Anti-settling well lid lifting device and construction method thereof

Abstract

The application discloses an anti-settling well lid lifting device and a construction method thereof, and relates to the technical field of municipal engineering construction equipment.The device can solve the problems of unstable lifting and misplacement of the existing lifting device, ensure stable lifting, and improve the construction safety and efficiency through the cooperation of the tripod main body, the hand winch, the fixed pulley and the multi-hook assembly.The method can ensure the smooth connection between the well lid and the road surface, solve the settlement problem of the area below and around the well lid, improve the asphalt compactness around the well, reduce the settlement, and guarantee the road construction quality through the elevation preprocessing, anti-adhesion and accurate filling and rolling.

Description

Technical Field

[0001] This invention relates to the field of municipal engineering construction equipment technology. More specifically, this invention relates to an anti-settlement manhole cover lifting device and its construction method. Background Technology

[0002] During municipal road construction, after manhole covers are installed and fixed, asphalt concrete is usually directly laid over the manhole cover and surrounding area using an asphalt paver. If the position or height of the manhole cover needs to be adjusted during construction, the filling is done by simply prying the edge of the manhole cover. Under this construction method, the asphalt concrete around the manhole is prone to settlement problems: on the one hand, the asphalt concrete under the manhole cover is difficult to fill completely; on the other hand, the compaction of the asphalt concrete around the manhole cover is carried out simultaneously with the overall road surface compaction. The density of the asphalt concrete around the manhole cover is insufficient. After long-term bearing the load of vehicles, the road surface will sink, affecting the smoothness of the road and the comfort of vehicle passage. It may also accelerate the damage to the road structure due to sinkholes and water accumulation, shortening the service life of the road. To address the settlement issue beneath and around manhole covers, attempts have been made to lift the covers during the asphalt paving stage for asphalt concrete filling. However, existing lifting methods have significant drawbacks: a lack of dedicated anti-settlement manhole cover lifting devices is present, and simple tools without stable support structures (such as temporary supports with single steel pipes or ordinary rope binding for hoisting) are often used. During lifting, imbalances in force can easily cause the manhole cover to tilt, and the lowering process may result in misalignment between the cover and the manhole casing, leading to low safety and requiring multiple personnel. Therefore, a new construction method for asphalt concrete anti-settlement paving of manhole covers and surrounding areas is urgently needed. Summary of the Invention

[0003] This invention provides an anti-settlement manhole cover lifting device, which can solve the problems of unstable lifting and misalignment of existing lifting devices. It achieves balanced force through the tripod body and multi-hook components, ensuring stable lifting and lowering, and improving construction safety and efficiency.

[0004] This invention provides a construction method for an anti-settlement manhole cover lifting device, which can solve the settlement problem under and around the manhole cover. Through elevation pretreatment, anti-adhesion, and precise filling and compaction, it ensures a smooth connection between the manhole cover and the road surface, improves the density of the asphalt around the manhole, reduces settlement, and ensures the quality of road construction.

[0005] To achieve these objectives and other advantages according to the present invention, an anti-settlement manhole cover lifting device is provided, comprising: The tripod body consists of three legs and a frame. The tops of the three legs are rotatably connected to the frame, and the bottom of each leg is fixedly connected to a grounding part. A hand-cranked winch is fixedly installed on the upper middle part of one of the outriggers. The hand-cranked winch includes a rope drum, a hand crank, and a self-locking structure. The hand crank is connected to the rope drum in a transmission manner. A fixed pulley is rotatably installed at the bottom center of the frame via a lifting ring. One end of the rope is fixedly connected to a rope drum, and the other end of the rope passes over the fixed pulley and is fixedly connected to a multi-hook assembly, which has a suspension part for the manhole cover.

[0006] Preferably, the multi-hook assembly includes a suspension hook and three lifting hooks. The suspension hook is fixedly connected to the other end of a rope, and the three lifting hooks are connected to the connecting ends of the suspension hook by ropes of equal length. The three lifting hooks form the suspension part of the manhole cover, and the opening size of the lifting hooks is adapted to the preset lifting hole size of the manhole cover.

[0007] Preferably, the self-locking structure is implemented as follows: a ratchet is fixedly installed on the rotating shaft of the rope drum of the hand-cranked winch, and a pawl that cooperates with the ratchet is installed on the support leg of the hand-cranked winch through a rotating shaft. A return spring is connected to the tail of the pawl, and the head of the pawl tends to embed into the ratchet tooth groove under the action of the spring to achieve one-way locking. An operating lever extends from the tail of the pawl for manually controlling the pawl to disengage from the ratchet to achieve reversal.

[0008] Preferably, the three outriggers are telescopic sleeve outriggers, fixed to the required length by pins, and the ground insertion part is a pointed ground nail.

