Construction method of firm drainage pipe

Abstract

The firm drainage pipe construction method comprises the steps that the pipe wall thickness and the outer sealing concrete thickness of a circular pipe culvert are calculated according to the permissible bearing capacity of a foundation; a concrete cushion layer is poured in the working pit, a winch and a counter-force base are installed at one end of the cushion layer, and positioning bases are installed at lofting positions on the two sides of the cushion layer; the round pipe culvert is hoisted to the positioning base, and a traction device connected with a winch is installed at one end of the round pipe culvert; the round pipe culvert is pulled in sequence, so that all the round pipe culverts are assembled; an outer sealing concrete formwork is erected on the concrete cushion layer; concrete is poured in the formwork to reach the thickness of outer sealing concrete, and the deformation joint is filled with asphalt hemp threads; and the working pit is backfilled to the original ground elevation. The rectangular outer sealing concrete is additionally arranged on the circular pipe culvert for reinforcement treatment, the construction convenience and the bearing strength of the circular pipe culvert are enhanced, the traction device is used for guaranteeing the smooth installation line shape and accurate butt joint of the circular pipe culvert, damage in the splicing process is reduced, and a calculation method for the thickness of the outer sealing concrete is provided.

Description

Technical Field

[0001] This invention relates to the field of drainage pipe construction, and more particularly to a method for constructing a robust drainage pipe. Background Technology

[0002] Circular culverts are commonly used drainage pipes in highway engineering. Due to their convenient construction, factory prefabrication, and simple structure, they are widely used in roadbed drainage systems. However, prefabricated circular culverts often encounter problems during construction, such as damage from hoisting collisions, poor installation accuracy, and excessively large joints. Furthermore, with increasingly heavy traffic, ordinary circular culverts cannot withstand repeated heavy vehicle loads, leading to frequent damage incidents. This is especially true for circular culverts buried on construction sites; damage during construction or being crushed or broken by heavy machinery such as tank trucks, freight trucks, cranes, loaders, and road rollers is common. When a circular culvert is damaged to the point of being unable to drain water properly, it is difficult to reinforce and repair it. The usual approach is to excavate the roadbed and re-bury a new circular culvert, which severely impacts normal traffic flow and causes unnecessary time and property loss. To address damage to circular culverts caused by their inability to withstand heavy vehicle loads, reinforcement methods typically include increasing the cross-section of the culvert and installing internal supports to improve its load-bearing capacity. To address the above issues, a robust drainage pipe construction method needs to be proposed, which provides construction safety and ensures installation accuracy, can withstand the loads of heavy traffic without being crushed, and has enhanced robustness. Summary of the Invention

[0003] To address the above problems, this invention proposes a robust drainage pipe construction method, the specific technical solution of which is as follows: A method for constructing a robust drainage pipe includes the following steps: Step 1: Calculate the wall thickness of the circular culvert and the thickness of the outer concrete seal based on the allowable bearing capacity of the foundation; Step 2: Pour a concrete foundation in the working pit, and install a winch and reaction seat at one end of the foundation, and install positioning seats at the layout positions on both sides of the foundation. Step 3: Lift the culvert onto the positioning seat and install a traction device connected to the winch at one end of the culvert; Step 4: Pull the circular culvert sections one by one to complete the assembly of the circular culvert sections; Step 5: Erect the outer concrete formwork on the concrete foundation and install multiple adjustable top rods on the outside of the formwork for support; Step 6: Pour concrete into the formwork to achieve the required thickness for the outer sealing concrete, and fill the expansion joint with asphalt-impregnated hemp fiber; Step 7: Backfill the working pit to the original ground elevation.

[0004] Furthermore, the calculation method for the wall thickness of the circular culvert and the thickness of the outer sealing concrete is as follows:

[0005] in: This refers to the dead load on the circular culvert. The unit weight of the backfill soil; H is the thickness of the backfill soil cover; The unit weight of the concrete material used in the circular culvert; The thickness of the circular culvert wall; This refers to the thickness of the outer concrete seal.

