Anti-cracking maintenance supporting system for early-dismantling formwork of pipe gallery top plate and construction method

Abstract

The invention provides an anti-cracking maintenance supporting system of a pipe gallery top plate early-dismantling formwork and a construction method, and belongs to the technical field of maintenance supporting. The outer formworks are arranged on the two sides of the pipe gallery structure correspondingly; an opposite-pull screw rod is arranged between the inner mold system and the outer mold plate, and the inner mold system and the outer mold plate keep a distance through the opposite-pull screw rod and jointly form a pipe gallery wall forming cavity; and the maintenance supporting assembly is arranged below the top plate formwork and used for continuously supporting the top plate before the concrete strength does not meet the design requirement so as to prevent cracking and sinking. The internal formwork system and the maintenance supporting assembly are arranged, the formwork can be recycled in advance, the formwork occupation period is shortened, the turnover rate and the construction efficiency are improved, the construction period delay and resource waste caused by too late formwork removal are reduced, meanwhile, through the arrangement of the maintenance supporting assembly, the construction period is shortened, and the construction efficiency is improved. A construction side can obtain balance between structural safety and efficiency, and long-term durability protection and quality guarantee of the pipe gallery top plate structure are achieved.

Description

Technical Field

[0001] This invention relates to the field of maintenance support technology, and in particular to a crack-preventing maintenance support system and construction method for early removal formwork of pipe gallery roof slab. Background Technology

[0002] With the acceleration of urbanization, underground utility tunnels, as an important part of urban infrastructure, are seeing an increasing scale of construction and demand. During construction, the roof slab of the utility tunnel needs to be shaped using formwork. The support and dismantling of the formwork directly affect the safety of the utility tunnel structure and the efficiency of construction. Traditional utility tunnel construction generally adopts the method of overall formwork support and unified formwork dismantling. After the concrete is poured, it is necessary to wait for it to reach a high strength before dismantling. Although this can ensure the structural strength of the roof slab, it will lead to an excessively long turnover cycle of the formwork, which will seriously affect the construction progress. Especially in large-scale utility tunnel projects, the number of roof slab formwork is large and the frequency of dismantling and assembly is high. Long-term occupation of formwork resources will increase the project cost.

[0003] To address the aforementioned issues, some construction sites have introduced early-stripping formwork systems. These systems allow for partial formwork removal once the concrete reaches a certain early strength, enabling reuse. However, this approach often suffers from inadequate support. Specifically, if the support is insufficient after early formwork removal, concrete cracking or subsidence can occur, affecting structural quality. Furthermore, existing early-stripping systems rely heavily on manual experience to determine the appropriate concrete strength, lacking scientific monitoring methods. This can lead to premature or delayed formwork removal, posing safety risks and delaying the construction schedule. Additionally, existing formwork systems largely rely on large machinery like cranes for formwork removal and movement, resulting in complex operations and safety hazards. This is especially problematic in narrow or irregularly shaped work areas, where stability during formwork movement is difficult to guarantee, potentially leading to tipping or displacement, increasing construction difficulty and risk. Therefore, based on these issues, this invention provides a crack-resistant curing support system and construction method for early-stripping formwork of utility tunnel roof slabs to meet these requirements. Summary of the Invention

[0004] The technical problem this invention aims to solve is to provide a crack-preventing curing support system and construction method for early formwork removal in utility tunnel roof slabs. By setting up an inner formwork system and curing support components, the system not only maintains stable support for the roof slab during the initial curing stage of concrete, effectively preventing cracking, subsidence, and structural damage caused by premature formwork removal, but also allows for partial formwork removal after the concrete reaches a set strength, enabling earlier formwork turnover, improving construction efficiency, and shortening the construction period. Simultaneously, the inner formwork system forms a stable molding frame through channel steel back ribs, film-coated plywood, and tie rods, ensuring the molding accuracy of the walls and roof slab. The curing support components retain late-removal uprights and joint adjustment steel plates at key locations on the roof slab, achieving continuous support for the roof slab. Through these measures, the problems of excessively long formwork turnover cycles, inaccurate reliance on manual experience for concrete strength assessment, and the difficulty in balancing formwork removal and curing in traditional utility tunnel construction are solved.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] The anti-cracking and curing support system for the early removal formwork of the pipe gallery roof slab includes: external formwork, which is arranged on both sides of the pipe gallery structure;

[0007] An inner mold system is provided with tie rods between the inner mold system and the outer mold. The inner mold system and the outer mold are maintained at a distance by the tie rods and together form the forming cavity of the pipe gallery wall. The cavity is specifically a power compartment, a comprehensive compartment I and a comprehensive compartment II.

