Fabricated two-way prestress gravity overflow dam and construction technology thereof

Abstract

The invention relates to the technical field of overflow dams in water conservancy and hydropower engineering, in particular to an assembly type bidirectional prestress gravity overflow dam and a construction technology thereof. The overflow dam comprises a bottom plate, a dam core prefabricated structure, a dam face prefabricated structure and a dam heel upstream face structure, the dam face prefabricated structure comprises an overflow panel and a prefabricated support, and the overflow panel is divided into an arc section, a linear section and a reverse arc section; the arc line section is arranged on the top face and the downstream face of the dam core prefabricated structure, and the straight line section is connected with the lower end of the arc line section and arranged on the downstream face of the dam core prefabricated structure. The reverse arc section is connected with the lower end of the linear section and arranged on the downstream face of the dam core prefabricated structure. The prefabricated supports are arranged above the two sides of the dam core prefabricated structure and located on the edges of the two sides of the lower surface of the overflow panel. The curve line type of the dam face can be guaranteed, the dam face construction difficulty is lowered, and the appearance quality of the gravity overflow dam is guaranteed; and construction is facilitated, and the construction period is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of overflow dams in water conservancy and hydropower projects, and in particular to an assembled bidirectional prestressed gravity overflow dam and a construction process thereof. Background Art

[0002] Gravity overflow dams are water discharge structures that can both block water and overflow through the dam top. They are mainly responsible for flood discharge and dam protection, water supply, sand removal, reservoir emptying, construction diversion and other tasks. Therefore, gravity overflow dams need to meet strength stability conditions and also meet flood discharge requirements. Gravity overflow dams are large-volume concrete structures. Their traditional construction process is to use cast-in-place concrete methods to build them, install steel bars, formwork and pour concrete on site, and the overflow surface formwork uses drawing, buckling and flipping forms. Since cement emits a large amount of hydration heat during the hydration process, there is a large temperature difference between the inside and outside of the dam body. Therefore, there is a high risk of cracks inside and outside the dam body due to temperature stress. In addition, the installation and reinforcement procedures of the dam body formwork are complicated, and the construction of large-volume overflow dams is time-consuming and labor-intensive. It is difficult to finish the overflow surface, the curve line shape of the dam surface is difficult to guarantee, the appearance quality is poor, and secondary repair is required.

[0003] Prior art CN110468795A discloses an assembled concrete gravity dam based on a superimposed structure and a construction method thereof, wherein the dam body is mainly cast by superimposed structure concrete, and the upstream concrete panel and the downstream concrete panel are cast on the upstream and downstream sides of the dam body; the plain concrete cushion is laid on the dam foundation, and the superimposed structure concrete is built on the plain concrete cushion. The superimposed structure concrete is composed of precast concrete components and post-cast concrete in the precast concrete components, wherein the post-cast concrete is connected to each other to form a space frame structure system, thereby enhancing the stability of the dam body. The gravity dam can make full use of the advantages of reliable quality of precast concrete components, can reduce temperature cracks in the dam body, and have high construction efficiency; at the same time, due to the space frame structure system formed by the post-cast concrete, the integrity and stability of the dam body can be improved, thereby ensuring the safety of the dam body.

[0004] However, the overflow surface of the gravity dam's crest is still cast in place, which makes finishing difficult and the dam surface curve difficult to guarantee.

[0005] Therefore, it is necessary to provide an assembled bidirectional prestressed gravity overflow dam and its construction process. Summary of the invention

[0006] In order to solve the above technical problems existing in the prior art, the present invention provides an assembled bidirectional prestressed gravity overflow dam and a construction process thereof.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] On the one hand, the present invention provides an assembled bidirectional prestressed gravity overflow dam, comprising a bottom plate, a dam core prefabricated structure, a dam surface prefabricated structure and a dam heel water-facing surface structure, wherein the dam core prefabricated structure is arranged on the bottom plate, the dam surface prefabricated structure is arranged on the top surface and the back surface of the dam core prefabricated structure, and the dam heel water-facing surface structure is arranged on the water-facing surface of the dam core prefabricated structure; the bottom plate is a cast-in-place structure, and the dam core prefabricated structure and the dam surface prefabricated structure are both structures that are cast-in-place and solidified on the basis of the prefabricated structure; The prefabricated structure of the dam surface includes an overflow panel and a prefabricated support. The overflow panel is divided into an arc segment, a straight segment and an inverse arc segment. The arc segment is arranged on the top surface and the back water surface of the dam core prefabricated structure. The straight segment is connected to the lower end of the arc segment and is arranged on the back water surface of the dam core prefabricated structure. The inverse arc segment is connected to the lower end of the straight segment and is arranged on the back water surface of the dam core prefabricated structure. The prefabricated support is arranged above both sides of the dam core prefabricated structure and is located at both side edges of the lower surface of the overflow panel.

[0009] Furthermore, an anti-slip protrusion is provided on the lower surface of the overflow panel, and an anti-slip groove is provided on the upper surface of the prefabricated support, and the anti-slip protrusion is embedded in the anti-slip groove.

[0010] Furthermore, the anti-slip protrusion is a trapezoidal structure, and the connection surface area between the anti-slip protrusion and the lower surface of the overflow panel is larger than the lower surface area of ​​the anti-slip protrusion.

[0011] Furthermore, the arc segment includes a plurality of arc panels, and a positioning protrusion is provided on the lower end surface of the arc panel;

[0012] The straight line segment includes a plurality of straight line panels, the upper end surface of the straight line panel is provided with a positioning groove, and the lower end surface of the straight line panel is provided with a positioning protrusion;

[0013] The anti-arc section includes a plurality of anti-arc panels, and the upper end surface of the anti-arc panel is provided with a positioning groove;

[0014] The positioning protrusion on the lower end surface of the arc panel is embedded in the positioning groove on the upper end surface of the straight segment, and the positioning protrusion on the lower end surface of the straight segment is embedded in the positioning groove on the upper end surface of the reverse arc panel.

[0015] Furthermore, a positioning groove is provided on one side of the curved panel, and a positioning protrusion is provided on the other side of the curved panel;

[0016] And / or, a positioning groove is provided on one side of the linear panel, and a positioning protrusion is provided on the other side of the linear panel;

[0017] And / or, a positioning groove is provided on one side of the reverse arc panel, and a positioning protrusion is provided on the other side of the reverse arc panel.

[0018] Furthermore, the bottom plate includes a base, a plurality of rows of foundation blocks are arranged above the base, a reverse arc foundation block is arranged at the toe end of the base, a dam core prefabricated structure is arranged above the foundation block, and the reverse arc segment is arranged above the reverse arc foundation block.

[0019] Furthermore, an anti-slip tenon is provided on the lower surface of the base plate.

[0020] Furthermore, one side surface of the anti-slip tenon is an inclined surface, and the other side surface is a vertical surface.

[0021] Furthermore, the dam core prefabricated structure includes A-type blocks, A2-type blocks, B-type blocks, B2-type blocks, and C-type blocks, wherein the A-type blocks and A2-type blocks are all cubes, and the B-type blocks, B2-type blocks, and C-type blocks are all cuboids;

[0022] From the backwater surface to the frontwater surface, a row of C-shaped blocks is arranged above the first row of foundation blocks;

[0023] A-type blocks and B-type blocks are set above the second to last rows of foundation blocks, with the requirement that there are no through seams on the horizontal and vertical surfaces of the dam core prefabricated structure;

[0024] A2 blocks and B2 blocks are set on the top surfaces of the second to last rows of foundation blocks, with the requirement that there are no through seams on the stepped top surface of the dam core prefabricated structure.

