Quantitative design method for sinking row arrangement

Abstract

The quantitative design method comprises the steps that according to the overall arrangement of a bank protection project, the protection range of a bank protection of the sinking mattress is determined, the protection range is divided into standard rectangular units, and the size of each standard rectangular unit is consistent with the size of a single sinking mattress during implementation; the riverbed terrain curved surface is segmented according to the obtained rectangular units, and geometric parameters of the riverbed terrain curved surface in each unit are analyzed; according to the obtained riverbed terrain curved surface geometric parameters in the protection range, the reduction rate psi of the actual coverage area after the single sinking mattress is laid is calculated in combination with sinking mattress structure material parameters; according to the obtained reduction rate psi, the designed lap length b of the sinking drainage in the downstream water flow direction and the designed length L of the sinking drainage in the direction perpendicular to the water flow direction are calculated; according to specific conditions such as riverbed terrain curved surface parameters, sinking mattress structure material parameters and engineering overall arrangement, the sinking mattress structure is quantitatively designed and arranged, and the rationality, safety and economical efficiency of the structure are guaranteed.

Description

Technical Field

[0001] The 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] The raft is a type of bank protection with obvious advantages in river regulation projects. It has high integrity, flexibility, scour resistance and durability, and can adapt to the deformation of the bank slope and riverbed. The raft structure consists of two parts: the lower part is the geotextile liner, and the upper part is the concrete blocks, sand pillows and other row bodies evenly spaced. The raft is a geotextile liner that fits the riverbed to block the scouring of the riverbed and the lower soil of the bank slope by the water flow. The ballast effect of the upper concrete blocks, sand pillows and other row bodies can prevent the geotextile from being lifted by the water flow.

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

[0004] The overlap length between adjacent sinkers is often determined based on the subjective experience of designers, lacking quantitative analysis, which can easily lead to waste of engineering materials or local protection gaps. At present, there is no mature and reasonable theoretical analysis and quantitative design method to determine the sinker layout plan, making it difficult to ensure a balance between the economy and safety of the engineering plan. Summary of the invention

[0005] The purpose of the present invention is to provide a quantitative design method for the arrangement 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 topographic 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 structures.

[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 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 revetment during implementation. The projection length of the standard rectangular unit perpendicular to the water flow direction is recorded as L 0, the length of the standard rectangular unit in the direction of water flow is recorded as B;

[0009] S2: Segment the riverbed topographic surface according to the rectangular units obtained in step S1, and analyze the geometric parameters of the riverbed topographic surface in each unit, wherein the geometric parameters of the riverbed topographic surface include the ratio k of the surface development area to the area of ​​the standard rectangular unit. 1 , the ratio of the surface standard deviation to the equivalent side length a k 2 , the ratio k of the maximum deviation value of a point on the surface to the equivalent side length a 3 ; According to the coordinate values ​​of the measured points on the segmented terrain surface, the least squares method is used to fit a plane as the projection base of the terrain surface. The distance between the points on the terrain surface and the projection surface is counted. The standard deviation of the statistical value is the surface standard deviation, and the maximum value of the statistical value 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 material parameters of the drainage structure, calculate the reduction rate ψ of the actual covered projection area after the single drainage is laid;

[0011] S4: According to 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] L 0 —Unit: m, the length of the standard rectangular unit perpendicular to the water flow direction;

[0017] B—Unit: 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] r 1 —Comprehensive coefficient, determined by multiple sets of three-dimensional modeling fitting, generally taken as 0.95;

[0023] r2 —The coefficient related to the ratio of tensile force per unit area of ​​the drainage geotextile to the elastic modulus can reflect the ability of the drainage to fit the riverbed. It is generally 1.0 to 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] k 1 —The ratio of the developed area of ​​the riverbed topography surface to the projected area of ​​the surface, which reflects the geometric characteristics of the surface development;

[0025] k 2 —The ratio of the standard deviation of the riverbed topography surface to the equivalent side length a, which reflects the flatness of the riverbed topography;

[0026] k 3 —The ratio of the maximum deviation value of a point on the riverbed topographic surface to the equivalent side length a. The larger the value, the larger the sedimentation folds.

[0027] Furthermore, the calculation method of the design overlap length b of adjacent sinking rows along the water flow direction 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 of a single piece of sedimentation drainage.

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

[0032]

[0033] Where L 0 —Unit: m, the length of the standard rectangular unit perpendicular to the water flow direction;

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

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

[0036] 1. The related influencing factors and general rules of partial fit 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 drainage rafts was derived, and a quantitative design method for drainage raft layout was proposed, which provided a theoretical basis for guiding and evaluating the economy and safety of drainage raft 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 project layout 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 a riverbed topographic 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 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 row; F is the overlap of adjacent rows; G is the horizontal expansion contour line of the first row; b is the overlap length; L 0 is the length of the standard rectangular unit in the direction perpendicular to the water flow; L is the design length of a single sink drain in the direction perpendicular to the water 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: According to the overall layout of the revetment project, determine the protection range of the 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 revetment during implementation. The projection length of a single standard revetment in the vertical direction of the water flow is recorded as L 0 , the length of a single sinker in the direction of water flow is recorded as B. The size of the rectangular unit depends on the size of the specific sinker. The size of the sinker has a regular size, but it is not the only 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] L 0 —The length of the standard rectangular unit in the direction perpendicular to the water flow; B—the unit is m, the length of the standard rectangular unit in the direction of water flow, commonly used is 20m.

[0052] S2: According to the unit division results obtained in step S1, the riverbed topographic surface is divided according to each sinking projection, 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 k of the surface development area to the surface vertical projection area. 1 , the ratio of the surface standard deviation to the equivalent side length a k 2 , the ratio k of the maximum deviation value of a point on the surface to the equivalent side length a 3 .