[0008] The top slab formwork is placed on top of the pipe gallery wall, and the top slab formwork is connected to the inner formwork system to form an overall frame structure;

[0009] A moving unit is located at the bottom of the inner mold system and the outer mold plate, and is used to achieve smooth movement of the mold plate when the mold plate is disassembled early;

[0010] The maintenance support components are installed below the top slab formwork to continuously support the top slab until the concrete strength reaches the design requirements, in order to prevent cracking and subsidence.

[0011] Optionally, the internal mold system includes several sets of channel steel back ribs movably mounted on the base plate. Each set of channel steel back ribs has two L-shaped channel steel back ribs facing each other. Each set of channel steel back ribs has a side-coated plywood and a top-coated plywood on its outer side. Several wooden I-beams are provided between the side-coated plywood, the top-coated plywood and the channel steel back ribs. Each channel steel back rib has a supporting upright on one side for support. One end of the supporting upright is supported on the base plate, and the other end of the supporting upright is in close contact with one side of the channel steel back rib. A pair of lower support rods are provided between two channel steel back ribs for support.

[0012] Optionally, each of the channel steel back ribs is provided with an adjustable diagonal brace at its top for top reinforcement. A template level adjuster is provided between the tops of the two channel steel back ribs for correcting and adjusting the inner mold system on both sides.

[0013] Optionally, the moving unit includes moving wheels fixedly installed at the bottom of the outer template and the channel steel back rib, and several guide rails can be provided on the top surface of the base plate to cooperate with the moving wheels for movement.

[0014] Optionally, the maintenance support assembly includes a joint adjustment steel plate disposed between the two top-coated plywood panels, with a late-removal upright at the bottom of the joint adjustment steel plate, the other end of which is fixed to the base plate, and the maintenance support assembly is provided in one or more sets according to the width and span of the compartment.

[0015] Optionally, a support rod is provided on one side of the outer template to prevent the outer template from tilting to one side when it moves.

[0016] Optionally, the inner mold system is equipped with a concrete strength monitoring module for real-time prediction of the demolding timing. The concrete strength monitoring module includes:

[0017] Embedded strain sensors are used to acquire the elastic modulus of concrete in real time.

[0018] A wireless transmission unit is used to send data to a control terminal;

[0019] An analysis algorithm is used to predict the demolding time point when the strength reaches 50%.

[0020] Optionally, the analysis algorithm is based on a temperature-intensity development model:

[0021]

[0022] Among them, f c (t) represents the compressive strength of concrete at age t days, f c28 The standard compressive strength of concrete at 28 days, where S is silicate cement and S = 0.25, and t is the age, is used for dynamic calibration of demolding instructions.

[0023] This application also discloses a method for constructing a crack-resistant curing support system for early-stripping formwork of utility tunnel roof slabs, which is applied to the aforementioned crack-resistant curing support system for early-stripping formwork of utility tunnel roof slabs, and includes the following steps:

[0024] S1: After the excavation of the foundation pit and the construction of the foundation layer are completed, the formwork of the guide wall section is erected to form the foundation structure;

[0025] S2: Install the inner mold system, outer mold, and top plate mold on the guide wall section mold. Fix them with tie rods and reinforce and correct them with mold level adjusters and diagonal braces to ensure the accuracy of the forming cavity.

[0026] S3: Tie the reinforcing bars and pour the concrete. During the concrete pouring and curing process, the concrete strength monitoring module detects the strength development in real time and determines the timing of early formwork removal.

[0027] S4: When the concrete strength reaches the set threshold, part of the inner and outer formwork is removed first, and the formwork is moved smoothly along the guide rail by the moving unit;

[0028] S5: After removing the inner and outer formwork, retain the curing support components at the top plate position to continuously support the top plate until the concrete strength reaches the design value, preventing cracking and subsidence.

