A quantitative design method for sinking arrangement

Abstract

The present invention discloses a quantitative design method for the arrangement of submerged drains, comprising determining the protection range of submerged drain revetments according to the overall arrangement of the revetment project, dividing the protection range into standard rectangular units, wherein the size of each standard rectangular unit is consistent with the size of a single submerged drain during implementation; dividing the riverbed topographic surface according to the obtained rectangular units, and analyzing the geometric parameters of the riverbed topographic surface in each unit; calculating the reduction rate ψ of the actual coverage area after the laying of a single submerged drain according to the obtained geometric parameters of the riverbed topographic surface within the protection range in combination with the material parameters of the submerged drain structure; calculating the design overlap length b of the submerged drain in the direction of the water flow and the design length L of the submerged drain in the direction perpendicular to the water flow according to the obtained reduction rate ψ; the present invention quantitatively designs and arranges the submerged drain structure according to the specific conditions such as the riverbed topographic surface parameters, the material parameters of the submerged drain structure and the overall arrangement of the project, so as to ensure the rationality, safety and economy of the structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of design of river regulation projects, and in particular relates to a quantitative design method for sinking and drainage arrangements. Background Art

[0002] A submerged raft is a distinctly advantageous type of bank protection in river regulation projects. It boasts high integrity, flexibility, erosion resistance, and durability, adapting to bank and riverbed deformation. The raft structure consists of two components: a geotextile liner at the bottom and a uniformly spaced arrangement of concrete blocks, sand pillows, and other structures at the top. The geotextile liner conforms to the riverbed, preventing erosion of the riverbed and the underlying soil beneath the bank. The ballast provided by the concrete blocks, sand pillows, and other structures at the top prevents the geotextile from being lifted by the current.

[0003] During the design phase, the standard unit of the submerged drainage is generally designed as a rectangle. However, the underwater riverbed in reality is undulating and difficult to be leveled artificially. After construction is completed, the submerged drainage can adapt to the complex riverbed terrain, thus forming a non-standard curved surface that fits the terrain, and wrinkles appear locally. This makes the projected area of ​​the submerged drainage on the riverbed inevitably smaller than the actual area of ​​the submerged drainage, that is, the designed protection area, so that part of the riverbed where the submerged drainage should be laid is not covered by the submerged drainage. To solve this problem, a certain length of overlap is considered between adjacent submerged drainage during the design. Through the firm overlap, the adjacent submerged drainage can cover the area that should be covered but is not covered by the submerged drainage.

[0004] The overlap length between adjacent rafts is often determined based on the designer's subjective experience, lacking quantitative analysis. This can lead to wasteful construction materials or localized gaps in protection. Currently, there are no mature and rational theoretical analysis or quantitative design methods to determine raft layouts, making it difficult to ensure a balanced economic and safety performance of engineering solutions. Summary of the Invention

[0005] The purpose of the present invention is to provide a quantitative design method for the layout of drainage structures. The purpose of the present invention is to quantitatively design and arrange the drainage structures according to the specific conditions such as the riverbed topography surface parameters, the drainage structure material parameters and the overall layout of the project, so as to ensure the rationality, safety and economy of the structure.

[0006] To achieve the above objectives, the technical solution of the present invention is:

[0007] A quantitative design method for sinking arrangement, the method comprising the following steps:

[0008] S1: According to the overall layout of the revetment project, determine the protection range of the submerged drainage revetment and divide the protection range into standard rectangular units. The size of each standard rectangular unit is consistent with the projection size of a single submerged drainage during implementation. The projection length of the standard rectangular unit perpendicular to the water flow direction is recorded as L0, and the length of the standard rectangular unit in the direction of water flow is recorded as B;

[0009] S2: Divide the riverbed terrain surface according to the rectangular units obtained in step S1, and analyze the geometric parameters of the riverbed terrain surface in each unit, wherein the geometric parameters of the riverbed terrain surface include the ratio k1 of the surface expansion area to the area of ​​the standard rectangular unit, the ratio k2 of the surface standard deviation to the equivalent side length a, and the ratio k3 of the maximum deviation value of a point on the surface to the equivalent side length a; according to the coordinate values ​​of the measured points on the divided terrain surface, use the least squares method to fit a plane as the projection base surface of the terrain surface, and count the distances between the points on the terrain surface and the projection surface. The standard deviation of the statistical values ​​is the surface standard deviation, and the maximum value of the statistical values ​​is the maximum deviation value.

[0010] S3: Based on the riverbed topographic surface parameters within the protection range obtained in step S2 and in combination with the sinking drainage structure material parameters, calculate the reduction rate ψ of the actual coverage projected area after the single sinking drainage is laid;

[0011] S4: Based on the reduction rate ψ obtained in step S3, calculate the design overlap length b of the drain in the direction of water flow and the design length L of the drain in the direction perpendicular to the water flow.