[0009] A construction method for an anti-settlement manhole cover lifting device, applied when the anti-settlement manhole cover is constructed simultaneously with asphalt concrete, the method includes the following steps: Before paving asphalt concrete, measure the elevation of the manhole cover and use high-strength stone blocks with a thickness of 1-2 cm and a compressive strength ≥ C30 to adjust the elevation of the manhole cover to the preset difference between the top surface of the manhole cover and the design elevation of the asphalt concrete surface layer. Clean the debris from the surface of the manhole cover, and use a brush to evenly apply the release agent to the surface of the manhole cover to form an anti-adhesion release layer; During the asphalt concrete paving process, continuously position the center of the manhole cover. After the asphalt concrete has passed the manhole, locate the lifting hole of the manhole cover, place the tripod body around the manhole cover, insert the ground part into the ground for fixation, then connect the suspension part of the multi-hook assembly to the lifting hole, crank the hand crank to drive the rope drum to wind up the rope, and the rope drives the multi-hook assembly through the fixed pulley to lift the manhole cover horizontally to 5-8 cm above the asphalt concrete surface level. Fill the area below the enlarged edge of the manhole cover with asphalt concrete; Slowly lower the manhole cover so that its widened edge presses against the asphalt concrete surface. After re-measuring the elevation of the manhole cover and confirming that it is correct, remove the device. Fill the depression with asphalt concrete around the manhole cover within a 10-20 cm radius to ensure that the asphalt concrete surface around the manhole is flat and dense. A vibratory roller is used to first statically compact the manhole cover and the surrounding asphalt concrete, and then vibrate to compact it. During compaction, the roller's steel wheel completely covers the manhole cover until it is compacted to the point where there are no wheel tracks and the surface is flat.

[0010] Preferably, the release agent is a diesel or emulsified asphalt type release agent or a silicone resin-based release agent, and the application rate is 0.2-0.5 kg / m². 2 .

[0011] Preferably, the speed is controlled at 2-5 cm / s during the lifting and lowering of the manhole cover.

[0012] Preferably, when filling asphalt concrete below the enlarged edge of the manhole cover, a loose-lay coefficient for the asphalt concrete is set to ensure that the asphalt concrete reaches the loose-lay thickness. The loose-lay coefficient for the asphalt concrete is 1.2-1.25.

[0013] Preferably, the loose paving coefficient of asphalt concrete is determined by the following method: Step 1: Obtain construction design parameters, including the design thickness of the asphalt concrete surface layer. H Diameter of the manhole cover body D Enlarged side width of manhole cover B The pre-set difference between the top surface of the manhole cover and the design elevation of the asphalt concrete surface layer. h ; Step 2: Calculate the circular area occupied by the manhole cover, including the enlarged side. S 1 and the annular area below the enlarged edge of the manhole cover S 2 : S 1 = π× ( D / 2+ B )² S 2 = π×[( D / 2+ B )²-( D / 2)²] Step 3: Calculate the baseline loose-lay factor K 0 : K 0 = ( α × h × S 1 + H × S 2 ) / ( H × S 2 × C ) in, α The compensation coefficient for the pressure applied under the manhole cover is set to 0.15-0.25. C The target compaction degree for the asphalt concrete surface layer is taken as 0.96-0.98; Step 4: Introduce thermal expansion compensation and calculate the final virtual laying coefficient. K : K = K 0 ×(1+ c ×( T - T 0 )) in, T The discharge temperature of the asphalt concrete on the day of construction. T 0 The preset standard compensation temperature reference value is determined based on the median recommended paving temperature of the asphalt concrete used. c The coefficient of thermal expansion of asphalt concrete is calculated based on the asphalt content and the asphalt-aggregate ratio, and is taken as 0.0012-0.0018 / ℃.

[0014] Preferably, the re-measurement of the well cover elevation is determined by the following method: Step 1: A rigid measuring beam is horizontally erected above the wellhead. At least three laser ranging sensors are integrated on the beam, and the measuring points of each sensor cover the key feature positions of the well cover body and the enlarged edge. Step 2: Set up a high-precision laser level on the compacted and accurately calibrated asphalt concrete pavement around the well, and emit a reference horizontal laser surface to synchronously calibrate the laser rangefinder on the crossbeam; Step 3: After the manhole cover is lowered into place, simultaneously read the distance values ​​from all laser rangefinders to the surface of the manhole cover. d i ( i =1, 2, ..., n , n ≥3), calculate the relative height deviation Δ of each measuring point. H i = d i -d 基准 ,in, d 基准 The calibration distance from the laser level reference plane to the crossbeam; Step 4: If both of the following conditions are met simultaneously, then the manhole cover elevation and installation levelness are deemed correct upon re-measurement: Absolute elevation tolerance condition: Max(|Δ H i |) ≤ d; Relative flatness tolerance condition: Max(Δ H i ) - Min(Δ H i ) ≤ e ; in, d For absolute elevation tolerance, e This is the tolerance for relative flatness; in, v The design speed for this road is given in km / h. v 0 For speed comparison, a value of 40-80 km / h is used, k δ The speed influence coefficient is taken as 0.8-1.0. d 0 The absolute elevation tolerance is taken as 2-5 mm. D 总成 The diameter of the manhole cover assembly includes the cover body and the enlarged side, measured in meters (m). D 0 For comparison, a fixed value of 0.6-1.0 m is used for the diameter of the manhole cover assembly. k ε The factor representing the influence of manhole cover size is taken as 0.2-0.5. e 0 The baseline relative flatness tolerance is 1-3 mm.