[0006] Furthermore, anchor bolts are pre-embedded in the padding layer, and the winch and positioning seat are connected to the anchor bolts via nuts.

[0007] Furthermore, the positioning seat is provided with a disassembly hole for removing the nut connected to the anchor bolt.

[0008] Furthermore, the traction device includes a threaded steel bar and a pair of grooved fasteners. The two grooved fasteners are symmetrically installed on the wall of the circular culvert. The threaded steel bar is radially across the circular culvert and its two ends are threadedly connected to the two grooved fasteners respectively. The winch is connected to the two grooved fasteners via a wire rope.

[0009] Furthermore, the two ends of the threaded steel bar are locked to the pipe wall of the circular culvert by adjusting screws.

[0010] Furthermore, the inner sides of the two grooved fasteners and the ends of the wire ropes are connected to lifting eye bolts, and the lifting eye bolts on the two grooved fasteners are connected to the lifting eye bolts on the wire ropes through short steel ropes.

[0011] Furthermore, the outer side of the template is reinforced with horizontal and vertical steel pipes, and cement nails are driven into the connection between the vertical steel pipes and the concrete pad to restrain the bottom of the template.

[0012] Furthermore, the top rod is installed between the foundation inclinedly supported on both sides of the template and the working pit, and includes a main rod and end rods threaded to both ends of it. The main rod is rotated so that the end rods extend outward or retract inward synchronously.

[0013] Furthermore, the main rod is provided with a torsion hole for inserting a reinforcing bar or a pin.

[0014] The beneficial effects of this invention are: (1) In response to the common practice of increasing the cross-section of the circular culvert and installing internal supports inside the pipe to improve the bearing capacity, a rectangular outer sealing concrete is added to the circular culvert for reinforcement, which enhances the construction convenience and bearing strength of the circular culvert. (2) A calculation method for the thickness of the outer sealing concrete is proposed, which saves the material of the outer sealing concrete while ensuring the structural bearing capacity and safety, and solves the problem that the thickness of the traditional outer sealing relies on the on-site experience of the construction personnel; (3) In response to the problems of poor alignment and inaccurate docking during the assembly of circular pipe culverts, the positioning seat was used to achieve accurate positioning of the circular pipe culvert during lowering, ensuring smooth alignment and accurate docking during the installation of the circular pipe culvert; (4) To address the problems of excessively large joints and collision damage in traditional circular pipe culvert construction methods, a traction device is used to achieve a tight fit between pipe culverts and reduce damage during the assembly process.

[0015] (5) Using adjustable top rods to support the formwork effectively prevents the formwork from deforming during the concrete pouring process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the assembly of the circular pipe culvert of the present invention.

[0017] Figure 2 This is a schematic diagram of the traction device for the circular pipe culvert of the present invention.

[0018] Figure 3 This is a schematic diagram of the installation of the groove-type fastener of the present invention.

[0019] Figure 4 This is a schematic diagram of the top rod installation according to the present invention.

[0020] Figure 5 This is a schematic diagram of the casting process of the present invention.

[0021] In the diagram: 1. Foundation; 11. Working pit; 2. Circular culvert; 3. Subbase; 31. Anchor bolt; 32. Winch; 33. Reaction seat; 34. Positioning seat; 35. Disassembly hole; 4. Traction device; 41. Threaded steel bar; 42. Channel fastener; 43. Adjusting screw; 44. Wire rope; 45. Lifting eye; 46. Lifting eye bolt; 47. Short steel rope; 5. Formwork; 6. Top rod; 61. End rod; 62. Main rod; 63. Torsion hole; 7. External sealing concrete; 8. Backfill soil. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In the description of this application, "multiple" means two or more, unless otherwise explicitly specified. It should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] like Figures 1 to 5 As shown, a method for constructing a robust drainage pipe includes the following steps: Step 1: Calculate the wall thickness of the circular culvert 2 and the thickness of the outer sealing concrete 7 based on the allowable bearing capacity of the foundation 1; Step 2: Pour a concrete cushion layer 3 into the working pit 2, and install a winch 32 and a reaction seat 33 at one end of the cushion layer 3. Install positioning seats 34 at the layout positions on both sides of the cushion layer 3. Step 3: Hoist the circular culvert 2 onto the positioning seat 34, and install the traction device 4 connected to the winch 32 at one end of the circular culvert 2; Step 4: Pull the circular culvert 2 sections one by one to complete the assembly of each section of the circular culvert 2; Step 5: Erect the outer sealing concrete 7 formwork 5 on the concrete cushion layer 3, and install multiple adjustable top rods 6 on the outside of the formwork 5 for support; Step 6: Pour concrete into formwork 5 to achieve the thickness of outer sealing concrete 7, and fill the expansion joint with asphalt hemp fiber; Step 7: Backfill the working pit 2 to the original ground elevation.

