Municipal road inspection well anti-sedimentation structure and construction method

Abstract

The invention discloses a municipal road inspection well anti-sedimentation structure and a construction method, and relates to the field of inspection well anti-sedimentation structures. The anti-sedimentation structure of the municipal road inspection well comprises a precast concrete shaft, the reinforcing steel bar reinforcing frame comprises a plurality of annular reinforcing steel bar sets which are arranged in the height direction of the prefabricated concrete shaft in a sleeving mode at intervals, each annular reinforcing steel bar set comprises at least one annular reinforcing steel bar, and the annular reinforcing steel bars are sequentially arranged in the circumferential direction of the prefabricated concrete shaft from inside to outside. And the number of the annular steel bars in each group is gradually reduced from bottom to top along the height direction of the precast concrete shaft. By arranging the frustum-shaped steel bar reinforcing frame which is integrally narrowed upwards, on one hand, the pressure around the well is diffused to peripheral concrete in a gradient mode, stress concentration is reduced, on the other hand, the bottom reinforcement density is increased, and the anti-floating stability is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of anti-settlement structures for manholes, specifically to anti-settlement structures and construction methods for manholes on municipal roads. Background Technology

[0002] Municipal road inspection manholes, as key nodes in underground pipe networks for drainage and sewage, are typically located at critical points such as pipe intersections and turns, serving functions such as pipe connection, routine maintenance, and emergency dredging. To address the issue of differential settlement between the manhole and the road surface caused by dynamic vehicle loads and environmental changes, it is necessary to construct an anti-settlement structure system using high-strength composite materials, optimized structural design, and refined construction techniques to ensure road traffic safety and extend the service life of the facilities.

[0003] However, the current anti-settlement design of municipal road inspection wells still has the following problems: Existing manhole structures generally employ a single reinforcement method, which is difficult to effectively distribute concentrated loads around the manhole. This leads to stress concentration at the junction of the manhole and the ground, which can easily cause local settlement or concrete cracking. At the same time, the traditional steel mesh has poor uniformity and cannot match the stress difference between the high-pressure area at the bottom of the manhole and the low-pressure area at the top. The high-pressure area is prone to cracks due to insufficient circumferential tension, while the low-pressure area suffers from wasted resources due to redundant reinforcement. In addition, the anchorage performance between steel bars depends on the binding or welding process, which not only takes a long time to construct, but also makes the steel bars prone to slippage due to vibration or temperature differences during long-term use, further aggravating structural damage.

[0004] Traditional manhole construction often involves hoisting the manhole casing to the foundation pit and then tying the reinforcing bars on-site. However, due to the limited space in the foundation pit, it is difficult to guarantee the accuracy of the reinforcing bar tying, and manual adjustment is time-consuming and labor-intensive. In addition, uneven spacing of the reinforcing bars can lead to local honeycomb and pitting during concrete pouring, weakening the overall structure. Loose tying joints may cause the reinforcing bars to shift, affecting the load transfer efficiency. Furthermore, the lack of rigid connection between the manhole casing and the reinforcing bar reinforcement frame makes the structure prone to tilting during hoisting due to shift in the center of gravity or external forces.

[0005] Existing mounting rings mostly adopt static load-bearing structures, resulting in a lack of adaptability of manhole cover components to dynamic loads such as vehicle rolling. During long-term use, the mounting ring is prone to cumulative settlement between itself and the manhole due to repeated pressure, causing local elevation differences. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a subsidence prevention structure and construction method for municipal road inspection wells, thus solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a settlement prevention structure for municipal road manholes, comprising: a precast concrete manhole cylinder; a reinforcing steel frame, wherein the reinforcing steel frame includes multiple ring-shaped steel reinforcement groups spaced apart along the height direction of the precast concrete manhole cylinder, each ring-shaped steel reinforcement group including at least one ring-shaped steel reinforcement, the multiple ring-shaped steel reinforcements being arranged sequentially from the inside to the outside along the circumference of the precast concrete manhole cylinder, and the number of ring-shaped steel reinforcements in each group decreasing progressively from bottom to top along the height direction of the precast concrete manhole cylinder, so that the reinforcing steel frame as a whole has an upwardly narrowing frustum-shaped structure, used to achieve progressive stress diffusion between the manhole cylinder and the surrounding soil; and lateral connecting steel reinforcements, wherein the lateral connecting steel reinforcements are evenly arranged along the circumference of the precast concrete manhole cylinder and are inserted into the ring-shaped steel reinforcements, and can be horizontally inserted into the precast concrete manhole cylinder, used to circumferentially fix the ring-shaped steel reinforcements and fix the ring-shaped steel reinforcements to the precast concrete manhole cylinder.

[0008] Furthermore, in each group of annular reinforcing bars, the lower end of the outermost annular reinforcing bar is equipped with multiple supporting reinforcing bars distributed along its circumference. Except for the bottommost supporting reinforcing bar, the lower ends of the supporting reinforcing bars in each of the other layers are respectively inserted and connected to the corresponding annular reinforcing bars below them.