[0025] Furthermore, vertical threaded steel bars are arranged inside the prefabricated structure of the dam core above the second to last rows of foundation blocks, and the lower ends of the threaded steel bars are buried inside the foundation blocks.

[0026] Furthermore, a positioning groove is arranged on the upper surface of the base block, and positioning protrusions are arranged on the lower surfaces of the A-type block, A2-type block, B-type block, B2-type block and C-type block, and the positioning protrusions are embedded in the positioning grooves.

[0027] Furthermore, the positioning groove is a rectangular groove, and the side wall of the rectangular groove is an inclined surface.

[0028] Furthermore, cross keyways are provided on the left and right sides of the A-type block, positioning grooves are provided on the upper surface of the A-type block, vertical prestressed channels and transverse prestressed channels are provided inside the A-type block, and transverse grouting holes are provided inside the A-type block, the grouting holes penetrate the A-type block and are connected to the vertical prestressed channels.

[0029] Furthermore, an anchor pit is arranged on the outer side of the A-type block located at the edge of the prefabricated structure of the dam core, and the anchor pit is concentric with the transverse prestressed channel of the A-type block; an anchor pad is arranged in the anchor pit.

[0030] Furthermore, cross keyways are arranged on the left and right sides of the A2 block, vertical prestressed channels and transverse prestressed channels are arranged inside the A2 block, and transverse grouting holes are arranged inside the A2 block, the grouting holes penetrate the A2 block and are connected to the vertical prestressed channels; an anchor pit is arranged on the upper surface of the A2 block, and the anchor pit is concentric with the A2 vertical prestressed channel.

[0031] Furthermore, double cross keyways are provided on the left and right sides of the B-type block, a positioning groove is provided on the upper surface of the B-type block, vertical prestressed channels and transverse prestressed channels are provided inside the B-type block, and transverse grouting holes are provided inside the B-type block, the grouting holes penetrate the B-type block and are connected to the vertical prestressed channels.

[0032] Furthermore, an anchor pit is arranged on the outer side of the B-type block located at the edge of the prefabricated structure of the dam core, and the anchor pit is concentric with the transverse prestressed channel of the B-type block; an anchor pad is arranged in the anchor pit.

[0033] Furthermore, double cross keyways are provided on the left and right sides of the B2 block, vertical prestressed channels and transverse prestressed channels are provided inside the B2 block, and transverse grouting holes are provided inside the B2 block, the grouting holes penetrate the B2 block and are connected to the vertical prestressed channels; an anchor pit is provided on the upper surface of the B2 block, and the anchor pit is concentric with the vertical prestressed channel of the B2 type; an anchor pad is provided in the anchor pit.

[0034] Furthermore, double cross keyways are arranged on the left and right sides of the C-shaped block, and a transverse prestressed channel is arranged inside the C-shaped block.

[0035] Furthermore, an anchor pit is arranged on the outer side of the C-shaped block located at the edge of the prefabricated structure of the dam core, and the anchor pit is concentric with the transverse prestressed channel of the C-shaped block; an anchor pad is arranged in the anchor pit.

[0036] Furthermore, threaded steel bars are arranged in the vertical prestressed channels of type A blocks, type A2 blocks, type B blocks and type B2 blocks, and steel strands are arranged in the transverse prestressed channels of type A blocks, type A2 blocks, type B blocks, type B2 blocks and type C blocks.

[0037] On the other hand, the present invention provides a construction process of an assembled bidirectional prestressed gravity overflow dam, which is used to construct the above-mentioned assembled bidirectional prestressed gravity overflow dam, and the construction process includes:

[0038] S1. Cast the base plate in situ according to the base plate structure, and embed threaded steel bars in the base plate;

[0039] S2. Install A-type blocks, A2-type blocks, B-type blocks, B2-type blocks, and C-type blocks on the bottom plate, so that the vertical prestressed holes of A-type blocks, A2-type blocks, B-type blocks, and B2-type blocks pass through the threaded steel bars;

[0040] S3. Insert steel strands in the transverse prestressed holes of the A-type blocks, A2-type blocks, B-type blocks, B2-type blocks, and C-type blocks;

[0041] S4, cutting the redundant threaded steel and steel strands, grouting from bottom to top, and pouring concrete to form the prefabricated dam core structure;

[0042] S5, install prefabricated supports and overflow panels, and pour concrete to form a prefabricated dam surface structure;

[0043] S6. Build the formwork support system for the dam heel water-facing surface and pour concrete to form the dam heel water-facing surface structure;

[0044] S7. Dismantle the formwork support system on the water-facing surface of the dam heel.

[0045] Furthermore, the dam surface of the gravity overflow dam is offset inward by 20 cm to obtain a control line. When installing type A blocks, type A2 blocks, type B blocks, type B2 blocks, and type C blocks, the top A2 blocks, type B2 blocks, and type C blocks in each row of base blocks of the dam core prefabricated structure shall not exceed the control line.

[0046] Furthermore, in step S4, redundant threaded steel bars and steel strands are cut, grouting is performed from bottom to top, and concrete is poured to form a prefabricated dam core structure; specifically, the steps include:

[0047] S41, tensioning threaded steel, and then tensioning steel strands;

[0048] S42, cutting excess rebar and stranded wire;

[0049] S43, the vertical prestressed duct is grouted from bottom to top through the grouting holes on the A-type block and the B-type block at the bottom until the grouting holes on the A2-type block and the B2-type block at the top are grouted;

[0050] S44, the transverse prestressed channel is grouted through the grouting holes on the anchor pad;

[0051] S45. After the grouting is completed, the anchor pad is sealed;

[0052] S46. Install the cast-in-place concrete formwork for the dam core and pour concrete to form the prefabricated structure of the dam core.

[0053] Furthermore, the cast-in-place concrete formwork of the dam core includes a formwork body, a fixing frame is arranged outside the formwork body, a steel pipe brace is arranged outside the fixing frame, and the steel pipe brace is arranged obliquely on the ground.

[0054] Furthermore, the concrete adopts self-compacting concrete.

[0055] Furthermore, in step S5, prefabricated supports and overflow panels are installed, and concrete is poured to form a prefabricated dam surface structure; specifically, the steps include:

[0056] S51. Install the prefabricated supports and overflow panels of the anti-arc section, and use adjustable support palms to support the upper opening;

[0057] S52, pouring the inner space of the anti-arc section, and removing the adjustable palm support after initial setting;

[0058] S53. After the concrete of the anti-arc section dam surface is finally set, the prefabricated supports and overflow panels of the straight section are installed, and the upper opening is supported by a special-shaped support;

[0059] S54, pour the inner space of the straight section, and after initial setting, remove the special-shaped support;

[0060] S55. After the concrete of the straight section dam surface is finally set, install the prefabricated supports and overflow panels of the curved section, and use special-shaped support palms to support the upper opening;

[0061] S56. Cast the inner space of the arc segment, and after initial setting, remove the special-shaped support.

