Bearing platform type dock wall structure and design method thereof

Abstract

The invention discloses a bearing platform type dock wall structure and a design method thereof, and relates to the technical field of hydraulic structures of water transportation engineering. The structure comprises a gallery, a bearing platform, a dock wall lining, an inner side cast-in-place pile, an outer side cast-in-place pile, a jet grouting pile water-stop wall, a grouting curtain and a middle cast-in-place pile, the gallery and the bearing platform are combined to form an unloading plate and optimize soil pressure distribution, the outer side cast-in-place pile and the jet grouting pile water-stop wall jointly form a water-stop soil-retaining outer wall, the inner side cast-in-place pile and the dock wall lining form an inner wall, and the grouting curtain and the middle cast-in-place pile form a grouting curtain. And the middle cast-in-place pile mainly bears a vertical load. According to the design method, the row piles are converted into the underground diaphragm wall, the pile-soil action is simulated by applying a hypothetical soil body spring method, and the horizontal force of the front and rear piles is distributed according to the conversion rigidity calculation result of the row piles. By arranging the three rows of cast-in-place piles on the inner side, the middle and the outer side, distinguishing of stress functions is achieved, and deformation is effectively controlled; the design method has the advantages of construction convenience and economical efficiency.

Description

Technical Field

[0001] This invention relates to the field of hydraulic structure technology in waterway engineering, and in particular to a pier-type dock wall structure and its design method. Background Technology

[0002] As dock engineering develops towards larger scale and deeper water, traditional gravity-type (such as cast-in-place buttress structures) and anchored-type (such as anchored sheet piles and anchored bored piles) dock wall structures often face challenges such as difficulty in displacement control, insufficient construction space, or significant impact on the surrounding environment under constraints such as complex geological conditions, small construction sites, or proximity to sensitive buildings. To address these challenges, various pier-type dock wall structures have emerged in existing technologies.

[0003] For example, Chinese utility model patent CN101806070A (publication date: August 18, 2010) discloses a self-supporting low-pile foundation dock wall structure based on double-row piles, including an upper breast wall and a low-pile foundation. Its characteristic is that the low-pile foundation consists of a front row of piles, a rear row of piles, and the foundation itself, which is set on a pile foundation formed by the front and rear rows of piles. A lining wall is provided on the outer side of the front row of piles, and a water-stop curtain is provided on its inner side. The upper breast wall is fixedly connected to the low-pile foundation to form a portal frame structure dock wall. Compared with existing technologies, this invention has the advantages of a smaller footprint, no need for large excavations, making it particularly suitable for use in confined spaces. Construction is more flexible, and it is easier and more convenient to handle underground obstacles. Furthermore, the renovation period is short and does not affect production, truly enabling renovation and expansion projects to be carried out simultaneously or concurrently with factory production.

[0004] Chinese invention patent CN106275311A (publication date: January 4, 2017) discloses a sloping pile cap type dock wall structure and its construction method. Its features include a dock corridor integrally connected to a pile cap set on sloping top piles and sloping tie piles; temporary inclined supports on the dock front wall, with the inclined supports mounted on columns and their ends diagonally connected to the dock bottom slab and the dock front wall respectively; the sloping tie piles may be anchored with reinforced steel. During construction, this dock wall structure also serves as the retaining structure for the foundation pit, with the inclined supports acting as temporary supports for the dock front wall. The specific construction includes: dock front wall, dock corridor, pile cap, and supports construction, as well as pouring the dock bottom slab and backfilling the site. Compared with existing technologies, this invention has less impact on existing buildings, better controls the displacement of existing buildings around the dock during construction and use, has a simple structure, is easy to construct, and has low project costs. It is particularly suitable for building docks in areas with high environmental protection requirements and limited construction space.