[0009] Furthermore, the lateral connecting steel bars located on the same side and in the same vertical plane are connected by inclined reinforcing steel bars, and the inclined reinforcing steel bars and the lateral connecting steel bars are interlocked.

[0010] Furthermore, the diameter of the annular steel bars in the same group increases sequentially from the inside to the outside, and the spacing between adjacent annular steel bars increases gradually from the inside to the outside; the lateral connecting steel bars and the inclined reinforcing steel bars are both conical in shape, wherein the smaller end of the lateral connecting steel bars faces the precast concrete well cylinder, and the smaller end of the inclined reinforcing steel bars is set upwards.

[0011] Furthermore, an annular base is provided below the precast concrete well shaft. The annular base is cone-shaped, and its upper end is provided with a mating ring that matches the lower end of the precast concrete well shaft. The annular base has evenly distributed through holes.

[0012] Furthermore, an installation ring is provided above the precast concrete well cylinder, and the lower end of the installation ring and the upper end of the precast concrete well cylinder are respectively provided with sawtooth grooves, and the upper and lower grooves mesh with each other; the inclined reinforcing steel bar and the installation ring are inserted into each other in an inclined state.

[0013] Furthermore, the mounting ring is provided with a reaction support structure, which is used to apply an upward lifting force to the manhole cover when the manhole cover is subjected to downward pressure; the reaction support structure includes a plurality of arc-shaped grooves evenly opened along the upper end of the mounting ring, an arc-shaped top plate is slidably arranged in the arc-shaped groove, and a uniformly distributed reset spring is connected between the lower end of the arc-shaped top plate and the bottom wall of the arc-shaped groove.

[0014] Furthermore, an avoidance groove communicating with the arc-shaped groove is provided on the outer side of the mounting ring corresponding to the position of the arc-shaped top plate. A rotating plate is hinged to the side of the arc-shaped top plate away from the center of the mounting ring by a pin. A rotating shaft is rotatably provided in the middle of the rotating plate. A pressure plate is hinged to the end of the rotating plate away from the arc-shaped top plate by a pin. Sliding grooves that slide with pins one and two are respectively provided on the rotating plate.

[0015] Furthermore, a manhole cover assembly is provided above the mounting ring, and the manhole seat insertion end of the manhole cover assembly has multiple slots evenly distributed around its circumference; a stress dispersion plate is provided on the outer side of the mounting ring, and multiple stress dispersion plates together form an annular cone-shaped structure that is smaller at the top and larger at the bottom, and its inner side engages with the slots of the manhole cover assembly; a connecting groove is provided on the lower end face of the stress dispersion plate to cooperate with the protective frame, and the upper end of the pressure plate passes through the protective frame and abuts against the lower end face of the stress dispersion plate; and auxiliary reinforcing bars are provided on the upper end face of the stress dispersion plate.

[0016] This invention also provides a method for preventing settlement of municipal road manholes, applicable to the construction of municipal road manholes for preventing settlement, including the following steps: Step 1: Excavate the foundation pit at the construction site according to the design elevation, compact the bottom of the foundation pit, lay a uniform sand and gravel cushion layer, place the conical ring base at the bottom of the foundation pit, and then pour micro-expansion concrete to fix the ring base, forming a stable foundation support layer. Step 2: Install ring-shaped steel bars layer by layer from bottom to top on the outside of the precast concrete well cylinder. At the same time, insert the lateral connecting steel bars horizontally into the precast concrete well cylinder and connect them with each ring-shaped steel bar. Also, insert inclined reinforcing steel bars between the upper and lower adjacent lateral connecting steel bars, and install the installation ring at the upper end of the precast concrete well cylinder. Step 3: Hoist the precast concrete well cylinder, installation ring, and steel reinforcement frame into the foundation pit as a whole, and pour high-strength concrete between the precast concrete well cylinder and the steel reinforcement frame; Step 4: Place the stress-dispersing plate on the outside of the mounting ring and fix the manhole cover assembly to the upper end of the mounting ring. Then, pour fine aggregate concrete between the precast concrete manhole, the mounting ring, the stress-dispersing plate and the manhole cover assembly. Finally, lay an asphalt layer flush with the ground on top of the fine aggregate concrete to complete the construction.

[0017] The present invention has the following beneficial effects: (1) The anti-settlement structure of the municipal road inspection well is constructed by setting up a cone-shaped steel reinforcement frame that narrows upwards. On the one hand, the pressure gradient around the well is diffused to the outer concrete, reducing stress concentration. On the other hand, the bottom reinforcement density is increased, significantly improving the anti-buoyancy stability. At the same time, multiple ring steel bars form circumferential constraints, effectively suppressing cracking of the outer concrete and enhancing the mechanical anchoring performance of the steel bars and concrete. In addition, the cone-shaped steel reinforcement frame can produce a wedge effect with the outer concrete, resisting the horizontal displacement caused by construction rolling.