[0062] Furthermore, the dam heel water-facing surface formwork support system in step S6 includes a prefabricated baffle, a prefabricated buttress and a steel pipe, wherein the prefabricated baffle includes a first prefabricated baffle and a second prefabricated baffle, and the length of the first prefabricated baffle is less than the length of the second prefabricated baffle;

[0063] A prefabricated baffle is arranged on the water-facing surface close to the prefabricated structure of the dam core, and a first prefabricated baffle and a second prefabricated baffle are alternately arranged on the prefabricated baffle so that there is no through seam on the prefabricated baffle;

[0064] A prefabricated buttress is arranged at the intersection of the outer side of a prefabricated baffle, a steel pipe is horizontally passed through the interior of the prefabricated buttress, and a plurality of horizontally passed steel pipes are connected by vertically arranged steel pipes.

[0065] Furthermore, the length of the second prefabricated baffle is twice the length of the first prefabricated baffle.

[0066] Furthermore, a slot is provided on the outer side surface of the first prefabricated baffle plate, and two slots are provided on the outer side surface of the second prefabricated baffle plate, and the prefabricated buttresses are inserted into the slots.

[0067] Furthermore, in step S6, a template support system for the water-facing surface of the dam heel is constructed, and concrete is poured to form a water-facing surface structure of the dam heel; specifically, the steps include:

[0068] S61. Install the first layer of prefabricated baffles and prefabricated buttresses on the bottom plate, insert steel pipes into the prefabricated buttresses, and set fasteners on the outer walls of the steel pipes on both sides of each prefabricated buttress;

[0069] S62, installing the second layer of prefabricated baffles and prefabricated buttresses, inserting steel pipes into the prefabricated buttresses, and setting fasteners on the outer walls of the steel pipes on both sides of each prefabricated buttress;

[0070] S63, repeat step S62 until the dam top, then install vertical steel pipes between the prefabricated buttresses, the vertical steel pipes are connected to the transverse buttresses through rotating fasteners, a bottom bracket is set at the bottom of the vertical steel pipe, and the vertical steel pipe is supported by a tossing support;

[0071] S64. Install casting formwork on both sides between one prefabricated baffle and the prefabricated structure of the dam core, and use a caster to support the casting formwork;

[0072] S65. Install the top prefabricated support and the top prefabricated overflow panel;

[0073] S66. Casting is carried out through the pouring port on the top prefabricated overflow panel.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] The assembled bidirectional prestressed gravity overflow dam and the construction process thereof provided by the present invention adopt an assembled structure as a whole. The overflow surface is assembled by overflow panels. The overflow panel is installed with a WES curve divided into arc segments, straight segments, and reverse arc segments, which can ensure the curve line shape of the dam surface, reduce the difficulty of dam surface construction, and ensure the appearance quality of the gravity overflow dam; in addition, an anti-slip protrusion is arranged under the overflow panel, which is conducive to construction and increases the stability of the dam surface structure.

[0076] The dam core of the present invention is assembled from prefabricated blocks, the surfaces of the prefabricated blocks are provided with anti-slip grooves distributed vertically and horizontally, and horizontal and vertical bidirectional prestressed channels are provided inside. Threaded steel is provided in the vertical prestressed channel, and steel strands are provided in the horizontal prestressed channel. The dam core structure after construction is stable and reliable.

[0077] The dam heel water-facing surface formwork support system of the present invention comprises prefabricated baffles and prefabricated buttresses, which are reinforced with steel pipes, fasteners and buttresses. After the construction is completed, the prefabricated baffles, prefabricated buttresses and accessories can be dismantled for recycling, thus saving construction costs.

[0078] The present invention as a whole greatly reduces the duration of processes such as template installation and reinforcement, speeds up construction progress, and reduces labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 This is a schematic diagram of the structure of the assembled gravity overflow dam provided by the present invention.

[0080] Figure 2 It is a structural schematic diagram of the base plate.

[0081] Figure 3 It is a structural schematic diagram of the positioning groove.

[0082] Figure 4 This is a schematic diagram of the structure of type A block.

[0083] Figure 5 This is a schematic diagram of the structure of the A2 type block.

[0084] Figure 6 This is a schematic diagram of the structure of the B-type block.

[0085] Figure 7 This is a schematic diagram of the structure of the B2 type block.

[0086] Figure 8 It is a structural diagram of a C-type block.

[0087] Fig. 9 This is a planar installation diagram of the prefabricated blocks in the dam core prefabricated structure after installation.

[0088] Fig.10 This is a schematic diagram of the facade installation after the prefabricated blocks in the dam core prefabricated structure are installed.

[0089] Fig.11 This is the structural schematic diagram of the dam core prefabricated structure after the first layer of prefabricated blocks are installed.

[0090] Fig.12 This is the structural schematic diagram after all prefabricated blocks of the dam core prefabricated structure are installed.

[0091] Fig.13 Schematic diagram of the prefabricated structure of the dam core after the steel strands are inserted.

[0092] Fig.14 Schematic diagram of steel strand structure.

[0093] Fig.15 This is a schematic diagram of the structure after the cast-in-place concrete formwork of the dam core is installed.

[0094] Fig.16 This is a schematic diagram of the structure after the dam core prefabricated structure is cast.

[0095] Fig.17 Schematic diagram of the dam surface WES curve and the location of the control line.

[0096] Fig.18 Schematic diagram of the overflow panel structure.

[0097] Fig.19 It is a schematic diagram of the straight panel structure.

[0098] Fig. 20 This is a schematic diagram of the prefabricated support structure.

[0099] Fig.21 This is a schematic diagram of the structure after the anti-arc section is installed.

[0100] Fig. 22 This is a schematic diagram of the structure of the adjustable palm support upper opening of the anti-arc section.

[0101] Fig.23This is a schematic diagram of the structure after the anti-arc section is cast.

[0102] Fig.24 This is a schematic diagram of the structure after the straight section is installed.

[0103] Fig.25 This is a schematic diagram of the structure of the special-shaped palm support supporting the upper opening of the straight line segment.

[0104] Fig.26 This is a schematic diagram of the structure after the straight section is cast.

[0105] Fig. 27 This is a schematic diagram of the structure after the arc segment is installed.

[0106] Fig.28 Schematic diagram of the structure of the upper opening of the arc segment supported by the special-shaped palm support.

[0107] Fig.29 This is a schematic diagram of the structure of the first prefabricated baffle.

[0108] Fig.30 This is a schematic diagram of the structure of the second prefabricated baffle.

[0109] Fig.31 This is a structural diagram of the prefabricated buttress.

[0110] Fig.32 This is a schematic diagram of the structure after the first layer of prefabricated baffles and prefabricated buttresses are installed.

[0111] Fig.33 It is a schematic diagram of the structure of the fastener in the clamped state.

[0112] Fig.34 This is a schematic diagram of the structure after the dam heel water-facing formwork support system is built.

[0113] Fig.35 for Fig.34 Enlarged view of point A in the middle.

[0114] Fig.36 for Fig.34 Enlarged view of point B in the middle.

[0115] Fig.37 This is a schematic diagram of the structure after the top prefabricated support is installed.

[0116] Fig.38 Schematic diagram of the structure of the top prefabricated overflow panel.

[0117] Fig.39 Schematic diagram of the structure after the top prefabricated overflow panel is installed.

