A rockfill dam cantilever lifting device

Abstract

The present invention relates to the technical field of concrete construction formwork, and provides a cantilever lifting device for a rockfill dam, which solves the problem that the existing device has a long installation and removal working time due to design defects. The present invention includes: a formwork; a back frame installed on the first surface of the formwork for bearing the load from the formwork; a cantilever frame installed below the back frame; a connecting member, the connecting member includes a U-shaped member, a limiting block, a grouting sleeve, a fixing nut and a fixing block, the U-shaped member is arranged on the second surface of the formwork, one end of the grouting sleeve is provided with the limiting block, the limiting block is slidably arranged in the U-shaped member, a plurality of grouting holes are arranged on the outer side of the grouting sleeve, and each of the grouting holes is obliquely opened downward, and the connecting member has an uncast state and a cast state; a tie bar, one end of the tie bar is provided with a bent section, and the bent section is hung on the U-shaped member; a pre-embedded part pre-embedded in the top of the cast concrete layer, and the other end of the tie bar is connected to the pre-embedded part.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete construction formwork, and particularly relates to a cantilever lifting device for a rockfill dam. Background Art

[0002] With the continuous development of construction engineering technology, the cantilever lifting formwork technology, as an advanced construction method, has been widely applied in various construction projects. Especially in the construction of large formwork concrete pouring, the cantilever lifting formwork technology has played an indispensable role. The cantilever lifting formwork is a formwork technology based on the principle of cantilever force, which has the advantages of fast construction speed, strong adaptability, and good economy. Through the lifting operation of the formwork, the continuous pouring of vertical concrete structures can be realized, improving the construction efficiency and quality. In addition, the cantilever lifting formwork technology is also widely applied in the fields of bridges, hydraulic engineering, underground engineering, etc.

[0003] Chinese Patent Publication No. CN105971271A discloses a single-sided self-climbing cantilever formwork. The single-sided self-climbing cantilever formwork includes a self-climbing formwork frame and a single-sided cantilever formwork. The single-sided cantilever formwork is installed on the self-climbing formwork frame. In this invention, tie rod embedments are used to connect the single-sided cantilever formwork to the already poured concrete layer. However, due to the weak shear resistance of the tie rod embedments, a high density of tie rod embedments needs to be set to avoid construction accidents, which will increase a large amount of installation and removal working hours. Summary of the Invention

[0004] Therefore, in view of the above problems, the present invention provides a cantilever lifting device for a rockfill dam to solve the problem of long installation and removal working hours caused by design defects in existing devices.

[0005] To achieve the above object, the present invention is realized through the following technical solutions:

[0006] A cantilever lifting device for a rockfill dam, comprising:

[0007] A formwork, the bottom of which has a fitting part with the already poured concrete layer;

[0008] A back frame, installed on the first surface of the formwork. The back frame and the formwork have a plurality of connection points, and the back frame is used to bear the load from the formwork;

[0009] A cantilever frame, installed below the back frame;

[0010] Connecting piece, the connecting piece includes a U-shaped piece, a limiting block, a grouting sleeve, a fixing nut and a fixing block. The U-shaped piece is arranged on the second surface of the formwork. One end of the grouting sleeve is provided with the limiting block, and the limiting block is slidably arranged in the U-shaped piece. A plurality of grouting holes are arranged on the outer side of the grouting sleeve, and each grouting hole is obliquely opened downward. The connecting piece has an uncast state and a cast state. In the uncast state, both ends of the U-shaped piece pass through the formwork and are connected to the fixing nut. In the cast state, the fixing block is locked to the end of the U-shaped piece through the fixing nut. A clamping groove is arranged at the top of the fixing block, and a receiving cavity is arranged on one side of the cantilever frame. A clamping piece matching the clamping groove is arranged on one side of the receiving cavity;

[0011] Tie bar, one end of the tie bar is provided with a bent section, and the bent section is hung on the U-shaped piece. The tie bar is arranged obliquely downward;

[0012] Embedded part, embedded in the top of the cast concrete layer, and the other end of the tie bar is connected to the embedded part.

[0013] Further, the connecting piece further includes a wedge block, and the wedge block is sleeved on one end of the limiting block.