[0018] (2) The anti-settlement structure of the municipal road inspection well has a ring steel bar with an increasing diameter from the inside to the outside. The outer layer of thick steel bars can effectively match the circumferential tensile force requirements of the high-pressure area and improve the crack resistance. The inner layer of thin steel bars inhibits the expansion of microcracks caused by concrete shrinkage through dense arrangement. At the same time, the spacing between adjacent ring steel bars increases gradually from the inside to the outside. The outer layer of large-spacing ring steel bars can ensure the concrete flow is dense and reduce honeycomb surface defects. The inner layer of small-spacing ring steel bars blocks the seepage path through dense distribution, further improving the structural durability and long-term stability.

[0019] (3) The anti-settlement structure of the municipal road inspection well achieves rapid assembly of the steel reinforcement frame by setting lateral connecting steel bars, inclined reinforcing steel bars and supporting steel bars. It can not only connect it to the well body, improve the connection strength and cooperative force-bearing capacity between the well and the steel reinforcement frame, but also enhance the overall structural stability of the steel reinforcement frame and the step-by-step transmission capacity of vertical force. In addition, the use of plug-in connection without binding achieves rapid assembly, which not only simplifies the construction process and shortens the operation time, but also ensures the balance between structural stability and construction efficiency.

[0020] (4) The anti-settlement structure of the municipal road inspection well adopts the construction process of pre-assembly and then hoisting, which is different from the traditional construction process of hoisting the well cylinder to the foundation pit and then tying the steel bars on site. Ground pre-assembly can avoid working in the confined space in the foundation pit, reduce the tedious procedures such as steel bar tying and positioning adjustment. At the same time, the pre-assembly stage forms an overall force system through the rigid connection between the steel reinforcement frame and the well cylinder. The structure is not easy to shift or deform during hoisting. Only concrete needs to be poured in the foundation pit for fixation, which greatly reduces construction errors and improves construction efficiency.

[0021] (5) The anti-settlement structure of the municipal road inspection well, by setting a reaction support structure, can apply an upward lifting force to the manhole cover assembly when it is subjected to downward pressure, realize the dynamic balance of the load, improve the compressive performance and structural stability of the manhole cover assembly, installation ring and manhole cylinder under long-term continuous pressure conditions, delay the difference in road surface elevation caused by cumulative settlement, and ensure the quality of road traffic and structural durability.

[0022] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 A schematic diagram of the cross-sectional planar structure; Figure 3 This is a schematic diagram of the steel reinforcement frame in this invention; Figure 4 This is a schematic diagram of the precast concrete well shaft, annular base, and mating ring in this invention; Figure 5 This is a partial structural schematic diagram of the supporting reinforcing bars, ring reinforcing bars, and lateral connecting reinforcing bars in this invention; Figure 6 This is a partial cross-sectional structural diagram of the precast concrete well shaft and the annular base in this invention; Figure 7 This is a schematic diagram of the inclined reinforcing bars, lateral connecting bars, and ring bars in this invention; Figure 8 This is a partial cross-sectional view of the mounting ring and the inclined reinforcing steel bar in this invention; Figure 9 This is a schematic diagram of the structure of the manhole cover assembly and stress dispersion plate in this invention; Figure 10 This is a partial cross-sectional view of the manhole cover assembly and stress dispersion plate in this invention; Figure 11 This is a schematic diagram of the mounting ring and reaction support structure in this invention; Figure 12 This is a partial cross-sectional view of the protective frame in this invention.

[0024] In the diagram, 1. Precast concrete manhole; 2. Annular base; 21. Matching ring; 22. Through hole; 3. Reinforcing steel frame; 31. Annular reinforcing steel; 32. Lateral connecting reinforcing steel; 321. Connecting hole; 33. Supporting reinforcing steel; 34. Inclined reinforcing steel; 4. Mounting ring; 41. Toothed groove; 42. Reaction support structure; 421. Arc-shaped top plate; 422. Return spring; 424. Rotating plate; 425. Rotating shaft; 426. Pressure plate; 427. Slide groove; 428. Protective frame; 43. Stress dispersion plate; 431. Auxiliary reinforcing steel rod; 5. Manhole cover assembly; 51. Slot; 6. Micro-expansion concrete; 7. High-strength concrete; 8. Fine aggregate concrete; 9. Asphalt layer. Detailed Implementation

[0025] 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.

[0026] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0027] The following reference Figures 1-12 This invention describes the anti-settlement structure and construction method for municipal road inspection wells provided in embodiments of the present invention.

[0028] On the one hand, the present invention provides a subsidence prevention structure for municipal road inspection wells.

[0029] Please see Figure 1 and Figure 2 The anti-settlement structure of the municipal road inspection well includes a precast concrete well cylinder 1. As the core structural component of the inspection well, the precast concrete well cylinder 1 is formed by prefabrication process, which has high structural strength and convenient construction and installation. Its main function is to provide an inspection and maintenance channel for underground rainwater pipes, sewage pipes and other pipeline systems. It has good structural load-bearing, protection and anti-settlement performance. During installation, the well cylinder is vertically set in the pre-excavated foundation pit. Its bottom is provided with a connection opening. After installation, it can be connected to the underground pipeline system to ensure the continuity of drainage or transportation functions.