[0005] Existing technologies, through the combination of pile foundations and pile caps, have achieved, to some extent, the goals of reducing excavation, adapting to confined spaces, or controlling deformation. However, they still suffer from limitations such as the complex collaborative force-bearing mechanism between the pile cap and the pile foundation, uneven distribution of internal forces in the pile body which may lead to low material utilization efficiency, construction complexity, requirements for specialized equipment, and high costs for later demolition or recycling. Currently, there is an urgent need for a dock wall structure and its design method that has better overall stiffness, a more reasonable force transmission path, and lower construction difficulty and project cost. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention provides a pier-type dock wall structure, including a corridor, a pier, dock wall lining, inner cast-in-place piles, outer cast-in-place piles, jet grouting pile waterstop wall, grouting curtain and central cast-in-place piles. The corridor is located above the dock wall; The pier is located below the corridor; The dock wall lining is located at the innermost side of the dock chamber, with its top fixedly connected to the lower side of the upper support platform and its lower part fixedly connected to the bottom plate. The upper end of the inner cast-in-place pile is fixedly connected to the bottom side of the pile cap, and its side is closely attached to the outer side of the dock wall lining. The outer cast-in-place pile jet grouting pile waterstop wall and the grouting curtain below form a water-stopping and soil-retaining outer wall structure. The top of the jet grouting pile waterstop wall is fixed to the pile cap, and its side is closely attached to the outside of the outer cast-in-place pile. The grouting curtain is located at the bottom of the jet grouting pile waterstop wall; The central cast-in-place piles are fixedly installed below the pile cap to bear the vertical load of the gantry crane above the dock wall, and at the same time, they serve as retaining walls.

[0007] Furthermore, the dock wall lining is bordered by soil on one side and water on the other, which is used to withstand external soil pressure and ship loads and water pressure inside the dock.

[0008] Furthermore, the inner cast-in-place piles and the dock wall lining together form the inner wall; the outer cast-in-place piles and the jet grouting pile waterstop wall form the outer wall, so that the soil under the pier and the inner and outer walls form an integral whole to resist bending and deformation.

[0009] Furthermore, the corridor can serve as an electrical, power, water supply and drainage corridor or a general corridor.

[0010] Furthermore, the combination of the pier cap and the corridor forms an unloading plate, which changes the distribution of earth pressure, creates a pressure relief zone, adjusts the slip surface, and reduces the load borne by the inner and outer cast-in-place piles.

[0011] Furthermore, the inner, outer, and middle cast-in-place piles must penetrate at least 3 meters into the underlying bedrock.

[0012] Furthermore, the spacing between the inner and outer cast-in-place piles is set to 3-5 times the pile diameter.

[0013] This application also provides a design method for a pier-type dock wall structure, including the following steps: Step S1: Based on the known geological conditions of the soil layers, calculate the stability and strength of the existing structure; Step S2: Move the jet grouting pile waterstop wall to the outer wall of the outer cast-in-place pile; Step S3: The cast-in-place piles are converted into underground continuous walls. The interaction between the piles and the soil is calculated according to the hypothetical soil spring method. The horizontal force of the front and rear piles is distributed based on the converted stiffness calculation results of the piles. Step S4: The proportion of horizontal load borne by the outer, middle, and inner cast-in-place piles is allocated by converting each row of piles into a continuous wall according to the principle of stiffness equivalence. The load proportions borne by the outer, middle, and inner cast-in-place piles are configured as 40%-50%, 30%-40%, and 10%-30% of the total horizontal load, respectively. The load proportion formula is as follows: In the formula, h A , h B , h C The thickness of the diaphragm wall is calculated based on the outer cast-in-place piles, the middle cast-in-place piles, and the inner cast-in-place piles. F A , F B , F C For the loads of the outer cast-in-place piles, the middle cast-in-place piles, and the inner cast-in-place piles; Step S5: Calculate the horizontal spring stiffness coefficient of the soil around the pile to determine the size, spacing and depth of the cast-in-place pile.

