Construction device for gravel blind ditch

Abstract

The invention relates to the technical field of road engineering, and particularly provides a construction device for a gravel blind ditch. The device comprises hot-rolled channel steel, twisted steel is vertically welded to the middle of the height direction of the hot-rolled channel steel, and flat-end finish-rolled nuts are arranged at the ends of the twisted steel in a matched mode. The connecting length of the flat-end finish rolling nut and the twisted steel is adjusted by rotating the flat-end finish rolling nut, and accurate control over the width of the gravel blind ditch is achieved. When the device is installed, the flat-end finish rolling nuts abut against the retaining wall or the side wall of the drainage ditch to form rigid support; during dismounting, the nut is reversely rotated to be separated from the contact face, and lossless removal is achieved. The device effectively solves the problem of blind ditch linear distortion caused by template displacement deviation in a traditional process, and the interlayer water drainage efficiency is remarkably improved. And meanwhile, full turnover use of formwork components is achieved, and the erosion risk of metal residues to a base structure is eliminated. The adjustable characteristic is suitable for blind ditch construction under different geological conditions, the operation process is simplified, and the comprehensive cost is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of road engineering technology, and specifically to a construction device for gravel blind drains. Background Technology

[0002] In road engineering, edge gravel blind drains are crucial structures for draining interlayer water from asphalt pavements. Their linear accuracy and forming quality directly affect the drainage efficiency of interlayer water. Traditional internal tension formwork construction has two inherent drawbacks: First, when the steel wires and nails fixing the formwork are subjected to enormous lateral thrust during the compaction of the base course by a road roller, insufficient anchoring force leads to accumulated formwork displacement deviations, causing the actual position of the blind drain to deviate from the design axis. This prevents interlayer water from draining along the intended path and instead seeps into the base course. Second, the steel wires and nails are permanently embedded in the base course after it is formed, creating structural weak points and preventing recycling, resulting in continuous material loss. Especially in permafrost areas, residual metal components exacerbate the risk of frost heave damage; in soft soil subgrades, formwork displacement deviations are further amplified. Current techniques cannot balance the contradiction between construction accuracy and economy, necessitating a solution that combines stable positioning with full component reusability. Summary of the Invention

[0003] To solve, or at least partially solve, the above-mentioned technical problems, the present invention provides a construction device for gravel blind drains.

[0004] This invention provides a construction device for gravel blind drains, comprising:

[0005] Hot-rolled channel steel, wherein a threaded steel bar is vertically welded to the middle of the hot-rolled channel steel in the height direction;

[0006] A flat-head precision-rolled nut, which is fitted onto the end of the threaded reinforcing bar.

[0007] The width of the crushed stone blind drain is controlled by adjusting the connection length between the flat-head precision rolled nut and the threaded steel bar, and the template installation and disassembly are realized.

[0008] Optional:

[0009] The hot-rolled channel steel is provided with anti-collision plates at both ends, and the anti-collision plates are fixed to the end vertical surface of the hot-rolled channel steel by intermittent welding.

[0010] Optional:

[0011] The hot-rolled channel steel is inclinedly welded with a diagonal support bar on its back side. The bottom end of the diagonal support bar is connected to the back vertical surface of the hot-rolled channel steel, and the top end of the diagonal support bar extends outward to the ground contact area.

[0012] Optional:

[0013] The hot-rolled channel steel is provided with a pin connection mechanism at its end, the pin connection mechanism comprising:

[0014] The connecting lugs are welded to the ends of the hot-rolled channel steel.

[0015] The pin hole is formed on the connecting ear plate.

[0016] And a reinforcing bar pin inserted into an adjacent pin hole.

[0017] Optional:

[0018] The threaded section of the threaded steel bar is fitted with an anti-loosening sleeve, which is a cylindrical geotextile layer. The two ends of the anti-loosening sleeve are tied and fixed to the smooth section of the threaded steel bar with iron wire. The anti-loosening sleeve covers the meshing area between the flat-head precision rolled nut and the threaded steel bar.

[0019] Optional:

[0020] A lifting ring is welded to the top of the hot-rolled channel steel, and the axis of the lifting ring is perpendicular to the length direction of the hot-rolled channel steel.

[0021] Optional:

[0022] The hot-rolled channel steel has a vibration buffer layer on its waist. The vibration buffer layer is made of waste rubber tire pads and is fixed to the outer side of the waist of the hot-rolled channel steel by U-shaped clamps.