[0030] Please see Figures 1-6 During construction, the bottom of the foundation pit needs to be compacted and a uniform sand and gravel cushion layer needs to be laid to enhance the bearing capacity of the foundation. To ensure the stable positioning and reliable support of the precast concrete well cylinder 1 in the foundation pit, an annular base 2 is set. The annular base 2 is cone-shaped and is placed horizontally in the foundation pit. It is firmly connected to the foundation by pouring micro-expansion concrete 6. The micro-expansion concrete 6 can effectively prevent cracks, improve impermeability and structural density. The upper end of the annular base 2 is provided with a matching ring 21 that matches the lower end of the precast concrete well cylinder 1 for precise centering and vertical support. The cone-shaped annular base 2 can effectively distribute the load at the bottom of the well cylinder. The annular base 2 has uniformly distributed through holes 22 to enhance the interlocking ability and drainage capacity between the annular base 2, the micro-expansion concrete 6 and the foundation pit.

[0031] Please see Figures 1-7To enhance the connection strength between the precast concrete shaft 1 and the foundation pit and surrounding concrete, and to improve the overall structural stability and anti-settlement capacity of the shaft, a steel reinforcement frame 3 is installed on the outside of the precast concrete shaft 1. The steel reinforcement frame 3 includes multiple ring steel reinforcement groups spaced apart along the height direction of the precast concrete shaft 1. Each ring steel reinforcement group includes at least one ring steel bar 31. The multiple ring steel bars 31 are arranged sequentially from the inside to the outside along the circumference of the precast concrete shaft 1, and the number of ring steel bars 31 in each group decreases gradually from bottom to top along the height direction of the precast concrete shaft 1, so that the steel reinforcement frame 3 has an upwardly narrowing frustum-shaped structure. On the one hand, it diffuses the pressure gradient around the shaft to the outer concrete, reducing stress concentration; on the other hand, it increases the bottom reinforcement density, significantly improving the anti-buoyancy stability. At the same time, the multiple ring steel bars 31 form a circumferential constraint, effectively suppressing the cracking of the outer concrete and enhancing the mechanical anchoring performance of the steel bars and concrete. In addition, the frustum-shaped steel reinforcement frame 3 can produce a wedge effect with the outer concrete, resisting the horizontal displacement caused by construction rolling.

[0032] In this group of annular reinforcing bars, the diameter of the annular reinforcing bars 31 increases sequentially from the inside to the outside. Since the pressure on the well shaft increases with depth and the maximum circumferential tensile force is concentrated in the outermost area, the outer layer of thick reinforcing bars can effectively match the circumferential tensile force requirements of the high-pressure area and improve crack resistance. The inner layer of thin reinforcing bars, through dense arrangement, inhibits the propagation of microcracks caused by concrete shrinkage. At the same time, the spacing between adjacent annular reinforcing bars 31 increases gradually from the inside to the outside. The gradual increase in the spacing of the reinforcing bars avoids local stress concentration and leaves a reasonable gap for concrete pouring, enhancing the interlocking performance between the reinforcing bars and concrete and ensuring coordinated stress. The outer layer of large-spacing annular reinforcing bars 31 can ensure the dense flow of concrete and reduce honeycomb and pitting defects. The inner layer of small-spacing annular reinforcing bars 31, through dense distribution, blocks the seepage path and further improves the structural durability and long-term stability.

[0033] To enhance the overall structural stability of the steel reinforcement frame 3 and enable rapid assembly, lateral connecting steel bars 32 are uniformly arranged around the precast concrete shaft 1 at corresponding positions of each group of annular steel bars. The lateral connecting steel bars 32 and the annular steel bars 31 of each layer are circumferentially fixed by interlocking. They can also be horizontally inserted into the pre-set connection holes 321 on the precast concrete shaft 1 body to form a through-type connection structure. The lateral connecting steel bars 32 pass through the corresponding annular steel bars 31 in sequence and are then embedded into the shaft connection holes 321. This not only achieves circumferential limitation and positioning of the annular steel bars 31, but also anchors the steel reinforcement frame 3 to the inside of the shaft, significantly enhancing the connection strength and cooperative stress-bearing capacity between the two. In addition, the use of a non-binding interlocking connection method enables rapid assembly, which not only simplifies the construction process and shortens the operation time, but also ensures a balance between structural stability and construction efficiency.

[0034] Furthermore, the lateral connecting steel bar 32 is tapered, with its smaller end fitting into the pre-set connecting hole 321 of the precast concrete shaft 1. The tapered self-positioning action enables precise insertion and fixation of the steel bar end, improving the pull-out resistance of the plug connection.

