Formwork-free construction method for concrete retaining wall and bottom plate of open channel

Abstract

The invention relates to the technical field of open channel construction, in particular to an open channel concrete retaining wall and bottom plate formwork-free construction method which comprises the following steps that S1, a groove is excavated; s2, the steel roller with the two conical ends is hoisted into the groove, so that the steel roller makes contact with the upper surface of the groove; s3, positioning calibration is carried out; the position of the steel roller is adjusted, the distance between the bottom of the steel roller and the groove bottom of the groove is the thickness of the open channel bottom plate, and the distance between the conical inclined face of the steel roller and the side wall of the groove is the thickness of the retaining wall; s4, concrete pouring; the front and two sides of the steel roller are continuously filled with concrete, a motor is started to drive the steel roller to rotate, and the concrete is uniform and compact; and S5, propelling construction is conducted, specifically, the steel roller is slowly moved forwards, and continuous pouring is conducted till all sections are completed. The method has the advantages that the construction efficiency is improved, the comprehensive cost is reduced, and the problems of insufficient concrete vibration, high template dependence and the like in the traditional process are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of open channel construction, and in particular to a construction method for a concrete retaining wall and a bottom slab of an open channel without formwork. Background Art

[0002] An open channel is a channel exposed on the ground. The traditional construction of a concrete open channel mainly adopts a formwork support process using wooden formwork or steel formwork, and there are the following technical problems: (1) High labor cost: A large number of skilled workers are required for formwork support and removal, and the formwork installation accuracy requirements are high, and the labor cost accounts for more than 30% of the total cost. (2) Long construction period: The formwork support process takes 40%-50% of the total construction cycle. In case of rainy seasons or complex terrains, the curing period is further extended, seriously affecting project delivery. (3) Material waste: The average number of times of repeated use of wooden formwork is only 3-5 times. Although steel formwork can be reused, the transportation and maintenance costs are high. (4) Difficult vibration: The vibration operation efficiency in narrow grooves is low, and quality defects such as honeycombing and pockmarks are likely to occur. Summary of the Invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a construction method for a concrete retaining wall and a bottom slab of an open channel without formwork.

[0004] A construction method for a concrete retaining wall and a bottom slab of an open channel without formwork provided by the present invention adopts the following technical solutions: A construction method for a concrete retaining wall and a bottom slab of an open channel without formwork includes the following steps: S1. Groove excavation; S2. Hoist steel rollers with conical ends to the groove so that the walking parts are in contact with the upper surface of the groove; S3. Positioning and calibration; Adjust the position of the steel rollers so that the distance from the bottom of the steel rollers to the bottom of the groove is the thickness of the bottom slab of the open channel, and the distance between the conical inclined surface of the steel rollers and the side wall of the groove is the thickness of the retaining wall; S4. Concrete pouring; Continuously fill concrete in front of and on both sides of the steel rollers, start the motor, and the motor drives the steel rollers to rotate to make the concrete uniform and dense; S5. Progressive construction: Slowly move the steel rollers forward and continuously pour until all sections are completed.

[0005] Optionally, when excavating the groove, use a trapezoidal bucket excavator for excavation and ensure that the bottom of the groove is flat and the slope is accurate.

[0006] Optionally, the steel roller (1) is made of Q345B high-strength steel, the yield strength of the steel roller (1) is ≥345 MPa, and the surface is galvanized, and the zinc layer thickness is ≥80 μm.

[0007] Compared with the prior art, the present invention has the following technical effects: This open channel construction method does not use wooden formwork or steel formwork for formwork support, thereby reducing the labor cost of formwork erection. This method is especially suitable for medium and small open channel projects, which can significantly improve construction efficiency, reduce comprehensive costs, and solve problems such as insufficient concrete vibration and strong formwork dependence in traditional processes. Description of the Drawings

[0008] Figure 1 is a perspective view of the present invention.

[0009] Figure 2 is the front view of the present invention.

[0010] Description of the reference numerals: 1, steel roller; 2, bearing; 3, connecting shaft; 4, hand push handle; 5, traveling wheel; 6, installation box. Detailed Description of the Embodiment

[0011] The following will Figure 1 - with reference to the Figure 2 further describe the present invention in detail.

[0012] Referring to Figure 1 and Figure 2 The embodiment of the present invention discloses a construction method for an open channel concrete retaining wall and a bottom slab without formwork, including the following steps: S1. Groove excavation.

[0013] Use a trapezoidal bucket excavator to excavate the groove according to the design drawings to ensure that the bottom of the groove is flat and the slope is accurate.

