Construction technology of movable formwork for deck culvert

Abstract

The application discloses a kind of cover slab culvert mobile mould frame construction technology, belong to municipal, highway culvert cast-in-place construction technical field.The process includes: construction preparation, import BIM design parameter;Mould frame intelligent sliding in place, laser inertial navigation autonomous walking, ultrasonic radar obstacle avoidance;Hydraulic automatic mode adjustment locking, formwork error ≤±2mm;Layered closed-loop pouring and vibrating, 3D visual monitoring liquid level dynamic control;Integrated constant-temperature curing in hole;Strength after automatic demoulding sliding;Full-process sensor data 5G upload cloud digital twin platform, realize remote monitoring and quality traceability.The application realizes the whole-process integrated intelligent construction of cover slab culvert mobile mould frame autonomous sliding, automatic mode adjustment, layered pouring and synchronous curing, cancels full-frame support, reduces manual intervention, eliminates construction joint, improves overall pouring quality and construction efficiency of culvert.

Description

Technical Field

[0001] This invention relates to the field of cast-in-place construction technology for culverts in municipal engineering and highway engineering, specifically to a construction process for movable formwork of slab culverts, which is particularly suitable for the overall cast-in-place operation of large-span, long linear slab culverts. Background Technology

[0002] Culverts, as common drainage structures in highway and municipal engineering projects, have long relied on traditional full-span scaffolding formwork for their cast-in-place construction. However, this traditional method has many insurmountable drawbacks.

[0003] First, the traditional full-span scaffolding formwork construction is extremely cumbersome in its erection and dismantling processes. The scaffolding occupies a large area, the working space inside the culvert is narrow, and material transportation is difficult. Second, traditional construction uses segmented formwork and pouring methods, resulting in numerous construction joints, leading to poor waterproofing and seepage prevention performance of the culvert, and difficulty in uniformly controlling the straightness and flatness of the culvert. Third, the manual erection, alignment, and dismantling of formwork involves numerous procedures, requiring a large number of personnel working at heights and inside the culvert, posing extremely high safety risks. Fourth, each process is carried out independently, lacking coordinated management, resulting in a chaotic sequence of pouring, vibration, and curing, and significant variations in concrete density and strength.

[0004] In recent years, some improved mobile formwork technologies have emerged in the industry. For example, a construction method for a mobile formwork platform for culverts (CN113430961B) is disclosed in the prior art, which uses a platform and formwork system to replace the tie rods for fixing the steel formwork, achieving the overall transfer of the formwork system. However, this type of existing simple mobile formwork only achieves the overall displacement of the formwork, lacking intelligent positioning and automatic formwork adjustment processes, and still relies heavily on manual correction. Another example is a variable-aperture self-propelled hydraulic formwork trolley for culvert abutments, which includes a moving wheel assembly and a track. However, this type of solution still only focuses on the mechanical displacement of the formwork, without an integrated process of layered quantitative pouring and simultaneous spray curing, resulting in fragmented construction quality control. A movable cast-in-place culvert cover formwork support (CN104674684A) is also disclosed in the prior art, which achieves support movement through uprights, crossbars, and moving wheels, but its essence is still a movable support system, lacking a complete intelligent construction process from sliding positioning and automatic formwork adjustment to pouring and curing. In addition, existing technologies generally lack digital monitoring methods, making it impossible to record formwork displacement and concrete pouring parameters in real time, and making quality traceability difficult.

[0005] In summary, existing culvert construction technology has not yet formed a complete integrated intelligent construction solution that integrates autonomous formwork movement, automatic formwork adjustment, layered pouring, and synchronous curing. There is an urgent need for a technical solution that can systematically solve the above problems. Summary of the Invention

[0006] This invention provides an integrated intelligent construction process for culvert movable formwork, aiming to achieve autonomous formwork sliding, automatic posture adjustment, precise layered pouring, synchronous curing, and full-process data monitoring. By eliminating full-span scaffolding, reducing manual intervention, and eliminating construction joints, this invention significantly improves the overall pouring quality and construction efficiency of culverts, while simultaneously establishing a proactive safety management system for the entire process of autonomous formwork movement, adjustment, pouring, and curing.