[0035] Please see Figure 2 and Figure 5 In each group of ring-shaped reinforcing bars, the lower end of the outermost ring-shaped reinforcing bar 31 is equipped with multiple supporting reinforcing bars 33 distributed along its circumference. Except for the bottommost supporting reinforcing bar 33 which is inserted into the ring base 2, the lower ends of the supporting reinforcing bars 33 in each layer are inserted into the corresponding ring-shaped reinforcing bars 31 below them. This is used to enhance the overall structural stability of the reinforcing bar reinforcement frame 3 and the step-by-step transmission capability of vertical force. Through the step-by-step connection of the supporting reinforcing bars 33, not only is rigid constraint between adjacent ring-shaped reinforcing bar groups achieved, ensuring the positioning accuracy and assembly efficiency of the reinforcing bar groups during construction, but the upper load can also be transferred down the ring-shaped reinforcing bars 31 to the ring base 2 step by step through the vertical extension structure of the supporting reinforcing bars 33, thereby improving the load-bearing continuity of the overall structure.

[0036] In particular, the insertion and connection of the bottommost supporting steel bar 33 with the annular base 2 enables the steel reinforcement frame 3 to form a stable connection with the foundation, effectively resisting the buoyancy of the bottom of the well. At the same time, the micro-expansion concrete 6 pre-cast on the annular base 2 forms a non-interference combination with the supporting steel bar 33 through the reserved insertion space, which ensures the dense filling of the concrete without affecting the insertion accuracy and mechanical properties of the supporting steel bar 33.

[0037] Please see Figure 2 , Figure 3 and Figure 7 Furthermore, the lateral connecting steel bars 32 located on the same side and in the same vertical plane are connected by inclined reinforcing steel bars 34, and the inclined reinforcing steel bars 34 and the lateral connecting steel bars 32 are inserted together. By the inclined arrangement of the inclined reinforcing steel bars 34, a rigid constraint is formed on the adjacent lateral connecting steel bars 32 in the longitudinal direction, which enhances the overall cooperative force-bearing capacity of the steel reinforcement frame 3, and also realizes the limiting effect on the lateral connecting steel bars 32, preventing displacement under construction and long-term load.

[0038] Among them, the inclined reinforcing steel bar 34 is conical in shape, with the smaller end of the inclined reinforcing steel bar 34 facing upward. In use, the inclined reinforcing steel bar 34 can be passed through the corresponding lateral connecting steel bar 32 from bottom to top. The gradually narrowing end face forms a self-locking mechanical engagement with the lateral connecting steel bar 32, which not only enhances the shear resistance of the connection part, but also effectively disperses the local stress at the plug joint. The conical inclined reinforcing steel bar 34 is conducive to increasing the stability and firmness of the connection.

[0039] Please see Figures 1-4 and Figure 10An installation ring 4 is installed above the precast concrete well cylinder 1. The installation ring 4 is usually made of ductile iron, which has high strength, durability and adjustability. It can effectively solve problems such as settlement, noise and sealing, and provide an installation foundation for the subsequent well cover assembly 5. The lower end of the installation ring 4 and the upper end of the precast concrete well cylinder 1 are respectively provided with sawtooth grooves 41. The upper and lower grooves 41 are tightly connected by meshing, which helps to distribute the concentrated load to multiple contact points, reduce local stress concentration, and prevent the well cylinder edge from cracking due to shear force. At the same time, the inclined surface of the groove 41 achieves precise centering through self-guidance during installation. It can effectively prevent the installation ring 4 from sliding or getting out of the well cylinder during construction, and improve the reliability of the connection.

[0040] Please see Figure 8 The inclined reinforcing steel bar 34 and the mounting ring 4 are inserted in an inclined state. During construction, when the inclined reinforcing steel bar 34 is connected to the lateral connecting steel bar 32, an installation space is reserved for incomplete insertion to avoid interference during the installation of the mounting ring 4. After the mounting ring 4 is accurately in place, the inclined reinforcing steel bar 34 is inserted tightly to its maximum embedded position. At this time, the inclined reinforcing steel bar 34 is inserted into the pre-set inclined hole on the outside of the mounting ring 4 at a predetermined angle to complete the connection with the mounting ring 4, thereby limiting the mounting ring 4 and preventing it from shaking. At the same time, the inclined reinforcing steel bar 34 transfers the load of the mounting ring 4 to the steel reinforcement frame 3 structure through an inclined force transmission path, which is beneficial to improving the overall anti-settlement and anti-deformation ability.

[0041] Please see Figure 1 and Figure 2 After assembling the precast concrete well shaft 1, the steel reinforcement frame 3, and the installation ring 4, the entire assembly is hoisted to the upper end of the annular base 2 in the foundation pit. Then, high-strength concrete 7 can be poured into the gap between the precast concrete well shaft 1 and the steel reinforcement frame 3. Through the filling and curing of the concrete, a rigid connection is formed. The high-strength concrete 7 can significantly improve the compressive strength and deformation resistance. It should be noted that the pouring height of the high-strength concrete 7 does not completely submerge the well shaft, but is controlled in the area where the steel reinforcement frame 3 connects to the well shaft, so as to facilitate the subsequent pouring of concrete.