[0023] Optional:

[0024] The hot-rolled channel steel has its upper waist width partially cut off in the area corresponding to the flat-head precision rolled nut to form a wrench operation avoidance opening.

[0025] Optional:

[0026] A horizontal calibration rod is welded to the outer side of the leg width of the hot-rolled channel steel, and a gravity plumb bob is suspended on the horizontal calibration rod. The tip of the gravity plumb bob is aligned with the ground reference line.

[0027] Optional:

[0028] The bottom of the hot-rolled channel steel is detachably equipped with a steel plate pad. The steel plate pad is connected to the leg width vertical surface of the hot-rolled channel steel by a U-bolt. The bearing area of ​​the steel plate pad is larger than the bottom projected area of ​​the hot-rolled channel steel.

[0029] The construction device for gravel blind drains provided by this invention has the following beneficial effects:

[0030] Traditional crushed stone blind drain construction using steel wire to fix the formwork suffers from the enormous lateral thrust generated by the roller compacting the base course, causing the steel wire to plastically extend and leading to gradual formwork displacement. This results in the blind drain's actual position deviating significantly from the design axis. Interlayer water cannot drain along the intended path and seeps into the base course, causing strength degradation and pumping defects in the base course material. This invention utilizes a high-bending-stiffness main frame provided by hot-rolled channel steel, combined with vertically welded threaded steel bars and flat-head precision-rolled nuts to form a rigid, adjustable support structure. During installation, rotating the flat-head precision-rolled nuts secures them against the retaining wall or drainage ditch sidewall, establishing stable constraints. This structure converts the roller thrust into an overall bending moment of the channel steel, rather than the localized tensile deformation of traditional steel wire, eliminating the risk of formwork displacement and ensuring the blind drain's axis matches the design trajectory.

[0031] Compared to the metal residue defects of traditional processes, the threaded adjustment structure of this device enables complete disassembly and recycling. Traditional steel wires, embedded in the base layer, form rust channels, accelerating interlayer water erosion and inducing frost heave damage. This device, by rotating the flat-head precision-rolled nut in the reverse direction during demolding, releases the constraint, allowing the hot-rolled channel steel to be extracted without damage, eliminating metal component residue. This eliminates the risk of structural weakening and enables unlimited reuse of the formwork.

[0032] Traditional steel wire anchoring requires redesigning the burial depth and density based on geological conditions. This device, however, adjusts the length of the threaded steel bars, allowing it to adapt to varying chemical conditions such as soft soil settlement and frozen soil expansion simply by changing the engagement position of the flat-head precision-rolled nut. In frozen soil areas, traditional steel wires are prone to brittle fracture upon cooling, leading to formwork loss of control. This device's rigid support system eliminates the risk of low-temperature brittleness. In soft soil subgrades, the continuous beam effect of the hot-rolled channel steel resists non-uniform settlement, avoiding the wave-like deformation caused by the failure of traditional discrete anchor points. Attached Figure Description

[0033] Figure 1 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0034] Figure 2 A top view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0035] Figure 3 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0036] Figure 4 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0037] Figure 5 A rear view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0038] Figure 6 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0039] Figure 7 A rear view of another construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0040] Figure 8 A rear view of another construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0041] Figure 9 A top view of another construction device for a gravel blind drain provided in an embodiment of the present invention;

[0042] Figure 10 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0043] Figure 11 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0044] Figure 12 A side view of a construction device for a crushed stone blind drain provided in an embodiment of the present invention;

[0045] Figure 13 This is a side view of another construction device for gravel blind drains provided in an embodiment of the present invention.

[0046] Figure Labels

[0047] 0. Retaining wall or drainage ditch lining; 1. Hot-rolled channel steel; 2. Threaded steel bar; 3. Flat-head precision rolled nut; 4. Anti-collision plate; 5. Diagonal support steel bar; 6. Connecting ear plate; 7. Pin hole; 8. Steel bar pin; 9. Anti-loosening wrapping sleeve; 10. Lifting ring; 11. Vibration buffer layer; 12. U-shaped clamp; 13. Wrench operation clearance opening; 14. Horizontal alignment rod; 15. Gravity plumb bob; 16. Steel plate pad; 17. U-shaped bolt; 18. Crushed stone splash plate; 19. Rotatable outrigger; 20. Hinge shaft. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this application and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not all of them.

[0049] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0050] See Figures 1-12 This invention provides a construction device for gravel blind drains, comprising:

[0051] Hot-rolled channel steel 1, wherein a threaded steel bar 2 is vertically welded to the middle of the height direction of the hot-rolled channel steel 1;

[0052] A flat-head precision-rolled nut 3 is fitted onto the end of the threaded steel bar 2.