[0007] To achieve the above-mentioned objectives, this invention provides a construction process for a movable formwork for a culvert cover, comprising the following steps: S1: Construction Preparation After completing the foundation pad construction of the culvert, the sliding needle beam frame moving formwork was assembled. The moving formwork includes a formwork cantilever beam (1), a moving hoist (2), a gantry (3), inner and outer steel formwork (4), an outer formwork working platform (5), diagonal bracing (6), horizontal bracing (7), a walking system (8), walking sensors (9), and formwork sensors (10). After completing the formwork assembly, the BIM design alignment parameters of the culvert were imported, and the positioning system, hydraulic system, pouring system, and maintenance monitoring system were debugged to ensure that each subsystem operates normally.

[0008] S2: Intelligent sliding positioning of the mold frame The hydraulic system drives the formwork to slide along the needle beam of the culvert body, with the displacement constrained by a limiting and guiding device. The formwork is equipped with a laser positioning and inertial navigation unit. After inputting the culvert design alignment parameters, the laser and inertial navigation work together to drive the formwork to autonomously move to the target construction section. Ultrasonic radar detects obstacles on the culvert sidewalls in real time, automatically fine-tunes the sliding trajectory, and automatically stops after positioning.

[0009] To ensure safety during the sliding process, this step is equipped with a triple safety mechanism: (1) Ultrasonic radar provides full-area obstacle detection and graded early warning, automatic deceleration for obstacles at close range, and direct cutting off of hydraulic pressure and sound and light alarm for dangerous distances; (2) Infrared human body sensing light curtains are installed on both sides of the mold frame, and the machine will stop immediately if personnel accidentally enter the sliding area; (3) The walking system is equipped with an emergency manual pressure relief valve, which can quickly unlock the mold frame in case of power failure or loss of control.

[0010] S3: Hydraulic automatic mold adjustment and locking The formwork frame incorporates multiple sets of hydraulic leveling and width adjusting cylinders. After the formwork frame is in place, the industrial control computer reads the culvert BIM design data, first comparing the measured cross-section with the design model to confirm the deviation, and then automatically driving the cylinders to adjust the elevation and span of the side and top forms. The formwork alignment error is controlled within ±2mm. After the formwork adjustment is completed, the hydraulic self-locking mechanism locks the formwork dimensions to prevent formwork deformation during the pouring process.

[0011] S4: Layered closed-loop quantitative pouring and vibration A vehicle-mounted concrete pumping and placing system is used to pour concrete in sections along the longitudinal direction of the culvert and in vertical layers. Each layer is set to a thickness of 200mm. A flow sensor and the concrete placing speed are linked in a closed loop to ensure uniform concrete distribution. A robotic arm equipped with an attached vibrator moves at a constant speed along the inside of the formwork to compact the concrete. 3D vision monitors the concrete level in real time, automatically replenishing the concrete when it is insufficient and pausing pumping when the concrete is too thick to prevent under-vibration and over-vibration.

[0012] S5: Integrated constant temperature maintenance inside the cave The formwork integrates spray curing pipelines and temperature and humidity sensors both inside and outside. After pouring, segmented spraying automatically starts, dynamically adjusting the water volume and interval based on the temperature and humidity inside the cavity. The outside of the formwork is covered with an insulation film, and electric heating is used in conjunction with it in low-temperature environments to ensure a stable curing environment for the concrete.

[0013] S6: Automatic demolding and sliding after strength meets the standard. Once the concrete reaches the demolding strength, the hydraulic cylinder contracts to automatically demold, and the formwork automatically slides to the next construction section, achieving continuous cast-in-place casting without construction joints.