[0029] Optionally, the template moving process in step S4 includes:

[0030] After loosening the tie rods and connectors, the adjustable bracing is used to shrink the formwork, allowing it to detach from the concrete wall. Then, the formwork is moved to the next construction position using the moving wheels and the base plate guide rail. The outer formwork is moved only after the inner formwork has been completely removed from the flow section. During the formwork movement, the formwork and the support system are connected as a whole using bracing and reinforcing members to prevent tipping and displacement deviation, thereby ensuring the stability and safety of the formwork removal process.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] In the above scheme, by setting up an internal formwork system and curing support components, the formwork of the utility tunnel roof slab can be removed in stages after the initial setting of the concrete. The internal formwork system, while ensuring the accuracy of structural forming, enhances the rigidity of the overall frame through the cooperation of tie rods, channel steel back ribs, and diagonal braces, keeping the formwork stable during concrete pouring and curing, and preventing wall deformation. The curing support components retain uprights and joint adjustment steel plates at key parts of the roof slab, ensuring that the roof slab can still receive reliable temporary support before the concrete strength fully reaches the design value, thereby effectively preventing cracking, subsidence, and early damage to the roof slab. Compared with the traditional method of overall formwork support and unified formwork removal, the formwork can be reused in advance, which shortens the formwork occupation period, improves the turnover rate and construction efficiency, and reduces the construction period delays and resource waste caused by late formwork removal. At the same time, by setting up the curing support components, the construction party can achieve a balance between structural safety and efficiency, and achieve long-term durability protection and quality assurance for the utility tunnel roof slab structure.

[0033] By incorporating mobile units, the formwork can be moved smoothly and controllably during early dismantling. Traditional formwork dismantling often requires cranes for transport, which not only increases the investment in construction machinery and labor costs but also poses operational risks. The formwork can be moved horizontally and transported using its own wheels and guide rails, significantly reducing safety risks during construction. Furthermore, the use of external formwork supports and reinforcing members between the inner and outer formwork during movement ensures overall stability, preventing tilting or displacement due to uneven weight distribution or external interference, thus significantly improving the safety and reliability of the movement.

[0034] By setting up a concrete strength monitoring module, including embedded strain sensors, wireless transmission units, and analysis algorithms, the construction team can obtain real-time information on the strength development of the concrete and dynamically predict the appropriate timing for early formwork removal. In traditional processes, the timing of formwork removal largely relies on the experience and judgment of construction personnel or the use of fixed age standards. This can easily lead to the risk of insufficient strength of the top slab structure due to premature formwork removal, or the problem of extended construction cycle and formwork resource occupation due to delayed formwork removal. However, the strength monitoring module of this invention can calculate the early strength of concrete in real time based on a temperature-strength development model. When the strength reaches a set threshold (such as 50%), a formwork removal signal is issued, ensuring that the formwork is removed as early as possible while ensuring the safety of the top slab structure. At the same time, the data is transmitted to the control terminal through the wireless unit, realizing intelligent and visual management of the construction process. This module not only improves the scientificity and accuracy of the construction process but also reduces the uncertainty caused by human judgment, achieving precise control over the early performance of concrete. Through this design, the construction cycle is shortened, the formwork turnover efficiency is improved, and the overall construction management level and project reliability are significantly enhanced. Attached Figure Description

[0035] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0036] Figure 1 A schematic diagram of the integrated support structure for crack prevention and maintenance of early-removal formwork for the roof slab of the utility tunnel;

[0037] Figure 2 A schematic diagram of the inner and outer formwork support structure of the early-removal formwork support system for the pipe gallery roof slab;

[0038] Figure 3 This is a schematic diagram of the internal planar structure of the power compartment;

[0039] Figure 4 This is a schematic diagram of the planar structure of the internal model of Integrated Module I;

[0040] Figure 5 Schematic diagram of the maintenance support component structure;

[0041] Figure 6 This is a schematic diagram showing the movement status of the outer template;

[0042] Figure 7 This is a schematic diagram of the movement state of the inner template;

[0043] Figure 8 This is a schematic diagram of the construction process for underground utility tunnels.

[0044] Figure 9 A flowchart of the construction method for crack prevention and maintenance support of early removal formwork for the top slab of the utility tunnel;

[0045] Figure 10 This is a schematic diagram of a concrete strength monitoring module.

[0046] Figure label:

[0047] 1. Outer formwork; 2. Side film-coated plywood; 3. Top film-coated plywood; 4. Channel steel back brace; 5. Tie rod; 6. Timber I-beam; 7. Diagonal brace; 8. Support upright; 9. Joint adjustment steel plate; 10. Late dismantling upright; 11. Lower support rod; 12. Casters; 13. Guide rail.

[0048] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0049] The crack-prevention and maintenance support system and construction method for early removal formwork of pipe gallery roof slab provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0050] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0051] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0052] It is understood that the meanings of “on”, “above”, and “above” in this invention should be interpreted in the broadest manner, such that “on” means not only “directly on” something, but also includes the meaning of being “on” something with an intervening feature or layer, and that “above” or “above” means not only “on” something, but also includes the meaning of being “on” something without an intervening feature or layer.