[0053] The width of the crushed stone blind drain is controlled by adjusting the connection length between the flat-head precision rolled nut 3 and the threaded steel bar 2, and the template installation and disassembly are realized.

[0054] Hot-rolled channel steel 1 can be a common engineering model, with a length of 3000mm. Threaded reinforcing bars 2 are vertically welded to the center of its height. The ends of the threaded reinforcing bars 2 are threaded and fitted with flat-head precision-rolled nuts 3. During actual construction, workers place the hot-rolled channel steel 1 at the designed location in the gravel blind ditch, and rotate the flat-head precision-rolled nuts 3 to adjust the extension length, ensuring the nut end face is tightly against the side of the retaining wall or drainage ditch 0. At this point, the hot-rolled channel steel 1 serves as the formwork boundary, and the threaded reinforcing bars 2 bear the lateral pressure, which is transmitted to the flat-head precision-rolled nuts 3. The nuts and the sidewall of the structure form a stable support structure.

[0055] When the paver lays the base course material, the mixture exerts continuous lateral pressure on the hot-rolled channel steel 1. Due to the high bending stiffness of the hot-rolled channel steel 1, combined with the rigid connection of the threaded steel bar 2, it effectively resists material compression deformation. During the compaction process, the flat-head precision-rolled nut 3 generates frictional reaction force at the contact surface with the structure. This reaction force is transformed into a stable constraint on the hot-rolled channel steel 1 through the threaded steel bar 2, avoiding the gradual displacement phenomenon caused by traditional flexible anchoring methods. Even when encountering impacts from large-diameter aggregates, the threaded meshing structure will not loosen.

[0056] After the base layer compaction is completed, workers use a wrench to clamp the outer edge of the flat-head precision-rolled nut 3. During reverse rotation, the flat-head precision-rolled nut 3 retracts axially along the threaded steel bar 2, and the end face of the nut gradually separates from the side wall of the structure. After the constraint is completely released, the worker holds the top edge of the hot-rolled channel steel 1 and pulls it upwards, and the entire template is vertically separated from the base material. A small amount of cement slurry adheres to the surface of the disassembled hot-rolled channel steel 1, which can be removed with simple hammering, and the threaded section of the threaded steel bar 2 remains intact and undamaged.

[0057] During construction in frozen soil sections, the flat-head precision-rolled nut 3 experienced temporary adhesion at its contact surface with the frozen ditch surface. Workers used a blowtorch to briefly heat the nut shell, and the unscrewing operation resumed normally after the ice melted. During construction in soft soil foundation sections, the bottom of the hot-rolled channel steel 1 experienced slight subsidence. This subsidence could be compensated for by increasing the outward extension length of the flat-head precision-rolled nut 3, thus maintaining the stability of the width of the gravel blind ditch.

[0058] The thread adjustment mechanism is relatively easy to use. New workers can master the correspondence between the rotation direction and width change with simple guidance. Occasionally, the threads of the threaded rebar 2 may be damaged after long-term use; however, they can be repaired on-site using a die threading tool and continue to be used. When the hexagonal edges of the flat-head precision-rolled nut 3 show wear, the edges can be ground with a grinding wheel to restore its function.

[0059] In this implementation, the hot-rolled channel steel 1 serves as the main load-bearing component, providing a stable boundary. The adjustment structure composed of the threaded steel bar 2 and the flat-head precision-rolled nut 3 forms a rigid support interface during the installation phase to ensure positioning accuracy. During the disassembly phase, the constraint is released through the movement of the threaded pair, achieving non-destructive recycling. This structure not only solves the problem of metal residue caused by the embedding of traditional anchors, but also avoids the time consumption of repeated measurements and laying out, while reducing the labor intensity of workers bending over to fix the steel wire.

[0060] To ensure that each hot-rolled channel steel 1 is subjected to uniform stress, precision-rolled threaded steel bars 2 and flat-head precision-rolled nuts 3 are installed at 375mm from each end of the hot-rolled channel steel 1 and at 1125mm from each end of the hot-rolled channel steel 1, for a total of four installations.

[0061] See Figure 2 In some implementation methods:

[0062] The hot-rolled channel steel 1 is provided with anti-collision plates 4 at both ends, and the anti-collision plates 4 are fixed to the end vertical surface of the hot-rolled channel steel 1 by intermittent welding.

