A trackless sliding technology structure

Abstract

The present invention relates to a trackless sliding formwork technology structure, comprising a sliding formwork main support beam, an operating platform truss, a scaffolding board, a traction end, a sunshade beam, a sliding formwork panel, a steel wire rope, a first base layer and a second base layer, wherein the first base layer is located at the top of the second base layer, and the first base layer and the second base layer are both placed at an inclined angle to the horizontal plane, and the top of the first base layer is fixedly connected to the sliding formwork main support beam. The present invention adopts a three-section split structure, and each traction unit is independent, all equipped with a "main rope" and "auxiliary rope" design, and is separately connected to the panel steel mesh, which greatly increases the construction safety factor. The traction system adopts a "synchronous start" switch to avoid the winches on both sides from failing to operate or start synchronously due to human factors during traction, resulting in "derailment", "steel wire rope breakage", "sliding formwork group deviation", etc., thereby improving the construction speed, ensuring the construction quality, and guaranteeing the construction safety.

Description

Technical Field

[0001] The invention relates to the technical field of panel concrete pouring construction, in particular to a trackless sliding formwork technical structure. Background Art

[0002] Nowadays, whether in the bidding stage or in the project implementation process, all participating units are paying more and more attention to the promotion and application of the "four new technologies". With the vigorous development of domestic water conservancy project construction projects, various innovative and improved processes and methods have emerged like mushrooms after rain, which has promoted the smooth progress of construction and production operations, ensured effectiveness, saved construction costs and improved production efficiency.

[0003] The traditional casting process of panel concrete uses "track sliding formwork" for construction. Due to the layout of its walking system, it has great constraints on the panel concrete casting process and after forming. This process is relatively complex and has low efficiency. Trackless sliding formwork has been gradually promoted and applied in recent years. The general trackless sliding formwork design is a two-section connected structure design of main sliding formwork + secondary finishing platform. There are the following problems in the panel concrete casting construction:

[0004] 1. After the secondary finishing of the concrete surface of the panel, the sliding formwork group begins to lift, and the lifting interval is 10 to 12 minutes. During this period, the concrete has not yet initially set, and the surface is relatively soft and cannot be covered and maintained in time, so the concrete is directly exposed to the natural environment, which creates quality risks;

[0005] 2. The slab concrete curing water pipe is usually suspended on the secondary finishing platform and rises with the lifting of the slipform group. Then, the valve is opened to spray water on the concrete for curing. Since the lower concrete has not yet initially set, this action can easily damage the concrete surface. If the concrete is sprayed after the initial setting, the initial setting time of concrete is generally about 3 hours. Based on the lifting speed of the slipform group of 1.8m / h, 5.4m of concrete surface is exposed to the environment, which can easily induce temperature cracks, thus affecting the overall quality of the slab concrete. Excessive cracks greatly increase the difficulty and cost of subsequent treatment.

[0006] 3. Cover and maintain heat preservation and moisture retention after 3 hours. Common covering materials include: geotextile + plastic film, straw mat + plastic film, geomembrane, etc. These maintenance measures all require manual laying and dragging. Since people cannot stand when the concrete has just set, most of such projects have untimely and inadequate maintenance, which affects the overall construction quality of the panel.

[0007] In summary, this project is based on the scientific research of Hanjiaxia panel rockfill dam project. In combination with the above problems, the sliding formwork group is optimized and improved to a split structure design of main sliding formwork + secondary plastering platform + tertiary repair and maintenance platform. The "Research on the Application Technology of Trackless Sliding Formwork in Thin-walled Concrete Construction" is carried out to achieve technological innovation and process innovation, find technical measures to solve the problem, and respond to the national development policy of energy conservation and environmental protection while improving project quality and reducing construction costs. It effectively solves the above problems and has a far-reaching impact and significance on the construction of similar panel concrete projects. Summary of the Invention

[0008] In order to solve the problems of the prior art, the present invention provides a trackless sliding formwork technical structure.

[0009] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0010] The lifting of the lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21. The lifting power is 21.

[0011] Preferably, the main support beam of the sliding formwork body is made of I-beams, and the top of the operating platform truss is paved with a template.

[0012] Preferably, the sunshade awning beam frame is made of angle steel, the circular connecting shaft is made of round steel, and the slipform panel is made of steel plate.

[0013] Preferably, the traction end is wrapped with round steel and made of steel plate.

