Active unloading sheet pile revetment reinforcement design method and structure

Abstract

The present application relates to a kind of active unloading sheet pile revetment reinforcement design method and structure, belong to revetment reinforcement technical field, by determining channel parameter and soil mechanics characteristics, design reinforcement pile is arranged with original pile foundation elevation along the back of revetment, based on soil arch effect establishment pile spacing calculation formula, and through adjusting pile diameter control design reinforcement pile load sharing ratio;The reinforcement structure designed by the method includes: prestressed sheet pile, pile cap, design reinforcement pile, gravity retaining wall, slope surface layer, concrete roof, original mud surface line and design mud surface line, design reinforcement pile diameter and pile spacing are dynamically adjusted according to dredging depth, the thicker the dredged soil layer is, the greater the soil pressure is, the larger the pile diameter is, and the closer the spacing is.The present application does not need to remove the upper structure of original revetment, greatly saves construction period and reduces resource waste;Revetment leading edge line does not move forward, does not affect the use of existing navigable water area;Construction mode is flexible, can be selected onshore dry land or water construction according to surrounding conditions, short construction period, fast speed, low engineering cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of revetment reinforcement, in particular to a method for designing a revetment structure with active unloading sheet piles and the structure. BACKGROUND

[0002] In the fields of water conservancy projects, port terminals and river regulation, revetment structures are key facilities for resisting water erosion, preventing bank collapse and ensuring the stability of the shoreline. Their performance directly affects the safety and service life of the project. Among them, sheet pile revetments have been widely used in silt coast and inland waterways due to their lightweight structure, convenient construction and strong adaptability to soft soil foundation. Inland shipping is increasingly valued for its large capacity, low cost, low energy consumption and environmental protection. However, existing waterways generally have low grades, which cannot meet the growing demand for shipping, and it is urgent to improve the navigation capacity through dredging and revetment reinforcement. Existing reinforcement methods mainly include traditional rigid structure reinforcement, flexible material reinforcement and composite material reinforcement, in addition to auxiliary reinforcement measures. However, these methods generally have poor environmental adaptability, high construction cost and long construction time.

[0003] For example, Chinese utility model patent CN221721498U (publication date: September 17, 2024) discloses a revetment reinforcement device, which belongs to the technical field of revetment reinforcement. It comprises: a plurality of reinforcing plates, which are detachable and adjustable in angle between adjacent reinforcing plates. The water-facing side of the reinforcing plate is elastically connected with a buffer plate. The two ends of the reinforcing plate are fixedly installed with ear plates. The application can be used for assembling and using revetments of different lengths by assembling multiple reinforcing plates. The angle between adjacent reinforcing plates can be adjusted to adapt the assembled reinforcing plates to revetments of different shapes. Finally, the ear plates are fixed on the revetment by expansion bolts, and the elastic connection between the buffer plate and the reinforcing plate can reduce the impact of water waves on the revetment.

[0004] Chinese invention patent CN112854131A (publication date: May 28, 2021) discloses an ecological revetment for water source protection area and a construction method thereof. The ecological revetment comprises a primary revetment arranged below the beach elevation, a secondary revetment arranged above the beach elevation, and an ecological sewage interception and grass planting ditch arranged between the primary revetment and the secondary revetment. The ecological sewage interception and grass planting ditch is in the form of a U-shaped groove and is arranged on one side of the second foundation close to the primary revetment. Compared with other reinforcement methods, the ecological revetment of the invention has the advantages of short construction time, large reinforcement depth, good reinforcement quality, significant economic benefits, etc. In particular, the ecological sewage interception and grass planting ditch specially arranged in the invention improves the functions of soil retaining, filtration and drainage of the revetment, and also improves the ecologicalization and humanistic landscape of the revetment.