[0118] Description of reference numerals:

[0119] 1-bottom plate, 101-base, 102-base block, 103-reverse arc base block, 104-anti-slip tenon, 105-positioning groove;

[0120] 2- dam core prefabricated structure, 201- A-type block, 202- A2-type block, 203- B-type block, 204- B2-type block, 205- C-type block, 206- threaded steel, 207- steel strand, 208- cross keyway, 209- positioning groove, 210- vertical prestressed channel, 211- transverse prestressed channel, 212- grouting hole, 213- anchor pit, 214- double cross keyway;

[0121] 3- prefabricated structure of dam surface, 301- arc panel, 302- straight panel, 303- reverse arc panel, 304- prefabricated support, 305- anti-slip protrusion, 306- anti-slip groove, 307- positioning protrusion, 308- positioning groove,

[0122] 4- Dam heel water-facing structure,

[0123] 5-formwork body, 6-fixed frame, 7-steel pipe support, 8-adjustable support, 9-special-shaped support, 10-first prefabricated baffle, 11-second prefabricated baffle, 12-prefabricated buttress, 13-steel pipe, 14-slot, 15-fastener, 16-rotating fastener, 17-bottom support, 18-support, 19-casting formwork, 20-top prefabricated support, 21-top prefabricated overflow panel, 22-casting port. DETAILED DESCRIPTION

[0124] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention, and all other embodiments obtained by ordinary technicians in the field without making creative work are within the protection scope of the present invention.

[0125] It should be noted that, unless otherwise specifically stated, the relative arrangements of components and steps, and numerical expressions set forth in these embodiments should not be construed as limiting the scope of the present invention.

[0126] The following description of the exemplary embodiments is merely illustrative and is not intended to limit the present invention and its application or use in any sense. Techniques, methods and devices known to ordinary technicians in the relevant field may not be discussed in detail here, but where applicable, these techniques, methods and devices should be considered as part of this specification.

[0127] Embodiment 1

[0128] This embodiment provides a prefabricated bidirectional prestressed gravity overflow dam, such as Figure 1As shown, it includes a bottom plate 1, a dam core prefabricated structure 2, a dam surface prefabricated structure 3 and a dam heel water-facing surface structure 4, the dam core prefabricated structure 2 is arranged on the bottom plate 1, the dam surface prefabricated structure 3 is arranged on the top surface and the back water surface of the dam core prefabricated structure 2, and the dam heel water-facing surface structure 4 is arranged on the water-facing surface of the dam core prefabricated structure 2; the bottom plate 1 is a cast-in-place structure, and the dam core prefabricated structure 2 and the dam surface prefabricated structure 3 are both structures that are cast-in-place and solidified on the basis of the prefabricated structure.

[0129] The structure of the bottom plate 1 is as follows Figure 2 As shown, the bottom plate 1 includes a base 101, a plurality of rows of base blocks 102 are arranged above the base 101, an anti-arc base block 103 is arranged at the toe end of the base 101, a dam core prefabricated structure 2 is arranged above the base block 101, and an anti-arc section of a dam surface prefabricated structure 3 is arranged above the anti-arc base block 103. An anti-slip tenon 104 is arranged on the lower surface of the bottom plate 1, and the anti-slip tenon 104 can increase the anti-slip ability of the dam body. One side of the anti-slip tenon 104 is an inclined surface, and the other side is a vertical surface.

[0130] A positioning groove 105 is disposed above each base block 102. The structure of the positioning groove 105 is as follows: Figure 3 As shown, the positioning groove 105 is a rectangular groove and the side of the groove is an inclined surface, so that the positioning groove 105 is expanded, which is conducive to the installation of the prefabricated blocks of the dam core prefabricated structure 2. A plurality of positioning grooves 105 are arranged above each base block 102, and the arrangement of the positioning grooves 105 makes each prefabricated block of the dam core prefabricated structure correspond to four positioning grooves. In other embodiments, the positioning groove 105 can also be a square groove, a circular groove, or a groove of other shapes.

[0131] The bottom plate 1 is a cast-in-place structure, and the fine-rolled threaded steel bars are pre-embedded during the casting.

[0132] The dam core prefabricated structure 2 includes a plurality of prefabricated blocks, and there are 5 types of prefabricated blocks, namely, A-type block 201, A2-type block 202, B-type block 203, B2-type block 204, and C-type block 205. The A-type block 201 and A2-type block 202 are both cubes, and the B-type block 203, B2-type block 204, and C-type block 205 are all cuboids.

[0133] like Figure 4As shown, the left and right sides of the A-type block 201 are provided with cross key slots 208, and the cross key slots 208 have a trapezoidal cross section; the upper surface of the A-type block 201 is provided with positioning slots 209, and there are 4 positioning slots 209, and the 4 positioning slots 209 are arranged in an array at the four corners of the A-type block 201. The A-type block 201 is provided with vertical prestressed channels 210 and transverse prestressed channels 211, and there are two vertical prestressed channels 210, which are distributed in the middle of the A-type block 201. There are 4 transverse prestressed channels 211, which are distributed on both sides of the vertical prestressed channels 210. And the A-type block 201 is provided with transverse grouting holes 212, which penetrate the A-type block 201 and are connected to the vertical prestressed channels 210.

[0134] like Figure 4 The A-type block 201 shown is an A-type block set at the edge of the dam core prefabricated structure 2, and an anchor pit 213 is set on its outer side. The anchor pit 213 is concentric with the transverse prestressed channel 211 of the A-type block 201, so that the transverse prestressed channel 211 has a stepped hole; an anchor pad is set in the anchor pit 213, and the anchor pad has a grouting hole for sealing the anchor. If the A-type block 201 is set inside the dam core prefabricated structure 2, and none of the four sides are exposed, then the side of the A-type block 201 may not be set with an anchor pit 213, but in this embodiment, there is no A-type block set inside the dam core prefabricated structure.

[0135] like Figure 5 As shown, a cross keyway 208 is provided on the left and right sides of the A2 block 202, and a vertical prestressed channel 210 and a transverse prestressed channel 211 are provided inside the A2 block 202. The vertical prestressed channel 210 and the transverse prestressed channel 211 of the A2 block 202 are provided in the same position and quantity as those of the A block 201. A transverse grouting hole 212 is provided inside the A2 block 202, and the grouting hole 212 passes through the A2 block 202 and is connected to the vertical prestressed channel 210; an anchor pit 213 is provided on the upper surface of the A2 block 202, and the anchor pit 213 is concentric with the vertical prestressed channel 210 of the A2 block 202. Usually, the A2 block 202 is provided at the top of the dam core prefabricated structure 2. In addition, the outer dimensions of the A2 block 202 are the same as those of the A block 201.

[0136] like Figure 6As shown, the left and right sides of the B-type block 203 are provided with double cross keyways 214, which are formed by connecting two cross keyways; the upper surface of the B-type block 203 is provided with positioning grooves 209, and there are 8 positioning grooves 209. The vertical prestressed channel 210 and the transverse prestressed channel 211 are provided inside the B-type block 203, and the transverse grouting holes 212 are provided inside the B-type block 203, and the grouting holes 212 penetrate the B-type block 203 and are connected to the vertical prestressed channel 210. The length of the B-type block 203 is greater than that of the A-type block 201. In this embodiment, the length of the B-type block 203 is twice the length of the A-type block 201, which is convenient for design and installation. Therefore, the position of the positioning groove 209 on the B-type block 203 can correspond to that of the A-type block 201.