[0053] Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for convenience to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. Spatially related terms are intended to cover different orientations in the use or operation of the device other than those depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially related descriptive terms used herein can be interpreted similarly.

[0054] like Figures 1 to 10As shown, embodiments of the present invention provide a crack-prevention and maintenance support system for early removal formwork of the top slab of a utility tunnel, including an outer formwork 1, which is respectively arranged on both sides of the utility tunnel structure; an inner formwork system, wherein tie rods 5 are provided between the inner formwork system and the outer formwork 1, and the inner formwork system and the outer formwork 1 are kept apart by the tie rods 5 and together form the forming cavity of the utility tunnel wall, the cavity specifically being an electrical compartment, an integrated compartment I, and an integrated compartment II; a top slab formwork, which is arranged on the top of the utility tunnel wall, and the top slab formwork is connected to the inner formwork system to form an integral frame structure; and a moving unit, which is provided with Placed at the bottom of the inner formwork system and outer formwork 1, it facilitates smooth movement of the formwork during early formwork removal. The curing support assembly, located below the top slab formwork, continuously supports the top slab until the concrete strength reaches the design requirements, preventing cracking and subsidence. The outer formwork 1 and the inner formwork system are locked together by tie rods 5. The top slab formwork connects the two side formworks on the top surface, jointly enclosing the forming cavity of the power compartment and integrated compartment I / II. This not only suppresses formwork bulging and slippage during pouring but also closes the lateral pressure of the freshly mixed concrete within the rigid formwork. In the curing ring, the linear and dimensional stability at the wall-top junction is significantly improved, creating conditions for subsequent early removal. The curing support components "hold" the top slab formwork for a long time, bearing the additional effects of short-term dead load and shrinkage creep before the concrete reaches its design strength, avoiding a sudden increase in deflection and crack initiation caused by premature unloading. After the inner and outer formworks are removed and moved early, the top slab remains in a "supported" and controlled state, reducing the risk of early cracking and subsidence of the top slab. The inner formwork system and the bottom of the outer formwork 1 are equipped with moving units, which can move along the bottom slab after the formwork is removed early. Stable relocation eliminates the need for extensive hoisting and interleaving, reducing high-altitude operations and cross-interference; rapid transfer of formwork to the next production line improves turnover efficiency and schedule certainty, while minimizing the risks of overturning and lateral displacement during dismantling and relocation; pre-set molding cavities according to compartment functions (power compartment, integrated compartment I / II) with clear geometric constraints, combined with a tie-type system and top plate connection, can stably obtain straight walls and straight top plate edges; the system is compatible with cross-sectional layouts of different clearances and widths, reducing the frequency of mold changes and lowering the systemic risk of dimensional deviations.

[0055] As one implementation method in this embodiment, such as Figures 1 to 7As shown, the internal mold system includes several sets of channel steel back ribs 4 movably mounted on the base plate. Each set of channel steel back ribs 4 has two L-shaped channel steel back ribs facing each other. Each set of channel steel back ribs 4 has side-coated plywood 2 and top-coated plywood 3 on its outer side. Several wooden I-beams 6 are set between the side-coated plywood 2, top-coated plywood 3 and channel steel back ribs 4. Each channel steel back rib 4 has a supporting upright 8 on one side for support. One end of the supporting upright 8 is supported on the base plate, and the other end of the supporting upright 8 is in close contact with one side of the channel steel back rib 4. A lower support rod 11 is set between two channel steel back ribs 4 for support. Each channel steel back rib 4 has an adjustable diagonal brace 7 at the top for top reinforcement. A template level adjuster is set between the tops of two channel steel back ribs 4 for adjusting the internal mold system on both sides. During the adjustment and construction process, the channel steel back ribs 4 are first installed on the base plate according to the design position to ensure that the spacing of the group arrangement meets the clear distance of the compartments. Then, the side-coated plywood 2 and the top-coated plywood 3 are installed on the outside of the channel steel back ribs 4 and connected and fixed laterally by several wooden I-beams 6, so that the steel back ribs and plywood form an integral load-bearing unit. Next, support poles 8 are erected on one side of each channel steel back rib 4, with the lower end abutting the base plate and the upper end tightly attached to the channel steel back rib 4, to bear vertical and inclined loads. Then, lower support poles 11 are installed between the two sets of opposite channel steel back ribs 4, so that the two sets of back ribs form a triangular stable system. After the assembly is completed, the verticality and symmetry of the inner formwork system are checked as a whole, and then the spacing is locked with the outer formwork 1 by tie rods 5 to form a complete wall forming cavity, ensuring that the formwork maintains rigidity stability and dimensional accuracy during the concrete pouring process.

