessel and sunk to the seabed around the pile foundation.

8. A construction method according to claim 7, characterized in that: In step S3, a lower solidified soil layer (1) with a thickness of d1 is formed by pumping slurry once to stabilize the anti-scour foundation.

9. A construction method according to claim 8, characterized in that: In step S4, riprap with a particle size of 80 to 150 mm is scattered into the mold cavity of the mold to a thickness twice the median particle size of the riprap to form a middle riprap layer (2) for dispersing fluid impact.

10. A construction method according to any one of claims 6 to 9, characterized in that: The solidified soil limiting mold (4) is set as a cylindrical steel plate surrounding the pile foundation and coaxial with the pile foundation, the inner diameter R of which is 2D to 3D, wherein D is the diameter of the pile foundation, and the thickness of the steel plate is 3 to 5 cm.

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