[0014] Full-process digital control In each of the above steps, various sensors on the formwork collect real-time data on sliding position, formwork dimensions, pouring flow rate, and temperature and humidity, which is then uploaded to the cloud-based digital twin platform via 5G. The platform automatically generates construction logs and quality inspection reports, enabling full-process traceability. Remote terminals can monitor the construction status in real time and remotely issue process adjustment instructions. The digital twin platform also features a safety risk early warning module, which pushes real-time safety alarms to mobile terminals when formwork misalignment exceeds tolerances, hydraulic cylinder pressure is abnormal, personnel intrusion occurs, or equipment malfunctions. It automatically records safety hazards in a ledger, forming a closed-loop rectification process for safety hazards.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention integrates intelligent navigation sliding, automatic formwork adjustment, layered pouring, synchronous curing, and digital control into a complete integrated construction process, which differs from the traditional segmented and fragmented construction process. It eliminates the need for full-span scaffolding erection and dismantling, significantly reducing material turnover costs and construction time. 2. This invention enables continuous cast-in-place casting across the entire span, significantly reducing construction joints and substantially improving the waterproofing and seepage prevention performance of the culvert. The template alignment error is controlled within ±2mm, and the multi-parameter linkage closed-loop control of pouring flow rate and vibration speed significantly reduces the dispersion of concrete density and strength. 3. This invention constructs a three-tiered safety management system combining hardware safety protection with a digital safety early warning closed loop. Independent safety self-locking and over-limit shutdown logic are set for each module of the entire process, including movement, formwork adjustment, pouring, and curing, ensuring that a single system failure does not trigger overall instability. Dual intrusion protection, including human body sensing and obstacle recognition, prevents personnel from accidentally entering the mechanical movement area. The number of on-site operators is reduced by 75%, and the frequency of high-risk operations inside the tunnel is significantly decreased. 4. This invention significantly improves management efficiency by retaining construction dimensions, concrete strength, and curing data throughout the entire process, and generating final acceptance quality data with a single click. The digital twin platform enables visualized monitoring and quality traceability throughout the entire construction process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the movable mold frame structure used in this invention; Figure 2 This is a side view of the movable mold frame structure used in this invention.

[0017] The component names corresponding to each mark in the diagram are as follows: 1. Formwork cantilever beam; 2. Mobile lifting device; 3. Gantry frame; 4. Inner and outer steel formwork; 5. Outer formwork working platform; 6. Diagonal brace; 7. Horizontal brace; 8. Walking system; 9. Walking sensor; 10. Formwork sensor. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: This example uses the construction of a large-span slab culvert in a highway project as an example to illustrate the specific implementation of the present invention.

[0020] I. Construction Preparation After the culvert foundation pad layer is completed, a sliding needle beam frame formwork is assembled inside the culvert. The formwork structure is as follows: Figure 1 As shown, the system includes a formwork cantilever beam (1), a mobile lifting device (2), a gantry (3), inner and outer steel formwork (4), an outer formwork working platform (5), diagonal braces (6), horizontal braces (7), a walking system (8), walking sensors (9), and formwork sensors (10). After the formwork is assembled, the BIM design alignment parameters of the culvert are imported into the industrial control computer. The laser positioning system, inertial navigation unit, hydraulic system, vehicle-mounted pumping and laying system, spray curing system, and various types of sensors are debugged one by one to confirm that all subsystems are operating normally.

[0021] II. Intelligent sliding positioning of the mold frame The hydraulic system is activated, driving the formwork to slide along the culvert's needle beam. The laser positioning system and inertial navigation unit work together to guide the formwork's autonomous movement according to the preset culvert design alignment parameters. During movement, ultrasonic radar uses a 360° omnidirectional scan to detect obstacles on the culvert's sidewalls in real time. When an obstacle is detected at different distances, the system executes a tiered response: distant obstacles only record warning information; medium-distance obstacles trigger automatic deceleration; close-range obstacles or dangerous distances directly cut off the hydraulic power and trigger an audible and visual alarm. Simultaneously, infrared human body sensing light curtains on both sides of the formwork continuously monitor the sliding area, immediately stopping the system if personnel are detected entering. The emergency manual pressure relief valve equipped with the walking system allows the operator to manually unlock the formwork in case of power failure or system malfunction. The formwork automatically stops upon reaching the target construction section.