[0014] Furthermore, the formula for calculating the reduced stiffness in step S3 is as follows: In the formula Let A be the elastic modulus of the cast-in-place pile. The elastic modulus of pile B is given. Let A be the section modulus of the cast-in-place pile. The section modulus of pile B is given. The elastic modulus of the diaphragm wall. L The distance between the outermost edges of adjacent cast-in-place piles A and B. h This refers to the thickness of the diaphragm wall as calculated.

[0015] Furthermore, the formula for calculating the horizontal spring stiffness coefficient in step S5 is as follows: , , In the formula, k is the horizontal spring stiffness coefficient, m0 is the horizontal foundation resistance coefficient m value, b0 is the calculated width of the pile, h0 is the soil unit height, z is the pile penetration depth, k' is the calculation correlation coefficient, b2 is the coefficient related to the number of piles in a row parallel to the direction of horizontal force action, when n=1, b2=1.0, when n=2, b2=0.6, when n=3, b2=0.5, when n≥4, b2=0.45; L1 is the net distance between piles, h1 is the calculated embedment depth of the pile below the ground or local scour line, taken as h1=3(d+1), where d is the pile diameter.

[0016] Compared with existing technologies, the advantages and effects of this application are as follows: 1. The design method for the pier-type dock wall structure provided in this application converts the piles into a continuous wall and uses the hypothetical soil spring method to simulate the pile-soil interaction. This provides a specific path for calculating the internal forces and deformations of the piles, and gives suggested load distribution ratios for the outer, middle, and inner cast-in-place piles, achieving optimized material usage. Based on geological survey conditions, this method calculates the stability and strength of the existing structure, load distribution, and soil spring stiffness, enabling more accurate prediction and control of the overall structure.

[0017] 2. In traditional double-row pile structures, the collaborative force-bearing mechanism between the pile cap and the pile foundation is complex, and uneven distribution of internal forces within the piles may lead to low material utilization efficiency. This application provides a pile cap-type dock wall structure with central cast-in-place piles to bear the vertical load of the gantry crane above the dock wall, solving the force-bearing problem caused by the vertical and horizontal loads being borne by the same row of piles in double-row pile structures. Compared to inclined pile cap structures, this structure reduces pressure by altering the distribution of earth pressure, making construction simpler.

[0018] 3. Without completely altering the existing dock wall structure, this application arranges the jet grouting pile waterstop wall on the outer cast-in-place pile. The outer cast-in-place pile bears the main load and controls the magnitude of displacement deformation. The soil under the pile cap forms an integral whole with the cast-in-place pile, thereby reducing the load on the inner cast-in-place pile and reducing the pile diameter to 0.7-0.9 times the original, thus reducing project investment.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings.

[0020] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In all drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale.

[0022] in: Figure 1 This is a structural schematic diagram of a pier-type dock wall structure according to the present invention; Figure 2 This is a structural diagram of an existing traditional pier-type dock wall structure; Figure 3 This is a flowchart illustrating the design method of the pier-type dock wall structure of the present invention; Figure 4 This is a structural stress diagram of a pier-type dock wall structure according to the present invention.

[0023] Among them: 1-corridor; 2-foundation; 3-dock wall lining; 4-inner cast-in-place pile; 5-outer cast-in-place pile; 6-jet jet grouting pile waterstop wall; 7-grouting curtain; 8-central cast-in-place pile. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. In the following description, specific details such as specific configurations and components are provided merely to help fully understand the embodiments of this 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 this application. In addition, for clarity and brevity, descriptions of known functions and structures are omitted in the embodiments.

[0025] It should be understood that the phrase "an embodiment" or "this embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "an embodiment" or "this embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0026] Furthermore, reference numerals and / or letters may be repeated in different examples within this 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 settings discussed.

[0027] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" describes another type of relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the related objects before and after it have an "or" relationship.

[0028] In this article, the term "at least one" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, "at least one of A and B" can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0029] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion.

[0030] Example 1 This embodiment describes a pier-type dock wall structure. Please refer to the appendix. Figure 1 , attached Figure 1 This is a structural schematic diagram of a pier-type dock wall structure according to the present invention.