[0042] The construction process of pre-assembly followed by hoisting differs from the traditional construction process of hoisting the well shaft to the foundation pit and then tying the reinforcing steel on site. Ground pre-assembly avoids working in the confined space inside the foundation pit and reduces tedious procedures such as reinforcing steel binding and positioning adjustment. At the same time, the pre-assembly stage forms an integral force system with the well shaft through the rigid connection of the reinforcing steel reinforcement frame 3. The structure is not prone to displacement or deformation during hoisting. Only concrete needs to be poured inside the foundation pit for fixation, which greatly reduces construction errors and improves construction efficiency.

[0043] Please see Figure 2 and Figures 10-12To improve the compressive strength and structural stability of the manhole cover assembly 5 under long-term continuous pressure, a reaction support structure 42 is provided on the mounting ring 4. The reaction support structure 42 includes multiple arc-shaped grooves evenly opened along the upper circumference of the mounting ring 4. An arc-shaped top plate 421 is slidably installed in the arc-shaped groove. When the manhole cover assembly 5 is subjected to downward pressure, the arc-shaped top plate 421 at the corresponding position can rise along the arc-shaped groove and apply an upward lifting force to the manhole cover assembly 5 to achieve dynamic balance of load. A uniformly distributed return spring 422 is connected between the lower end of the arc-shaped top plate 421 and the bottom wall of the arc-shaped groove. The return spring 422 is a small-stroke elastic element that helps the arc-shaped top plate 421 return to its initial position after the pressure is released. It should be noted that the upward movement distance of the arc-shaped top plate 421 is limited to ensure that the lifting force is applied within a reasonable range, which avoids the manhole cover assembly 5 being excessively lifted off the ground and maintains its close fit with the road.

[0044] Please see Figures 10-12 To achieve the lifting action of the arc-shaped top plate 421, a clearance groove communicating with the arc-shaped groove is provided on the outer side of the mounting ring 4 corresponding to the position of the arc-shaped top plate 421. A rotating plate 424 is hinged to the side of the arc-shaped top plate 421 away from the center of the mounting ring 4 via a pin. A rotating shaft 425 is rotatably mounted in the middle of the rotating plate 424, allowing the rotating plate 424 to rotate around the rotating shaft 425. A pressure plate 426 is hinged to the end of the rotating plate 424 away from the arc-shaped top plate 421 via a pin. Sliding grooves 427 are respectively provided on the rotating plate 424 to slide with pins one and two. A protective frame 428 is installed on the outside of the rotating plate 424 and the pressure plate 426. It is used to isolate the poured concrete and protect its internal structure from interference. The rotating shaft 425 is fixedly connected to the protective frame 428. When the pressure plate 426 is subjected to the downward pressure transmitted by the manhole cover assembly 5, the pressure plate 426 moves down along the protective frame 428. Through the cooperation of the second pin and the slide groove 427, the rotating plate 424 is driven to rotate around the rotating shaft 425. When the rotating plate 424 rotates, it drives the first pin and the arc-shaped top plate 421 to move upward through the slide groove 427, thereby realizing the lifting action of the arc-shaped top plate 421.

[0045] Please see Figure 9 and Figure 10 Stress dispersion plates 43 are uniformly distributed circumferentially on the outside of the mounting ring 4. The stress dispersion plates 43 are arranged in a one-to-one correspondence with the arc-shaped top plate 421. The lower end face of the stress dispersion plate 43 is provided with a connecting groove that matches the protective frame 428. The upper end of the pressure plate 426 passes through the protective frame 428 and abuts against the lower end face of the stress dispersion plate 43. When the stress dispersion plate 43 is subjected to the downward pressure transmitted by the manhole cover assembly 5, the pressure can be transmitted to the pressure plate 426 through the connecting groove.

[0046] Please see Figure 3 , Figure 9 and Figure 10The manhole cover assembly 5 is an existing technology, typically consisting of a manhole cover body and a manhole seat. To achieve a stable connection between the manhole cover assembly 5 and the mounting ring 4 and to distribute the load evenly, multiple slots 51 are evenly provided circumferentially at the insertion end of the manhole seat of the manhole cover assembly 5. The aforementioned multiple stress-dispersing plates 43 together form an annular cone-shaped structure that is smaller at the top and larger at the bottom. The inner side of the stress-dispersing plate 43 engages with the slots 51 of the manhole cover assembly 5. The manhole cover assembly 5 is embedded into the upper end of the mounting ring 4 through the slots 51, achieving circumferential positioning and vertical fitting of the manhole cover assembly 5, ensuring installation accuracy and structural stability. At the same time, the multiple annular cone-shaped stress-dispersing plates 43 can diffuse the concentrated load on the manhole cover assembly 5 outward along the cone surface, reducing the single-point stress intensity and avoiding local damage.