[0025] Specifically, in step 1, the calculation method for the wall thickness of the circular culvert 2 and the thickness of the outer sealing concrete 7 is as follows:

[0026] in: —The dead load on the circular culvert; —The bulk density of the backfill soil; H—thickness of the backfill soil; —The density of the concrete material used in the circular pipe culvert; —Thickness of the wall of the circular culvert; —Thickness of the outer concrete seal.

[0027] Calculate the live load on circular culvert 2 based on the heavy vehicle traffic conditions at the construction site. The wheel loads are distributed downwards at a pressure diffusion angle of 30°. Calculate the lateral distribution width 'a' and longitudinal distribution width 'b' of the vehicle loads on circular culvert 2, as well as the live load 'q' on circular culvert 2. v :

[0028]

[0029] ; In the formula: S —The number of lanes on the road above the culvert; G —Standard value of rear axle weight of vehicle under load.

[0030] The circular culvert 2 is mainly subjected to bending moments generated by the backfill pressure, its own weight, and vehicle loads. Calculate the maximum bending moment of the circular culvert 2 under dead load. M h Bending moment generated under live load M v :

[0031]

[0032]

[0033] In the formula: λ —The lateral pressure coefficient of the backfill soil; — The internal friction angle of the backfill soil.

[0034] D— The outer diameter of a circular culvert.

[0035] Will M h and M v By performing basic combinations, frequent combinations, and quasi-permanent combinations, the design values ​​of bending moments under the ultimate limit state of bearing capacity are obtained respectively. M ud Design value of bending moment under normal serviceability limit state M fd and M qd :

[0036]

[0037]

[0038] In the formula: γ 0 — Design safety level.

[0039] Calculate the effective height of section 2 of the circular culvert. h 0, Calculate the height of the compression zone at section 2 of the circular culvert. x And determine the height of the pressure zone. x Does it meet the relative limit pressure zone height? ξ b h Requirements for 0:

[0040]

[0041] In the formula: a s —Thickness of the concrete cover for reinforcing bars; f sd —Design value of tensile strength of steel reinforcement; A s — Area of ​​the reinforcing steel section; f cd —Design value of axial compressive strength of concrete; b — Width of the circular culvert section; ξ b —Relative limit pressure zone height.

[0042] Following the above workflow, trial calculations were performed on culvert 2, and the final calculation was determined based on the on-site construction conditions. t y and t w After the optimal dimensions, cross-sectional strength, crack width, and reinforcement ratio are verified and approved, the dimensions can be laid out and on-site construction can proceed.

[0043] The detailed construction process is as follows: like Figure 1 , 4 As shown, in step 2, an excavator is first used to excavate the working pit 2 of the circular culvert 2 in the foundation 1. The slope ratio of the pit is determined according to the soil type and the depth of the working pit 2, and the bottom of the working pit 2 is leveled. In order to prevent uneven settlement of the foundation 1 from affecting the structural safety of the circular culvert 2 and to ensure the bearing capacity of the foundation 1, anchor bolts 31 are pre-embedded in the leveled working pit 2. The bottom of the working pit 2 is then poured, vibrated, and leveled to form a concrete cushion layer 3 and a concrete reaction seat 33.