[0014] Further, the embedded part includes anchor bars and a conical sleeve. The conical sleeve is arranged outside the anchor bars, and one end of the anchor bar is hook-shaped.

[0015] Further, arc-shaped grooves are arranged on both sides of the limiting block, and the U-shaped piece is passed through the arc-shaped grooves.

[0016] Further, the back frame adopts a truss structure, and the number of bays n of the truss and the formwork span L satisfy the following relationship:

[0017] When L ≤ 3m, n ≥ L;

[0018] When L > 3m, n ≥ 2L.

[0019] Further, the matching relationship between the number a of the tie bars and the formwork span L is: a = 2×L / 3, where the unit of L is m, a is the number of tie bars arranged along the height direction of the formwork, and the tensile strength of a single tie bar is not less than 150kN.

[0020] Further, the height h1 of the fitting part ≥ 200mm, the distance between the connecting piece and the top of the formwork is h2, and h2 = h1 + 50mm.

[0021] Further, a one-way stop groove is arranged at the edge of the formwork, and adjacent formworks are connected by bolts in a biting manner.

[0022] Further, the distance between both ends of the U-shaped piece is 8 - 16cm.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The prestress generated by the locking of the tension bars and the formwork in the present invention can actively offset the shrinkage stress during the solidification of concrete, reduce the generation of structural cracks, and increase the bonding strength between the connecting members and the layers.

[0025] 2. The present invention can fix the tension bars through the sliding fit between the limit blocks and the U-shaped members, avoiding the inclination of the tension bars during the pouring of the concrete layer.

[0026] 3. By connecting the connecting members with the cantilever frames, the present invention can increase the setting spacing of the connecting members, thereby reducing the installation and removal working hours.

[0027] 4. Through the inclined grouting holes of the grouting sleeve, the present invention can, according to the working conditions, select to grout after the concrete layer has solidified, improving the strength of the connection nodes and increasing the shear strength of a single connecting member. Description of the Drawings

[0028] Figure 1 Schematic diagram of the structure of the first layer of concrete not poured in the embodiment of the present invention;

[0029] Figure 2 Schematic diagram of the structure of the (N + 1)-th layer of concrete not poured in the embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the structure of the (N + 1)-th layer of concrete poured in the embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the structure of the cooperation between the clamping piece and the clamping groove in the embodiment of the present invention;

[0032] Figure 5 Top view structure schematic diagram of the connecting member in the embodiment of the present invention;

[0033] Figure 6 Cross-sectional structure schematic diagram of the connecting member in the embodiment of the present invention;

[0034] Figure 7 Schematic diagram of the structure of the one-way rabbet in the embodiment of the present invention;

[0035] Figure 8 For Figure 1 Enlarged structure schematic diagram at position A in

[0036] Figure 9 For Figure 1 Enlarged structure schematic diagram at position B in

[0037] Figure 10 For Figure 3 Enlarged structure schematic diagram at position C in

[0038] Explanation of the reference numerals in the drawings:

[0039] Formwork 1; one-way rabbet 11;

[0040] Back frame 2;

[0041] Cantilever frame 3; accommodation cavity 31; clamping piece 32;

[0042] Connecting piece 4; U-shaped piece 41; limiting block 42; arc groove 421; grouting sleeve 43; fixing nut 44; fixing block 45; clamping groove 451; grouting hole 46;

[0043] Tie bar 5; bent section 51;

[0044] Embedded part 6; anchor bar 61; conical sleeve 62. Detailed implementation manner

[0045] The following will combine specific embodiments to elaborate in detail on the implementation manner of the present invention, so as to fully understand how the present invention uses technical means to solve technical problems and the implementation process of achieving technical effects and implement accordingly.