[0022] III. Hydraulic Automatic Mold Adjustment Lock After the formwork is in place, the industrial control computer reads the cross-sectional dimension information from the culvert BIM design data and compares it with the measured cross-sectional data. Based on the comparison results, the system automatically drives multiple sets of hydraulic leveling and width-adjusting cylinders to adjust the elevation and span of the side formwork and top formwork. During the adjustment process, the formwork sensor (10) provides real-time feedback on the formwork position data, forming a closed-loop control to ensure that the formwork alignment error is controlled within ±2mm. After the formwork adjustment is completed, the hydraulic self-locking mechanism automatically locks each cylinder to fix the formwork size and prevent the formwork from deforming due to the lateral pressure of concrete during the pouring process.

[0023] IV. Layered closed-loop quantitative pouring and vibration The vehicle-mounted concrete pumping and placing system is activated, and concrete is poured in sections longitudinally and layers vertically along the culvert body. Each layer is set to a thickness of 200mm. Flow sensors monitor the pumping flow rate in real time and establish a closed-loop linkage with the placing speed—the placing speed automatically adjusts according to flow rate changes to ensure uniform thickness of each layer. During pouring, a robotic arm equipped with an attached vibrator moves at a uniform speed along the inside of the formwork, matching the vibration frequency and movement speed to the pouring speed. A 3D vision system monitors the concrete level in real time: when a localized material shortage is detected, a replenishment command is automatically triggered to increase the pumping volume in that area; when excessive concrete thickness is detected, pumping in that area is automatically paused, and pumping resumes after the concrete has been leveled through vibration, ensuring no under-vibration or over-vibration.

[0024] V. Integrated constant temperature maintenance inside the cave After pouring, the formwork is not moved, and the curing process begins directly. The integrated spray curing pipeline inside and outside the formwork automatically starts segmented spraying. Temperature and humidity sensors collect real-time environmental data from inside the tunnel, and the control system dynamically adjusts the spray water volume and spray interval based on the measured temperature and humidity. An insulation film covering the outside of the formwork reduces heat loss. When the temperature inside the tunnel falls below a preset threshold, the electric heating system automatically starts to assist in heating, ensuring the concrete curing environment remains within a suitable temperature and humidity range.

[0025] VI. Automatic demolding and sliding after strength meets the standard After the concrete has cured to the designed demolding strength, the control system commands the hydraulic cylinders to contract, causing the inner and outer steel formwork (4) to detach from the concrete surface. After demolding, the formwork automatically slides to the next construction section, repeating the above steps S2 to S6 to achieve continuous cast-in-place casting without construction joints.

[0026] Full-process digital control Throughout all the above construction steps, various sensors, including the walking sensor (9), formwork sensor (10), flow sensor, and temperature and humidity sensor, continuously collect data on sliding position, formwork dimensions, pouring flow rate, and temperature and humidity. All data is uploaded to the cloud-based digital twin platform in real time via a 5G communication module. The platform automatically generates construction logs and quality inspection reports. When the formwork offset exceeds tolerance, the cylinder pressure is abnormal, personnel intrude, or equipment malfunctions, the platform's safety risk warning module pushes a safety alarm to the management personnel's mobile terminal in real time, and automatically records the safety hazard log. The remote terminal can view the construction status in real time and issue process adjustment instructions remotely when necessary.

[0027] Example 2: The difference between this example and Example 1 is that this example is applicable to culvert construction in low-temperature environments. In step S5, the integrated constant-temperature curing inside the culvert, due to the low ambient temperature (below 5℃), the spray curing system is adjusted to an intermittent low-water-volume spraying mode, while the electric heat tracing system operates throughout the process, and the insulation film is thickened to ensure that the concrete curing environment temperature is maintained between 15℃ and 25℃. The remaining steps are the same as in Example 1.

[0028] Example 3: The difference between this example and Example 1 is that this example is applicable to the construction of small-span slab culverts. In step S3, hydraulic automatic formwork adjustment and locking, since the culvert span is small, only some of the width-adjusting cylinders need to be activated to complete the formwork adjustment. The system automatically identifies the cross-sectional dimensions and selectively drives the corresponding cylinder group. The remaining steps are the same as in Example 1.

[0029] Industrial applicability The movable formwork construction technology for slab culverts provided by this invention can be widely applied to the cast-in-place construction of large-span, long linear slab culverts in municipal engineering, highway engineering, and other fields. Compared with traditional construction techniques, this invention has significant advantages such as high construction efficiency, good casting quality, low safety risks, and traceable quality control, and possesses good industrial practical value and promising prospects for widespread application.

