Construction method for drainage side ditch of test site

Abstract

The invention discloses a construction method for a drainage side ditch of a test site. The construction method comprises the steps of surveying and setting out, excavation of a foundation trench, pouring of a cushion layer, hot melting installation of a PE600 pipe, installation of a PE water-collecting well, concrete encapsulation pouring of the PE600 pipe, installation of a PE300 pipe and pouring of a shallow V-shaped ditch in a compacted gravel layer. The drainage side ditch provided by the construction method is high in drainage capacity, high in safety coefficient, simple in structure and convenient to construct.

Description

Technical Field

[0001] The present invention relates to the construction field of subgrade engineering, and particularly relates to a construction method for a drainage side ditch in a test site. Background Art

[0002] As a test site for vehicle and tire testing and certification, most of the test roads therein need to detect high-speed test indicators. Such test roads cover a large area and are highly dangerous during the test process. The water collection area of this large-area test road is larger than that of conventional roads. Generally, a 1.5m * 1.5m rectangular ditch made of grouted rubble is used for the large-area drainage system in the test site. Most of the existing drainage side ditches are rectangular drainage side ditches or V-shaped drainage side ditches. As Figure 1 shown, for the V-shaped drainage side ditch, due to the particularity of the test site, after an accident occurs during high-speed testing, the V-shaped ditch will cause secondary damage to the vehicle. As Figure 2 shown, for the rectangular drainage side ditch, including a precast concrete manhole cover 1, a gravel cushion layer 2, and concrete 3, its water seepage property is poor, and the water flow is not smooth, the resistance is large, and the average flow velocity of the water passing section is small. Based on the problems existing in the existing drainage side ditches, there is an urgent need for a construction method for a drainage side ditch with strong drainage capacity and high safety factor. Summary of the Invention

[0003] The purpose of the present invention is to provide a construction method for a drainage side ditch in a test site. The drainage side ditch provided by this method has strong drainage capacity, high safety factor, and is simple in structure and convenient for construction.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A construction method for a drainage side ditch in a test site includes the following steps:

[0006] Step 1, measurement and lofting. Surveyors conduct on-site lofting. For the straight section, a drainage ditch center line elevation control point is determined at a certain interval S, and for the curved section, an elevation control point is determined at a certain interval S'. Where S > S'. The elevation control points are connected by a lime line pairwise as the central control line for the excavation of the foundation trench.

[0007] Step 2, excavation of the foundation trench. The excavation of the foundation trench adopts a method of manual cooperation with machinery. Use a lime line spraying vehicle to accurately loft the excavation edge line of the drainage ditch foundation trench, and then use an excavator to excavate the foundation trench with the lofted edge line as the reference line.

[0008] Step 3, pouring of the cushion layer. Manually level the bottom surface of the excavated and formed foundation trench. Use a level to adjust the elevation during the leveling of the base. After the elevation is adjusted appropriately, pour the cushion layer.

[0009] Step 4: hot-melt installation of PE600 pipe, cutting, centering and checking the coaxiality of PE600 pipe, heating, switching, melting and docking, cooling and pressure reduction to zero;

[0010] Step 5: PE water collection well installation: first install the PE water collection well in the excavated foundation trench, then adjust the direction of the PE water collection well pipe opening after installation, and finally use a level to measure and adjust the elevation of the top surface of the PE water collection well. After the PE water collection is installed properly, install and fix the PE600 pipe and the PE water collection well opening tightly;

[0011] Step 6: PE600 pipe concrete encapsulation pouring. First, half of the PE600 pipe concrete is encapsulated and poured. When the half-encapsulated concrete reaches the initial setting time, the remaining part is fully encapsulated and poured. After pouring and forming, artificial plastering is used, and finally a "U" shape is made on the surface before the final setting of the concrete.

[0012] Step 7: PE300 pipe installation: drilling and installation of PE300 pipe, followed by gravel backfilling and gravel compaction;

[0013] Step 8: Pour a shallow "V"-shaped groove on the compacted gravel layer.