[0005] The existing revetment reinforcement methods mostly adopt demolition and reconstruction or large-scale soil replacement, which leads to high cost and large carbon emission, and is difficult to dynamically adapt to different dredging depth requirements. SUMMARY

[0006] Based on the shortcomings of the prior art, the present application provides a kind of active unloading sheet pile revetment reinforcement design method and structure.A kind of design method of active unloading sheet pile revetment reinforcement structure, comprising the following steps:

[0007] Step S1: determine the pile load and original revetment structure parameters after channel dredging, obtain the internal friction angle of soil And cohesion c;

[0008] Step S2: arrange the design reinforcement pile along the back of the revetment, and the pile length and top elevation are consistent with the original pile foundation;

[0009] Step S3: adjust the design reinforcement pile diameter to make the pressure load bearing ratio of the design reinforcement pile 40%-60%;

[0010] Step S4: based on soil arching effect, establish a formula for calculating the spacing of design reinforcement pile ;

[0011] Step S5: determine the distance between the front sheet pile and the design reinforcement pile by the formula .

[0012] Further, the pile load in step S1 is determined according to the dredging depth, internal friction angle of soil, cohesion of soil, perennial groundwater level and designed minimum navigation water level.

[0013] Further, in step S3, D is the distance between the front sheet pile and the design reinforcement pile, l is the net distance between the design reinforcement pile minus the pile diameter, is the internal friction angle of soil.

[0014] Further, the distance between the front sheet pile and the design reinforcement pile in step S3 is 3-5 times the pile diameter, and the distance increases by 0.8-1.2 times the pile diameter for every 10 kPa increase in cohesion c of soil.

[0015] Further, in step S4, l is the net distance between the design reinforcement pile minus the pile diameter, b is the diameter of the design reinforcement pile, the width for square pile, c is the cohesion of soil, is the internal friction angle of soil, is the angle between the failure surface and the minimum principal stress surface (depending on the internal friction angle of soil ), q is the load behind the pile, is the angle between the pressure zone of soil arch intersection and the horizontal direction, i.e. the angle between the local area behind the pile and the horizontal direction.

[0016] Further, the pile diameter of the design reinforcement pile in the step S5 is valued according to the front sheet pile body pressure load and the pressure load bearing ratio.

[0017] Further, the pressure load bearing ratio of the design reinforcement pile in the step S5 is calculated by Integral formula and Calculation, wherein, The pressure load is x, y, and d is the integral symbol, The pile pressure load bearing ratio is p, and p1 is the residual pressure load in front of the pile.

[0018] Further, the pile diameter of the design reinforcement pile is positively correlated with the load, and the smaller the pile spacing between the design reinforcement pile and the front pile, the smaller the pile spacing between the design reinforcement piles, and the greater the load of the design reinforcement pile.

[0019] The application also provides an active unloading sheet pile revetment reinforcement structure, which comprises prestressed sheet piles, a pile cap, design reinforcement piles, a gravity retaining wall, a slope protection surface layer, a concrete pressure top, an original mud surface line and a design mud surface line.

[0020] The prestressed sheet piles are located at the outermost side, and the original mud surface line and the design mud surface line are arranged on the water side;

[0021] The pile cap is located above the prestressed sheet piles;

[0022] The gravity retaining wall is located above the pile cap;

[0023] The design reinforcement piles are located at the rear edge of the existing upper structure, and the length and top elevation are consistent with the original pile foundation.

[0024] Further, the design reinforcement piles are sunk in a static pressure mode, and the spacing between the design reinforcement piles and the prestressed sheet piles is greater than the transverse width of the upper structure and is 3-5 times the pile diameter.

[0025] Further, the design mud surface line is formed by deepening the original mud surface line through dredging, and the height is positively correlated with the load sharing capacity of the design reinforcement pile.

[0026] Compared with the prior art, the application has the following advantages and effects:

[0027] 1. The active unloading sheet pile revetment reinforcement design method provided by the application adopts a structure system in which the rear reinforcement piles and the front row of sheet piles cooperate to bear the load, and the load is effectively transferred and distributed through the soil arch effect. This structure arrangement not only enables the sheet pile revetment to adapt to the engineering requirements of increasing water depth, but also avoids the structure front edge from moving towards the waterway, thereby not affecting the use of the existing navigable water area.