[0012] Furthermore, the calculation method of the equivalent side length a in step S2 is:

[0013]

[0014] in:

[0015] a—unit: m, equivalent length of the standard rectangular unit projection surface;

[0016] L0—unit: m, length of standard rectangular unit perpendicular to water flow direction;

[0017] B—Unit is m, the length of the standard rectangular unit in the direction of water flow, usually 20m.

[0018] Furthermore, the calculation method of the reduction rate ψ in step S3 is:

[0019]

[0020] in:

[0021] ψ—reduction rate of actual coverage projection area after single-block laying;

[0022] r1—comprehensive coefficient, determined by multiple sets of three-dimensional modeling fitting, generally taken as 0.95;

[0023] r2 - coefficient related to the ratio of tensile strength and elastic modulus per unit area of ​​the drainage geotextile, which can reflect the ability of the drainage to fit the riverbed. It is generally set between 1.0 and 1.1. When the tension of the drainage geotextile is small or the elongation is low, a smaller value is taken, otherwise a larger value is taken;

[0024] k1—the ratio of the developed area of ​​the riverbed topography surface to the projected area of ​​the surface, reflecting the geometric characteristics of the surface development;

[0025] k2—the ratio of the standard deviation of the riverbed topography to the equivalent side length a, which reflects the smoothness of the riverbed topography;

[0026] k3—The ratio of the maximum deviation value of a point on the riverbed topography surface to the equivalent side length a. The larger the value, the larger the sedimentation folds.

[0027] Furthermore, the calculation method of the designed overlap length b of adjacent sinking rows in the direction of water flow in step S4 is:

[0028]

[0029] Where B is in meters, the length of the standard rectangular unit in the direction of water flow, usually 20 meters;

[0030] ψ—The reduction rate of the actual coverage projection area after laying a single piece of sedimentation.

[0031] Furthermore, the calculation method for the design length L of the sinking drain in the direction perpendicular to the water flow in step S4 is:

[0032]

[0033] Where L0 is the length of the standard rectangular unit perpendicular to the water flow direction in meters;

[0034] ψ—The reduction rate of the actual coverage projection area after laying a single piece of sedimentation.

[0035] The beneficial effects of the present invention are:

[0036] 1. The related influencing factors and general rules of partial conformity and partial folds formed when sedimentation drainage is laid on irregular riverbed terrain are theoretically analyzed.

[0037] 2. A relatively simple formula for calculating the reduction rate of the actual covered projected area after laying of the submerged drainage system was derived, and a quantitative design method for the submerged drainage system layout was proposed, which provides a theoretical basis for guiding and evaluating the economy and safety of the submerged drainage system layout.

[0038] 3. The present invention quantitatively designs and arranges the drainage structure according to the specific conditions such as the riverbed topographic surface parameters, the drainage structure material parameters and the overall layout of the project to ensure the rationality, safety and economy of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic flow chart of a quantitative design method for sinking and drainage arrangement provided in an embodiment of the present invention.

[0040] Figure 2 A schematic diagram of segmenting the riverbed terrain surface by sedimentation projection provided in an embodiment of the present invention.

[0041] Figure 3 A schematic diagram of the sink arrangement provided in an embodiment of the present invention.

[0042] Among them: 1 is the first sedimentation row; 2 is the second row; A is the direction of downstream flow; B is the length of the standard rectangular unit in the direction of downstream flow; C is the riverbed topography; D is the cross-section of the riverbed topography; E is the horizontally expanded sedimentation row; F is the overlap of adjacent sedimentation rows; G is the horizontal expansion contour line of the first sedimentation row; b is the overlap length; L0 is the length of the standard rectangular unit perpendicular to the direction of downstream flow; L is the design length of a single sedimentation row perpendicular to the direction of downstream flow. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the invention clearer, the present invention is further described below with reference to the accompanying drawings.

[0044] The present invention provides a quantitative design method for sinking arrangement, comprising the following steps:

[0045] S1: Based on the overall layout of the revetment project, determine the protection range of the raft revetment and divide it into standard rectangular units. The size of each standard rectangular unit is consistent with the projected size of a single raft during implementation. The projected length of a single standard raft perpendicular to the water flow is recorded as L0, and the length of a single raft in the direction of water flow is recorded as B. The size of the rectangular unit depends on the size of the specific raft. Raft sizes are of standard sizes, but not limited to a single size.