[0015] The present invention has at least the following beneficial effects: First, the anti-settlement manhole cover lifting device of the present invention has good support stability through the cooperation of the three legs of the tripod body and the ground insertion part. The hand-cranked winch does not require external power, is suitable for sites without power supply, and is easy to operate, saving time and effort. The fixed pulley and multi-hook assembly ensure that the rope is evenly stressed, preventing the manhole cover from tilting. The entire device can be erected by a single person within one minute, saving time and effort and improving construction safety and efficiency.

[0016] Secondly, the construction method of the present invention involves filling the manhole cover with high-temperature and pre-compacted asphalt concrete, and then using the weight of the manhole cover and a road roller to compact it forcefully, making the material around the manhole very dense. The entire construction process is coherent and highly repeatable, making it suitable for large-scale manhole cover anti-settlement construction on municipal roads and improving the service life and smoothness of municipal roads.

[0017] Third, the construction method of this invention provides a precise method for calculating the paving coefficient for thin asphalt concrete surface layers. It comprehensively considers the amount of manhole cover pressure, design thickness, and material compaction characteristics, solves the compaction quality problem caused by empirical value deviation, and ultimately achieves that the elevation of the asphalt concrete in the area after pressure is completely consistent with the design surface layer elevation, ensuring the compaction quality around the manhole, avoiding the risk of milling damage or sinking settlement, and achieving the ideal smoothness effect in one construction.

[0018] Fourth, the construction method of this invention uses a rigid crossbeam integrating multiple sensors and a high-precision laser level to construct a temporary measurement system. Based on the road design speed and the outer diameter of the manhole cover assembly, a dynamic tolerance standard is determined, abandoning the one-size-fits-all fixed tolerance standard. This enables the synchronous, rapid, and automated collection of elevation data from multiple points on the manhole cover surface, effectively ensuring the final flatness of the manhole cover installation, improving the overall construction quality and driving comfort of the road, and further meeting the stringent requirements for the flatness of manhole cover installation on high-grade roads such as urban expressways.

[0019] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an anti-settlement manhole cover lifting device according to a technical solution of the present invention. 1-Tripod body; 2-Hand-cranked winch; 3-Fixed pulley; 4-Suspension hook; 5-Hook. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0022] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0023] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] To address the issues that existing methods often employ simple tools without stable support structures (such as temporary supports with single steel pipes or ordinary rope binding for hoisting), which can easily lead to manhole cover tilting due to stress imbalance during lifting and misalignment between the manhole cover and the manhole casing during lowering, the following solutions are proposed. Figure 1 As shown, the present invention provides an anti-settlement manhole cover lifting device, comprising: The tripod body (1) is used to support the weight of the entire device and the manhole cover. It consists of three legs and a frame. The legs are supporting components, and the frame is the top connection structure. It is also used to install fixed pulleys (3). The tops of the three legs are rotatably connected to the frame, for example, by hinges, to ensure that the legs can rotate flexibly so as to adjust the unfolding angle of the legs according to the slope of the construction site and keep the frame horizontal. The bottom of each leg is fixedly connected to a ground insertion part, for example, made of steel in a pointed shape, which is inserted into the ground to enhance the fixing effect of the legs. A hand-cranked winch (2) is used to drive the rope to wind up to lift the manhole cover. It is fixedly installed on the upper middle part of one of the legs. The installation height is matched so that adults can operate it without bending over. The hand-cranked winch (2) includes a rope drum, a hand crank and a self-locking structure. Circular baffles are welded to both ends of the rope drum to prevent the rope from falling off from both sides of the rope drum during the winding process. The hand crank is connected to the rope drum in a transmission. The hand crank manually drives the rope drum to rotate. The rope drum has a self-locking structure. The fixed pulley (3) is installed at the bottom center of the frame via a lifting ring. The lifting ring can rotate 360° to effectively avoid stress concentration. One end of the rope is fixedly connected to the rope drum, and the other end of the rope is fixedly connected to the multi-hook assembly after passing over the fixed pulley (3). The multi-hook assembly has a suspension part for the manhole cover, which enables the lifting and lowering of the manhole cover.

[0025] When using, first unfold the three outriggers outwards, with the unfolding angle controlled between 60° and 90°. Adjust the angle of each outrigger according to the slope of the construction site, and observe that the frame remains horizontal. Then, insert the bottom part of each outrigger into the ground about 8-10 cm to ensure it is secure. Next, align and connect the suspension part of the multi-hook assembly with the pre-set lifting hole of the manhole cover. The operator stands on one side of the hand-cranked winch (2) and rotates the hand crank clockwise, which drives the rope drum to rotate synchronously. During the rotation of the rope drum, the wire rope is wound around the rope drum. At the same time, the other end of the wire rope passes around the fixed pulley (3) to change the direction of force, which drives the multi-hook assembly to move upwards. The multi-hook assembly then lifts the manhole cover. When the manhole cover is lifted to the preset height, stop rotating the hand crank to complete the lifting operation. The lowering operation is the same as before, and the hand crank is rotated counterclockwise.