[0063] The anti-collision plate 4 is fixed to the end of the hot-rolled channel steel 1 by intermittent welding. The anti-collision plate 4 can be cut into rectangular plates. The welder divides the vertical surface of the end of the hot-rolled channel steel 1 into several welding sections, and the length of each weld is controlled within an appropriate range, with sufficient gaps maintained between adjacent welds.

[0064] For example, during transportation and loading / unloading, forklift forks may occasionally collide with the end of the hot-rolled channel steel 1. In this case, the anti-collision plate 4 initially absorbs the impact, but the main structure of the hot-rolled channel steel 1 remains intact. As another example, during installation, workers drag the hot-rolled channel steel 1 into place, and the end of the channel steel frequently bumps against the curb, causing the anti-collision plate 4 to rub against the stone. Compared to channel steel without the anti-collision plate 4, its end edges remain intact and undamaged.

[0065] The addition of anti-collision plates 4 significantly reduces the probability of end damage to the hot-rolled channel steel 1. Unprotected channel steel exhibits a high degree of end deformation after a period of use, while channel steel equipped with anti-collision plates 4 maintains good geometric shape under the same working conditions. When the collision energy is excessive, the anti-collision plates 4 absorb energy through plastic deformation, preventing the energy from being completely transferred to the main structure of the hot-rolled channel steel 1.

[0066] See Figure 3In some implementation methods:

[0067] The hot-rolled channel steel 1 has a diagonal support bar 5 welded to its back side. The bottom end of the diagonal support bar 5 is connected to the back vertical surface of the hot-rolled channel steel 1, and the top end of the diagonal support bar 5 extends outward to the ground contact area.

[0068] Specifically, before welding, workers use the ends of rebars to make positioning marks on the back of the hot-rolled channel steel 1, and the length of the diagonal support rebar 5 is cut according to experience. The bottom end of the diagonal support rebar 5 is welded to the back surface of the hot-rolled channel steel 1 in full contact, and the top end is flattened to increase the ground contact area. During actual installation on site, workers step the top end of the diagonal support rebar 5 into the soil to a suitable depth.

[0069] The grounding end design of the inclined support steel bar 5 significantly improves system stability. Under the strong vibration condition of the road roller, the channel steel without support exhibits visible swaying, while the channel steel with the inclined support steel bar 5 shows a significantly reduced degree of swaying. In the settlement test of soft soil subgrade, the inclined support steel bar 5 automatically compensates for height loss by continuously inserting downwards, ensuring that the hot-rolled channel steel 1 maintains the design elevation.

[0070] See Figure 4 In some implementation methods:

[0071] The hot-rolled channel steel 1 is provided with a pin connection mechanism at its end, the pin connection mechanism comprising:

[0072] The connecting lug 6 is welded to the end of the hot-rolled channel steel 1.

[0073] The pin hole 7 is formed on the connecting ear plate 6.

[0074] And a steel bar pin 8 that passes through the adjacent pin hole 7.

[0075] Specifically, the welder can position the connecting ear plate 6 at the center line of the end face of the hot-rolled channel steel 1 and fix it by full perimeter welding. The connecting ear plate 6 is then cut with an oxy-acetylene torch to create a pin hole 7 in the middle.

[0076] When assembling multiple sections of hot-rolled channel steel 1, workers align the pin holes 7 of adjacent connecting ear plates 6. The reinforcing bar pins 8 can be made from leftover threaded steel, with a length slightly longer than the combined thickness of the double ear plates. After the reinforcing bar pins 8 are fully inserted into the pin holes 7, both ends of the reinforcing bar pins 8 are exposed with equal lengths, without any additional fixing clips.

[0077] During the compaction process of the road roller, the reinforcing bar pin 8 bears shear load. Under strong vibration conditions, the reinforcing bar pin 8 bends. It can be pushed out by striking it in the opposite direction with a sledgehammer during disassembly. The maintenance workshop straightens the bent reinforcing bar pin 8 with a press, and continues to use it after checking that the diameter of the through hole is normal.

[0078] Over long-term use, a bright friction band forms on the inner wall of the pin hole 7. Workers can periodically apply grease to reduce insertion and removal resistance. When excessive grease attracts dust and forms sludge, it can be cleaned by inserting a steel bar to restore smooth operation. If the corner of the connecting ear plate 6 is dented or deformed, the protruding part can be removed by oxy-acetylene cutting without affecting the pin's function. In cases of extreme deformation, the connecting ear plate 6 can be directly removed by oxy-acetylene cutting, and a new ear plate can be welded onto the hot-rolled channel steel 1 body.