[0014] S2. Hoist the steel roller 1 into the groove.

[0015] Both ends of the steel roller 1 are conical. The conical inclined surfaces of different steel balls correspond to the groove cross-sections with different slopes, and the conical inclined surface is consistent with the inclined surface of the groove. The radius (D) of the steel roller 1 and the designed height (H) of the retaining wall satisfy the relational expression D = H + 0.2 m, and the designed height of the retaining wall is the vertical distance from the bottom of the groove to the upper surface of the groove.

[0016] The steel roller 1 is made of Q345B high-strength steel (yield strength ≥ 345 MPa) and is surface galvanized with a zinc layer thickness ≥ 80 μm to ensure the corrosion resistance of the steel roller 1 in a humid environment and a service life of more than ten years.

[0017] When the steel roller 1 rotates, it can generate a gradient centrifugal force to uniformly compact the concrete from the bottom upwards and avoid collapse. The rotating conical surface can generate a non-uniform force field (gradient centrifugal force) through the geometric shape (inclination angle) and the radial dependence of the centrifugal force, thereby realizing the directional transportation of objects.

[0018] Both ends of the steel roller 1 are fixed with connecting shafts 3. An installation box 6 is arranged at one end of each connecting shaft 3 away from the steel roller 1. A motor for driving the connecting shaft 3 to rotate is arranged in the installation box 6. The motor is a variable-frequency motor, and a 7.5kW motor (model: Y2-160M-4) is selected. The stepless speed regulation (50~400r / min) is realized through the frequency converter, which is suitable for concrete with a slump of 80~120mm. A bearing is fixed on the side wall of the installation box 6, and the connecting shaft 3 passes through the bearing 2. The bearing 2 adopts a UC212 pedestal-mounted spherical roller bearing 2 with an internal sealing structure, which can bear a radial load of ≥12kN to ensure the stability when the roller 5 rotates at a high speed. A walking wheel 5 is installed at the bottom of the box body 6, and the walking wheel 5 contacts the upper surface of the groove. A hand push handle 4 is fixed on the box body 6.

[0019] S3. Positioning and calibration.

[0020] Adjust the position of the steel roller 1 so that the distance from the bottom of the steel roller 1 to the bottom of the groove is the thickness of the open channel bottom slab, and the distance between the conical inclined surface of the steel roller 1 and the side wall of the groove is the thickness of the retaining wall. After placing the walking wheel 5 on the upper surface of the groove, the distance from the bottom of the steel roller 1 to the bottom of the groove is the thickness of the bottom slab. By controlling the distance between the left and right box bodies and their respective groove edges, the axial direction of the steel roller is positioned.

[0021] S4. Concrete pouring.

[0022] Continuously fill the concrete in front of and on both sides of the steel roller 1, start the motor, and the motor drives the steel roller 1 to rotate. The centrifugal force (F = mω²r) makes the concrete evenly dense. The measured density is ≥98%, and the 28-day compressive strength reaches 35MPa, with the compressive strength increased by 10%-15%.

[0023] S5. Construction propulsion: Slowly move the steel roller 1 device forward and continuously pour until all sections are completed.

[0024] The above are all the preferred embodiments of the present invention, and the protection scope of the present invention is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A construction method for a concrete retaining wall and bottom slab of an open channel without formwork, characterized in that, It includes the following steps: S1. Groove excavation; S2. Hoist the steel roller (1) with conical ends into the groove so that the travel wheels (5) contact the upper surface of the groove; S3. Positioning and calibration; Adjust the position of the steel roller (1) so that the distance from the bottom of the steel roller (1) to the bottom of the groove is the thickness of the open channel bottom slab, and the distance between the conical inclined surface of the steel roller (1) and the side wall of the groove is the thickness of the retaining wall; S4. Concrete pouring; Continuously fill the concrete in front of and on both sides of the steel roller (1), start the motor, and the motor drives the steel roller (1) to rotate to make the concrete evenly dense; S5. Advance construction: Slowly move the steel roller (1) forward and continuously pour until the completion of all sections.

2. The construction method without formwork for the open-channel concrete retaining wall and floor according to claim 1, characterized in that, During groove excavation, a trapezoidal bucket excavator is used for excavation, and it is ensured that the bottom of the groove is flat and the slope is accurate.

3. The construction method for a concrete open channel retaining wall and floor without formwork according to claim 1, characterized in that, The steel roller (1) is made of Q345B high-strength steel, the yield strength of the steel roller (1) is ≥345 MPa, and the surface is galvanized, with a zinc layer thickness of ≥80 μm.

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