[0046] Regarding the size of the sink drain, if it is measured by length and width, it is easy to cause confusion in actual engineering. To avoid confusion, the size of the sink drain is usually measured by the length perpendicular to the water flow direction and the length along the water flow direction. Figure 1 Arrow A in the figure indicates the direction of water flow. Figure 1 C is the riverbed topography, D is the cross section of the riverbed topography, and E is the horizontally expanded sedimentation.

[0047] According to the coordinate values ​​of the measured points on the terrain surface, the least square method is used to fit a plane as the projection base of the terrain surface, and the equivalent side length a of the standard rectangular unit projection surface is calculated.

[0048]

[0049] in:

[0050] a—unit: m, equivalent length of the standard rectangular unit projection surface;

[0051] L0—the length of the standard rectangular unit perpendicular to the water flow direction; B—the unit is m, the length of the standard rectangular unit in the direction of water flow, commonly used is 20m.

[0052] S2: Based on the unit division results obtained in step S1, the riverbed topographic surface is divided according to the projection of each sedimentation drainage block, and the geometric parameters of the riverbed topographic surface in each unit are analyzed. The geometric parameters of the riverbed topographic surface include the ratio of the surface unfolded area to the vertical projection area of ​​the surface k1, the ratio of the surface standard deviation to the equivalent side length a k2, and the ratio of the maximum deviation value of a point on the surface to the equivalent side length a k3.

[0053] Regarding the ratio k1 of the unfolded area of ​​the terrain surface to the vertical projection area of ​​the surface, in actual operation, commercial software such as Civil3D can be used to read the projection area and three-dimensional area of ​​the terrain surface. In theoretical analysis, the three-dimensional area, i.e., the unfolded area of ​​the surface, is obtained by dividing the triangular mesh.

[0054] The distance between the points on the terrain surface and the projection surface is calculated. The standard deviation of the statistical value is the surface standard deviation, and the maximum value of the statistical value is the maximum deviation.

[0055] S3: Based on the riverbed topographic surface parameters within the protection range obtained in step S2 and combined with the sedimentation structure material parameters, calculate the reduction rate ψ of the actual coverage projected area after the laying of a single sedimentation block.

[0056] In calculating the reduction rate of the actual projected area covered by a single pile after laying, the reduction rate ψ can be calculated using the following formula:

[0057]

[0058] in:

[0059] ψ—reduction rate of actual coverage projection area after single-block laying;

[0060] r1—comprehensive coefficient, determined by multiple sets of three-dimensional modeling fitting, generally taken as 0.95;

[0061] r2 - coefficient related to the ratio of tensile strength and elastic modulus per unit area of ​​the drainage geotextile, which can reflect the ability of the drainage to fit the riverbed. It is generally set between 1.0 and 1.1. When the tension of the drainage geotextile is small or the elongation is low, a smaller value is taken, otherwise a larger value is taken;

[0062] k1—the ratio of the developed area of ​​the riverbed topography surface to the projected area of ​​the surface, reflecting the geometric characteristics of the surface development;

[0063] k2—the ratio of the standard deviation of the riverbed topography to the equivalent side length a, which reflects the smoothness of the riverbed topography;

[0064] k3—The ratio of the maximum deviation value of a point on the riverbed topography surface to the equivalent side length a. The larger the value, the larger the sedimentation folds.

[0065] S4: According to the reduction rate ψ obtained in step S3, determine the size and overlap length of a single sinker, specifically calculate the design overlap length b of the sinker in the direction of water flow and the design length L of the sinker in the direction perpendicular to the water flow.

[0066] like Figure 2 As shown, two adjacent rows include a first row 1 and a second row 2. Figure 3 As shown, F is the overlap of two adjacent sinking rows along the direction of water flow. One of the purposes of the present invention is to determine the overlap length b of the overlap of the first sinking row 1 and the second sinking row 2 along the direction of water flow, and G is the horizontal expansion contour line of the first sinking row.

[0067] The following calculation formula is used to determine the overlapping length b of adjacent sinking rafts and the design length L of sinking rafts perpendicular to the water flow direction:

[0068]

[0069] Where B is in meters, the length of the standard rectangular unit in the direction of water flow, which is usually 20 meters;

[0070] Where Ψ is the reduction rate of the actual covered projected area after the single-block sedimentation is laid;

[0071]

[0072] Where L0 is in meters, the length of the standard rectangular unit perpendicular to the water flow direction.

[0073] Regarding the design length of the submergence drain in the direction of water flow, a set value is generally given according to actual needs. For example, when the length of each standard rectangular unit dividing the riverbed terrain surface in the direction of water flow is 20m, the design length of the submergence drain in the direction of water flow can be slightly greater than 20m.