[0026] In the above technical solution, the three legs of the tripod body (1) cooperate with the ground insertion part to provide good support stability. The hand-cranked winch (2) does not require external power, is suitable for sites without power supply, and is convenient to operate, saving time and effort. The fixed pulley (3) cooperates with the multi-hook assembly to ensure that the rope is evenly stressed, avoids the manhole cover from tilting, and improves construction safety and efficiency.

[0027] In another technical solution, the multi-hook assembly includes a suspension hook (4) and three hooks (5). The suspension hook (4) is fixedly connected to the other end of a rope. The three hooks (5) are connected to the connecting end of the suspension hook (4) by ropes of equal length. After the connection is completed, the bottom of the three hooks (5) is at the same horizontal height. The three hooks (5) form the suspension part of the manhole cover. The opening size of the hooks (5) is adapted to the preset lifting hole size of the manhole cover. Since the three hooks (5) are evenly distributed at 120°, they can accurately match the three lifting holes of the manhole cover. During the lifting process, the force is balanced, which can ensure that the manhole cover always remains horizontal and will not tilt or shake due to uneven force.

[0028] In another technical solution, the self-locking structure is implemented as follows: a ratchet is fixedly installed on the rotating shaft of the rope drum of the hand-cranked winch (2) to achieve unidirectional rotation restriction. A pawl that cooperates with the ratchet is installed on the support leg of the hand-cranked winch (2) through a rotating shaft. The pawl is used to prevent the ratchet from rotating in the opposite direction. A reset spring is connected to the tail of the pawl. The head of the pawl tends to embed into the ratchet tooth groove under the action of the spring to achieve unidirectional locking. An operating rod extends from the tail of the pawl to manually control the pawl to disengage from the ratchet to achieve reversal. During the lifting of the manhole cover, turning the hand crank clockwise causes the rope drum to rotate clockwise simultaneously. At this time, the pawl head, under the action of the return spring, engages in the groove of the ratchet. Because the wedge-shaped head of the pawl cooperates with the working surface of the ratchet groove, the clockwise rotation of the ratchet pushes the pawl head slightly upward, further compressing the return spring. After the ratchet rotates one tooth pitch, the pawl head, under the action of the return spring, engages in the next groove, achieving one-way locking and preventing the rope drum from rotating in the opposite direction, thus avoiding sudden lowering of the manhole cover. During the lowering process, pressing down on the operating lever moves the tail of the pawl downward, causing the pawl to rotate around its axis. The pawl head lifts upward and disengages from the groove of the ratchet, allowing the rope drum to rotate freely in the opposite direction. Turning the hand crank counterclockwise drives the rope drum to rotate counterclockwise, releasing the wire rope and slowly lowering the manhole cover. This locking structure design is flexible in operation, highly safe, and suitable for both lifting and lowering manhole covers.

[0029] In another technical solution, the three outriggers are telescopic sleeve outriggers, consisting of an inner sleeve and an outer sleeve, used to adjust the length of the outriggers, facilitating construction on sloping roads. They are fixed to the required length by pins. The ground insertion part is a pointed ground nail, which is easier to insert into the ground than a flat-head structure, especially in soft or gravelly areas. This improves the applicability of the lifting device to various road surfaces, further enhances the stability of the equipment, and meets the diverse needs of municipal construction.

[0030] To address the problem of insufficient compaction of asphalt concrete under and around manhole covers, leading to road surface settlement, existing asphalt concrete paving methods often result in road surface settlement due to insufficient compaction of the asphalt concrete. This application provides a construction method specifically applied when anti-settlement manhole covers are constructed simultaneously with asphalt concrete. The method includes the following steps: Step S1: Before paving asphalt concrete, use a laser rangefinder to measure the elevation of the manhole cover, calculate the required number of pad blocks, and use high-strength stone pad blocks with a thickness of 1-2cm and a compressive strength ≥C30 to adjust the elevation of the manhole cover to the preset difference between the top surface of the manhole cover and the design elevation of the asphalt concrete surface layer. Step S2: Clean debris such as dust and gravel from the surface of the manhole cover. Apply the release agent evenly to the surface of the manhole cover using a brush. The release agent can be diesel, emulsified asphalt, or silicone resin-based. The application rate is 0.2-0.5 kg / m². 2This forms an anti-adhesion isolation layer, preventing subsequent asphalt concrete from adhering to the manhole cover; Step S3: Asphalt concrete is laid using an asphalt paver. During the asphalt concrete laying process, a dedicated person is assigned to continuously position the center of the manhole cover to quickly and accurately determine the position of the manhole cover. After the asphalt concrete has been laid over the manhole, the lifting hole of the manhole cover is found with a flat shovel. The tripod body (1) is placed in the center on the side of the manhole cover, and the ground insertion part is inserted into the ground to fix it. The frame is horizontal. Then the suspension part of the multi-hook assembly is connected to the lifting hole. The hand crank is turned to drive the rope drum to wind the rope. The rope is driven by the fixed pulley (3) to drive the multi-hook assembly to lift the manhole cover horizontally to 5-8cm above the elevation of the asphalt concrete surface. During the lifting process, the speed is controlled to be 3-5 cm / s. Step S4: After the manhole cover is raised, hot asphalt concrete is filled below the enlarged edge of the manhole cover with a shovel. When filling, start from the center of the manhole cover and work outwards to ensure uniform filling without gaps. Preferably, when filling the asphalt concrete below the enlarged edge of the manhole cover, a loose-lay coefficient for the asphalt concrete is set, which is the ratio of the loose-lay thickness of the asphalt concrete during paving to the design thickness after compaction, so that the asphalt concrete reaches the loose-lay thickness. The loose-lay coefficient of the asphalt concrete is taken as 1.2-1.25. Taking a 900 mm manhole cover and a 4 cm thick asphalt concrete surface layer as an example, it is calculated that removing the asphalt concrete above the manhole cover and filling it below the enlarged edge of the manhole cover can meet the requirement of a loose-lay thickness of 4.8 cm (4 cm × 1.2). Step S5: Slowly lower the manhole cover at a speed of 2-4 cm / s. When lowering, control the lowering speed of the manhole cover by using a hand winch (2) to make the manhole cover expand and press against the asphalt concrete surface. After lowering, use a laser rangefinder to re-measure the elevation of the manhole cover. If the elevation is correct, remove the device. Step S6: Fill the depression area within a 10-20 cm radius around the manhole cover with hot asphalt concrete. After filling, use a scraper to smooth the surface to ensure that the asphalt concrete surface around the manhole is flat and dense. Step S7: Use a vibratory roller to statically compact the manhole cover and surrounding asphalt concrete once to initially shape the asphalt concrete. Then vibratory compact 2-3 times, with the roller's steel wheel completely covering the manhole cover during compaction, until there are no wheel tracks and the surface is flat. After construction, check the elevation and flatness of the manhole cover. The elevation of the manhole cover should be consistent with the design elevation of the asphalt concrete surface layer.