[0014] In step 2, slope control is performed when the foundation pit is excavated, and the lower bottom width is smaller than the upper opening width.

[0015] In step 4, the PE600 pipe cutting method is: place the PE600 pipe in a flat position, place the hot-melt connection end on the butt joint machine, open the frame, put in the milling cutter, rotate the locking knob, fix the milling cutter on the frame, turn on the milling cutter power switch first, and then close the two ends of the pipe and apply appropriate pressure until continuous chips appear at both ends, remove the pressure, wait for a while, then withdraw the movable frame and turn off the milling cutter power.

[0016] Adjusting the height of the milling blade can adjust the chip thickness. In step 4, fusion butt welding is the key to welding, and the butt welding process should always be carried out under fusion pressure.

[0017] In step 4, during cooling, maintain the docking pressure unchanged and allow the interface to cool slowly. The cooling time is based on the length of time when the curled edge is stiff and no heat can be felt when touched.

[0018] The PE300 pipe catchment water and the shallow "V" ditch catchment water flow into the PE600 main drainage pipe through the PE collection well. The PE600 pipe is the main drainage pipe of the drainage system, which is used to discharge the PE300 pipe catchment water and the shallow "V" ditch catchment water.

[0019] When pouring the semi-enclosed PE600 pipe concrete, the hot-melt installed PE600 pipe is hoisted on the cast concrete cushion. After the hoisting is completed, the center line is aligned so that the center line of the PE600 pipe coincides with the center line of the cushion.

[0020] When pouring in a semi - enclosed manner, the concrete submerges half of the diameter of the pipe body.

[0021] After the concrete full - enclosing pouring of the PE600 pipe is completed, cover the poured concrete with geotextile and sprinkle water for curing on time to prevent cracks from appearing on the concrete surface.

[0022] The beneficial effects of the present invention are as follows:

[0023] (1) Strong drainage capacity. The shallow "V" - shaped side ditch + PE300 pipe (buried) + PE600 pipe (buried) are used for the collection and discharge of road rainwater. The upper PE300 pipe (buried) is backfilled with gravel, which is convenient for the discharge of seepage water inside the road, reducing the probability of road diseases caused by water; the PE600 pipe (buried) is encapsulated with concrete, and the cross - sectional area of water passing meets the needs of road drainage. Compared with the conventional rectangular drainage ditch and trapezoidal drainage ditch, the water - seepage property is better, the water flow is smooth, the resistance is small, the average flow velocity of the cross - sectional area of water passing is large, and the drainage capacity is increased by 1.8 times.

[0024] (2) High safety factor. During the high - speed driving of the test vehicle, traffic accidents are likely to occur, and the roadside side ditch will cause more serious secondary injuries to traffic accidents. The design of the new drainage side ditch optimizes the original trapezoidal open drainage ditch design. The flowing water depth is 12.5 cm, the height difference is small, and the degree of damage caused by the vehicle accidentally entering the side ditch and colliding is greatly reduced. Therefore, this drainage ditch has the risk of reducing secondary injuries and improving the safety guarantee of the test.

[0025] (3) Simple structure, energy - saving and environmental - friendly. The split - assembly structure is adopted, and the wellbore can be cut, adjusted and installed on site, adapting to various installation depth requirements, effectively reducing costs, greatly improving the construction progress, and shortening the construction period to more than 10 times that of the traditional inspection well. The material is made of high - density polyethylene, which is non - toxic and odorless, belonging to chemical environmental - friendly building materials, in line with the national environmental protection policy. The corresponding construction technology is lighter in weight than the traditional inspection well, easy to transport and install, reliable in performance, strong in bearing capacity, low in comprehensive cost, less in maintenance cost, and can be recycled, reducing energy use. Brief Description of the Drawings

[0026] Figure 1 It is a structural schematic diagram of a V - type drainage side ditch in the prior art.