[0074] The following combination Figure 1 、 Figure 2 and Figure 3 The present invention will be further described in detail to facilitate a clear understanding of the present invention. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no technical significance. Any structural modifications, changes in proportions, or adjustments in sizes should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and objectives that can be achieved by the present invention.

[0075] The present invention comprises the following steps: determining the layout scheme of a single-block drainage system on a geometric projection; dividing the riverbed topography surface according to the drainage projection and analyzing the surface geometric parameters; calculating the reduction rate of the actual drainage coverage area; and determining the size and overlap length of a single-block drainage system.

[0076] In the step of calculating the reduction rate of the actual coverage area of ​​the drainage, the geometric parameters obtained from the riverbed terrain surface analysis in the previous step should be used, and the terrain flatness, drainage folds and deformation adaptability should be comprehensively considered and calculated according to the formula.

[0077] In the steps of determining the overlap length and size of the geotextile, for safety reasons, the redundant length of the geotextile in both warp and weft directions is calculated using the same reduction rate ψ.

[0078] Example:

[0079] The initial protection range of a single sinking drainage in a certain revetment project is 20m in the direction of water flow and 50m in the direction perpendicular to water flow. The riverbed topography surface is cut according to this projected area, and the cut topography surface is fitted. The analysis and calculation shows that its expanded area is 1070m 2 , the standard deviation of the cutting surface and the fitting surface is 0.36m, the maximum deviation distance is 2.10m, and the calculated reduction rate ψ is 0.87. Then according to step S4, the overlap length b is calculated to be 2.99m, and the length of the drainage perpendicular to the water flow direction L is 57.16m. Through this embodiment, it can be found that since the riverbed terrain surface is an irregular surface, the drainage can only partially fit with the riverbed terrain, and wrinkles will be formed to varying degrees in some parts, which makes the actual coverage area of ​​the drainage smaller than its actual area, and it is difficult to analyze and calculate. If it is arranged conventionally, when the riverbed terrain is relatively flat and regular, it may cause waste. When the riverbed terrain is uneven and regular, the drainage may not be able to completely cover the designed protection area, which may easily lead to safety hazards.

[0080] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

[0081] It should be noted that the contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field. The above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A quantitative design method for sinking arrangement, characterized in that: The method comprises the following steps: S1: According to the overall layout of the revetment project, determine the protection range of the submerged drainage revetment and divide the protection range into standard rectangular units. The size of each standard rectangular unit is consistent with the projection size of a single submerged drainage during implementation; S2: Segment the riverbed topography surface according to the rectangular units obtained in step S1, and analyze the geometric parameters of the riverbed topography surface in each unit, including the ratio of the surface expansion area to the area of ​​the standard rectangular unit. , the ratio of the surface standard deviation to the equivalent side length a , the ratio of the maximum deviation value of a point on the surface to the equivalent side length a ; S3: Based on the riverbed topographic surface parameters within the protection range obtained in step S2 and combined with the sinking structure material parameters, calculate the reduction rate of the actual coverage projection area after the single sinking is laid ; S4: The reduction rate obtained according to step S3 , calculate the design overlap length of the sinking raft in the direction of water flow Design length of the drainage pipe perpendicular to the water flow direction ; The calculation method of the equivalent side length a in step S2 is: ； The S3 step reduction rate The calculation method is: ； The design overlap length of adjacent sinking rows in the direction of water flow in step S4 The calculation method is: ； The design length of the sinking drain in step S4 is perpendicular to the water flow direction The calculation method is: ； in: a represents the equivalent side length of the standard rectangular unit projection surface; L0 represents the length of the standard rectangular unit perpendicular to the water flow direction; B represents the length of the standard rectangular unit in the direction of water flow; Indicates the reduction rate of the actual covered projected area after the laying of a single pile of sedimentation; represents the comprehensive coefficient, which is determined by multiple sets of three-dimensional modeling fitting; It represents the coefficient related to the ratio of tensile strength and elastic modulus per unit area of ​​geotextile; It represents the ratio of the developed area of ​​the riverbed topography surface to the projected area of ​​the surface; It represents the ratio of the standard deviation of the riverbed topography surface to the equivalent side length; It represents the ratio of the maximum deviation value of a point on the riverbed terrain surface to the equivalent side length.

2. A quantitative design method for sinking arrangement according to claim 1, characterized in that: The method for determining the surface standard deviation and the maximum deviation value of the points on the surface in the step S2 is: based on the coordinate values ​​of the measured points on the segmented riverbed terrain surface, use the least squares method to fit a plane as the projection base surface of the terrain surface, and count the distances between the points on the terrain surface and the projection surface. The standard deviation of the statistical values ​​is the surface standard deviation, and the maximum value of the statistical values ​​is the maximum deviation value.

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