[0056] Furthermore, the moving unit includes moving wheels 12 fixedly installed at the bottom of the outer formwork 1 and the channel steel back rib 4, and several guide rails 13 can be set on the top surface of the base plate to cooperate with the moving wheels 12 for movement. A support rod is set on one side of the outer formwork 1. The support rod is used to prevent the outer formwork 11 from tilting to one side when it moves. After the main structure of the pipe gallery is poured, when the concrete reaches a certain strength, the tie rods 5 are loosened to allow the outer formwork 1 to detach from the wall. Then, it is moved using the moving wheels 12 and the ground guide rails 13 below the outer formwork 1. No crane is needed. When moving, the base is raised, and the moving wheels 12 sit on the guide rails 13 to push forward. When the outer formwork moves, in order to prevent the formwork from tilting to one side, diagonal braces 7 (such as...) are set on the outer formwork 1. Figure 6 As shown), in order to prevent the outer formwork 1 from tipping over, it is supported on the slope. However, in the case of irregular working surfaces, the movement of the outer formwork will be handled separately. The construction site will adopt a relatively safe movement method according to the actual construction situation. If the working surfaces cannot be in a straight line and are at different elevations, the outer formwork will be transferred by hoisting.

[0057] In addition, when dismantling the inner formwork system, after the main structure of the pipe gallery has been poured and the concrete has reached a certain strength, the tie rods 5 are loosened, and then the corresponding connecting components (such as formwork level adjusters, adjustable braces, etc.) are removed. During demolding, the adjustable braces can be used to shrink the formwork, allowing the formwork on both sides to detach from the concrete wall. Then, the heavy supports and the weight of the formwork system itself cause the formwork to detach. Once the formwork leaves the main wall, the moving wheels 12 of the inner formwork system enable half of the formwork to move as a whole. To ensure the stability of the formwork during movement, connecting rods (such as...) are added between the formwork and the heavy supports, and between the front and rear heavy supports. Figure 7 (As shown). Once half of the template is in a stable state, push it forward to the next station. If it tilts to one side due to uneven weight distribution, add counterweights to the other side to ensure the template moves forward at a constant speed.

[0058] In this embodiment, as Figures 2 to 5 As shown, the maintenance support assembly includes a joint adjustment steel plate 9 set between two top-coated plywood panels 3. A late-removal upright 10 is installed at the bottom of the joint adjustment steel plate 9, with the other end of the late-removal upright 10 fixed to the base plate. One or more sets of maintenance support assemblies are set according to the width and span of the compartment. After the installation of the pipe gallery roof formwork system is completed and the concrete is poured, as the roof strength gradually increases, construction workers loosen the tie rods 5 and remove the outer connecting parts according to the early removal plan, allowing some formwork to be demolded and removed first. However, at key locations on the roof, the joint adjustment steel plate 9 set between the two top-coated plywood panels 3 and the late-removal upright 10 below it remain in place. 0. Maintain support to ensure that the top slab will not sink or crack due to its own weight or construction load when its strength is insufficient. Different number of support groups are arranged in different compartments according to the span size. Only one set of support is retained in the power compartment and integrated compartment II, while two sets of support are retained in the integrated compartment I with a larger span, thus forming a zoned support effect. After the concrete strength reaches the design requirements, the late-removed uprights 10 and joint adjustment steel plates 9 are removed in a unified manner, thus completing the complete recycling of the formwork. Throughout the process, the formwork system realizes the dynamic support strategy of "removing parts first and then key parts", which not only ensures the rapid turnover of the formwork, but also ensures the safety and durability of the top slab structure.

[0059] In this embodiment, as Figures 1 to 2 and Figure 10 As shown, the inner formwork system is equipped with a concrete strength monitoring module for real-time prediction of the formwork removal timing. The concrete strength monitoring module includes:

[0060] Embedded strain sensors are used to acquire the elastic modulus of concrete in real time.

