Design method of face rockfill dam with folded line crest

Abstract

The application discloses a design method of a face rockfill dam with a folded-line dam top, and the face rockfill dam comprises a dam body; the top elevation of the dam body at different sections is the sum of the static water level in normal use and the reserved settlement amount; the upstream face panel slope of the dam body is unique and fixed; and the front edge of the upstream face panel and the bottom plate of the wave protection wall intersect with each other in a folded line; when the design is performed, ① the dam top road center line is designed according to the reserved settlement amount of the dam top and the face panel slope; ② a folded-line wave protection wall and dam top road model is established; ③ an upstream face panel overall model is established; and ④ a face panel model is established according to the wave protection wall bottom plate surface, and the face rockfill dam with the folded-line dam top is constructed. The wave protection wall bottom plate and the dam top road are ingeniously arranged into the folded-line structure which is not collinear with the dam axis, the face panel top elevation and the reserved settlement amount can meet the design requirements, the face panel is prevented from being folded, the stability of the overall dam structure is improved, and the purposes of reducing the construction difficulty, reducing the dam filling amount and saving the engineering investment are achieved.

Description

Technical Field

[0001] This invention relates to the field of rockfill dam construction technology, and in particular to a design method for a face rockfill dam with a zigzag dam crest. Background Technology

[0002] Faced rockfill dams have been widely used in water conservancy and hydropower projects due to their good economic efficiency and practicality. The design of faced rockfill dams typically requires consideration of allowances for deformation. The allowance for deformation is greatest in the middle of the riverbed, and decreases progressively along the dam axis on the bank slopes. According to specifications, the elevation of the face crest of a faced dam is determined based on the normal operating static water level and the allowable settlement of the dam. The face crest elevation should be greater than the normal operating static water level plus the allowable settlement of the dam.

[0003] To ensure that the top elevation of the face panel of a rockfill dam meets the specifications, two methods are commonly used in the design: Method 1: The top elevation of the face panel is uniformly determined by the normal operating static water level plus the maximum allowable settlement at the riverbed location. The elevation of the bottom plate of the wave wall is uniform, and the centerline of the dam crest road is parallel to the dam axis. The roadbed of the dam crest road is designed according to the longitudinal slope of the allowable settlement. This method usually results in a large dam fill section and increased investment. Method 2: The top elevation of the face panel for different sections is determined separately by the normal operating static water level plus the allowable settlement at the corresponding section location. The elevation of the bottom plate of wave wall a varies according to the allowable settlement changes in the longitudinal section of the dam axis. The centerline of the dam crest road b is also parallel / coincides with the dam centerline. However, the face panel needs to be sloped to accommodate the different allowable settlement amounts for different sections of the dam crest (see...). Figure 1 , 2 This method is extremely difficult to design and construct because it uses a folded panel (with a folded panel line c). Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a design method for a face-supported rockfill dam with a zigzag crest that is structurally stable, low-cost, and easy to construct. Specifically, the following technical solution can be adopted: The design method for a face-panel rockfill dam with a polygonal dam crest described in this invention, wherein, The face rockfill dam with a zigzag dam crest includes a dam body. The elevation of the face crest of different sections of the dam body is the sum of the static water level at normal operation and the reserved settlement. The slope of the upstream face of the dam body is unique and fixed. The leading edge of the upstream face intersects the bottom plate of the wave wall with a zigzag line. The design method for the panel rockfill dam is based on CATIA 3D design software and includes the following steps: 1) Design the centerline of the road on the dam crest based on the allowable settlement on the dam crest and the slope of the dam face: The riverbed is divided into sections. The maximum allowable settlement deformation in the middle CD section is Δy. The allowable settlement deformation in the AC and DB sections on both sides of the river gradually decreases until the allowable settlement deformation at the control points A and B of the dam axis on both sides is 0. The horizontal distance Δx corresponding to the maximum reserved settlement deformation Δy is calculated based on the slope of the upstream panel, where Δx = 1.4 * Δy; Establish a local xy coordinate system with the boundary point C between the riverbed and the left bank slope as the origin, and draw a point (Δx, Δy) in the xy plane as point E; Establish a local xy coordinate system with the boundary point D between the riverbed and the right bank slope as the origin, and draw a point (Δx, Δy) as point F in the xy plane; The spatial broken line formed by connecting AEB with a straight line is the centerline of the road on the dam crest. 2) Establish a model of the polygonal wave wall and the road on the dam crest: Establish a local xy coordinate system with the left bank control point A of the dam axis as the origin, and construct a cross-sectional view of the wave wall and the road on the dam crest in the xy plane; The wave wall profile and the dam crest road profile were scanned along the centerline of the dam crest road to form a polygonal wave wall and dam crest road model. 3) Establish an overall model of the upstream panel: A local xy coordinate system is established with the left bank control point A of the dam axis as the origin. An upstream panel profile is established in the xy plane, and the upstream panel profile satisfies the following three conditions: ① The thickness of the upstream panel gradually increases from the top to the bottom, and its thickness is determined according to t=0.3+0.0035H, where t is the panel thickness and H is the vertical distance from the calculated section to the top of the panel; ②The elevation of the top of the upstream panel is equal to the normal water level elevation plus the maximum value of the reserved settlement deformation Δy; ③The slope of the upstream face dam is unique and fixed; The upstream panel profile is stretched along the dam axis AB, and then trimmed using a toe plate to form the overall model of the upstream panel; 4) Construct a panel model based on the bottom slab of the wave wall, and build a rockfill dam with a polygonal dam crest: Extract the front surface of the bottom plate of the breakwater wall, trim the overall model of the upstream panel, and the top of the upstream panel follows the breakwater wall in a zigzag pattern to obtain a rockfill dam with a zigzag dam top.