[0028] 2. The active unloading sheet pile revetment reinforcement design method provided by the application can be used for land construction when the surrounding conditions permit, or water construction when the land conditions are limited, is flexible, short in construction period and fast in construction speed.

[0029] 3. The active unloading sheet pile revetment reinforcement structure provided by the application does not need to remove the upper structure of the original revetment, greatly reduces the amount of construction waste, makes the revetment more solid, reduces unnecessary engineering investment, and has the advantages of green economy.

[0030] The above description is only a summary of the technical solutions of the application. In order to more clearly understand the technical means of the application, the contents of the description can be implemented, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following will be described in detail with the preferred embodiments of the application and the accompanying drawings.

[0031] According to the detailed description of the specific embodiments of the application in the following text combined with the accompanying drawings, those skilled in the art will more clearly understand the above and other purposes, advantages and characteristics of the application. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0033] Among them:

[0034] Figure 1 It is a schematic flow chart of the active unloading sheet pile revetment reinforcement design method;

[0035] Figure 2 It is a schematic view of the active unloading sheet pile revetment reinforcement structure;

[0036] Among them: 1-prestressed sheet pile; 2-keel; 3-design reinforcement pile; 4-gravity retaining wall; 5-slope surface layer; 6-concrete top; 7-original mud surface line; 8-design mud surface line. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. In the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, in order to be clear and concise, the description of known functions and structures is omitted in the embodiments.

[0038] It should be understood that the "one embodiment" or "the embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "one embodiment" or "the embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0039] In addition, reference numerals and / or letters can be repeated in different examples in the present application. Such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0040] The term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, B exists alone, and A and B exist together. The term "and" herein is a description of another association relationship of the associated objects, which means that there can be two relationships, for example, A and B can mean that A exists alone and A and B exist together. In addition, the character " / " herein generally indicates that the associated objects before and after the " / " are in an "or" relationship.

[0041] The term "at least one" herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, at least one of A and B can mean that A exists alone, A and B exist together, and B exists alone.

[0042] It should also be noted that the relationship terms such as first and second in the present document 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 the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion.

[0043] Embodiment 1

[0044] The embodiment introduces a kind of active unloading sheet pile revetment reinforcement design method, its instruction flow chart please see attached Figure 1 , comprising the following steps:

[0045] Step S1: the pile load after channel dredging and the original revetment structure parameters are determined, and the internal friction angle of soil is obtained And cohesion c;

[0046] Step S2: design reinforcement pile 3 is arranged at the back of revetment, and the pile length and top elevation of the design reinforcement pile 3 are consistent with the original pile foundation;

[0047] Step S3: the pressure load bearing ratio of design reinforcement pile 3 is 40%-60% by adjusting the diameter of design reinforcement pile 3;

[0048] Step S4: based on soil arch effect, the formula for calculating the spacing of design reinforcement pile 3 is established Wherein, l is the net distance of design reinforcement pile 3 spacing minus pile diameter, b is the diameter of design reinforcement pile 3, and the width of square pile is width, c is the cohesion of soil, It is the internal friction angle of soil, It is the angle between failure surface and minimum principal stress surface (depends on the internal friction angle of soil ), q is the load behind the pile, It is the angle between soil arch intersection compression zone and horizontal direction, that is, the angle between local area on the side of pile behind and the arch force of soil on both sides of pile and horizontal direction;

[0049] Step S5: the distance between front sheet pile and design reinforcement pile 3 is determined by formula Wherein, D is the distance between front sheet pile and design reinforcement pile 3, l is the net distance of design reinforcement pile 3 spacing minus pile diameter, It is the internal friction angle of soil.