[0031] In the above technical solution, the problem of road surface settlement due to insufficient compaction around the manhole is solved by lifting the manhole cover, filling it with asphalt, feeding hot asphalt, and compacting it. The entire construction process is coherent and highly repeatable, making it suitable for large-scale manhole cover anti-settlement construction on municipal roads and improving the service life and smoothness of municipal roads.

[0032] In well expansion construction, the annular area below the enlarged edge of the manhole cover is a weak point in compaction. While the loose thickness of the asphalt concrete can be determined empirically under normal circumstances, this empirical value has significant limitations in thin-layer construction. It easily leads to either excessive compaction (requiring milling and damaging the pavement structure) or insufficient compaction (forming a depression around the manhole, causing potential settlement risks), making it almost impossible to guarantee successful completion in one go and failing to meet the requirements of precise construction. In another technical solution, the loose-lay coefficient of the asphalt concrete is determined using the following method: Step 1: Obtain construction design parameters, including the design thickness of the asphalt concrete surface layer. H Diameter of the manhole cover body D Enlarged side width of manhole cover B The pre-set difference between the top surface of the manhole cover and the design elevation of the asphalt concrete surface layer. h ; Step 2: Calculate the circular area occupied by the manhole cover, including the enlarged side. S 1 and the annular area below the enlarged edge of the manhole cover S 2 : S 1 = π× ( D / 2+ B )² S 2 = π×[( D / 2+ B )²-( D / 2)²] in, S 2 This area is a critical zone that requires asphalt concrete filling and special compaction control; after compaction, it must reach the designed thickness. H And bear the main downward pressure of the manhole cover, directly below the manhole cover S 1 - S 2 The lining material or foundation soil in the area (i.e., the area projected by the manhole cover) will also be compressed, consuming a portion of the downward pressure. h .

[0033] Step 3: Calculate the baseline loose-lay factor K 0 This refers to the ratio of the loose thickness of the mixture in the annular zone to the design thickness, without considering the effect of temperature. K 0 = ( α × h × S 1 + H ×S 2 ) / ( H × S 2 × C ) in, α This is the compensation coefficient for the pressure applied to the manhole cover, representing the total pressure applied to the manhole cover. h In this context, the proportion borne by the compression of asphalt concrete is taken as 0.15-0.25. When the foundation soil is relatively soft or no padding material is provided, it is taken as 0.20-0.25; conversely, when the foundation soil is dense or padding material is provided, it is taken as 0.15-0.20. h × S 1 + H × S 2 The total virtual volume that needs to be compacted. α × h × S 1 To compensate for the downward pressure of the manhole cover h At a certain height, the virtual volume corresponding to the portion of compression borne by the asphalt mixture. H × S 2 To make the ring area S 2 To achieve the required virtual cubic volume for the designed thickness, H × S 2 × C To make the ring area S 2 The compacted volume of the solid volume. C The target compaction degree for the asphalt concrete surface layer is taken as 0.96-0.98; Step 4: Introduce thermal expansion compensation and calculate the final virtual laying coefficient. K : K = K 0 ×(1+ c ×( T - T 0 )) in, T The discharge temperature of the asphalt concrete on the day of construction. T 0 The preset standard compensation temperature reference value is determined based on the median recommended paving temperature of the asphalt concrete used. c The coefficient of thermal expansion of asphalt concrete is calculated based on the asphalt content and the asphalt-aggregate ratio, and is taken as 0.0012-0.0018 / ℃.