[0044] Installation of winch 32 and positioning seat 34: hoist and lower winch 32 for installation. Winch 32 is installed on the side of reaction seat 33 away from the circular culvert 2. Positioning seat 34 is installed at the layout position. Winch 32 and positioning seat 34 are connected to pre-embedded anchor bolts 31 by nuts to achieve temporary fixation.

[0045] In one embodiment, the positioning seat 34 has a disassembly hole 35 for disassembling the nut connected to the anchor bolt 31.

[0046] like Figure 2 , 3 As shown, in step 3, the circular culvert 2 is lifted by a crane to the positioning seat 34 area on the concrete cushion 3, and the end of the circular culvert 2 near the concrete reaction seat 33 is placed on the positioning seat 34. In one embodiment, the traction device 4 includes a threaded steel bar 41 and a pair of grooved fasteners 42. The two grooved fasteners 42 are symmetrically installed on the pipe wall of the circular culvert 2. The threaded steel bar 41 is radially across the circular culvert 2 and its two ends are threadedly connected to the two grooved fasteners 42 respectively. The winch 32 is connected to the two grooved fasteners 42 through a wire rope 44.

[0047] Preferably, the two ends of the threaded steel bar 41 are locked to the pipe wall of the circular pipe culvert 2 by adjusting screws 43.

[0048] The adjusting screw 43 is also equipped with a washer. After moving the washer and adjusting screw 43 to the appropriate position, tightening the adjusting screw 43 will cause the slotted fastener 42 to engage with the pipe wall, thus achieving the locking function of the slotted fastener 42. The threaded steel bar 41 ensures that the force applied to the pipe wall of the circular culvert 2 by the slotted fasteners 42 on both sides is uniform and balanced, preventing corner damage to the circular culvert 2 due to uneven force.

[0049] In another embodiment, the inner sides of the two grooved fasteners 42 and the ends of the wire rope 44 are connected to lifting rings 45 by lifting ring bolts 46, and the lifting rings 45 on the two grooved fasteners 42 are connected to the lifting rings 45 on the wire rope 44 by short steel ropes 47.

[0050] The short steel ropes 47 on the two grooved fasteners 42 are of the same length. The winch 32 can adjust the winding position of the wire rope 44 using the roller bracket. Through the reliable connection of the lifting ring 45, the position of the wire rope 44 is aligned with the axis of the circular culvert 2 when the winch 32 winds it up. This ensures that the grooved fasteners 42 on both sides of the circular culvert 2 are subjected to balanced force, reducing damage during assembly. By controlling the speed of the winch 32, the installation alignment of the circular culvert 2 can be ensured to be smooth, the connection accurate, and the speed controllable.

[0051] In step 4, the positioning seat 34 is provided with a disassembly hole 35 to facilitate the removal of the positioning seat 34 from the anchor bolt 31; after the Nth section of the circular culvert 2 is assembled, the worker disassembles the positioning seat 34 and reinstalls it at the N+1th section positioning position, repeating the hoisting and assembly work until all sections of the circular culvert 2 are assembled.

[0052] like Figure 4 As shown, in step 5, the outer sealing concrete 7 formwork 5 is erected manually on the concrete foundation 3. Horizontal and vertical steel pipes are used to reinforce the outside of the formwork 5. Cement nails are driven into the connection points between the vertical steel pipes and the concrete foundation 3 to restrain the bottom of the formwork 5. Adjustable top rods 6 are used manually to support the outer sealing concrete 7 formwork 5.

[0053] In one embodiment, the top rod 6 is installed between the foundation 1, which is inclinedly supported on both sides of the template 5 and the working pit 2. It includes a main rod 62 and end rods 61 threaded to both ends. The main rod 62 is rotated so that the end rods 61 extend outward or retract inward synchronously.

[0054] Preferably, the main rod 62 is provided with a torsion hole 63 for inserting a reinforcing bar or a pin.

[0055] Twist the two end rods 61 to adjust the length of the top rod 6 via the thread, and lock it between the foundation 1 and the formwork 5. Insert a steel bar or pin into the twist hole 63 and twist the main rod 62 until it is tightly pressed against the foundation 1 and the formwork 5.