[0014] Preferably, the top of the operating platform truss is used for laying scaffolding boards, and a plurality of the scaffolding boards are laid equidistantly on the top of the operating platform truss.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention adopts a three-section split structure. Each traction unit is independent and equipped with a "main rope" and "auxiliary rope" design. They are independently connected to the panel steel mesh, which greatly increases the construction safety factor. The traction system adopts a "synchronous start" switch to avoid the "derailment", "wire rope breakage", "slip formwork deviation" and other situations caused by the winches on both sides not running or starting synchronously due to human factors during traction. This improves the construction speed, ensures the construction quality and guarantees the construction safety.

[0017] 2. According to the initial setting time of concrete (2h46min) and the lifting speed of the slipform group (1.8m / h) proposed in the concrete mix design, through calculation, the third section "three-time repair and maintenance platform" is 4.98m away from the "main slipform body", which just meets the requirements of the initial setting time of concrete, and can timely cover and insulate the concrete and maintain moisture. With reliable support parts, a sunshade is set up between the "main slipform body and the three-time repair and maintenance platform" to prevent the poured concrete from being exposed to the sun and rain before covering and curing. When the slipform group is hoisted, the curing material (geomembrane) used is placed on the platform, which can timely cover and maintain the concrete, effectively avoiding damage to the concrete surface caused by manual laying, and eliminating safety hazards such as people falling and materials rolling during manual laying. At the same time, before laying the curing material, check the concrete surface again for quality defects, which can be dealt with in time to ensure the appearance quality of the panel concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural design diagram of the three-section split sliding module of the present invention.

[0019] Figure 1 Middle: 1. Main support beam of sliding formwork; 2. Truss of operating platform; 3. Scaffolding board; 4. Traction end; 5. Awning beam; 6. Circular coupling; 7. Sliding formwork panel; 8. Wire rope; 9. First base layer; 10. Second base layer. DETAILED DESCRIPTION

[0020] like Figure 1The trackless sliding formwork technology structure shown in the figure includes a sliding formwork main support beam frame 1, an operating platform truss 2, a scaffolding board 3, a traction end 4, a sunshade beam frame 5, a sliding formwork panel 7, a wire rope 8, a first base layer 9 and a second base layer 10. The first base layer 9 is located at the top of the second base layer 10. The first base layer 9 and the second base layer 10 are both placed at an inclined angle to the horizontal plane. The top of the first base layer 9 is fixedly connected to the sliding formwork main support beam frame 1. The number of the sliding formwork main support beam frames 1 is set to multiple. The sliding formwork main support beam frames 1 are used for sliding. The formwork panel 7 is welded to support the slipform panel 7, which is the main force-bearing body. The top of the main support beam 1 of the slipform body is welded with a slipform panel 7. The top of the first base layer 9 is fixedly connected with an operating platform truss 2. The number of the operating platform trusses 2 is set to multiple. The operating platform truss 2 is used to lay scaffolding boards 3, which is convenient for workers to walk and place small tools. The top of the operating platform truss 2 is laid with scaffolding boards 3. The number of scaffolding boards 3 is set to multiple. One end of the main support beam 1 of the slipform body is fixedly connected with a traction end 4. The number of traction ends 4 is set to multiple. The traction end 4 is connected to the steel wire rope 8 for pulling and sliding each split unit. The bottom end of the traction end 4 is fixedly connected to the steel wire rope 8. The number of the steel wire rope 8 is set to multiple. The steel wire rope 8 is used to connect and pull each split unit. The top side of the operating platform truss 2 is fixedly connected to the sunshade beam frame 5. The sunshade beam frame 5 is used to build a sunshade (rainproof) shed to ensure that the concrete is not exposed to the sun and rain, and is also used as a safety guardrail. The top of the first base layer 9 is fixedly connected to the circular coupling 6. The number of the circular coupling 6 is set to multiple The circular coupling 6 is improved to be made of round steel, which reduces the contact area with the side formwork and reduces the sliding friction resistance, making it easier to slide. The main support beam 1 of the sliding formwork body is made of I-steel, and the top of the operating platform truss 2 is paved with a template. The awning beam 5 is made of angle steel, the circular coupling 6 is made of round steel, and the sliding formwork panel 7 is made of steel plate. The traction end 4 is wrapped with round steel, and the traction end 4 is made of steel plate. The top of the operating platform truss 2 is used to lay the scaffolding board 3, and multiple scaffolding boards 3 are laid equidistantly on the top of the operating platform truss 2.

[0021] Research and verification of the innovative trackless sliding structure optimization design of the present invention

[0022] The research ideas of the present invention are as follows:

[0023] Through research into the application of trackless slipforms in thin-wall concrete construction, the structural design of the slipform group has been improved, resolving the constraints that restrict concrete placement and curing. This also significantly reduces and prevents cracks in the panels after forming. Based on initial setting time data from concrete mix tests, precise calculations are used to strictly control the pulling distances between the slipform body, secondary finishing platform, and tertiary finishing and curing platform. This ensures normal concrete placement and slipform lifting speed, while addressing concrete pouring quality issues caused by untimely concrete curing. The "three-section" split structural design ensures construction progress, quality, and safety.