[0031] The pier-type dock wall structure in this invention includes a corridor 1, a pier 2, a dock wall lining 3, inner cast-in-place piles 4, outer cast-in-place piles 5, a jet grouting pile waterstop wall 6, a grouting curtain 7, and a central cast-in-place pile 8. The corridor 1 is located above the dock wall; The foundation 2 is located below the corridor 1; The dock wall lining 3 is located at the innermost side of the dock chamber, and its top is fixedly connected to the lower side of the upper support 2, and its lower part is fixedly connected to the bottom plate. The upper end of the inner cast-in-place pile 4 is fixedly connected to the bottom side of the pile cap 2, and its side is closely attached to the outer side of the dock wall lining 3. The outer cast-in-place pile 5 and the jet grouting pile waterstop wall 6 together with the grouting curtain below form a water-stopping and soil-retaining outer wall structure. The top of the jet grouting pile waterstop wall 6 is fixed to the pile cap 2, and its side is closely attached to the outside of the outer cast-in-place pile 5. The grouting curtain 7 is located at the bottom of the jet grouting pile waterstop wall 6; The central cast-in-place pile 8 is fixedly installed below the pile cap 2 to bear the vertical load of the gantry crane above the dock wall, and at the same time, it serves as a retaining wall.

[0032] Furthermore, the dock wall lining 3 is bordered by soil on one side and water on the other, and is used to withstand external soil pressure and ship loads and water pressure inside the dock.

[0033] Furthermore, the inner cast-in-place piles 4 together with the dock wall lining 3 form the inner wall; the outer cast-in-place piles 5 together with the jet grouting pile waterstop wall 6 form the outer wall, so that the soil under the foundation and the inner and outer walls form an integral whole to resist bending and deformation.

[0034] Furthermore, the corridor 1 can serve as an electrical, power, water supply and drainage corridor or a general corridor.

[0035] Furthermore, the combination of the foundation 2 and the corridor 1 forms an unloading plate, which changes the distribution of earth pressure, creates a pressure relief zone, adjusts the slip surface, and reduces the load borne by the inner cast-in-place pile 4 and the outer cast-in-place pile 5.

[0036] Furthermore, the inner cast-in-place pile 4, the outer cast-in-place pile 5, and the middle cast-in-place pile 8 must penetrate more than 3m into the underlying rock foundation.

[0037] Furthermore, the spacing between the inner cast-in-place pile 4 and the outer cast-in-place pile 5 should not be too large, with the optimal spacing set at 3-5 times the pile diameter.

[0038] Furthermore, in the aforementioned pier-type dock wall structure, the combination of outer cast-in-place piles and jet grouting pile waterstop can be replaced by an interlocking pile structure. The interlocking pile is constructed by alternating plain concrete piles (A piles) and reinforced concrete piles (B piles). A piles use slow-setting concrete to ensure that B piles can be cut during construction. B piles are constructed before the initial setting of A piles and are embedded into A piles to form an interlock. The interlocking piles form an interlocking structure by cutting adjacent piles, making the piles seamless and effectively blocking the seepage path of groundwater. B piles can be designed and constructed according to the original outer cast-in-place piles. A piles replace the function of jet grouting pile waterstop and provide greater horizontal and vertical bearing capacity. Interlocking piles are suitable for deeper structural types and can further reduce the load borne by the internal pile foundation.

[0039] The technical effects achieved in this embodiment are as follows: The pier-type dock wall structure provided in this embodiment, by introducing central cast-in-place piles to bear the vertical load of the gantry crane above the dock wall, and at the same time act as retaining soil, solves the problem of complex stress and coupling of vertical and horizontal loads in traditional structures. Arranging the jet grouting pile waterstop wall on the outer cast-in-place piles isolates groundwater from the outside, reducing the pressure on the inner piles. Without changing the amount of excavation work, it reduces the bending moment on the inner cast-in-place piles and dock wall lining, reduces displacement and pile diameter requirements, and ensures the overall stability of the pier-type dock wall structure. Simultaneously, it reduces the amount of excavation and pile foundation work, saving on project investment costs.