[0079] The fact that this structure requires no special tools lowers the skill threshold for workers, allowing new workers to operate it independently after training. Studies have found that the loss rate of the reinforcing bar pin 8 is significantly lower than that of traditional connecting components.

[0080] See Figure 5 In some implementation methods:

[0081] The threaded section of the threaded steel bar 2 is fitted with an anti-loosening sleeve 9, which is a cylindrical geotextile layer. The two ends of the anti-loosening sleeve 9 are tied and fixed to the smooth section of the threaded steel bar 2 with iron wire. The anti-loosening sleeve 9 covers the meshing area between the flat-head precision rolled nut 3 and the threaded steel bar 2.

[0082] Specifically, the anti-loosening sleeve 9 can be made by cutting geotextile rolls, sewing them longitudinally into a cylindrical shape, and then inserting them into the threaded section. Workers wrap wire around the smooth section of the threaded reinforcing bar 2 and tighten both ends with pliers. The anti-loosening sleeve 9 covers the meshing area between the flat-head precision-rolled nut 3 and the threaded reinforcing bar 2, forming a soft protective layer. During installation, the natural wrinkles of the geotextile do not affect the rotation of the nut.

[0083] During heavy rain, mud splashes into the adjustment area. The outer layer of the anti-loosening sleeve 9 can absorb the mud, preventing corrosion of the internal threads. The unprotected thread sections, with their thread grooves filled with hardened cement, require oxygen cutting treatment. After continuous operation of the vibratory roller, even if wear holes appear on the surface of the anti-loosening sleeve 9, there are no direct metal-to-metal friction marks on the thread meshing surfaces.

[0084] During maintenance, the damaged anti-loosening sleeve 9 can be removed. After soaking the new fabric tube in waste machine oil, it should be inserted, with the wire binding point placed at the original indentation location. Long-term testing of the threaded area shows that the threaded pairs with added protection exhibit extremely low wear. During rough demolding, when the wrench slips and impacts the protective layer, the geotextile cushions the impact, and the thread profile remains intact.

[0085] During construction in frozen soil, the surface of the anti-loosening wrapping sleeve 9 became icy, but its internal function remained unaffected. When removing the formwork in soft soil subgrade, the wrapping sleeve was covered with wet mud, but after being washed away by water, its intact threaded structure was revealed.

[0086] The anti-loosening sleeve 9 can physically isolate mud and water erosion, cushion accidental impacts from tools, and absorb vibration energy. After adopting the protection, the maintenance frequency of the threaded pair is significantly reduced, and the nut turning torque remains stable.

[0087] See Figure 6 In some implementation methods:

[0088] A lifting ring 10 is welded to the top of the hot-rolled channel steel 1, and the axis of the lifting ring 10 is perpendicular to the length direction of the hot-rolled channel steel 1.

[0089] A lifting ring 10 is welded to the center of the top of the hot-rolled channel steel 1. During actual lifting, the excavator operator inserts the shovel teeth into the inner cavity of the lifting ring 10, slowly lifts it to a reasonable height off the ground, and then moves it to another location for transport.

[0090] In muddy sections after heavy rain, traditional manual transport requires four people working together. With the use of the lifting ring 10, an excavator suspends and transports the channel steel to the work site, maintaining sufficient clearance between the bottom of the channel steel and the mud surface. When working on narrow curves, the operator uses the robotic arm to rotate at multiple angles, guiding the channel steel through scaffold gaps, ensuring that its deviation from the blind ditch design line is within a reasonable range after landing. In situations with insufficient lighting at night, reflective strips are attached to the surface of the lifting ring 10 to create positioning markers, assisting the robotic arm in quickly identifying the lifting points. Compared to manual transport, the use of the lifting ring 10 and mechanical lifting significantly reduces manpower consumption.

[0091] See Figure 7 In some implementation methods:

[0092] A vibration buffer layer 11 is provided on the waist of the hot-rolled channel steel 1. The vibration buffer layer 11 is a waste rubber tire piece. The vibration buffer layer 11 is fixed to the outer side of the waist of the hot-rolled channel steel 1 by a U-shaped clamp 12.

[0093] Specifically, the vibration buffer layer 11 can be taken from the sidewall of a scrap tire, cut into strips, and then attached to the back side of the channel steel. Workers can use steel bars to bend U-shaped clamps 12, with both ends of the clamps passing through the pre-reserved holes in the tire layer and hammered to tighten them.