[0061] A wireless transmission unit is used to send data to a control terminal;

[0062] An analysis algorithm is used to predict the demolding time when the strength reaches 50%;

[0063] The analysis algorithm is based on the temperature-intensity development model:

[0064]

[0065] Among them, f c (t) represents the compressive strength of concrete at age t days, f c28 The standard compressive strength of concrete at 28 days, where S is silicate cement and s = 0.25, and t is the age, is used for dynamic calibration of formwork removal instructions;

[0066] After concrete pouring is completed, embedded strain sensors in the inner formwork system begin to collect real-time data on concrete strain and elastic modulus. This data is then transmitted wirelessly to the control terminal. The control terminal's built-in analysis algorithm processes the collected data, combining it with a temperature-strength development model to calculate the strength changes at different stages of concrete age, dynamically plotting a strength development curve. When the prediction results show that the concrete strength has reached 50% of the design strength, the system automatically issues a reminder or instruction, prompting construction personnel to begin early formwork removal. Based on this, the construction personnel proceed with the planned phased removal of the inner and outer formwork, while simultaneously protecting the top slab structure with the assistance of curing support components. The entire process achieves closed-loop control from sensor detection, wireless transmission, terminal analysis to automatic judgment, ensuring the scientific and safe operation of early removal. This concrete strength monitoring module not only collects data through sensors but also incorporates a temperature-strength development model.

[0067]

[0068] This formula can dynamically adjust the strength development rate under different construction environments, and is especially suitable for situations with large temperature fluctuations on site. Using this model, the system can more accurately predict when the concrete strength reaches 50% of the design strength, rather than relying on fixed numbers of days or human experience. This not only ensures the scientific nature of the demolding timing but also reduces the risk of cracking due to insufficient curing. After the concrete is poured, embedded strain sensors begin to collect real-time strain and modulus data of the concrete and transmit them to the control terminal via a wireless transmission module. The control terminal first performs preliminary strength conversion based on the collected data, and then calls the temperature-strength development model for dynamic calibration. The system inputs the construction environment temperature, concrete age, and material property parameter S into the model formula to calculate the compressive strength value of the concrete at any time point.

[0069] f c (t), when the prediction results show that the concrete strength reaches f c28When the formwork reaches 50%, the terminal automatically generates a demolding instruction or prompt to notify the construction personnel to carry out early demolding. Subsequently, the construction personnel loosen the tie rod 5 and auxiliary components in sequence according to the prompt, and cooperate with the moving unit and maintenance support components to remove the formwork. Through this process, the system realizes closed-loop control from data acquisition to mathematical modeling, strength prediction and instruction output, so that the early demolding operation has data support and scientific basis, which greatly improves the safety and reliability of construction.

[0070] It is worth noting that, in the embodiments of the present invention, the parameter S in the temperature-strength development model is used to characterize the early strength growth rate of concrete. Its value is related to the cement type, admixture and additive system, water-cement ratio, and curing temperature. Under normal conditions, S = 0.25 can be used as an initial empirical value for ordinary Portland cement. For composite Portland cement systems with high slag or fly ash content, the S value is usually larger and can be adjusted to about 0.30–0.40. For early-strength or fast-hardening cement systems, the development is faster, and the S value is correspondingly reduced, which can be 0.18–0.25. In construction applications, the system can combine the on-site curing temperature and the measured strength of the specimen to perform rolling corrections on the S value to ensure the accuracy of the prediction. Through the above parameter correction method, the present invention enables the model to be applicable to different cement systems and construction environments, thereby improving the reliability of concrete strength prediction and demolding timing determination.

[0071] As one implementation method in this embodiment, such as Figures 8 to 10 As shown, the present invention also provides a method for constructing a crack-resistant curing support system for early-stripping formwork of a utility tunnel roof slab, which is applied to the aforementioned crack-resistant curing support system for early-stripping formwork of the utility tunnel roof slab, and includes the following steps:

[0072] S1: After the excavation of the foundation pit and the construction of the foundation layer are completed, the formwork of the guide wall section is erected to form the foundation structure;

[0073] S2: Install the inner mold system, outer mold 1 and top plate mold on the guide wall section mold, fix them with tie rods 5 and reinforce and correct them with mold level adjusters and diagonal braces 7 to ensure the accuracy of the forming cavity;

[0074] S3: Tie the reinforcing bars and pour the concrete. During the concrete pouring and curing process, the concrete strength monitoring module detects the strength development in real time and determines the timing of early formwork removal.