[0056] like Figure 4 , 5 As shown, in step 6, the outer sealing concrete 7 is poured using a pump or hopper to achieve the required thickness. During pouring, manual tamping is used, and expansion joints are reserved to ensure that the culvert 2 will not crack or break due to expansion and contraction caused by temperature and humidity changes. Asphalt hemp fiber is manually prepared as the filling material for the expansion joint of the culvert 2, and the asphalt hemp fiber is stuffed into the expansion joint of the culvert 2 to ensure the expansion and contraction performance of the culvert 2 while preventing water or debris from entering the expansion joint.

[0057] In step 6, after the outer sealing concrete 7 of the circular culvert 2 reaches the design compressive strength, the backfill soil 8 is filled to the original ground elevation by excavation and backfilling, and the ground is compacted by a road roller.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a robust drainage pipe, characterized in that, Includes the following steps: Step 1: Calculate the wall thickness of the circular culvert and the thickness of the outer concrete seal based on the allowable bearing capacity of the foundation; Step 2: Pour a concrete foundation in the working pit, and install a winch and reaction seat at one end of the foundation, and install positioning seats at the layout positions on both sides of the foundation. Step 3: Lift the culvert onto the positioning seat and install a traction device connected to the winch at one end of the culvert; Step 4: Pull the circular culvert sections one by one to complete the assembly of the circular culvert sections; Step 5: Erect the outer concrete formwork on the concrete foundation and install multiple adjustable top rods on the outside of the formwork for support; Step 6: Pour concrete into the formwork to achieve the required thickness for the outer sealing concrete, and fill the expansion joint with asphalt-impregnated hemp fiber; Step 7: Backfill the working pit to the original ground elevation.

2. The method for constructing a robust drainage pipe according to claim 1, characterized in that, The calculation methods for the wall thickness and the outer sealing concrete thickness of the circular culvert are as follows: in: This refers to the dead load on the circular culvert. The unit weight of the backfill soil; H is the thickness of the backfill soil cover; The unit weight of the concrete material used in the circular culvert; The thickness of the circular culvert wall; This refers to the thickness of the outer concrete seal.

3. The method for constructing a robust drainage pipe according to claim 1, characterized in that, Anchor bolts are pre-embedded in the padding layer, and the winch and positioning seat are connected to the anchor bolts by nuts.

4. The method for constructing a robust drainage pipe according to claim 3, characterized in that, The positioning seat has a disassembly hole for removing the nut connected to the anchor bolt.

5. The method for constructing a robust drainage pipe according to claim 1, characterized in that, The traction device includes a threaded steel bar and a pair of grooved fasteners. The two grooved fasteners are symmetrically installed on the wall of the circular culvert. The threaded steel bar is radially across the circular culvert and its two ends are threadedly connected to the two grooved fasteners respectively. The winch is connected to the two grooved fasteners through a wire rope.

6. The method for constructing a robust drainage pipe according to claim 5, characterized in that, The two ends of the threaded steel bar are locked to the pipe wall of the circular culvert by adjusting screws.

7. The method for constructing a robust drainage pipe according to claim 5, characterized in that, The inner side of the two grooved fasteners and the end of the wire rope are connected to lifting eye bolts. The lifting eye bolts on the two grooved fasteners are connected to the lifting eye bolts on the wire rope through short steel ropes.

8. The method for constructing a robust drainage pipe according to claim 1, characterized in that, The outer side of the template is reinforced with horizontal and vertical steel pipes. Cement nails are driven into the connection between the vertical steel pipes and the concrete pad to restrain the bottom of the template.

9. The method for constructing a robust drainage pipe according to claim 1, characterized in that, The top rod is installed between the foundation, which is inclined and supported on both sides of the template and the working pit. It includes a main rod and end rods threaded to both ends. The main rod is rotated so that the end rods extend outward or retract inward synchronously.

10. A method for constructing a robust drainage pipe according to claim 9, characterized in that, The main rod is provided with a torsion hole for inserting a reinforcing bar or a pin.

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