[0094] When the road roller compacts the base course, visible ripples are generated on the surface of the vibration buffer layer 11, effectively absorbing vibration. Compared with the channel steel without the buffer layer, which emits a high-frequency humming sound at its waist, the channel steel with the vibration buffer layer 11 only emits a low, muffled sound, and the noise level is significantly reduced.

[0095] Compared to devices without a vibration buffer layer, this device alters the vibration energy transmission path: the roller's vibration wave is first dissipated by the vibration buffer layer 11, and the residual energy is dispersed and transmitted via the U-shaped clamp 12. Under the same working conditions, the probability of loosening of the flat-head precision-rolled nut 3 decreases significantly, and the overall displacement of the channel steel is narrowed to a reasonable range.

[0096] See Figure 8 In some implementation methods:

[0097] The hot-rolled channel steel 1 has its upper waist width partially cut off in the area corresponding to the flat-head precision rolled nut 3 to form a wrench operation clearance opening 13.

[0098] In the area corresponding to the flat-head precision-rolled nut 3, the upper waist width of the hot-rolled channel steel 1 is partially cut off to form a wrench operation clearance opening 13. During actual demolding, the worker inserts the wrench sleeve vertically into the wrench operation clearance opening 13, and the inner wall of the sleeve fully fits the hexagonal surface of the flat-head precision-rolled nut 3. At this time, the axis of the wrench rod is parallel to the axis of the threaded steel bar 2, and there is no angular deviation during the rotational force application process.

[0099] In situations involving splashing mud and water, traditional operations require repeated wiping of the nut surface to prevent slippage. The wrench operation clearance 13 creates a semi-enclosed space, preventing most of the mud from splashing into the wrench's meshing surface. During low-temperature demolding in frozen soil regions, the wrench operation clearance 13 provides a heat radiation channel, allowing the blowtorch flame to directly heat the nut's outer shell, significantly accelerating the melting of the ice layer.

[0100] The shock wave from the road roller is dispersed and transmitted through the side plates on both sides of the clearance opening 13 operated by the wrench. The stress concentration coefficient at the root of the threaded steel bar 2 is reduced, and the number of weld cracks is reduced by a reasonable proportion after long-term use. The service life of the channel steel threaded pair with the clearance opening is significantly extended, and the thread repair time is significantly reduced.

[0101] See Figure 9 In some implementation methods:

[0102] A horizontal calibration rod 14 is welded to the outer side of the leg width of the hot-rolled channel steel 1. A gravity plumb bob 15 is suspended on the horizontal calibration rod 14, and the tip of the gravity plumb bob 15 is aligned with the ground reference line.

[0103] Specifically, the horizontal calibration rod 14 can be cut from a galvanized water pipe and fixed along the length of the channel steel. The gravity plumb bob 15 can be made by welding an M30 nut to a steel bar, and the suspension wire is wrapped around the pre-drilled hole in the horizontal calibration rod 14. During installation, the height of the gravity plumb bob 15 is adjusted by rotating the wire so that the tip of the plumb bob is aligned with the ground baseline marker.

[0104] During the construction of the soft soil subgrade, uneven settlement occurred in the hot-rolled channel steel 1. The offset of the gravity plumb bob 15 indicated that the left end was sinking beyond the tolerance. By unscrewing the flat-head precision-rolled nut 3 on that side to increase the extension length, the tip of the plumb bob cone was realigned with the baseline. During the construction of the curved transition section, the extension length of the horizontal calibration rod 14 compensated for the parallax of the curve, and the trajectory of the gravity plumb bob 15 maintained a constant distance from the arc-shaped baseline.

[0105] In strong winds, the swing amplitude of a gravity-fed plumb bob (15) increases. Applying damping oil to the suspension point can shorten the oscillation decay time of the plumb bob to a reasonable range.

[0106] The gravity plumb bob 15 enables vertical reference transfer, while the horizontal calibration rod 14 provides axial positioning reference. With this structure, the traditional total station layout process can be eliminated during straight section construction, and the frequency of measurement verification in complex alignment sections is reduced to a reasonable proportion.

[0107] See Figure 10 In some implementation methods:

[0108] The bottom of the hot-rolled channel steel 1 is detachably equipped with a steel plate pad 16. The steel plate pad 16 is connected to the leg width vertical surface of the hot-rolled channel steel 1 by a U-shaped bolt 17. The bearing area of ​​the steel plate pad 16 is larger than the bottom projected area of ​​the hot-rolled channel steel 1.