[0137] In addition, an anchor pit 213 is arranged on the outer side of the B-type block 203 located at the edge of the dam core prefabricated structure 2, and the anchor pit 213 is concentric with the transverse prestressed channel 211 of the B-type block 203; an anchor pad is arranged in the anchor pit 213, and a grouting hole is arranged on the anchor pad for sealing the anchor. The B-type block 203 located inside the dam core prefabricated structure is not exposed, so the anchor pit 213 is not arranged on its outer side.

[0138] like Figure 7 The B2 block 204 is shown. The B2 block 204 has the same external dimensions as the B block 203. The left and right sides of the B2 block 204 are provided with double cross keyways 214, which are formed by connecting two cross keyways. The B2 block 204 is provided with a vertical prestressed channel 210 and a transverse prestressed channel 211, and the B2 block 204 is provided with a transverse grouting hole 212, which penetrates the B2 block 204 and is connected to the vertical prestressed channel 210. The upper surface of the B2 block 204 is provided with an anchor pit 213, which is concentric with the vertical prestressed channel 210 of the B2 block 204. An anchor pad is provided in the anchor pit 213, and a grouting hole is provided on the anchor pad for sealing the anchor. Usually, the B2 block 204 is arranged at the top of the dam core prefabricated structure 2.

[0139] like Figure 8 As shown, the left and right sides of the C-shaped block 205 are provided with double cross keyways 214, and the C-shaped block 205 is provided with a transverse prestressed channel 211. In addition, an anchor pit 213 is provided on the outer side of the C-shaped block 205 located at the edge of the dam core prefabricated structure, and the anchor pit 213 is concentric with the transverse prestressed channel 211 of the C-shaped block 205; an anchor pad is provided in the anchor pit 213. The outer side of the C-shaped block 205 located inside the dam core prefabricated structure is not provided with an anchor pit 213.

[0140] like Fig. 9 and Fig.10As shown, from the backwater side to the frontwater side, a row of C-shaped blocks 205 is arranged above the first row of foundation blocks 102. The dam surface prefabricated structure 3 is arranged above this row of C-shaped blocks 205;

[0141] A-type blocks 201 and B-type blocks 203 are arranged above the second to last row of foundation blocks, on the basis that there are no through seams on the horizontal and vertical surfaces of the dam core prefabricated structure 2; A2-type blocks 202 and B2-type blocks 204 are arranged on the top surfaces of the second to last row of foundation blocks, on the basis that there are no through seams on the stepped top surfaces of the dam core prefabricated structure 2.

[0142] In this embodiment, the arrangement order from the second row to the last row is:

[0143] The second row, the first layer: A-type block 201, B-type block 203, B-type block 203, B-type block 203, B-type block 203, A-type block 201;

[0144] The first layer of the third row: B-type block 203, B-type block 203, B-type block 203, B-type block 203, B-type block 203, B-type block 203;

[0145] The first layer of the fourth row is the same as the first layer of the second row, the first layer of the fifth row is the same as the first layer of the third row, and then alternately repeat until the first layer of the last row: A-type block 201, B-type block 203, B-type block 203, B-type block 203, B-type block 203, A-type block 201; such an arrangement ensures that there is no through seam on the horizontal surface of the dam core prefabricated structure, such as Fig.11 shown.

[0146] Then the second row, second layer: B-type block 203, B-type block 203, B-type block 203, B-type block 203, B-type block 203, B-type block 203;

[0147] The second layer of the third row: A-type block 201, B-type block 203, B-type block 203, B-type block 203, B-type block 203, A-type block 201;

[0148] The second layer of the fourth row is the same as the second layer of the second row, the second layer of the fifth row is the same as the second layer of the third row, and then it is repeated alternately until the second layer of the last row: B-type block 203, B-type block 203, B-type block 203, B-type block 203, B-type block 203, B-type block 203; this arrangement ensures that there are no through seams on the vertical surface (elevation) of the dam core prefabricated structure.

[0149] Until the top surface of the second to last row of foundation blocks is provided with A2 type blocks 202 and B2 type blocks 204, the top surface of the stepped prefabricated structure of the dam core shall be free of through seams. Fig.12 shown.

[0150] The lower surfaces of the A-type blocks 201, A2-type blocks 202, B-type blocks 203, B2-type blocks 204, and C-type blocks 205 are all provided with positioning protrusions, the positioning protrusions of the upper prefabricated blocks are embedded in the positioning grooves 209 of the lower prefabricated blocks, and the positioning protrusions of the lowermost prefabricated blocks are embedded in the positioning grooves 105 above the base blocks. The vertical prestressed channels 210 of the A-type blocks 201, A2-type blocks 202, B-type blocks 203, and B2-type blocks 204 are all provided with threaded steel bars 206, and the bottom of the threaded steel bars 206 is embedded in the base blocks 102; the transverse prestressed channels 211 of the A-type blocks 201, A2-type blocks 202, B-type blocks 203, B2-type blocks 204, and C-type blocks 205 are all provided with steel strands 207. The threaded steel bars 206 and the steel strands 207 form a vertical and transverse bidirectional reinforcement structure to enhance the stability of the dam body.

[0151] The dam surface prefabricated structure 3 includes an overflow panel and a prefabricated support 304. Fig.18 As shown, the overflow panel is divided into an arc segment, a straight segment and an inverse arc segment; the arc segment is arranged on the top surface and the back water surface of the dam core prefabricated structure, the straight segment is connected to the lower end of the arc segment, and is arranged on the back water surface of the dam core prefabricated structure 2; the inverse arc segment is connected to the lower end of the straight segment, and is arranged on the back water surface of the dam core prefabricated structure 2; the prefabricated support 304 is arranged above both sides of the dam core prefabricated structure 2, and is located at the two side edges of the lower surface of the overflow panel.

[0152] The lower surface of the overflow panel is provided with anti-slip protrusions 305, such as Fig. 20 As shown, the upper surface of the prefabricated support 304 is provided with an anti-slip groove 306, and the anti-slip protrusion 305 is embedded in the anti-slip groove 306. The anti-slip protrusion 305 is a trapezoidal structure, that is, the connecting surface area of ​​the anti-slip protrusion 305 and the lower surface of the overflow panel is larger than the lower surface area of ​​the anti-slip protrusion 305.

[0153] The arc segment includes a plurality of arc panels 301, and a positioning protrusion 307 is provided on the lower end surface of the arc panel 301; Fig.19 As shown, the straight section includes a plurality of straight panels 302, the upper end surface of the straight panel 302 is provided with a positioning groove 308, and the lower end surface of the straight panel 302 is provided with a positioning protrusion 307; the reverse arc section includes a plurality of reverse arc panels 303, and the upper end surface of the reverse arc panel 303 is provided with a positioning groove 308;

[0154] The positioning protrusion 307 on the lower end surface of the curved panel 301 is embedded in the positioning groove 308 on the upper end surface of the straight segment, and the positioning protrusion 307 on the lower end surface of the straight segment is embedded in the positioning groove 308 on the upper end surface of the reverse arc panel. The positioning groove 308 is provided on one side of the curved panel 301, and the positioning protrusion 307 is provided on the other side of the curved panel 301; and / or, the positioning groove 308 is provided on one side of the straight panel 303, and the positioning protrusion 307 is provided on the other side of the straight panel 302; and / or, the positioning groove 308 is provided on one side of the reverse arc panel 303, and the positioning protrusion 307 is provided on the other side of the reverse arc panel 303.