[0075] S4: When the concrete strength reaches the set threshold, part of the inner and outer formwork is removed first, and the formwork is moved smoothly along the guide rail 13 by the moving unit;

[0076] S5: After removing the inner and outer formwork, a curing support component is retained at the top slab location to continuously support the top slab until the concrete strength reaches the design value, preventing cracking and subsidence. By retaining the curing support component at the top slab location after early formwork removal, stable support can be continuously provided to the top slab before the concrete fully reaches its design strength, effectively avoiding cracking, subsidence, or local deformation problems caused by insufficient concrete strength. This component is arranged differently in different compartments according to the span size and stress conditions, making the support function more targeted, thus realizing the process logic of "early formwork removal, late support removal". This design not only ensures the safety and structural integrity of the top slab during the critical curing stage, but also avoids construction delays caused by completely delaying formwork removal, greatly improving construction efficiency and safety. Its beneficial effects are: by retaining the curing support, both formwork turnover rate and concrete quality control can be taken into account, achieving the dual goals of shortening the construction cycle and improving project quality.

[0077] The template movement process in step S4 includes:

[0078] After loosening the tie rods 5 and the connectors, the adjustable bracing is used to retract the formwork, detaching it from the concrete wall. Then, the moving wheels 12, in conjunction with the base plate guide rails 13, push the entire formwork to the next construction position. The outer formwork is moved only after the inner formwork has completely moved out of the flow section. During the formwork movement, the formwork and support system are connected as a whole by bracing and reinforcing members to prevent tipping and displacement deviation, thus ensuring stability and safety during early formwork removal. The use of moving wheels 12 and guide rails 13 during early formwork removal ensures smooth overall formwork movement, avoiding the impact and safety hazards caused by traditional hoisting methods on the formwork and concrete. The adjustable bracing allows for rapid detachment of the formwork from the concrete, reducing the time required for formwork dismantling. To mitigate the risk of damage to the concrete surface, the installation of struts and connecting rods during the movement process effectively prevents the formwork from tipping over or shifting due to uneven weight distribution or external disturbances, thus ensuring the stability and safety of the formwork transfer. Overall, this process not only significantly improves the turnover efficiency of the formwork and shortens the construction period, but also reduces reliance on mechanical hoisting and the risks of manual operation, enhancing the safety and economy of the construction site. During the movement, by adding struts and reinforcing rods between the formwork and the support system, a stable frame is formed for the overall structure. Even if uneven loads or thrusts are encountered, it can prevent the formwork from tipping over or shifting. The entire movement process realizes a continuous operation flow from "demolding - movement - stabilization and reinforcement," ensuring the efficiency and safety of early demolition operations.

[0079] The working principle of the technical solution provided by this invention is as follows:

[0080] Through the coordinated combination of the inner formwork system, outer formwork 1, top slab formwork, moving unit, curing support components and concrete strength monitoring module, an overall structure is formed that enables rapid early formwork removal, real-time monitoring of concrete strength and continuous support of the top slab. The inner and outer formwork maintain a stable spacing through tie rods 5 and adjusters. Together with the top slab formwork, they form the forming framework of the pipe gallery wall and top slab. The concrete strength monitoring module runs through the entire construction process, realizing the prediction and control of the early-age strength of concrete, providing a scientific basis for formwork removal, thereby achieving early removal and rapid turnover under the premise of ensuring structural safety.

[0081] When the concrete strength reaches the preset demolding threshold, the construction workers loosen the tie rods 5 and related connecting parts, and use the adjustable bracing to shrink the formwork as a whole, thereby achieving smooth separation of the formwork from the concrete. Subsequently, the formwork is smoothly pushed to the next construction position by the cooperation of the moving wheels 12 at the bottom and the guide rails 13 on the base plate. With the assistance of the bracing rods and reinforcing rods, the formwork remains stable during the movement, avoiding tilting and displacement deviation caused by uneven force or external disturbances, thus ensuring the safety and efficiency of early demolding and transportation of the formwork, and avoiding potential damage to the concrete surface and construction environment caused by traditional hoisting demolding methods.

[0082] After the formwork is removed early, the curing support components are still retained at the top slab position to continuously support the top slab before the concrete strength fully reaches the design value, preventing cracking, subsidence, or local damage. As the concrete strength gradually increases, the monitoring module provides real-time feedback on the strength development until the design requirements are met. Then, the construction personnel remove the curing support to achieve final shaping. Through this process logic of "early formwork removal and late support removal," combined with the linkage control of strength monitoring and formwork moving device, the system realizes the organic unity of rapid turnover of pipe gallery formwork construction, safe support, and concrete quality control, forming a complete closed-loop operation mode.