[0109] The steel plate pad 16 mounted at the bottom of the hot-rolled channel steel 1 is designed to meet the settlement compensation requirements of soft soil subgrades. The large bottom surface of the steel plate pad 16 expands the ground contact area, suppressing uneven settlement through pressure dispersion. During installation, the nuts are pre-tightened by hand. After adding a crushed stone cushion layer in the soft soil section, the settlement of the steel plate pad 16 stops—at this point, the pressure transmission path becomes: channel steel load → U-bolt 17 → steel plate pad 16 → crushed stone cushion layer → foundation, and the settlement control effect is clearly visible.

[0110] Before application in frozen soil sections, steel plate pads 16 can be removed and coated with waste engine oil, using the oil film to prevent direct contact between metal and ice crystals. After reinstallation, during vibratory compaction by the road roller, the oil film layer generates a fluid lubrication effect, reducing the resistance during demolding and lifting to an operable threshold. For sloping terrain, leveling is achieved by increasing or decreasing the number of steel plate pads 16 on one side, using the difference in pad thickness to compensate for elevation: when the plumb bob 15 shows axial deviation, the lower side pads are stacked to correct the channel steel inclination angle in real time, simultaneously improving the accuracy of the blind drain slope.

[0111] See Figure 11 In some implementation methods:

[0112] A gravel splash guard 18 is welded to the inner side of the hot-rolled channel steel 1. The gravel splash guard 18 is an L-shaped structure formed by bending steel plate. The vertical section of the gravel splash guard 18 is welded and fixed to the inner side of the waist of the hot-rolled channel steel 1. The horizontal section of the gravel splash guard 18 extends towards the center of the gravel blind ditch.

[0113] A gravel splash guard 18 is welded to the inner side of the waist of the hot-rolled channel steel 1. The gravel splash guard 18 is bent into an L-shaped structure. The vertical section is fixed to the waist of the channel steel, and the horizontal section extends to the center of the blind ditch for a suitable length. When the loader unloads gravel, larger aggregates impact the vertical section of the splash guard, while the horizontal section prevents the gravel from rolling towards the area of ​​the threaded steel bar 2.

[0114] Under the strong vibration conditions of the road roller, the horizontal section of the crushed stone splash plate 18 elastically warps upwards due to compression. An isolation layer forms between the horizontal section and the base material, preventing fine particles from seeping into the threaded engagement area. After heavy rain, the blind drain floods the crushed stone splash plate 18, and the horizontal section forms a water barrier to prevent mud splashing; the engagement surface of the flat-head precision-rolled nut 3 shows no silt consolidation. In frozen soil areas, the crushed stone freezes into clumps, and the crushed stone splash plate 18 undergoes slight deformation under frost heave force; the weld seam of the hot-rolled channel steel 1 shows no cracking.

[0115] The channel steel threaded assemblies without splash guards required frequent maintenance; adding splash guards effectively reduced this frequency. The 18-inch gravel splash guard restrained gravel distribution, significantly improving the neatness of the ditch walls.

[0116] See Figure 12 In some implementation methods:

[0117] The bottom of the hot-rolled channel steel 1 is hinged with a rotatable support leg 19. The rotatable support leg 19 is connected to the leg of the hot-rolled channel steel 1 through a hinge shaft 20. When the device is fixed, the rotatable support leg 19 is in an inclined support position. When the device is removed upward, it automatically rotates to a vertical position under the action of gravity.

[0118] Specifically, during installation, workers tilt the outriggers to a 45° angle and hammer the top to embed them into the ground. When the road roller generates lateral thrust, the rotatable outriggers 19 decompose the load into vertical components and horizontal resistance, effectively reducing the displacement of the hot-rolled channel steel 1.

[0119] During formwork removal, workers lift the channel steel, and the rotatable outrigger 19 automatically swings back to a vertical position under the influence of gravity. The rotation of the rotatable outrigger 19 simultaneously pushes away the encased gravel, eliminating the bottom jamming problem common in traditional formwork removal. In permafrost areas, the rotatable outrigger 19 forms an ice bond with the permafrost layer, requiring additional pulling force to break the ice seal initially. However, once the outrigger rotates to 70°, the ice layer collapses, and subsequent lifting resistance drops sharply.

[0120] During maintenance, dirt buildup at hinge shaft 20 caused sluggish rotation. After soaking the hinge point in diesel fuel, rotation returned to smooth. When the tip of the rotatable outrigger 19 was worn into a spherical shape, grinding the bevel with an oxy-acetylene torch restored its function.