[0005] The centerline of the road on the top of the dam body is set parallel to the front edge of the bottom plate of the wave wall.

[0006] The design method of the rockfill dam with a face panel and a zigzag dam crest provided by this invention cleverly sets the bottom plate of the wave wall and the road on the dam crest as a zigzag structure that is not collinear with the dam axis. This ensures that the elevation of the face panel and the reserved settlement meet the design requirements, while avoiding the appearance of zigzag slopes in the face panel. This increases the stability of the overall dam structure and achieves the goals of reducing construction difficulty, reducing dam fill volume, and saving project investment. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of an existing rockfill dam.

[0008] Figure 2 yes Figure 1 KK cross-section diagram.

[0009] Figure 3 This is a schematic diagram of the structure of the rockfill dam with a face panel and a broken dam crest in this invention.

[0010] Figure 4 yes Figure 3 NN cross-section diagram.

[0011] Figure 5 This is a schematic diagram of the design of the centerline of the road on the dam crest in this embodiment.

[0012] Figure 6 This is a design model diagram of the wave wall, dam crest road, and upstream panel in this embodiment. Detailed Implementation

[0013] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the scope of protection of the present invention is not limited to the following embodiments.

[0014] like Figure 3-6 As shown, the design method for a face-panel rockfill dam with a zigzag crest according to the present invention is applicable to face-panel rockfill dams with a zigzag crest, comprising a dam body. The elevation of the face-panel crest of different sections of the dam body is the sum of the static water level at normal operation and the reserved settlement. The slope of the upstream face-panel 1 of the dam body is unique and fixed (in this embodiment, the slope of the upstream face-panel 1 is 1:1.4). The upstream face-panel 1 intersects the leading edge of the bottom plate of the wave wall 2 with a zigzag line. The centerline 3 of the dam crest road of the above-mentioned dam body is set parallel to the leading edge of the bottom plate of the wave wall 2, and neither of them is collinear with the dam axis 4.

[0015] The design method for a face-panel rockfill dam with a polygonal dam crest described in this invention can be used for model design using CATIA 3D design software. The specific steps are as follows: 1) Design the centerline of the road on the dam crest based on the allowable settlement deformation and the slope of the dam face: The riverbed is divided into sections. The maximum allowable settlement deformation in the middle CD section is Δy. The allowable settlement deformation in the AC and DB sections on both sides of the river gradually decreases until the allowable settlement deformation at the control points A and B of the dam axis on both sides is 0. The horizontal distance Δx corresponding to the maximum reserved settlement deformation Δy is calculated based on the slope i of the upstream panel 1 (1:1.4 in this embodiment), where Δx = 1.4 * Δy; Establish a local xy coordinate system with the boundary point C between the riverbed and the left bank slope as the origin, and draw a point (Δx, Δy) in the xy plane as point E; Establish a local xy coordinate system with the boundary point D between the riverbed and the right bank slope as the origin, and draw a point (Δx, Δy) as point F in the xy plane; Connecting AEB with straight lines to form a spatial polygonal line is the centerline of the dam crest road (see [reference]). Figure 5 ).

[0016] 2) Establish a model of the polygonal wave wall and the road on the dam crest: Establish a local xy coordinate system with the left bank control point A of the dam axis as the origin, and establish the wave wall 2 and the dam crest road profile in the xy plane; By sweeping the cross-sections of the wave wall 2 and the dam crest road along the centerline 3 of the dam crest road, a polygonal model of the wave wall 2 and the dam crest road is formed (see...). Figure 6 ).