[0083] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0084] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A crack-prevention and curing support system for early-removal formwork of pipe gallery roof slab, characterized in that, include: External formwork is arranged on both sides of the pipe gallery structure; An inner mold system is provided with tie rods between the inner mold system and the outer mold. The inner mold system and the outer mold are maintained at a distance by the tie rods and together form the forming cavity of the pipe gallery wall. The cavity is specifically a power compartment, a comprehensive compartment I and a comprehensive compartment II. The top slab formwork is placed on top of the pipe gallery wall, and the top slab formwork is connected to the inner formwork system to form an overall frame structure; A moving unit is located at the bottom of the inner mold system and the outer mold plate, and is used to achieve smooth movement of the mold plate when the mold plate is disassembled early; The maintenance support components are installed below the top slab formwork to continuously support the top slab until the concrete strength reaches the design requirements, in order to prevent cracking and subsidence.

2. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 1, characterized in that, The internal mold system includes several sets of channel steel back ribs movably mounted on the base plate. Each set of channel steel back ribs has two L-shaped channel steel back ribs facing each other. Each set of channel steel back ribs has a side-coated plywood and a top-coated plywood on its outer side. Several wooden I-beams are set between the side-coated plywood, the top-coated plywood and the channel steel back ribs. Each channel steel back rib has a supporting upright on one side for support. One end of the supporting upright is supported on the base plate, and the other end of the supporting upright is in close contact with one side of the channel steel back rib. A pair of lower support rods are set between two channel steel back ribs for support.

3. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 2, characterized in that, Each of the channel steel back ribs is equipped with an adjustable diagonal brace at the top, which is used for top reinforcement. A template level adjuster is provided between the tops of the two channel steel back ribs for correcting and adjusting the inner mold system on both sides.

4. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 3, characterized in that, The moving unit includes moving wheels fixedly installed at the bottom of the outer template and the channel steel back rib, and several guide rails can be provided on the top surface of the base plate to cooperate with the moving wheels for movement.

5. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 4, characterized in that, The maintenance support assembly includes a joint adjustment steel plate disposed between the two top-coated plywood panels. The bottom of the joint adjustment steel plate is provided with a late-removal upright, and the other end of the late-removal upright is fixed to the base plate. The maintenance support assembly is provided in one or more sets according to the width and span of the compartment.

6. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 1, characterized in that, A support rod is provided on one side of the outer template to prevent the outer template from tilting to one side when it moves.

7. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 1, characterized in that, The inner mold system is equipped with a concrete strength monitoring module for real-time prediction of the demolding timing. The concrete strength monitoring module includes: Embedded strain sensors are used to acquire the elastic modulus of concrete in real time. A wireless transmission unit is used to send data to a control terminal; An analysis algorithm is used to predict the demolding time point when the strength reaches 50%.

8. The anti-cracking curing support system for early removal formwork of pipe gallery roof slab according to claim 7, characterized in that, The analytical algorithm is based on a temperature-intensity development model: Among them, f c (t) represents the compressive strength of concrete at age t days, f c28 The standard compressive strength of concrete at 28 days, where S represents silicate cement and S = 0.25, and t represents the age, is used for dynamic calibration of demolding instructions.

9. A method for constructing a crack-resistant curing support system for early-stripping formwork of a utility tunnel roof, applied to the crack-resistant curing support system for early-stripping formwork of a utility tunnel roof as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: After the excavation of the foundation pit and the construction of the foundation layer are completed, the formwork of the guide wall section is erected to form the foundation structure; S2: Install the inner mold system, outer mold, and top plate mold on the guide wall section mold. Fix them with tie rods and reinforce and correct them with mold level adjusters and diagonal braces to ensure the accuracy of the forming cavity. S3: Tie the reinforcing bars and pour the concrete. During the concrete pouring and curing process, the concrete strength monitoring module detects the strength development in real time and determines the timing of early formwork removal. S4: When the concrete strength reaches the set threshold, part of the inner and outer formwork is removed first, and the formwork is moved smoothly along the guide rail by the moving unit; S5: After removing the inner and outer formwork, retain the curing support components at the top plate position to continuously support the top plate until the concrete strength reaches the design value, preventing cracking and subsidence.

10. The method for preventing cracking and maintaining support of early-removal formwork for pipe gallery roof slabs according to claim 9, characterized in that, The template movement process in step S4 includes: After loosening the tie rods and connectors, the adjustable bracing is used to shrink the formwork, allowing it to detach from the concrete wall. Then, the formwork is moved to the next construction position using the moving wheels and the base plate guide rail. The outer formwork is moved only after the inner formwork has been completely removed from the flow section. During the formwork movement, the formwork and the support system are connected as a whole using bracing and reinforcing members to prevent tipping and displacement deviation, thereby ensuring the stability and safety of the formwork removal process.

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