[0155] In this embodiment, positioning grooves 308 and positioning protrusions 307 are provided on the sides of the curved panel 301 , the straight panel 302 , and the reverse curved panel 303 , and the positioning grooves 308 and positioning protrusions 307 are used to connect multiple panels.

[0156] Embodiment 2

[0157] This embodiment provides a construction process of an assembled bidirectional prestressed gravity overflow dam, which is used to construct the assembled bidirectional prestressed gravity overflow dam provided in Example 1. The construction process includes:

[0158] S1, cast the bottom plate 1 in situ according to the bottom plate structure, and embed threaded steel bar 206 on the bottom plate 1, such as Figure 2 As shown;

[0159] S2, installing A-type block 201, A2-type block 202, B-type block 203, B2-type block 204, and C-type block 205 on the bottom plate, so that the vertical prestressed channels 210 of A-type block 201, A2-type block 202, B-type block 203, and B2-type block 204 pass through the threaded steel bar 206;

[0160] The dam surface of the gravity overflow dam adopts the WES curve. In order to ensure that at least a 20cm thick cast-in-place anti-seepage layer is formed between the dam core prefabricated structure and the dam surface, the dam surface of the gravity overflow dam is offset 20cm inward to obtain a control line, such as Fig.17 As shown, when installing A-type blocks 201, A2-type blocks 202, B-type blocks 203, B2-type blocks 204, and C-type blocks 205, the corners of the top A2-type blocks 202, B2-type blocks 204, and C-type blocks 205 of each row of base blocks 102 of the dam core prefabricated structure do not exceed the control line.

[0161] S3, inserting steel strands 207 in the transverse prestressed channels 211 of the A-type block 201, the A2-type block 202, the B-type block 203, the B2-type block 204, and the C-type block 205; Fig.13 As shown, each transverse prestressed channel 211 includes a plurality of steel strands, such as Fig.14shown.

[0162] S4, cutting the redundant threaded steel and steel strands, grouting from bottom to top, and pouring concrete to form the dam core prefabricated structure; specifically including:

[0163] S41, first tensioning the threaded steel bar 206, and then tensioning the steel strand 207;

[0164] S42. After tensioning is completed, use a grinding wheel to cut off excess threaded steel and stranded wire;

[0165] S43, the vertical prestressed duct 210 is grouted from bottom to top through the grouting holes 212 on the A-type block 201 and the B-type block 203 at the bottom, until the grouting holes 212 of the A2-type block 202 and the B2-type block 204 at the top are grouted;

[0166] S44, grouting the transverse prestressed channel 211 through the grouting holes on the anchor pad;

[0167] S45. After the grouting is completed, the anchor plate is sealed with mortar having the same proportion as the prefabricated block;

[0168] S46, install the cast-in-place concrete formwork for the dam core, pour concrete to form the prefabricated structure of the dam core, such as Fig.16 shown.

[0169] like Fig.15 As shown, the cast-in-place concrete formwork of the dam core includes a formwork body 5, a fixing frame 6 is arranged outside the formwork body 5, the fixing frame 6 is made of square timber, the fixing frame 6 includes a vertical square timber and a plurality of horizontal square timbers, the horizontal square timbers are connected to the formwork body 5, and a steel pipe brace 7 is arranged outside the vertical square timber, and the steel pipe brace 7 is arranged obliquely on the ground.

[0170] Among them, the concrete uses self-compacting concrete, which does not require vibration and can ensure the casting quality in narrow spaces.

[0171] S5, installing the prefabricated support 304 and the overflow panel, and pouring concrete to form the dam surface prefabricated structure; specifically including:

[0172] S51, install the prefabricated support 304 and overflow panel of the anti-arc section, and use the adjustable support 8 to support the upper opening; Fig.21 and Fig. 22 As shown, one end of the adjustable palm 8 is a steel pipe with threads inside the steel pipe, the threads inside the steel pipe are connected to the support rod, the support rod has external threads, a handle is provided on the support rod, and a palm is provided on the end surface of the support rod to support the reverse arc panel. One end of the steel pipe is supported on the prefabricated block by square wood and wedge blocks.

[0173] S52. Pour the anti-seepage self-compacting concrete on the dam surface in the inner space of the anti-arc section. After the initial setting, remove the adjustable support. Fig.23 As shown;

[0174] S53, after the concrete of the anti-arc section dam surface is finally set, the prefabricated support 304 and the overflow panel of the straight section are installed, and the upper opening is supported by a special-shaped support 9, such as Fig.24 and Fig.25 As shown, the special-shaped support palm 9 is also a steel pipe at one end, and an L-shaped plate is arranged at the lower end of the steel pipe, and the L-shaped plate is clamped on the corner of the prefabricated block; the upper end of the steel pipe is internally threaded to connect the support rod, a handle is arranged on the support rod, and a support palm is arranged on the end face of the support rod;

[0175] S54. Pour the anti-seepage self-compacting concrete on the dam surface in the inner space of the straight section. After the initial setting, remove the special-shaped support. Fig.26 As shown;

[0176] S55, after the straight section dam surface concrete is finally set, install the arc section prefabricated support 304 and the overflow panel, and use the special-shaped support 9 to support the upper opening, such as Fig. 27 and Fig.28 As shown;

[0177] S56, pouring the inner space of the arc segment, after initial setting, disassembling the special-shaped support 9.

[0178] S6. Build the formwork support system for the dam heel water-facing surface and pour concrete to form the dam heel water-facing surface structure;

[0179] The dam heel water-facing surface formwork support system includes a prefabricated baffle, a prefabricated buttress 12 and a steel pipe 13. The prefabricated baffle includes a first prefabricated baffle 10 and a second prefabricated baffle 11. The length of the first prefabricated baffle 10 is less than the length of the second prefabricated baffle 11. Fig.29 As shown, a slot 14 is provided on the outer side of the first prefabricated baffle 10, and the prefabricated buttress 12 is inserted into the slot 14. A protrusion is provided on one side and the bottom, and a groove is provided on the other side and the top. Fig.30 As shown, two slots 14 are arranged on the outer side of the second prefabricated baffle 11, and the prefabricated buttress 12 is inserted into the slots 14. A protrusion is arranged on one side and the bottom surface, and a groove is arranged on the other side and the top surface.

[0180] In this embodiment, in order to facilitate installation and design, the length of the second prefabricated baffle 11 is twice that of the first prefabricated baffle 10 .

[0181] A prefabricated baffle is arranged on the water-facing surface close to the prefabricated structure of the dam core. A first prefabricated baffle 10 and a second prefabricated baffle 11 are alternately arranged on the prefabricated baffle so that there is no through seam on the prefabricated baffle. A prefabricated buttress 12 is arranged at the intersection of the outer side of the prefabricated baffle. The structure of the prefabricated buttress 12 is as follows: Fig.31 As shown, a steel pipe 13 is transversely penetrated inside the prefabricated buttress 12, and a plurality of transversely penetrated steel pipes 13 are connected by a vertically arranged steel pipe 13.