Claims

1. A construction process for a movable formwork for a culvert cover, characterized in that, Includes the following steps: S1: Construction preparation, assembling the sliding needle beam frame moving formwork, importing the BIM design alignment parameters of the culvert cover, and debugging the positioning system, hydraulic system, pouring system and curing monitoring system; S2: Intelligent sliding positioning of the formwork, relying on the limiting and guiding device to constrain the displacement of the formwork, laser positioning and inertial navigation work together to drive the formwork to move autonomously to the target construction section, ultrasonic radar detects obstacles on the side wall of the culvert in real time and automatically fine-tunes the sliding trajectory, and automatically decelerates or stops when encountering obstacles. S3: Hydraulic automatic mold adjustment and locking. The industrial control computer drives multiple sets of hydraulic cylinders to adjust the elevation and span of the top mold and side mold based on BIM data. The template line error is controlled within ±2mm. After the mold adjustment is completed, the hydraulic self-locking mechanism locks the template size. S4: Layered closed-loop pouring and vibration. The vehicle-mounted pumping system divides the concrete into sections along the longitudinal direction of the culvert and distributes it in vertical layers in a quantitative manner. The thickness of each layer is set to 200mm. The flow sensor is linked with the material walking speed in a closed loop. The robotic arm is equipped with an attached vibrator and moves at a uniform speed along the inside of the template to vibrate. 3D vision monitors the concrete liquid level in real time and dynamically adjusts the pouring flow. S5: Integrated constant temperature curing inside the tunnel, with integrated spray curing pipelines and temperature and humidity sensors inside and outside the formwork. After pouring, segmented spraying is automatically started, and the spraying volume and interval are dynamically adjusted according to the temperature and humidity inside the tunnel. The outside of the formwork is covered with a heat insulation film. S6: Automatic demolding after strength meets the standard, and the formwork slides to the next construction section for continuous casting; Throughout the process, sensors collect data on sliding position, template size, pouring flow rate, and temperature and humidity, which are then uploaded in real time to a cloud-based digital twin platform via 5G to enable remote monitoring and quality traceability.

2. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, The intelligent sliding positioning of the formwork in step S2 also includes a triple safety mechanism: ultrasonic radar full-area obstacle detection and graded early warning, automatic deceleration for obstacles at close range, direct cut-off of hydraulic pressure and audible and visual alarm for dangerous distances; infrared human body sensing light curtains are set on both sides of the formwork, and the machine stops immediately if personnel accidentally enter the sliding area; the walking system is equipped with an emergency manual pressure relief valve.

3. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, Before the hydraulic automatic mold adjustment and locking described in step S3, the system first compares the measured cross-section with the BIM design model, confirms the deviation, and then drives the hydraulic cylinder to make adjustments.

4. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, In step S4, the 3D vision system monitors the concrete liquid level in real time, automatically replenishes material when it is insufficient, and suspends pumping when it is too thick.

5. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, The integrated constant temperature curing inside the tunnel mentioned in step S5 also includes: using electric heat tracing for insulation in low-temperature environments to ensure a stable curing environment for the concrete.

6. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, The cloud-based digital twin platform is equipped with a safety risk early warning module. When the mold frame offset exceeds the tolerance, the cylinder pressure is abnormal, personnel intrusion occurs, or equipment failure occurs, a safety alarm is pushed to the mobile terminal in real time, and the safety hazard ledger is automatically recorded.

7. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, The mobile formwork includes a formwork cantilever beam (1), a mobile hoist (2), a gantry (3), inner and outer steel formwork (4), an outer formwork working platform (5), diagonal bracing (6), horizontal bracing (7), a walking system (8), a walking sensor (9), and a formwork sensor (10).

8. The construction process of a movable formwork for a culvert according to claim 1, characterized in that, The automatic demolding described in step S6 is achieved by the retraction of the hydraulic cylinder. After demolding, the mold frame automatically slides to the next construction section, realizing continuous cast-in-place casting without construction joints.

Images