[0034] In one example, step 1 obtains the design parameters: surface layer design thickness. H = 4 cm, diameter of the manhole cover body D = 0.7m, width of the enlarged side of the manhole cover B = 0.1 m, the preset difference between the top surface of the manhole cover and the surface elevation. h = 2 cm; Step 2: Calculate the circular area occupied by the manhole cover, including the enlarged side. S 1 =0.6362 m 2 and the annular area below the enlarged edge of the manhole cover S 2 =0.2513 m 2 ; Step 3: Take the compensation coefficient for the pressure applied to the manhole cover. α =0.2, target compaction degree C = 0.97 (according to standard JTG F40), calculate the baseline loose-lay factor. K 0 = 1.292; Step 4: Daily material temperature during construction T = 155℃, the asphalt concrete mixture is AC-13, and its recommended paving temperature range is 140-160℃, so the median value is taken. T 0 = 150℃, and the thermal expansion compensation coefficient is selected based on the asphalt-aggregate ratio of the mixture of 4.6%. c =0.0015 / ℃, calculate the final virtual paving factor. K = 1.302.

[0035] Traditional empirical values ​​(1.2-1.25) cannot account for temperature fluctuations, which can easily lead to the compacted elevation being too high or too low. Thin surface layers (such as 4 cm in the example) are extremely sensitive to changes in the filling amount. Even a small thickness deviation can cause the manhole cover elevation to deviate significantly from the design value. A larger paving factor (1.302>1.25) than that at normal temperature is required to ensure that the same design thickness is achieved after compaction, accurately adapting to the actual working conditions during construction.

[0036] In the above technical solution, a method for accurately calculating the paving coefficient is provided for thin surface layers, which solves the compaction quality problem caused by the deviation of empirical values. Ultimately, after the asphalt concrete in the area is compacted, its elevation is completely consistent with the design surface layer elevation, ensuring the compaction quality around the well and avoiding the risk of milling damage or sinking settlement.

[0037] During the construction of manhole covers, when re-measuring the elevation after the cover is lowered, using a laser rangefinder for direct measurement still has the problem of not simultaneously measuring the levelness. This may result in some areas meeting the standard but the entire cover tilting, leading to misjudgments of the elevation, which is difficult to meet the stringent requirements for the flatness of manhole cover installation on high-grade roads such as urban expressways. In another technical solution, the re-measuring of the manhole cover elevation is achieved through the following method: Step 1: A rigid measuring beam is horizontally erected above the wellhead. At least three laser ranging sensors are integrated on the beam, and the measuring points of each sensor cover the key feature positions of the well cover body and the enlarged edge. Step 2: Set up a high-precision laser level on the compacted and accurately calibrated asphalt concrete pavement around the well, and emit a reference horizontal laser surface to synchronously calibrate the laser rangefinder on the crossbeam; Step 3: After the manhole cover is lowered into place, simultaneously read the distance values ​​from all laser rangefinders to the surface of the manhole cover. d i ( i =1, 2, ..., n , n ≥3), calculate the relative height deviation Δ of each measuring point. H i = d i -d 基准 ,in, d 基准 The calibration distance from the laser level reference plane to the crossbeam; Step 4: If both of the following conditions are met simultaneously, then the manhole cover elevation and installation levelness are deemed correct upon re-measurement: Absolute elevation tolerance condition: Max(|Δ H i |) ≤ d ; Relative flatness tolerance condition: Max(Δ H i ) - Min(Δ H i ) ≤ e ; in, d To account for the absolute elevation tolerance, the design speed of the road v The higher the elevation, the higher the requirements for road surface smoothness, and the greater the allowable elevation deviation. d It should be as small as possible. e To allow for relative flatness tolerance, the diameter of the manhole cover... D+B The larger the surface area, the more difficult it is to achieve a high degree of uniformity, and therefore the allowable relative flatness deviation is... e The restrictions can be relaxed appropriately; in, v The design speed for this road is given in km / h. v 0 For speed comparison, a value of 40-80 km / h is used, k δ The speed influence coefficient is taken as 0.8-1.0. d 0 The absolute elevation tolerance is taken as 2-5 mm. D 总成 The diameter of the manhole cover assembly includes the cover body and the enlarged side, measured in meters (m). D 0 For comparison, a fixed value of 0.6-1.0 m is used for the diameter of the manhole cover assembly. k ε The factor representing the influence of manhole cover size is taken as 0.2-0.5. e 0 The baseline relative flatness tolerance is 1-3 mm.