[0024] Structural load calculation of the present invention:

[0025] First point: load calculation

[0026] Working conditions

[0027] The concrete design index of the panel rockfill dam of this project is C30W8F250. The anti-seepage panel concrete is ordinary concrete. From top to bottom, it is a concrete slab of equal thickness. The panel thickness is 40 cm. There are 16 panels in total. The panel slope ratio is 1:1.4. The width of the standard panel block is 13 meters, 6.5 meters on both sides, single-layer bidirectional reinforcement, panel area is 8232.13m2, and panel concrete is 3292.85m3.

[0028] Second point: Calculation basis:

[0029] Construction Blueprint for Concrete Face Rockfill Dam

[0030] Sliding Formwork Engineering Technical Standard GB / T 50113-2019

[0031] Technical Specifications for Construction of Concrete Face Rockfill Dams SL 49-2015

[0032] Handbook of Building Construction Calculations (Fourth Edition)

[0033] Mandatory Provisions of Engineering Construction Standards for Water Conservancy Projects (2020 Edition)

[0034] Specification for Hydraulic Concrete Construction SL677-2014

[0035] Third point: Load calculation:

[0036] Quoting formula:

[0037] Formula 1: (G1+G2)Cosα≥P

[0038] Where:

[0039] G1 and G2 are the weight and counterweight of the sliding form, unit: KN;

[0040] a - Angle between the sliding panel and the horizontal plane;

[0041] P - the buoyancy of the newly poured concrete on the slipform on the slope surface, unit: KN;

[0042] P is calculated by the following formula:

[0043] Formula 2: P = Pn × L × b × Sinα

[0044] Where:

[0045] Pn - concrete side pressure of inward-inclined formwork, unit: KPa;

[0046] L - width of the poured concrete block, unit: m;

[0047] b - width of sliding template, unit: m;

[0048] Formula 3: Pn=0.22γct0β1β2V1 / 2

[0049] According to the "Construction Calculation Manual" (4th edition), Chapter 9, 9.1, when the pouring slope angle is less than 45°, Pn is taken as 5KPa.

[0050] Concrete uplift pressure (buoyancy) calculation, the new pouring layer refers to the fluid dynamics calculation. Each pouring layer thickness is calculated as 0.3m, while considering the load generated by concrete vibration of 4kN / m2.

[0051] Solution value table

[0052]

[0053]

[0054] P = 45.34 kN, and the counterweight G2 ≥ 27.5 kN, meaning a minimum of 2.75 t is required. To allow for a certain margin and ensure the balance of the sliding formwork, a total of 3.5 t is required. The counterweight is made of precast concrete cubes, measuring 0.4 (thickness) × 0.8 (length) × 0.5 (width) = 0.16 m3. Each piece weighs 0.384 t, and there are 10 pieces in total.

[0055] The traction force calculation of the present invention:

[0056] First point: winch pulling force calculation

[0057] The magnitude of the sliding form traction force in the traction system is related to the sliding form deadweight and the bonding force between the sliding form and the newly poured concrete.

[0058] Quoting formula:

[0059] Formula 1: T = [τA + G × sina + |Gcosa - P | f] K

[0060] Where:

[0061] T - sliding mode traction, unit: KN;

[0062] τ - bonding strength between the sliding formwork and concrete, for steel formwork, 0.5KN / m2;

[0063] A - contact area between the sliding form and the concrete, unit: m2;

[0064] a - the angle between the slope and the horizontal plane;

[0065] G - sliding form weight plus counterweight, unit: KN;

[0066] P - buoyancy of concrete, unit: KN;

[0067] f - friction coefficient between steel formwork and concrete, taken as 0.4~0.5;

[0068] K - traction safety factor, take 1.5~2.0.

[0069] According to actual production conditions and reference to relevant data, the values ​​and calculations of each item in the above formula are shown in Table 1.

[0070] Solution value table 1

[0071]

[0072] Second point: winch counterweight calculation

[0073] Formula 2: μG ≥ KT

[0074] Where:

[0075] G - weight of counterweight

[0076] μ - static friction coefficient, take 0.65

[0077] T - the pulling force on the winch. The maximum pulling force on the winch is 30.38KN.

[0078] K - safety factor, take 2.5

[0079] With reference to relevant data, the values ​​and calculations of each item in the above formula are shown in Table 2.