[0050] Preferably, the pile load in step S1 is determined according to the dredging depth, the internal friction angle of soil, the cohesion of soil, the perennial underground water level and the designed lowest navigation water level.

[0051] Preferably, the diameter of design reinforcement pile 3 in step S3 is calculated according to the pressure load of front sheet pile and the pressure load bearing ratio.

[0052] Preferably, the pressure load bearing ratio of design reinforcement pile 3 is calculated by Integral formula and Wherein, It is pressure load, x and y are coordinate system, d is integral symbol, It is the pressure load bearing ratio of pile, p is the total pressure load behind the pile, and p1 is the remaining pressure load in front of the pile.

[0053] Preferably, the front sheet pile in step S5 is 3-5 times the pile diameter away from the design reinforcement pile 3.

[0054] Preferably, the distance between the front sheet pile in step S5 and the design reinforcement pile 3 increases by 0.8-1.2 times the pile diameter for every 10 kPa increase in the soil cohesion c.

[0055] Preferably, the calculation formula for the inter-pile spacing of the design reinforcement pile 3 in step S4 is derived based on the soil arching effect between piles, using static equilibrium and Mohr-Coulomb criteria.

[0056] Preferably, the pile diameter of the design reinforcement pile 3 is positively correlated with the load it bears, and the smaller the inter-pile spacing between the design reinforcement pile 3 and the front pile, the smaller the inter-pile spacing between the design reinforcement piles 3, and the greater the load borne by the design reinforcement pile 3.

[0057] The technical effect achieved by the embodiment is that the active unloading sheet pile revetment reinforcement design method provided by the embodiment utilizes the soil arching effect to form a cooperative stress system with the rear reinforcement pile and the front row of sheet piles, without the need to demolish the upper structure of the original revetment for reconstruction, and the structure front does not have to be moved towards the waterway, without affecting the use of the existing navigable water area. The pile diameter size is determined based on the pile pressure load and load sharing ratio, achieving precise control of material usage and avoiding resource waste caused by traditional demolition and reconstruction.

[0058] Embodiment 2

[0059] Based on embodiment 1, this embodiment introduces an active unloading sheet pile revetment reinforcement structure, please refer to the accompanying Figure 2 , which comprises a prestressed sheet pile 1, a pile cap 2, a design reinforcement pile 3, a gravity retaining wall 4, a slope surface layer 5, a concrete top 6, an original mud surface line 7, and a design mud surface line 8.

[0060] The prestressed sheet pile 1 is located at the outermost side, with one side adjacent to water and the other side adjacent to soil, and is a U-shaped sheet pile.

[0061] The pile cap 2 is located above the prestressed sheet pile 1.

[0062] The gravity retaining wall 4 is located above the pile cap 2, and is matched with the prestressed sheet pile 1 and the pile cap 2 to form a multi-level revetment.

[0063] The slope surface layer 5 is located on the side of the gravity retaining wall 4 close to the river bank.

[0064] The concrete top 6 is located at the top of the gravity retaining wall 4.

[0065] The original mud surface line 7 is located outside the prestressed sheet pile 1.

[0066] The design mud surface line 8 is formed by dredging the original mud surface line 7.

[0067] The design reinforcement pile 3 is located at the rear of the existing superstructure, and the length and top elevation are consistent with the original pile foundation.

[0068] Preferably, the height of the design mud surface line 8 should be deepened based on the original mud surface line 7 according to the reinforcement degree of the design reinforcement pile 3 to the original revetment.

[0069] Preferably, the design reinforcement pile 3 is sunk into a precast pile or a construction cast-in-place pile in a static pressure mode.

[0070] Preferably, the precast pile is an H-shaped pile, a steel pipe pile, a precast concrete square pile, a precast concrete pipe pile, or a sheet pile.

[0071] Preferably, the soil penetration depth of the design reinforcement pile 3 is consistent with the front pile.

[0072] Preferably, the pile spacing between the design reinforcement pile 3 and the pre-stressed sheet pile 1 is greater than the size of the pile cap 2.