[0038] In one example, step 1: A rigid beam with a length of 1.8 m is horizontally erected above the wellhead, and four laser rangefinders are integrated on the beam; Step 2: Perform synchronous calibration of the laser rangefinder sensor; Step 3: Calibration distance from the laser level reference plane to the crossbeam d 基准 = 0.700 m, distance values ​​from the four sensors to the manhole cover surface d 1 = 0.699 m (located on the expanding side), d 2 = 0.703 m (located in the main body), d 3 = 0.698 m (located on the expanding side), d 4 = 0.701 m (located in the body); The relative height deviation Δ between the four sensors and the reference plane H 1 = -1 mm, Δ H 2 = 3 mm, Δ H 3 = -2 mm, Δ H 4 = 1 mm; Step 4: ① Calculate the dynamic tolerance of absolute elevation d : Road design speed v = 60 km / h, the design speed dividing line between Class I and Class II highways and Class III and Class IV highways based on the "Technical Standards for Highway Engineering" (JTG B01), speed comparison value. v 0 = 60 km / h, based on the strict requirements for the smoothness of high-grade road surface in standards such as the "Code for Construction and Quality Acceptance of Urban Road Engineering" (CJJ 1), the allowable deviation of the benchmark absolute elevation is... d 0 = 3 mm, the rate of tolerance tightening is slower than the rate of vehicle speed increase, vehicle speed influence coefficient k δ = 0.8, calculate the absolute elevation tolerance. d = 3 mm; ② Calculate the dynamic tolerance of relative flatness e : manhole cover assembly diameter D 总成 = 0.9 m, based on the standard dimensions of manhole covers for drainage pipes, the diameter of the manhole cover assembly is compared with the fixed value. D 0 = 0.8 m, based on the requirements for road surface smoothness, the benchmark relative smoothness tolerance value e 0 = 2 mm, tolerance e Depending on size D 总成 The increase in size does not lead to a significant relaxation, and the influence coefficient of manhole cover size is relatively small. k ε = 0.3, calculate the relative flatness tolerance. e =2.07mm; ③ Absolute elevation tolerance condition Max(|Δ H i |) = 3 mm, d = 3 mm, 3 mm = 3 mm, the absolute elevation tolerance condition is met; Relative flatness tolerance condition: Max(Δ H i ) - Min(Δ H i = 5 mm, e =2.14 mm, 5 mm > 2.07 mm, the relative flatness tolerance condition is not met.

[0039] The absolute elevation of the manhole cover (maximum deviation 3 mm) is qualified, but the relative flatness (maximum height difference 5 mm) exceeds the tolerance, indicating that there is local tilting or warping on the surface of the manhole cover and it has not reached the absolute level. This method can strictly evaluate the overall flatness of the manhole cover by multi-point synchronous measurement and the introduction of dynamic tolerance standards.

[0040] In the above technical solution, a temporary measurement system is constructed by using a rigid crossbeam integrating multiple sensors and a high-precision laser level. Based on the road design speed and the outer diameter of the manhole cover assembly, a dynamic tolerance standard is determined, abandoning the one-size-fits-all fixed tolerance standard. This enables the synchronous, rapid, and automated collection of elevation data at multiple points on the manhole cover surface, effectively ensuring the final flatness of the manhole cover installation and improving the overall construction quality and driving comfort of the road.

[0041] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0042] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A construction method for an anti-settlement manhole cover lifting device, characterized in that, The device includes: The tripod body consists of three legs and a frame. The tops of the three legs are rotatably connected to the frame, and the bottom of each leg is fixedly connected to a grounding part. A hand-cranked winch is fixedly installed on the upper middle part of one of the outriggers. The hand-cranked winch includes a rope drum, a hand crank, and a self-locking structure. The hand crank is connected to the rope drum in a transmission manner. A fixed pulley is rotatably installed at the bottom center of the frame via a lifting ring. One end of the rope is fixedly connected to a rope drum, and the other end of the rope passes around the fixed pulley and is fixedly connected to a multi-hook assembly. The multi-hook assembly has a suspension part for the manhole cover. When the device is applied to the simultaneous construction of anti-settlement manhole covers and asphalt concrete, the construction method includes the following steps: Before paving asphalt concrete, measure the elevation of the manhole cover and use high-strength stone blocks with a thickness of 1-2 cm and a compressive strength ≥ C30 to adjust the elevation of the manhole cover to the preset difference between the top surface of the manhole cover and the design elevation of the asphalt concrete surface layer. Clean the debris from the surface of the manhole cover, and use a brush to evenly apply the release agent to the surface of the manhole cover to form an anti-adhesion release layer; During the asphalt concrete paving process, continuously position the center of the manhole cover. After the asphalt concrete has passed the manhole, locate the lifting hole of the manhole cover, place the tripod body around the manhole cover, insert the ground part into the ground for fixation, then connect the suspension part of the multi-hook assembly to the lifting hole, crank the hand crank to drive the rope drum to wind up the rope, and the rope drives the multi-hook assembly through the fixed pulley to lift the manhole cover horizontally to 5-8 cm above the asphalt concrete surface level. Fill the area below the enlarged edge of the manhole cover with asphalt concrete; Slowly lower the manhole cover so that its widened edge presses against the asphalt concrete surface. After re-measuring the elevation of the manhole cover and confirming that it is correct, remove the device. Fill the depression with asphalt concrete around the manhole cover within a 10-20 cm radius to ensure that the asphalt concrete surface around the manhole is flat and dense. A vibratory roller is used to first statically compact the manhole cover and the asphalt concrete around the manhole, and then vibrate to compact it. During compaction, the steel wheel of the roller completely covers the manhole cover until it is compacted to the point that there are no wheel tracks and the surface is flat. When filling asphalt concrete below the enlarged edge of the manhole cover, a loose-lay coefficient for the asphalt concrete is set to ensure that the asphalt concrete reaches the loose-lay thickness. The loose-lay coefficient for the asphalt concrete is 1.2-1.