[0046] Embodiment

[0047] As Figures 1 to 10 shown, a cantilever lifting device for a rockfill dam includes: a formwork 1, the bottom of which has a fitting part with the already poured concrete layer; a back frame 2, installed on the first surface of the formwork 1, the back frame 2 and the formwork 1 having multiple connection points, the back frame 2 being used to bear the load from the formwork; a cantilever frame 3, installed below the back frame 2; a connecting piece 4, the connecting piece 4 including a U-shaped piece 41, a limiting block 42, a grouting sleeve 43, a fixing nut 44 and a fixing block 45, the U-shaped piece 41 being arranged on the second surface of the formwork 1, one end of the grouting sleeve 43 being provided with the limiting block 42, the limiting block 42 being slidably arranged in the U-shaped piece 41, several grouting holes 46 being arranged on the outer side of the grouting sleeve 43, each of the grouting holes 46 being obliquely downwardly opened, the connecting piece 4 having an un-poured state and a poured state, in the un-poured state, both ends of the U-shaped piece 41 pass through the formwork 1 and are connected to the fixing nut 44, in the poured state, the fixing block 45 is locked to the end of the U-shaped piece 41 through the fixing nut 44, a clamping groove 451 being provided at the top of the fixing block 45, a clamping piece 32 matching the clamping groove 451 being arranged on one side of the accommodation cavity 31 of the cantilever frame 3; a tie bar 5, one end of the tie bar 5 being provided with a bent section 51, the bent section 51 being hung on the U-shaped piece 41, the tie bar 5 being obliquely downwardly arranged; an embedded part 6, embedded in the top of the already poured concrete layer, the other end of the tie bar 5 being connected to the embedded part 6.

[0048] The present application does not specifically limit the number of the grouting holes 46, which is adjusted according to the actual situation.

[0049] In other preferred embodiments, to strengthen the fixing effect of the limiting block 42 on the tension bar 5, a notch (not shown in the figure) is provided on the side of the limiting block 42 close to the tension bar.

[0050] Arc-shaped grooves 421 are provided on both sides of the limiting block 42, and the U-shaped member 41 is inserted into the arc-shaped grooves 421. That is, both sides of the limiting block 42 are recessed inward, and the U-shaped member 41 is inserted into the recess for preventing the limiting block 42 from detaching from the U-shaped member 41 transversely without additional on-site assembly.

[0051] In other preferred embodiments, the connecting member 4 further includes a wedge block (not shown in the figure). The wedge block is sleeved on one end of the grouting sleeve 43. A through groove matching the outer side of the grouting sleeve 43 is provided on the wedge block 43, and the grouting sleeve 43 is inserted into the through groove. The side of the wedge block away from the grouting sleeve 43 is a slope for contacting the tension bar 5 to fix the inclination angle of the tension bar 5. In this embodiment, no embedded part 6 is provided, that is, one end of the tension bar 5 is connected to the connecting member 4 and the other end is a free end. This situation is applicable to small-span formwork 1 or when the density of the connecting member 4 is high.

[0052] The embedded part 6 includes anchor bars 61 and a conical sleeve 62. The conical sleeve 62 is provided outside the anchor bars 61. One end of the anchor bars 61 is hook-shaped, and the hook-shaped end of the anchor bars 61 protrudes from the top of the already poured concrete. In this embodiment, bending sections 51 are provided at both ends of the tension bar 5. When setting the tension bar 5, one end of the tension bar 5 is first hooked with the anchor bars 61, then the other end of the tension bar 5 is hooked with the U-shaped member 41, and finally the U-shaped member 41 is fixed to the formwork 1.

[0053] The back frame 2 adopts a truss structure, and the number of bays n of the truss and the span L of the formwork 1 satisfy the following relationship:

[0054] When L ≤ 3m, n ≥ L;

[0055] When L > 3m, n ≥ 2L.

[0056] In this embodiment, the formwork 1 is 3m × 3m, and the back frame 2 adopts a two-bay truss structure.

[0057] The matching relationship between the number a of the tension bars 5 and the span L of the formwork 1 is: a = 2 × L / 3, where the unit of L is m, a is the number of tension bars arranged along the height direction of the formwork 1, and the tensile strength of a single tension bar 5 is not less than 150 kN.

[0058] In this embodiment, the number of the tension bars 5 is 2.