[0182] In step S6, a template support system for the water-facing surface of the dam heel is constructed, and concrete is poured to form a water-facing surface structure of the dam heel; specifically, the steps include:

[0183] S61, install the first layer of prefabricated baffles and prefabricated buttresses 12 on the bottom plate, insert the steel pipes 13 into the prefabricated buttresses 12, set fasteners 15 on the outer walls of the steel pipes 13 on both sides of each prefabricated buttress 12, and use the fasteners 15 to determine the position of the prefabricated buttresses 12, so that all the prefabricated buttresses 12 of the first layer are connected to form a whole; Fig.32 As shown, the prefabricated baffles are installed close to the dam core prefabricated structure 2, the outermost is the first prefabricated baffle 10, and the inner is the second prefabricated baffle 11. Fasteners 15 are provided on both sides of each prefabricated buttress 12, such as Fig.33 As shown, the fastener 15 is similar to an annular clamp, which surrounds the steel pipe and then sets a flat plate at the cross section. The flat plates on both sides overlap and are fastened with screws.

[0184] S62, installing the second layer of prefabricated baffles and prefabricated buttresses 12, inserting steel pipes 13 into the prefabricated buttresses 12, and setting fasteners 15 on the outer walls of the steel pipes 13 on both sides of each prefabricated buttress 12;

[0185] S63, repeat step S62 until the dam top, then install the vertical steel pipe 13 between the prefabricated buttresses 12, the vertical steel pipe 3 is connected to the horizontal steel pipe 13 by a rotating fastener 16, a bottom support 17 is set at the bottom of the vertical steel pipe 13, and the vertical steel pipe 13 is supported by a tossing support 18; Fig.34 , Fig.35 As shown,

[0186] S64, install casting templates 19 on both sides between one prefabricated baffle and the dam core prefabricated structure 2, and the casting templates 19 are supported by a caster; Fig.36 As shown,

[0187] S65, installing the top prefabricated support 20 and the top prefabricated overflow panel 21;

[0188] The structure of the top prefabricated support 20 is as follows: Fig.37 As shown, the top prefabricated support 20 is installed above the last row of prefabricated blocks. Then the top prefabricated overflow panel 21 is installed. The structure of the top prefabricated overflow panel 21 is as shown in FIG. Fig.38 As shown, a protrusion is arranged on the lower end surface so that the top prefabricated overflow panel 21 can be embedded in the prefabricated baffle, and a pouring port 22 is arranged on the top prefabricated overflow panel 21 .

[0189] S66, pouring the anti-seepage concrete on the arc overflow surface and the anti-seepage concrete on the water-facing surface of the dam heel through the pouring port 22 on the top prefabricated overflow panel 21, such as Fig.39 shown.

[0190] S7. After pouring is completed, the formwork support system on the water-facing surface of the dam heel will be removed for recycling.

[0191] The present invention adopts an integral assembled structure. The dam core is assembled from dam core prefabricated blocks. The surface of the prefabricated blocks has anti-slip grooves distributed vertically and horizontally, and prestressed channels are reserved horizontally and vertically. After the dam core prefabricated blocks are installed, they are reinforced with bidirectional prestressing. The dam body has high structural strength and stable structure. In addition, it avoids tedious processes such as template installation and reinforcement, speeding up the construction progress; the overflow surface adopts prefabricated panels, avoiding the shortcomings of difficult to ensure the quality of the cast-in-place method and the uneven curve line of the dam surface; self-compacting concrete is poured between the dam core and the overflow surface and the water-facing surface of the dam heel to form a dense anti-seepage layer, which greatly reduces the possibility of penetration damage.

[0192] The above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, a person skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. An assembled bidirectional prestressed gravity overflow dam, characterized in that: It comprises a bottom plate, a dam core prefabricated structure, a dam surface prefabricated structure and a dam heel water-facing surface structure, wherein the dam core prefabricated structure is arranged on the bottom plate, the dam surface prefabricated structure is arranged on the top surface and the back surface of the dam core prefabricated structure, and the dam heel water-facing surface structure is arranged on the water-facing surface of the dam core prefabricated structure; The bottom plate is a cast-in-place structure, and the dam core prefabricated structure and the dam surface prefabricated structure are structures that are cast in-place and solidified on the basis of the prefabricated structure; the dam surface prefabricated structure includes an overflow panel and a prefabricated support, and the overflow panel is divided into an arc segment, a straight segment and an anti-arc segment; the arc segment is arranged on the top surface and the back water surface of the dam core prefabricated structure, and the straight segment is connected to the lower end of the arc segment and is arranged on the back water surface of the dam core prefabricated structure; the anti-arc segment is connected to the lower end of the straight segment and is arranged on the back water surface of the dam core prefabricated structure; the prefabricated support is arranged above both sides of the dam core prefabricated structure, and is located at both side edges of the lower surface of the overflow panel.

2. The assembled bidirectional prestressed gravity overflow dam according to claim 1, characterized in that: The arc segment includes a plurality of arc panels, and a positioning protrusion is provided on the lower end surface of the arc panel; The straight line segment includes a plurality of straight line panels, the upper end surface of the straight line panel is provided with a positioning groove, and the lower end surface of the straight line panel is provided with a positioning protrusion; The anti-arc section includes a plurality of anti-arc panels, and the upper end surface of the anti-arc panel is provided with a positioning groove; The positioning protrusion on the lower end surface of the arc panel is embedded in the positioning groove on the upper end surface of the straight segment, and the positioning protrusion on the lower end surface of the straight segment is embedded in the positioning groove on the upper end surface of the reverse arc panel; A positioning groove is provided on one side of the curved panel, and a positioning protrusion is provided on the other side of the curved panel; And / or, a positioning groove is provided on one side of the linear panel, and a positioning protrusion is provided on the other side of the linear panel; And / or, a positioning groove is provided on one side of the reverse arc panel, and a positioning protrusion is provided on the other side of the reverse arc panel.

3. The assembled bidirectional prestressed gravity overflow dam according to claim 1, characterized in that: The bottom plate comprises a base, a plurality of rows of foundation blocks are arranged above the base, an anti-arc foundation block is arranged at the toe end of the base, a dam core prefabricated structure is arranged above the foundation block, and the anti-arc segment is arranged above the anti-arc foundation block; The lower surface of the bottom plate is provided with an anti-slip tenon.

4. The assembled bidirectional prestressed gravity overflow dam according to claim 3 is characterized in that: The dam core prefabricated structure includes A-type blocks, A2-type blocks, B-type blocks, B2-type blocks, and C-type blocks. The A-type blocks and A2-type blocks are all cubes, and the B-type blocks, B2-type blocks, and C-type blocks are all cuboids. From the backwater surface to the frontwater surface, a row of C-shaped blocks is arranged above the first row of foundation blocks; A-type blocks and B-type blocks are set above the second to last rows of foundation blocks, with the requirement that there are no through seams on the horizontal and vertical surfaces of the dam core prefabricated structure; A2 blocks and B2 blocks are set on the top surfaces of the second to last rows of foundation blocks, with the requirement that there are no through seams on the stepped top surface of the dam core prefabricated structure.