25. The loose-lay coefficient of asphalt concrete is determined by the following method: Step 1: Obtain construction design parameters, including the design thickness of the asphalt concrete surface layer. H Diameter of the manhole cover body D Enlarged side width of manhole cover B The pre-set difference between the top surface of the manhole cover and the design elevation of the asphalt concrete surface layer. h ; Step 2: Calculate the circular area occupied by the manhole cover, including the enlarged side. S 1 and the annular area below the enlarged edge of the manhole cover S 2 : S 1 = π× ( D / 2+ B ) 2 S 2 = π×[( D / 2+ B ) 2 -( D / 2) 2 ] Step 3: Calculate the baseline loose-lay factor K 0 : K 0 = ( α × h × S 1 + H × S 2 ) / ( H × S 2 × C ) in, α The compensation coefficient for the pressure applied under the manhole cover is set to 0.15-0.

25. C The target compaction degree for the asphalt concrete surface layer is taken as 0.96-0.98; Step 4: Introduce thermal expansion compensation and calculate the final virtual laying coefficient. K : K = K 0×(1+ γ ×( T - T 0)) in, T The discharge temperature of the asphalt concrete on the day of construction. T 0 is the preset standard compensation temperature reference value, determined based on the median recommended paving temperature of the asphalt concrete used. γ The coefficient of thermal expansion of asphalt concrete is calculated based on the asphalt content and the asphalt-aggregate ratio, and is taken as 0.0012-0.0018 / ℃.

2. The construction method according to claim 1, characterized in that, The multi-hook assembly includes a suspension hook and three lifting hooks. The suspension hook is fixedly connected to the other end of a rope. The three lifting hooks are connected to the connection end of the suspension hook by ropes of equal length. The three lifting hooks form the suspension part of the manhole cover. The opening size of the lifting hook is adapted to the preset lifting hole size of the manhole cover.

3. The construction method according to claim 1, characterized in that, The self-locking structure is implemented as follows: a ratchet is fixedly installed on the rotating shaft of the rope drum of the hand-cranked winch, and a pawl that cooperates with the ratchet is installed on the support leg of the hand-cranked winch through a rotating shaft. A return spring is connected to the tail of the pawl, and the head of the pawl tends to embed into the ratchet tooth groove under the action of the spring to achieve one-way locking. An operating lever extends from the tail of the pawl for manually controlling the pawl to disengage from the ratchet to achieve reversal.

4. The construction method according to claim 1, characterized in that, The three outriggers are telescopic sleeve outriggers, which are fixed to the required length by pins, and the ground insertion part is a pointed ground nail.

5. The construction method according to claim 1, characterized in that, The release agent is a diesel or emulsified asphalt-based release agent or a silicone resin-based release agent, with a coating amount of 0.2-0.5 kg / m². 2 .

6. The construction method according to claim 1, characterized in that, During the lifting and lowering of the manhole cover, the speed should be controlled at 2-5 cm / s.

7. The construction method according to claim 1, characterized in that, The re-measurement of manhole cover elevation is achieved through the following methods: Step 1: A rigid measuring beam is horizontally erected above the wellhead. At least three laser ranging sensors are integrated on the beam, and the measuring points of each sensor cover the key feature positions of the well cover body and the enlarged edge. Step 2: Set up a high-precision laser level on the compacted and accurately calibrated asphalt concrete pavement around the well, and emit a reference horizontal laser surface to synchronously calibrate the laser rangefinder on the crossbeam; Step 3: After the manhole cover is lowered into place, simultaneously read the distance values ​​from all laser rangefinders to the surface of the manhole cover. d i ( i =1,2, ..., n , n ≥3), calculate the relative height deviation Δ of each measuring point. H i = d i -d 基准 ,in, d 基准 The calibration distance from the laser level reference plane to the crossbeam; Step 4: If both of the following conditions are met simultaneously, then the manhole cover elevation and installation levelness are deemed correct upon re-measurement: Absolute elevation tolerance condition: Max(|Δ H i |) ≤ δ ; Relative flatness tolerance condition: Max(Δ H i ) - Min(Δ H i ) ≤ ε ; in, δ For absolute elevation tolerance, ε This is the tolerance for relative flatness; in, v The design speed for this road is given in km / h. v 0 is a fixed value for vehicle speed comparison, taken as 40-80 km / h, k δ The speed influence coefficient is taken as 0.8-1.

0. δ 0 is the baseline absolute elevation tolerance value, which is 2-5 mm. D 总成 The diameter of the manhole cover assembly includes the cover body and the enlarged side, measured in meters (m). D 0 represents a fixed value for the diameter of the manhole cover assembly, ranging from 0.6 to 1.0 m. k ε The factor representing the influence of manhole cover size is taken as 0.2-0.

5. ε 0 is the baseline relative flatness tolerance value, which is 1-3 mm.

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