[0040] Example 2 Based on Example 1, this example introduces a design method for a pier-type dock wall structure. Please refer to the appendix. Figure 2 , attached Figure 2 This is a flowchart illustrating the design method for a pier-type dock wall structure.

[0041] The design method includes the following steps: Step S1: Based on the known geological conditions of the soil layers, calculate the stability and strength of the existing structure; Step S2: Move the jet grouting pile waterstop wall 6 to the outer wall of the outer cast-in-place pile 5; Step S3: The cast-in-place piles are converted into underground continuous walls. The interaction between the piles and the soil is calculated according to the hypothetical soil spring method. The horizontal force of the front and rear piles is distributed based on the converted stiffness calculation results of the piles. Step S4: The design recommends that the outer piles (5) bear 40-50% of the total load, the middle piles (8) bear 30-40% of the total load, and the inner piles (4) bear 10-30% of the total load. The load proportion formula is as follows: In the formula, h A , h B , h C The thickness of the diaphragm wall is calculated based on the outer cast-in-place pile 5, the middle cast-in-place pile 8, and the inner cast-in-place pile 4. F A , F B , F C The loads are for the outer cast-in-place pile 5, the middle cast-in-place pile 8, and the inner cast-in-place pile 4. Step S5: Calculate the horizontal spring stiffness coefficient of the soil along the pile.

[0042] Furthermore, the formula for calculating the reduced stiffness in step S3 is as follows: In the formula Let A be the elastic modulus of the cast-in-place pile. The elastic modulus of pile B is given. Let A be the section modulus of the cast-in-place pile. The section modulus of pile B is given. The elastic modulus of the diaphragm wall. L The distance between the outermost edges of adjacent cast-in-place piles A and B. h This refers to the thickness of the diaphragm wall as calculated.

[0043] Furthermore, the formula for calculating the horizontal spring stiffness coefficient in step S5 is the formula from the "Code for Design of Highway Bridge and Culvert Foundations". , , In the formula, m0 is the horizontal foundation resistance coefficient m value, b0 is the calculated width of the pile, h0 is the soil unit height, z is the pile penetration depth, b2 is a coefficient related to the number of piles in a row parallel to the direction of horizontal force action. When n=1, b2=1.0, when n=2, b2=0.6, when n=3, b2=0.5, and when n≥4, b2=0.45; L1 is the net distance between piles, and h1 is the calculated embedment depth of the pile below the ground or local scour line, which can be taken as h1=3(d+1), where d is the pile diameter.

[0044] Furthermore, since the jet grouting wall on the outside of the inner cast-in-place piles is cancelled, the inner cast-in-place piles take on the role of retaining soil for the side wall support of the foundation pit. Their spacing cannot be too large, and the net distance generally needs to be controlled below 150mm.

[0045] Furthermore, after moving the jet grouting pile waterstop wall to the outer side of the outer cast-in-place pile, the cast-in-place piles near the dock wall lining are subjected to less stress, so the pile diameter can be reduced to 0.7-0.9 times the original size.

[0046] The technical effect achieved in this embodiment is that the design method of the pier-type dock wall structure in this embodiment realizes the calculation and simulation of pile-soil interaction and load transfer between piles by converting the cast-in-place piles into underground continuous walls and calculating the interaction between the piles and the soil according to the hypothetical soil spring method.

[0047] Example 3 Based on Embodiments 1 and 2, this embodiment introduces an improved design method for a pier-type dock wall structure of a given specification. Please refer to the attached diagram for a structural stress diagram of the pier-type dock wall. Figure 3-4 .