[0121] In some implementations, a drainage channel can be added to the waist of the hot-rolled channel steel. The drainage channel can be constructed by welding together cut sections of angle steel, with an inclination angle consistent with the drainage slope of the blind drain. During heavy rain, water accumulated in the blind drain is quickly diverted along the surface of the drainage channel, preventing water from soaking the threaded steel bars. When the loader fills the gravel, the inclined surface of the drainage channel guides the water flow, carrying away mud and sand, thus ensuring no siltation in the threaded meshing area. During disassembly, the inner wall of the drainage channel is generally only covered with a thin layer of mud, which can be easily cleared with a high-pressure water gun. This structure reduces the downtime rate during heavy rain to a reasonable level.

[0122] In some implementations, corrugated buffer ribs can also be welded to the back of the hot-rolled channel steel. These corrugated buffer ribs can be hydroformed from reinforcing bars, with continuous distribution of crests and troughs. Under the strong vibration conditions of a road roller, the corrugated buffer ribs undergo elastic buckling deformation. The rib deformation absorbs most of the impact energy, and the peak stress at the root of the threaded reinforcing bar decreases significantly. After disassembly, the corrugated buffer ribs spring back to their original shape.

[0123] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the claims.

Claims

1. A construction device for gravel blind drains, characterized in that, include: Hot-rolled channel steel (1), wherein a threaded steel bar (2) is vertically welded to the middle of the height direction of the hot-rolled channel steel (1); A flat-head precision-rolled nut (3) is fitted onto the end of the threaded steel bar (2). The width of the crushed stone blind drain is controlled by adjusting the connection length between the flat-head precision rolled nut (3) and the threaded steel bar (2), and the template installation and disassembly are realized.

2. The apparatus according to claim 1, characterized in that: The hot-rolled channel steel (1) is provided with anti-collision plates (4) at both ends, and the anti-collision plates (4) are fixed to the end vertical surface of the hot-rolled channel steel (1) by intermittent welding.

3. The apparatus according to claim 1, characterized in that: The hot-rolled channel steel (1) has inclined support steel bars (5) welded to its back side. The bottom end of the inclined support steel bars (5) is connected to the back side of the hot-rolled channel steel (1), and the top end of the inclined support steel bars (5) extends outward to the ground contact area.

4. The apparatus according to claim 1, characterized in that: The hot-rolled channel steel (1) is provided with a pin connection mechanism at its end, the pin connection mechanism comprising: Connecting lugs (6) welded to the end of the hot-rolled channel steel (1). A pin hole (7) is provided on the connecting ear plate (6). And a steel bar pin (8) passing through the adjacent pin hole (7).

5. The apparatus according to claim 1, characterized in that: The threaded section of the threaded steel bar (2) is fitted with an anti-loosening wrapping sleeve (9), which is a cylindrical geotextile layer. The two ends of the anti-loosening wrapping sleeve (9) are tied and fixed to the bare section of the threaded steel bar (2) by iron wire. The anti-loosening wrapping sleeve (9) covers the meshing area between the flat-head precision rolled nut (3) and the threaded steel bar (2).

6. The apparatus according to claim 1, characterized in that: The top of the hot-rolled channel steel (1) is welded with a lifting ring (10), and the axis of the lifting ring (10) is perpendicular to the length direction of the hot-rolled channel steel (1).

7. The apparatus according to claim 1, characterized in that: The waist of the hot-rolled channel steel (1) is provided with a vibration buffer layer (11), which is a waste rubber tire piece. The vibration buffer layer (11) is fixed to the outer side of the waist of the hot-rolled channel steel (1) by a U-shaped clamp (12).

8. The apparatus according to claim 1, characterized in that: The hot-rolled channel steel (1) has its upper waist width partially cut off in the area corresponding to the flat-head precision rolled nut (3) to form a wrench operation clearance opening (13).

9. The apparatus according to claim 1, characterized in that: A horizontal calibration rod (14) is welded to the outer side of the leg width of the hot-rolled channel steel (1), and a gravity plumb bob (15) is suspended on the horizontal calibration rod (14). The tip of the gravity plumb bob (15) is aligned with the ground reference line.

10. The apparatus according to claim 1, characterized in that: The bottom of the hot-rolled channel steel (1) is detachably equipped with a steel plate pad (16). The steel plate pad (16) is connected to the leg width facade of the hot-rolled channel steel (1) by a U-bolt (17). The bearing area of ​​the steel plate pad (16) is greater than the bottom projection area of ​​the hot-rolled channel steel (1).

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