[0080] Solution value table 2

[0081] project G(KN) μ T(KN) K Numerical 116.9 0.65 30.38 2.5

[0082] Based on the above calculations and the configuration of the movable pulleys, two 5-ton winches were selected as the traction equipment for the slipform construction. The pulling force on each winch is T / 4 = 30.38 kN. Therefore, the counterweight of each winch is 11.7 tons.

[0083] Each winch is equipped with two counterweights. The counterweight blocks are made of precast concrete filled cubes. The size of a single block is: 1.0 (height) × 2.0 (length) × 1.5 (width) = 3.3m3. The weight of a single block is 7.92t. There are 4 blocks in total.

[0084] According to the above calculation, the traction force ∑T> the total sliding load ∑P, and the sliding system operates stably and safely.

[0085] The main conclusions of the present invention are:

[0086] The research results of this invention have been successfully applied to the concrete pouring construction of the face rockfill dam of the Hanjiaxia Reservoir Project in Jinchang City. It effectively solved the technical difficulties encountered in the concrete pouring process and post-pouring maintenance, ensured the overall quality of the face concrete after molding, and suppressed the inducement of cracks in the face concrete. The construction measures adopted, the new equipment and technologies developed have achieved good application effects. At present, a high-tech research project (research on high crack resistance face concrete technology) and a science and technology progress award have been applied for, achieving the purpose of the research project. The main application technologies have been formed as follows:

[0087] First, through the innovative and improved "trackless sliding formwork" three-section split structure design, efficient and rapid concrete pouring was achieved, concrete maintenance was carried out in a timely and effective manner, and the engineering construction task was completed with quality and quantity guaranteed.

[0088] Second, through precise calculations and a rational layout of the traction units, the concrete is immediately covered and watered for curing as soon as it reaches its initial setting stage. This effectively suppresses the causes of concrete cracks, resolves conflicts and constraints between the concrete pouring and curing processes, and addresses potential quality issues associated with concrete pouring due to temperature fluctuations and the natural environment.

[0089] Through improved slipforms and innovative process technologies, rapid pouring and curing were achieved, resolving the technical constraints inherent in the concrete slab pouring and curing processes. This ensured the physical and visual quality of the finished slab concrete, accelerating construction progress (completed 20 days ahead of schedule). This effectively reduced the time and expense of addressing subsequent quality defects, further enhancing the overall quality of the project. This provides a valuable reference for future similar projects and informs theoretical research on key technologies for preventing and controlling cracking in slab concrete.

[0090] Table 5-1 Research results of new trackless sliding formwork

[0091]

[0092] The economic and social benefits of this invention are:

[0093] First point: economic benefits

[0094] By resolving the technical contradictions between the dam slab concrete pouring and maintenance technologies, the root cause of concrete cracks was eliminated, improving both the appearance and physical quality of the concrete slab (only 17 Category II cracks and no Category III cracks were observed in the post-molding concrete slab). The slab concrete pouring was also completed 20 days ahead of the original design (the original design planned for 60 days, but the actual completion time was only 40 days).

[0095] First, save construction costs

[0096] The construction period was advanced by 20 days. A total of 98 people of various types were engaged in concrete construction in this project. The main rental equipment included 1 crane, 1 excavator, 4 tankers and 2 loaders, which saved a total of about RMB 990,700 in construction costs.

[0097] The average monthly salary per person is 12,000 yuan, and the labor cost savings = 98 × (12,000 ÷ 3 × 2) = 784,000 yuan;

[0098] Equipment cost = (55,000 ÷ 3 × 2 + 71,000 ÷ 3 × 2 + 31,000 ÷ 3 × 2 × 4 + 30,000 ÷ 3 × 2 × 2) = 20.67 yuan;

[0099] Second, save the cost of handling quality defects in the later stage

[0100] A survey revealed that Class I cracks accounted for 96.3% (2,729.14 m), Class II cracks accounted for 3.7% (104.86 m), and there were no Class III cracks. According to the standard crack classification and treatment methods, Class I cracks were treated with surface sealing, while Class II and Class III cracks were treated with chemical grouting. Chemical grouting generally costs 275 yuan per m.

[0101] Savings in processing costs = 275 yuan / m × (2729.14 ÷ 2) = 375,300 yuan.

[0102] Third, save total costs

[0103] Savings on total construction costs - R&D investment for this project = 990,700 yuan + 375,300 yuan - 276,300 yuan = 1,089,700 yuan.