[0048] The existing dock wall foundation has a front row of φ1200mm cast-in-place piles with a spacing of 1300mm, a second row of φ1500mm cast-in-place piles with a spacing of 2850mm, and a third row of φ1500mm cast-in-place piles with a spacing of 3400mm. A 2000t gantry crane is installed above the second and third rows of piles, and there is a surcharge on the structure. The geology below is plain fill, silty clay and moderately weathered limestone.

[0049] According to the formula for calculating the equivalent stiffness In the formula, Let A be the elastic modulus of the cast-in-place pile. The elastic modulus of pile B is given. Let A be the section modulus of the cast-in-place pile. The section modulus of pile B is given. The elastic modulus of the diaphragm wall. L The distance between the outermost edges of adjacent cast-in-place piles A and B. h The equivalent thickness of the diaphragm wall is calculated as follows: the equivalent thickness of the diaphragm wall for the first row of piles is 979 mm, the equivalent thickness for the second row of piles is 1015 mm, and the equivalent thickness for the third row of piles is 957 mm. The load ratios they bear are 33%:36%:31%.

[0050] The horizontal spring stiffness coefficient of the soil along the pile was calculated using the formula in the "Design Code for Highway Bridge and Culvert Foundations". The final result shows that the standard value of the bending moment that the first row of piles needs to bear is 1285 N·m, the standard value of the bending moment that the second row of piles needs to bear is 6803 N·m, the standard value of the bending moment that the third row of piles needs to bear is 4015 N·m, and the maximum displacement is 20 mm.

[0051] According to the improved design method recommended by this invention, the jet grouting pile waterstop wall is arranged on the outer side of the cast-in-place piles to bear the water pressure. At the same time, the pile diameter of the first row of piles is reduced and the spacing of the third row of piles is reduced. After the final adjustment, the size of the first row of piles is φ800mm cast-in-place piles with a spacing of 900mm, the second row is φ1500mm cast-in-place piles with a spacing of 2850mm, and the third row is φ1500mm cast-in-place piles with a spacing of 2450mm.

[0052] Calculations were performed as above, and the equivalent thickness of the diaphragm wall for the first row of piles was 645mm, the equivalent thickness for the second row of piles was 1015mm, and the equivalent thickness for the third row of piles was 1068mm. The loads borne by the three piles accounted for 11%: 41%: 48%.

[0053] Based on the soil rupture angle, the soil springs around the piles are arranged sequentially. Following the classical elastoplastic model, the standard bending moment required by the first row of piles is 439 N·m, the standard bending moment required by the second row of piles is 5121 N·m, and the standard bending moment required by the third row of piles is 3621 N·m, with a maximum displacement of 14 mm.

[0054] Analysis and calculation results show that, in this embodiment, the bending moment borne by the dock wall pile foundation of the improved design recommended by the present invention is reduced by 66%, 25%, and 10% respectively compared with the existing design, and the displacement is reduced by 30% compared with the existing design. Furthermore, the amount of concrete reduced in the first row of piles is greater than the amount of concrete increased in the third row. The amount of concrete used in the pile foundation in the improved design is reduced by 5.5% compared with the existing dock wall. At the same time, since the bending moment borne by the pile foundation is significantly reduced while its axial force remains almost unchanged, the amount of steel reinforcement used to improve the strength of the pile foundation is also significantly reduced.