5. The assembled bidirectional prestressed gravity overflow dam according to claim 4 is characterized in that: The left and right sides of the A-type block are provided with cross keyways, the upper surface of the A-type block is provided with a positioning groove, the A-type block is provided with a vertical prestressed channel and a transverse prestressed channel, and the A-type block is provided with a transverse grouting hole, the grouting hole penetrates the A-type block and the grouting hole is connected to the vertical prestressed channel; A cross keyway is arranged on the left and right sides of the A2 block, a vertical prestressed channel and a transverse prestressed channel are arranged inside the A2 block, and a transverse grouting hole is arranged inside the A2 block, the grouting hole penetrates the A2 block and the grouting hole is connected to the vertical prestressed channel; an anchor pit is arranged on the upper surface of the A2 block, and the anchor pit is concentric with the vertical prestressed channel of the A2 type; The left and right sides of the B-type block are provided with double cross keyways, the upper surface of the B-type block is provided with a positioning groove, the interior of the B-type block is provided with a vertical prestressed channel and a transverse prestressed channel, and the interior of the B-type block is provided with a transverse grouting hole, the grouting hole penetrates the B-type block and the grouting hole is connected to the vertical prestressed channel; The left and right sides of the B2 block are provided with double cross keyways, the B2 block is provided with vertical prestressed channels and transverse prestressed channels, and the B2 block is provided with transverse grouting holes, the grouting holes penetrate the B2 block and are connected to the vertical prestressed channels; an anchor pit is provided on the upper surface of the B2 block, the anchor pit is concentric with the B2 vertical prestressed channel; an anchor pad is provided in the anchor pit; Double cross keyways are arranged on the left and right sides of the C-shaped block, and a transverse prestressed channel is arranged inside the C-shaped block.

6. The assembled bidirectional prestressed gravity overflow dam according to claim 5, characterized in that: Threaded steel bars are installed in the vertical prestressed channels of Type A blocks, Type A2 blocks, Type B blocks and Type B2 blocks, and steel strands are installed in the transverse prestressed channels of Type A blocks, Type A2 blocks, Type B blocks, Type B2 blocks and Type C blocks.

7. A construction process for an assembled bidirectional prestressed gravity overflow dam, used for constructing the assembled bidirectional prestressed gravity overflow dam according to claim 5 or 6, characterized in that: The construction process includes: S1. Cast the base plate in situ according to the base plate structure, and embed threaded steel bars in the base plate; S2. Install A-type blocks, A2-type blocks, B-type blocks, B2-type blocks, and C-type blocks on the bottom plate, so that the vertical prestressed holes of A-type blocks, A2-type blocks, B-type blocks, and B2-type blocks pass through the threaded steel bars; S3. Insert steel strands in the transverse prestressed holes of the A-type block, A2-type block, B-type block, B2-type block and C-type block; S4, cutting the redundant threaded steel and steel strands, grouting from bottom to top, and pouring concrete to form the dam core prefabricated structure; S5, install prefabricated supports and overflow panels, and pour concrete to form a prefabricated dam surface structure; S6. Build the formwork support system for the dam heel water-facing surface and pour concrete to form the dam heel water-facing surface structure; S7. Dismantle the formwork support system on the water-facing surface of the dam heel.

8. The construction process of the assembled bidirectional prestressed gravity overflow dam according to claim 7 is characterized in that: In step S4, redundant threaded steel bars and steel strands are cut, grouting is performed from bottom to top, and concrete is poured to form a prefabricated dam core structure; specifically, the steps include: S41, tensioning threaded steel, and then tensioning steel strands; S42, cutting excess rebar and stranded wire; S43, the vertical prestressed duct is grouted from bottom to top through the grouting holes on the A-type block and the B-type block at the bottom until the grouting holes of the A2-type block and the B2-type block at the top are grouted; S44, the transverse prestressed channel is grouted through the grouting holes on the anchor pad; S45. After the grouting is completed, the anchor pad is sealed; S46, installing cast-in-place concrete formwork for the dam core, and pouring concrete to form a prefabricated structure of the dam core; The cast-in-place concrete formwork of the dam core comprises a formwork body, a fixing frame is arranged outside the formwork body, a steel pipe brace is arranged outside the fixing frame, and the steel pipe brace is arranged obliquely on the ground.

9. The construction process of the assembled bidirectional prestressed gravity overflow dam according to claim 7, characterized in that: In step S5, prefabricated supports and overflow panels are installed, and concrete is poured to form a prefabricated dam surface structure; specifically, the steps include: S51. Install the prefabricated supports and overflow panels of the anti-arc section, and use adjustable support palms to support the upper opening; S52, pouring the inner space of the anti-arc section, and removing the adjustable palm support after initial setting; S53. After the concrete of the anti-arc section dam surface is finally set, the prefabricated supports and overflow panels of the straight section are installed, and the upper opening is supported by a special-shaped support; S54, pour the inner space of the straight section, and after initial setting, remove the special-shaped support; S55. After the concrete of the straight section dam surface is finally set, install the prefabricated supports and overflow panels of the curved section, and use special-shaped support palms to support the upper opening; S56. Cast the inner space of the arc segment, and after initial setting, remove the special-shaped support.

10. The construction process of the assembled bidirectional prestressed gravity overflow dam according to claim 7, characterized in that: The dam heel water-facing surface formwork support system in step S6 includes prefabricated baffles, prefabricated buttresses and steel pipes, wherein the prefabricated baffles include a first prefabricated baffle and a second prefabricated baffle, and the length of the first prefabricated baffle is less than the length of the second prefabricated baffle; A prefabricated baffle is arranged on the water-facing surface close to the prefabricated structure of the dam core, and a first prefabricated baffle and a second prefabricated baffle are alternately arranged on the prefabricated baffle so that there is no through seam on the prefabricated baffle; A prefabricated buttress is arranged at the intersection of the outer side of a prefabricated baffle, a steel pipe is horizontally passed through the interior of the prefabricated buttress, and a plurality of horizontally passed steel pipes are connected by vertically arranged steel pipes; A slot is provided on the outer side of the first prefabricated baffle plate, and two slots are provided on the outer side of the second prefabricated baffle plate, and the prefabricated buttresses are inserted into the slots; In step S6, a template support system for the water-facing surface of the dam heel is constructed, and concrete is poured to form a water-facing surface structure of the dam heel; specifically, the steps include: S61. Install the first layer of prefabricated baffles and prefabricated buttresses on the bottom plate, insert steel pipes into the prefabricated buttresses, and set fasteners on the outer walls of the steel pipes on both sides of each prefabricated buttress; S62, installing the second layer of prefabricated baffles and prefabricated buttresses, inserting steel pipes into the prefabricated buttresses, and setting fasteners on the outer walls of the steel pipes on both sides of each prefabricated buttress; S63, repeat step S62 until the dam top, then install vertical steel pipes between the prefabricated buttresses, the vertical steel pipes are connected to the horizontal steel pipes through rotating fasteners, a bottom support is set at the bottom of the vertical steel pipe, and the vertical steel pipe is supported by a tossing support; S64. Install casting formwork on both sides between one prefabricated baffle and the prefabricated structure of the dam core, and use a caster to support the casting formwork; S65. Install the top prefabricated support and the top prefabricated overflow panel; S66. Casting is carried out through the pouring port on the top prefabricated overflow panel.

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