[0047] Please see Figure 1 and Figure 2 To achieve a stable connection between the well shaft, mounting ring 4, stress dispersion plate 43, and well cover assembly 5, fine aggregate concrete 8 is poured into the gap between the precast concrete well shaft 1 and mounting ring 4 before placing the stress dispersion plate 43 and well cover assembly 5 to form a preliminary fixation. Subsequently, after the stress dispersion plate 43 and well cover assembly 5 are installed, fine aggregate concrete 8 is poured between the well shaft, mounting ring 4, and stress dispersion plate 43 to complete the coordinated stress connection of the multi-layer structure. Fine aggregate concrete 8 can solve the problem of difficult vibration and improve construction efficiency. The first pour ensures the initial anchoring of the well shaft and mounting ring 4, and avoids loosening of the connection due to vibration or displacement during the installation of stress dispersion plate 43 and well cover assembly 5. The second pour fills the gap between stress dispersion plate 43 and mounting ring 4, eliminates interface voids, and improves the overall structural density.

[0048] Please see Figure 3 and Figure 9 Furthermore, evenly distributed auxiliary steel bars 431 are provided on the upper end face of the stress dispersion plate 43. The auxiliary steel bars 431 are embedded in the secondary poured fine stone concrete 8. Through mechanical interlocking, the bond strength between the stress dispersion plate 43 and the concrete layer is enhanced, effectively resisting the interface slippage caused by concrete shrinkage or external loads, and ensuring the continuity of the load transfer path.

[0049] Please see Figure 1 and Figure 2 To ensure a smooth connection between the manhole cover assembly 5 and the road surface and reduce the concentration of impact stress when vehicles pass, an asphalt layer 9 flush with the ground needs to be laid on top of the fine aggregate concrete layer 8. This asphalt layer 9 forms a continuous transition surface through a rolling process, which not only meets the requirements for road flatness but also absorbs local settlement differences through the properties of flexible materials. During construction, the asphalt layer 9 must be tightly bonded to the fine aggregate concrete layer 8 to avoid water leakage or structural separation caused by interface gaps, ultimately achieving an integrated connection between the manhole cover assembly 5 and the road surface.

[0050] On the other hand, the present invention also provides a method for preventing settlement of municipal road manholes, applicable to the construction of municipal road manholes for preventing settlement, combined with Figures 1-3 This includes the following steps: Step 1: Excavate the foundation pit at the construction site according to the design elevation, compact the bottom of the foundation pit, lay a uniform sand and gravel cushion layer, place the conical ring base 2 at the bottom of the foundation pit, and then pour micro-expansion concrete 6 to fix the ring base 2, forming a stable foundation support layer. Step 2: Install ring-shaped steel bars layer by layer from bottom to top on the outside of the precast concrete well cylinder 1. At the same time, insert the lateral connecting steel bars 32 horizontally into the precast concrete well cylinder 1 and connect them with each ring-shaped steel bar 31. Also, insert inclined reinforcing steel bars 34 between adjacent lateral connecting steel bars 32 and install the installation ring 4 on the upper end of the precast concrete well cylinder 1. Step 3: The precast concrete well cylinder 1, the installation ring 4 and the steel reinforcement frame 3 are hoisted into the foundation pit as a whole, and high-strength concrete 7 is poured between the precast concrete well cylinder 1 and the steel reinforcement frame 3. Step 4: Arrange the stress dispersion plate 43 on the outside of the mounting ring 4 and fix the manhole cover assembly 5 on the upper end of the mounting ring 4. Then, pour fine stone concrete 8 between the precast concrete manhole 1, the mounting ring 4, the stress dispersion plate 43 and the manhole cover assembly 5. Finally, lay an asphalt layer 9 flush with the ground on top of the fine stone concrete 8 to complete the construction.

[0051] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0052] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A settlement-prevention structure for municipal road inspection wells, characterized in that, include: Precast concrete shaft (1); The steel reinforcement frame (3) includes multiple ring steel reinforcement groups spaced apart along the height direction of the precast concrete well cylinder (1). Each ring steel reinforcement group includes at least one ring steel reinforcement (31). Multiple ring steel reinforcements (31) are arranged sequentially from the inside to the outside along the circumference of the precast concrete well cylinder (1). The number of ring steel reinforcements (31) in each group decreases from bottom to top along the height direction of the precast concrete well cylinder (1), so that the steel reinforcement frame (3) has an upwardly narrowing frustum-shaped structure, which is used to realize the gradual stress diffusion between the well cylinder and the surrounding soil. Lateral connecting steel bars (32) are evenly arranged around the precast concrete well cylinder (1) and are inserted into the ring steel bars (31). They can be horizontally inserted into the precast concrete well cylinder (1) to fix the ring steel bars (31) around the circumference and fix the ring steel bars (31) to the precast concrete well cylinder (1).

2. The anti-settlement structure for municipal road inspection wells according to claim 1, characterized in that: In each group of ring steel bars, the lower end of the outermost ring steel bar (31) is equipped with multiple supporting steel bars (33) distributed along its circumference. Except for the bottommost supporting steel bar (33), the lower ends of the supporting steel bars (33) of each layer are respectively inserted and matched with the corresponding ring steel bar (31) below them.