[0073] Preferably, the distance between the design reinforcement pile 3 and the pre-stressed sheet pile 1 is 3-5 times the pile diameter.

[0074] The technical effect achieved by the embodiment is that the active unloading sheet pile revetment reinforcement structure provided by the embodiment is economical and efficient, can share the load through the rear reinforcement pile without damaging the existing revetment structure, shortens the construction period, improves the material utilization rate, reduces the engineering cost, and is suitable for large-area popularization and application in the sheet pile revetment of the channel with shallow water depth that needs to be dredged.

[0075] Embodiment 3

[0076] Based on embodiment 1, the embodiment introduces a design method of a given specification of a revetment reinforcement structure.

[0077] The original front sheet pile has a size of 1000mm×500mm×150mm, a length of 10m, and a design value of a crack bending moment of 240kN•m. The internal friction angle of the field soil is 30°, and the cohesion is 10kPa. Due to the need for channel dredging, the design value of the bending moment that the sheet pile needs to bear is increased to 400kN•m, which exceeds its bearing capacity. In this embodiment, a steel pipe pile with a diameter of 500mm and a thickness of 14mm is set as a design reinforcement pile 3 by using a static pressure sinking pile mode at the rear of the structure, and the bending bearing capacity of the steel pipe pile is 271kN•m.

[0078] According to the design reinforcement pile 3 pile spacing calculation formula and the recommended distance formula of the design reinforcement pile 3 , l is the net distance excluding the pile diameter, b is the diameter of the pile, and the width of the square pile, is the internal friction angle of the soil, In order to destroy the angle between the surface and the minimum principal stress surface, q is the load behind the pile, c is the soil cohesion, is the angle between the soil arch intersection compression area and the horizontal direction, that is, the angle between the local area behind the pile and the soil arch force on both sides of the pile and the horizontal direction, and D is the distance between the front sheet pile and the design reinforced pile 3.

[0079] The calculation shows that the pile spacing l is 2m, that is, 4 times the pile diameter, and the distance D between the front sheet pile and the design reinforced pile 3 is 1.587m, which meets the recommended 3-5 times the pile diameter. In addition, the soil cohesion is 10kPa, so 2m is taken as 4 times the pile diameter.

[0080] This arrangement makes the pressure load bearing ratio of the design reinforced pile 3 reach 48.99%, which meets the design requirement of 40%-60% and basically realizes the ideal balanced state that the front and rear piles each bear 50% of the load.

[0081] The technical effect achieved by the embodiment is that the design method of the revetment reinforcement structure of a given specification provided by the embodiment uses the post-reinforced pile cooperative stress technology to make the design reinforced pile bear 40%-60% of the load. Compared with the traditional scheme of replacing the sheet pile and removing the upper retaining wall and the pile cap, the embodiment not only maintains the integrity of the original revetment structure, but also avoids the resource waste caused by the traditional reinforcement method of removing and rebuilding, can reduce the amount of earth excavation and the generation of construction waste, and at the same time, reduces the engineering cost and shortens the construction period.

[0082] The above embodiments are only used to illustrate the technical solutions of the present application, and are not limited to the present application. Any equivalent replacement, parameter adjustment or reasonable change of the function implementation mode made by those skilled in the art under the guidance of the principles of the present application should be included in the protection scope of the present application.