[0017] 3) Establish an overall model of the upstream panel: A local xy coordinate system is established with the left bank control point A of the dam axis as the origin. An upstream panel 1 profile is established in the xy plane. The upstream panel 1 profile satisfies the following three conditions: ① The thickness of the upstream panel 1 gradually increases from the top to the bottom, and its thickness is determined according to t=0.3+0.0035H, where t is the panel thickness and H is the vertical distance from the calculated section to the top of the panel; ②The elevation of the top of the upstream panel 1 is equal to the normal water level elevation plus the maximum value of the reserved settlement deformation Δy; ③The slope of the upstream panel 1 is unique and fixed (in this embodiment, the slope of the upstream panel 1 is 1:1.4). The upstream panel 1 section was stretched along the dam axis AB, and then trimmed using toe plate 5 to form the overall model of the upstream panel 1 (see...). Figure 6 ).

[0018] 4) Construct a panel model based on the bottom slab of the wave wall, and build a rockfill dam with a polygonal dam crest: Extract the front surface of the bottom plate of the breakwater wall 2, trim the overall model of the upstream panel 1, and the top of the upstream panel 1 follows the breakwater wall 2 in a zigzag pattern to obtain a zigzag-shaped panel rockfill dam.

[0019] It should be noted that in the description of this invention, terms such as "front," "rear," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

Claims

1. A design method for a face-panel rockfill dam with a polygonal dam crest, characterized in that: The face rockfill dam with a zigzag dam crest includes a dam body. The elevation of the face crest of different sections of the dam body is the sum of the static water level at normal operation and the reserved settlement. The slope of the upstream face of the dam body is unique and fixed. The leading edge of the upstream face intersects the bottom plate of the wave wall with a zigzag line. The design method for the panel rockfill dam is based on CATIA 3D design software and includes the following steps: 1) Design the centerline of the road on the dam crest based on the allowable settlement on the dam crest and the slope of the dam face: The riverbed is divided into sections. The maximum allowable settlement deformation in the middle CD section is Δy. The allowable settlement deformation in the AC and DB sections on both sides of the river gradually decreases until the allowable settlement deformation at the control points A and B of the dam axis on both sides is 0. The horizontal distance Δx corresponding to the maximum reserved settlement deformation Δy is calculated based on the slope of the upstream panel, where Δx = 1.4 * Δy; Establish a local xy coordinate system with the boundary point C between the riverbed and the left bank slope as the origin, and draw a point (Δx, Δy) in the xy plane as point E; Establish a local xy coordinate system with the boundary point D between the riverbed and the right bank slope as the origin, and draw a point (Δx, Δy) as point F in the xy plane; The spatial broken line formed by connecting AEB with a straight line is the centerline of the road on the dam crest. 2) Establish a model of the polygonal wave wall and the road on the dam crest: Establish a local xy coordinate system with the left bank control point A of the dam axis as the origin, and construct a cross-sectional view of the wave wall and the road on the dam crest in the xy plane; The wave wall profile and the dam crest road profile were scanned along the centerline of the dam crest road to form a polygonal wave wall and dam crest road model. 3) Establish an overall model of the upstream panel: A local xy coordinate system is established with the left bank control point A of the dam axis as the origin. An upstream panel profile is established in the xy plane, and the upstream panel profile satisfies the following three conditions: ① The thickness of the upstream panel gradually increases from the top to the bottom, and its thickness is determined according to t=0.3+0.0035H, where t is the panel thickness and H is the vertical distance from the calculated section to the top of the panel; ②The elevation of the top of the upstream panel is equal to the normal water level elevation plus the maximum value of the reserved settlement deformation Δy; ③The slope of the upstream face dam is unique and fixed; The upstream panel profile is stretched along the dam axis AB, and then trimmed using a toe plate to form the overall model of the upstream panel; 4) Construct a panel model based on the bottom slab of the wave wall, and build a rockfill dam with a polygonal dam crest: Extract the front surface of the bottom plate of the breakwater wall, trim the overall model of the upstream panel, and the top of the upstream panel follows the breakwater wall in a zigzag pattern to obtain a rockfill dam with a zigzag dam top.

2. The design method for a face-supported rockfill dam with a broken-line crest according to claim 1, characterized in that: The centerline of the road on the top of the dam body is set parallel to the front edge of the bottom plate of the wave wall.

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