[0053] On the ratio k of the terrain surface development area to the surface vertical projection area 1 In actual operation, the projection area and three-dimensional area of ​​the terrain surface can be read by commercial software such as Civil3D. In theoretical analysis, the three-dimensional area, that is, the surface expansion area, is obtained by dividing the triangular mesh.

[0054] The distance between the points on the terrain surface and the projection surface is counted. 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 drainage structure material parameters, calculate the reduction rate ψ of the actual coverage projection area after the laying of a single drainage.

[0056] In calculating the reduction rate of the actual covered projected area after the laying of a single pile of submerged drainage, 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] r 1 —Comprehensive coefficient, determined by multiple sets of three-dimensional modeling fitting, generally taken as 0.95;

[0061] r 2—The coefficient related to the ratio of tensile force per unit area of ​​the drainage geotextile to the elastic modulus can reflect the ability of the drainage to fit the riverbed. It is generally 1.0 to 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] k 1 —The ratio of the developed area of ​​the riverbed topography surface to the projected area of ​​the surface, which reflects the geometric characteristics of the surface development;

[0063] k 2 —The ratio of the standard deviation of the riverbed topography surface to the equivalent side length a, which reflects the flatness of the riverbed topography;

[0064] k 3 —The ratio of the maximum deviation value of a point on the riverbed topographic 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 water flow direction. 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 water flow direction. G is the horizontal unfolding contour line of the first sinking row.

[0067] Determine the overlapping length b of adjacent sinkers and the design length L of sinkers in the direction perpendicular to the water flow using the following calculation formula:

[0068]

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

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

[0071]

[0072] Where L 0 —Unit: m, the length of the standard rectangular unit perpendicular to the water flow direction.

[0073] Regarding the design length of the submergence drainage 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 drainage in the direction of water flow can be slightly greater than 20m.

[0074] Combine the following Figure 1 , Figure 2 and Figure 3 The present invention is 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 the present specification are only used to match the contents disclosed in the specification for understanding and reading, and are not used to limit the limiting conditions under which the present invention can be implemented, so they have no technical substantive significance. Any structural modification, change in proportion or adjustment of size should still fall within the scope of the technical contents disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0075] The invention comprises the following steps: determining the layout scheme of a single drainage block on geometric projection; dividing the riverbed topographic 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 drainage block.

[0076] In the step of calculating the reduction rate of the actual coverage area of ​​the drainage, it is necessary to calculate according to the formula based on the geometric parameters obtained from the riverbed terrain surface analysis in the previous step, taking into account the terrain flatness, drainage folds and adaptability to deformation.

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

[0078] Example:

[0079] The initial protection range of a single sinking drainage in a certain bank protection project is 20m long in the direction of water flow and 50m long in the direction perpendicular to water flow. The riverbed topographic surface is cut according to this projection area, and the cut topographic 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. According to step S4, the overlap length b is calculated to be 2.99m, and the length of the drainage in the direction perpendicular to the water flow 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 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 pose a safety hazard.

[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 familiar with 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still 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 used to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions recorded in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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 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 revetment during implementation; S2: Segment the riverbed topographic surface according to the rectangular units obtained in step S1, and analyze the geometric parameters of the riverbed topographic surface in each unit, wherein the geometric parameters of the riverbed topographic surface include the ratio k1 of the surface development 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; S3: Based on the riverbed topographic surface parameters within the protection range obtained in step S2 and in combination with the drainage structure material parameters, calculate the reduction rate ψ of the actual covered projection area after the single drainage is laid; S4: According to 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.

2. A quantitative design method for sinking arrangement according to claim 1, characterized in that: The calculation method of the equivalent side length a in step S2 is: in: a—equivalent length of the standard rectangular unit projection surface; L0—the length of the standard rectangular unit perpendicular to the water flow direction; B—The length of the standard rectangular unit in the direction of water flow.

3. The quantitative design method of sinking arrangement according to claim 1 is 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: according to the coordinate values ​​of the measured points on the segmented riverbed terrain surface, a plane is fitted using the least squares method as the projection base of the terrain surface, and the distance between the points on the terrain surface and the projection surface is counted. The standard deviation of the statistical value is the surface standard deviation, and the maximum value of the statistical value is the maximum deviation.

4. The quantitative design method of sinking arrangement according to claim 1 is characterized by: The calculation method of the reduction rate ψ in step S3 is: in: ψ—reduction rate of actual coverage projection area after single-block laying; r1—comprehensive coefficient, determined by multiple sets of three-dimensional modeling fitting; r2—coefficient related to the ratio of tensile and elastic modulus per unit area of ​​geotextile; k1—the ratio of the developed area of ​​the riverbed topography surface to the projected area of ​​the surface; k2—ratio of the standard deviation of the riverbed topography surface to the equivalent side length; k3—The ratio of the maximum deviation value of a point on the riverbed terrain surface to the equivalent side length.

5. The quantitative design method of sinking arrangement according to claim 1 is characterized in that: The calculation method of the design overlap length b of adjacent sinking rows along the water flow direction in step S4 is: Where B is the length of a single sink in the direction of water flow; ψ—The reduction rate of the actual coverage projection area after laying of a single piece of sedimentation drainage.

6. The quantitative design method of sinking arrangement according to claim 1 is characterized in that: The calculation method of the design length L of the sinking row perpendicular to the water flow direction in step S4 is: Where L0 is the projection length of a single sink vertical to the water flow direction; ψ—The reduction rate of the actual coverage projection area after laying of a single piece of sedimentation drainage.

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