3. The anti-settlement structure for municipal road inspection wells according to claim 1, characterized in that: The lateral connecting steel bars (32) located on the same side and in the same vertical plane are connected by inclined reinforcing steel bars (34), and the inclined reinforcing steel bars (34) and the lateral connecting steel bars (32) are inserted into each other.

4. The anti-settlement structure for municipal road inspection wells according to claim 3, characterized in that: The diameter of the ring bars (31) in the same group of ring bars increases from the inside to the outside, and the spacing between adjacent ring bars (31) increases gradually from the inside to the outside. Both the lateral connecting steel bar (32) and the inclined reinforcing steel bar (34) are conical in shape, with the smaller end of the lateral connecting steel bar (32) facing the precast concrete well shaft (1) and the smaller end of the inclined reinforcing steel bar (34) facing upward.

5. The anti-settlement structure for municipal road inspection wells according to claim 1, characterized in that: A ring base (2) is provided below the precast concrete well cylinder (1). The ring base (2) is cone-shaped, and a matching ring (21) is provided at its upper end to match the lower end of the precast concrete well cylinder (1). The ring base (2) has uniformly distributed through holes (22).

6. The anti-settlement structure for municipal road inspection wells according to claim 4, characterized in that: An installation ring (4) is provided above the precast concrete well shaft (1). The lower end of the installation ring (4) and the upper end of the precast concrete well shaft (1) are respectively provided with sawtooth grooves (41), and the upper and lower grooves (41) mesh with each other. The inclined reinforcing steel bar (34) and the mounting ring (4) are inserted in an inclined state.

7. The anti-settlement structure for municipal road inspection wells according to claim 6, characterized in that: The mounting ring (4) is provided with a reaction support structure (42) for applying an upward lifting force to the manhole cover when the manhole cover is subjected to downward pressure; The reaction support structure (42) includes multiple arc-shaped grooves evenly opened along the upper circumference of the mounting ring (4). An arc-shaped top plate (421) is slidably arranged in the arc-shaped groove. A uniformly distributed reset spring (422) is connected between the lower end of the arc-shaped top plate (421) and the bottom wall of the arc-shaped groove.

8. The anti-settlement structure for municipal road inspection wells according to claim 7, characterized in that: The mounting ring (4) has an avoidance groove connected to the arc-shaped groove at the position corresponding to the arc-shaped top plate (421) on the outer side. A rotating plate (424) is hinged to the side of the arc-shaped top plate (421) away from the center of the mounting ring (4) by a pin. A rotating shaft (425) is rotatably provided in the middle of the rotating plate (424). A pressure plate (426) is hinged to the end of the rotating plate (424) away from the arc-shaped top plate (421) by a pin. A sliding groove (427) is provided on the rotating plate (424) to slide with the pin and the pin.

9. The anti-settlement structure for municipal road inspection wells according to claim 8, characterized in that: A manhole cover assembly (5) is provided above the mounting ring (4), and multiple slots (51) are evenly provided around the manhole seat insertion end of the manhole cover assembly (5). The mounting ring (4) is provided with stress dispersion plates (43) evenly distributed in the circumference on the outside. Multiple stress dispersion plates (43) together form an annular cone structure with a smaller top and a larger bottom. Its inner side is engaged with the slot (51) of the well cover assembly (5). The lower end face of the stress dispersion plate (43) is provided with a connecting groove that matches the protective frame (428), and the upper end of the pressure plate (426) passes through the protective frame (428) and abuts against the lower end face of the stress dispersion plate (43). The upper surface of the stress dispersion plate (43) is provided with uniformly distributed auxiliary steel bars (431).

10. A method for preventing settlement of municipal road manholes, applicable to the anti-settlement structure of municipal road manholes as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Excavate the foundation pit at the construction site according to the design elevation, compact the bottom of the foundation pit, lay a uniform sand and gravel cushion layer, place the conical ring base (2) at the bottom of the foundation pit, and then pour micro-expansion concrete (6) to fix the ring base (2) to form a stable foundation support layer. Step 2: Install ring-shaped steel bars layer by layer from bottom to top on the outside of the precast concrete well cylinder (1). At the same time, insert the lateral connecting steel bars (32) horizontally into the precast concrete well cylinder (1) and connect them with each ring-shaped steel bar (31). Also, insert inclined reinforcing steel bars (34) between the upper and lower adjacent lateral connecting steel bars (32) and install the installation ring (4) on the upper end of the precast concrete well cylinder (1). Step 3: The precast concrete well cylinder (1), the installation ring (4) and the steel reinforcement frame (3) are hoisted into the foundation pit as a whole, and high-strength concrete (7) is poured between the precast concrete well cylinder (1) and the steel reinforcement frame (3). Step 4: Arrange the stress dispersion plate (43) on the outside of the mounting ring (4) and fix the manhole cover assembly (5) on the upper end of the mounting ring (4). Then, pour fine stone concrete (8) between the precast concrete manhole (1), the mounting ring (4), the stress dispersion plate (43) and the manhole cover assembly (5). Finally, lay an asphalt layer (9) flush with the ground on top of the fine stone concrete (8) to complete the construction.

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