Claims

1. A design method for active unloading sheet pile revetment reinforcement, characterized in that, Includes the following steps: Step S1: Measure the pile load and original revetment structure parameters after the channel dredging is completed, and obtain the internal friction angle of the soil. and soil cohesion c; Step S2: Arrange reinforcement piles (3) along the back edge of the revetment, with the pile length and top elevation being consistent with the original pile foundation; Step S3: Adjust the diameter of the design reinforcement pile (3) so that the pressure load bearing ratio of the design reinforcement pile (3) is 40%-60%; Step S4: Based on the soil arching effect, establish the formula for calculating the spacing of the reinforced piles (3). Where l is the net distance between the designed reinforced piles (3) minus the pile diameter, b is the diameter of the designed reinforced piles (3), and for square piles it is the width, c is the soil cohesion. The internal friction angle of the soil. The angle between the failure surface and the surface of minimum principal stress. Depends on the internal friction angle of the soil q is the load behind the pile. It is the angle between the pressure zone where the soil arches meet and the horizontal direction, that is, the angle between the resultant force of the soil arches on both sides of the pile and the horizontal direction in the local area behind the pile; Step S5: Using the formula Determine the distance between the front sheet pile and the designed reinforcement pile (3), where D is the distance between the front sheet pile and the designed reinforcement pile (3), and l is the net distance between the designed reinforcement piles (3) minus the pile diameter. The friction angle within the soil.

2. The active unloading sheet pile revetment reinforcement design method according to claim 1, characterized in that, The pile load in step S1 is determined comprehensively based on the dredging depth, soil internal friction angle, soil cohesion, annual groundwater level, and design minimum navigable water level.

3. The active unloading sheet pile revetment reinforcement design method according to claim 1, characterized in that, The diameter of the reinforced pile (3) in step S3 is calculated based on the pressure load and pressure load bearing ratio of the front sheet pile.

4. A design method for active unloading sheet pile revetment reinforcement according to claim 1 or 3, characterized in that, In step S3, the pressure load bearing ratio of the reinforced pile (3) is designed through... Integral formula and calculate, in, The load is a pressure load, x and y are coordinate systems, and d is the integral sign. p is the pile pressure load bearing ratio, p is the total pressure load behind the pile, and p1 is the remaining pressure load in front of the pile.

5. The active unloading sheet pile revetment reinforcement design method according to claim 1, characterized in that, The distance between the front sheet pile and the designed reinforcement pile (3) in step S5 is 3-5 times the diameter of the designed reinforcement pile (3).

6. A design method for active unloading sheet pile revetment reinforcement according to claim 1 or 5, characterized in that, The distance between the front sheet pile and the designed reinforcement pile (3) in step S5 increases by 0.8-1.2 times the pile diameter for every 10 kPa increase in soil cohesion c.

7. The active unloading sheet pile revetment reinforcement design method according to claim 1, characterized in that, After calculating the pressure load borne by the designed reinforced pile (3) in step S4, the calculation formula for the pile spacing of the designed reinforced pile (3) is established based on the mechanical mechanism of the static equilibrium condition of the soil between the piles under the limit state and the Mohr-Coulomb criterion.

8. An active unloading sheet pile revetment reinforcement structure designed according to the design method of any one of claims 1-7, characterized in that, The active unloading sheet pile revetment reinforcement structure includes: prestressed sheet piles (1), pile cap (2), design reinforcement piles (3), gravity retaining wall (4), slope protection surface layer (5), concrete capping (6), original mud line (7) and design mud line (8); The prestressed sheet pile (1) is located on the outermost side, with the original mud surface line (7) and the design mud surface line (8) on the water-facing side; the pile cap (2) is located above the prestressed sheet pile (1); the design reinforcement pile (3) is located at the rear edge of the existing superstructure, with its length and top elevation consistent with the original pile foundation; the gravity retaining wall (4) is located above the pile cap (2); the slope protection surface layer (5) is located on the side of the gravity retaining wall (4) near the riverbank; the concrete capping (6) is located at the top of the gravity retaining wall (4); the design mud surface line (8) is formed by dredging and deepening the original mud surface line (7).

9. The active unloading sheet pile revetment reinforcement structure according to claim 8, characterized in that, The diameter of the reinforced pile (3) is positively correlated with the load it bears.

10. The active unloading sheet pile revetment reinforcement structure according to claim 8, characterized in that, The design reinforcement pile (3) is driven in by static pressure, and the distance between it and the prestressed sheet pile (1) is greater than the transverse width of the superstructure.

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