[0055] The technical effect achieved by this embodiment is that the improved design method of the pier-type dock wall structure of a given specification provided by this embodiment shows that the bending moment borne by the dock wall pile foundation of this application is less than that of the original design, and the amount of pile foundation concrete and steel reinforcement is less.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Any equivalent substitutions, parameter adjustments, or reasonable changes to the functional implementation methods made by those skilled in the art under the guidance of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A platform-type dock wall structure, characterized in that, It includes the corridor (1), the foundation (2), the dock wall lining (3), the inner cast-in-place piles (4), the outer cast-in-place piles (5), the jet grouting pile waterstop wall (6), the grouting curtain (7), and the central cast-in-place piles (8). The corridor (1) is arranged above the dock wall and is integrated with the pier (2) to form an unloading plate; The upper ends of the inner cast-in-place pile (4), the middle cast-in-place pile (8) and the outer cast-in-place pile (5) are all fixedly connected to the bottom side of the pile cap (2). The three rows of piles are arranged in sequence at intervals in the horizontal direction, and the middle cast-in-place pile (8) is located between the inner cast-in-place pile (4) and the outer cast-in-place pile (5). The inner side of the cast-in-place pile (4) is closely attached to the dock wall lining (3). A jet grouting wall (6) is provided on the outside of the outer cast-in-place pile (5). The outer cast-in-place pile (5), the middle cast-in-place pile (8) and the inner cast-in-place pile (4) jointly bear the horizontal load, and the outer cast-in-place pile (5) bears the largest proportion of the horizontal load. The arrangement and cross-sectional dimensions of the inner cast-in-place piles (4), the middle cast-in-place piles (8), and the outer cast-in-place piles (5) are determined by the loads they bear.

2. The pier-type dock wall structure according to claim 1, characterized in that, The proportion of horizontal load borne by the outer cast-in-place piles (5), the middle cast-in-place piles (8) and the inner cast-in-place piles (4) is distributed by converting each row of piles into a continuous wall according to the principle of stiffness equivalence. The proportion of load borne by the outer cast-in-place piles (5), the middle cast-in-place piles (8) and the inner cast-in-place piles (4) is configured as 40%-50%, 30%-40% and 10%-30% of the total horizontal load, respectively.

3. A pier-type dock wall structure according to claim 1 or 2, characterized in that, The spacing between the inner cast-in-place piles (4) and the outer cast-in-place piles (5) is set to 3-5 times the pile diameter.

4. A pier-type dock wall structure according to claim 1 or 2, characterized in that, The inner cast-in-place pile (4), the outer cast-in-place pile (5), and the middle cast-in-place pile (8) all penetrate more than 3m into the underlying bedrock.

5. A pier-type dock wall structure according to claim 1, characterized in that, The top of the jet grouting pile waterstop wall (6) is fixedly connected to the pile cap (2).

6. A pier-type dock wall structure according to claim 5, characterized in that, The grouting curtain (7) is located at the bottom of the jet grouting pile waterstop wall (6).

7. A pier-type dock wall structure according to claim 1, characterized in that, The top of the dock wall lining (3) is fixedly connected to the lower side of the foundation (2).

8. The design method for a pier-type dock wall structure according to claims 1-7, characterized in that, Includes the following steps: Step S1: Based on the known geological conditions of the soil layers, calculate the stability and strength of the existing structure; Step S2: Move the jet grouting pile waterstop wall (6) to the outer wall of the outer cast-in-place pile (5); Step S3: The cast-in-place piles are converted into underground continuous walls. The interaction between the piles and the soil is calculated according to the hypothetical soil spring method. The horizontal force of the front and rear piles is distributed based on the converted stiffness calculation results of the piles. Step S4: Calculate the load percentages of the inner cast-in-place piles (4), the outer cast-in-place piles (5), and the middle cast-in-place piles (8); Step S5: Calculate the horizontal spring stiffness coefficient of the soil along the pile.

9. The design method for a pier-type dock wall structure according to claim 8, characterized in that, The formula for calculating the reduced stiffness in step S3 is as follows: In the formula Let A be the elastic modulus of the cast-in-place pile. The elastic modulus of pile B is given. Let A be the section modulus of the cast-in-place pile. The section modulus of pile B is given. The elastic modulus of the diaphragm wall. L The distance between the outermost edges of adjacent cast-in-place piles A and B. h This refers to the thickness of the diaphragm wall as calculated.

10. A design method for a pier-type dock wall structure according to claim 8 or 9, characterized in that, The load proportion formula in step S4 is: In the formula, h A , h B , h C The thickness of the diaphragm wall is calculated. F A , F B , F C The loads are for the outer cast-in-place pile (5), the middle cast-in-place pile (8), and the inner cast-in-place pile (4).

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