[0104] Second point: social benefits

[0105] The design and application of the "three-section split trackless sliding formwork" achieved complete success, achieving technological and process innovations while improving the quality, safety, and progress of the project. Testing revealed that all cracks in the concrete panels were classified as "Class I," achieving the desired results and objectives (there were only 17 Class II cracks, accounting for 7.3% and 0.0005% of the panel area, resulting in an excellent quality assessment for the project). Under the design conditions of ultra-thin concrete panels, innovations and breakthroughs were achieved in the key technologies of rapid pouring and timely curing, earning recognition from all parties involved in the project, the Jinchang Municipal Quality Supervision Station, and the Gansu Provincial Department of Water Resources. The Jinchang Municipal Quality and Safety Supervision Station is currently submitting applications for the Gansu Provincial Innovation and Technology Progress Award and the Outstanding Engineering Award (Feitian Award) on this topic. Furthermore, our company's technical management work during the construction of this project has been recognized and affirmed by industry insiders.

[0106] In summary, the present invention has the following beneficial effects: According to the concrete initial setting time (2h46min) and the lifting speed of the slipform group (1.8m / h) proposed in the concrete mix design, through calculation, the third section "three-time repair and maintenance platform" is 4.98m away from the "main slipform body", which just meets the requirements of the initial setting time of concrete, and can timely cover and insulate the concrete and maintain moisture. With reliable support members, a sunshade is set up between the "main slipform body and the three-time repair and maintenance platform" to prevent the poured concrete from being exposed to the sun and rain before covering and curing. When the slipform group is hoisted, the maintenance material (geomembrane) used is placed on the platform, which can timely cover and maintain the concrete, effectively avoiding damage to the concrete surface caused by manual laying, and eliminating safety hazards such as people falling and materials rolling down during manual laying. At the same time, before laying the maintenance material, the concrete surface is checked again for quality defects, which can be dealt with in time to ensure the appearance quality of the panel concrete.

Claims

1. A trackless sliding formwork structure, comprising a sliding formwork main support beam (1), an operating platform truss (2), a scaffolding board (3), a traction end (4), a sunshade beam (5), a sliding formwork panel (7), a steel wire rope (8), a first base layer (9) and a second base layer (10), characterized in that: The first base layer (9) is located at the top of the second base layer (10), and the first base layer (9) and the second base layer (10) are both placed at an inclined angle to the horizontal plane. The top of the first base layer (9) is fixedly connected to the main support beam frame (1) of the sliding formwork body, and the number of the main support beam frames (1) of the sliding formwork body is set to be multiple. The top of the main support beam frame (1) of the sliding formwork body is welded with a sliding formwork panel (7). The top of the first base layer (9) is fixedly connected to the operating platform truss (2), and the number of the operating platform truss (2) is set to be multiple. 2) is paved with a scaffolding board (3), the number of the scaffolding board (3) is set to be multiple, one end of the main support beam frame (1) of the sliding formwork body is fixedly connected to a traction end (4), the number of the traction ends (4) is set to be multiple, the bottom end of the traction end (4) is fixedly connected to a steel wire rope (8), the number of the steel wire rope (8) is set to be multiple, the top side of the operating platform truss (2) is fixedly connected to a sunshade beam frame (5), the top of the first base layer (9) is fixedly connected to a circular connecting shaft (6), the number of the circular connecting shaft (6) is set to be multiple; The overall structure adopts a three-section split structure. Each traction unit is independent and equipped with a "main rope" and "auxiliary rope" design. They are individually connected to the panel steel mesh, which greatly increases the construction safety factor. The traction system adopts a "synchronous start" switch to avoid the winches on both sides from not running or starting synchronously due to human factors during traction. A sunshade is set up between the "main sliding formwork and the tertiary repair and maintenance platform" to protect the poured concrete from the sun and rain before covering and curing. When the sliding formwork group is hoisted, the curing materials used are placed on the platform, so that the concrete can be covered and cured in time.

2. A trackless sliding form technology structure according to claim 1, characterized in that: The main support beam frame (1) of the sliding formwork body is made of I-steel, and the top end of the operating platform truss (2) is paved with a template.

3. A trackless sliding form technology structure according to claim 2, characterized in that: The sunshade awning beam frame (5) is made of angle steel, the circular connecting shaft (6) is made of round steel, and the sliding form panel (7) is made of steel plate.

4. The trackless sliding form technology structure according to claim 3, characterized in that: The traction end (4) is wrapped with round steel and is made of steel plate.

5. The trackless sliding form technology structure according to claim 4, characterized in that: The top of the operating platform truss (2) is used for laying scaffolding boards (3), and a plurality of scaffolding boards (3) are laid at equal intervals on the top of the operating platform truss (2).

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