[0059] The height h1 of the bonding part is 200 mm, the distance between the connecting piece 4 and the top of the formwork 1 is h2, and h2 = 250 mm. When the initial concrete layer is poured, after the initial concrete layer is poured and solidified, the cantilever frame 3 has not been installed under the back frame 2. After the initial concrete layer is poured and solidified, the formwork 1 is lifted upward by a crane to achieve turning up. The cantilever frame 3 is installed under the back frame 2 through bolts and nuts, and the cantilever frame 3 is fixed to the concrete pouring layer through the connecting piece 4, and so on for upward pouring and turning up.

[0060] A one-way rabbet 11 is provided at the edge of the formwork 1. Adjacent formworks 1 are connected by bolts in a bite connection. The bite connection can be repeatedly disassembled and used, and the misalignment amount at the joint of adjacent formworks 1 can be reduced, improving the flatness of the pouring surface.

[0061] The distance between the two ends of the U-shaped part 41 is 12 cm, ensuring the single-point anti-overturning moment, and this size range is adapted to the operating space of a standard wrench, avoiding installation difficulties in a narrow space.

[0062] Although the present invention has been specifically shown and described in combination with preferred embodiments, those skilled in the art should understand that various changes can be made to the present invention in form and detail without departing from the spirit and scope of the present invention defined by the appended claims, and all are within the protection scope of the present invention.

Claims

1. A cantilever lifting device for a rockfill dam, characterized in that, Comprising: A template, the bottom of which has a fitting portion with the cast concrete layer; A back frame, installed on the first surface of the template, the back frame and the template having a plurality of connection points, the back frame being used to bear the load from the template; A cantilever frame, installed below the back frame; A connecting member, the connecting member includes a U-shaped member, a limiting block, a grouting sleeve, a fixing nut and a fixing block, the U-shaped member is arranged on the second surface of the template, one end of the grouting sleeve is provided with the limiting block, the limiting block is slidably arranged in the U-shaped member, a plurality of grouting holes are arranged on the outer side of the grouting sleeve, and each of the grouting holes is obliquely downwardly opened. The connecting member has an uncast state and a cast state. In the uncast state, both ends of the U-shaped member pass through the template and are connected to the fixing nut. In the cast state, the fixing block is locked to the end of the U-shaped member through the fixing nut. A clamping groove is arranged on the top of the fixing block, and a receiving cavity is arranged on one side of the cantilever frame, and a clamping piece matching the clamping groove is arranged on one side of the receiving cavity; A tension bar, one end of the tension bar is provided with a bent section, the bent section is hung on the U-shaped member, and the tension bar is arranged obliquely downward; A pre-embedded part, pre-embedded in the top of the cast concrete layer, and the other end of the tension bar is connected to the pre-embedded part.

2. The cantilever lifting device for a rockfill dam according to claim 1, wherein: The connecting member further includes a wedge block, and the wedge block is sleeved on one end of the limiting block.

3. The cantilever lifting device for a rockfill dam according to claim 1, wherein: The pre-embedded part includes anchor bars and a conical sleeve, the conical sleeve is arranged outside the anchor bars, and one end of the anchor bars is hook-shaped.

4. A cantilever lifting device for a rockfill dam according to claim 1, characterized in that: Arc-shaped grooves are arranged on both sides of the limiting block, and the U-shaped member is inserted into the arc-shaped grooves.

5. A rockfill dam cantilever lifting device according to claim 1, characterized in that, The back frame adopts a truss structure, and the number of bays n of the truss and the span L of the template satisfy the following relationship: When L≤3m, n≥L; When L>3m, n≥2L.

6. The cantilever lifting device for a rockfill dam according to claim 1, characterized in that, The matching relationship between the number a of the tension bars and the span L of the template is: a = 2×L / 3, where L is in meters, a is the number of tension bars arranged along the height direction of the template, and the tensile strength of a single tension bar is not less than 150kN.

7. A cantilever lifting device for a rockfill dam according to claim 1, characterized in that, The height h1 of the fitting portion is h1≥200mm, the distance between the connecting member and the top of the template is h2, and h2 = h1 + 50mm.

8. A cantilever lifting device for a rockfill dam according to claim 1, characterized in that: A one-way stop is arranged at the edge of the template, and adjacent templates are connected by bolts in a bite manner.

9. The cantilever lifting device for a rockfill dam according to claim 1, characterized in that: The distance between both ends of the U-shaped member is 8-16cm.

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