[0027] Figure 2 It is a structural schematic diagram of a rectangular drainage side ditch in the prior art.

[0028] Figure 3 It is a structural schematic diagram of the PE600 pipe + PE300 pipe + V - type drainage ditch of the present invention.

[0029] In the figure: 1 - precast concrete manhole cover; 2 - gravel cushion; 3 - concrete; 4 - shallow "V"-shaped ditch; 5 - crushed stone for PE300 pipe; 6 - PE300 pipe; 7 - enclosed concrete; 8 - PE600 pipe. Specific implementation manner

[0030] To make the design concept and method of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Referring to Figure 3 , a construction method for a drainage side ditch of a test site, comprising the following steps:

[0032] Step 1, surveying and lofting: Surveyors use GPS for on-site lofting. One elevation control point for the center line of the drainage ditch is determined every 10 m in the straight section, and one elevation control point is determined every 5 m in the curve section. The elevation control points are marked with eye-catching colors, and lime lines are used to connect between two elevation control points as the central control line for the excavation of the foundation trench.

[0033] Step 2, excavating the foundation trench: The foundation trench is excavated by means of manual cooperation with machinery. The layout of the excavation edge line of the drainage ditch foundation trench is accurately lofted by using a lime line spraying vehicle, and then an excavator is used to excavate the foundation trench with the lofted edge line as the reference line. When excavating the foundation trench, the slope is controlled at 1:0.5, the excavation depth is 2 m, the bottom width of the lower part is 1 m, the upper width is 1.5 m, and the ground slope of the foundation trench is 0.1%.

[0034] Step 3, pouring the cushion: The bottom surface of the excavated and formed foundation trench is leveled manually, and a level is used to adjust the elevation during the leveling of the foundation bottom. After the elevation is adjusted appropriately, the cushion is poured. The pouring thickness of the cushion is 20 cm, the pouring width is 1 m, and the concrete grade is C20.

[0035] Step 4, Hot-melt installation of PE600 pipe: First, prepare the hot-melt equipment for PE600 pipe and connect the power supply of each component of the hot-melt machine. 220V, 50Hz alternating current should be used, and the voltage change of the alternating current is within ±10%, and the power supply should have a ground wire. Second, prepare the PE600 pipe. First, place the PE600 pipe horizontally in the foundation trench (or along the outer edge of the foundation trench). Place the PE600 pipe joint on the ring of the hot-melt butt welding machine, leaving a cutting allowance of 10 - 20mm. Third, cut the PE600 pipe. Place the PE600 pipe in a flat position and place the hot-melt connection end on the butt welding machine. Open the frame, put in the milling cutter, rotate the locking knob to fix the milling cutter on the frame. First, turn on the power switch of the milling cutter, then close the two ends of the pipe and apply appropriate pressure until continuous chips appear at both ends (the chip thickness is 0.5 - 10mm, and the chip thickness can be adjusted by adjusting the height of the milling cutter blade). Remove the pressure, wait for a moment, then retract the movable frame and turn off the power of the milling cutter; when starting the pump station, it should be carried out when the direction control handle is in the middle position, and it is strictly prohibited to start under high pressure. Start the milling cutter, close the clamp, and cut the end faces of the pipe and fittings. When continuous cutting is formed, reduce the pressure, open the clamp, and turn off the milling cutter. This process must be carried out in the order of first reducing the pressure, then opening the clamp, and finally turning off the milling cutter. Remove the milling cutter, close the clamp, close the two pipe ends, and check the alignment of the two ends (the misalignment amount at both ends of the pipe cannot exceed 10% of the wall thickness, and it can be improved by adjusting the straightness of the pipe and the tightness of the chuck. Check the gap between the two ends of the PE600 pipe. The gap amount shall not be greater than 0.3mm (for pipes with de less than or equal to 225mm). If the requirements are not met, milling shall be carried out again until the requirements are met. When removing the milling cutter from the frame, avoid the milling cutter colliding with the end face. If it has occurred, re-milling is required; do not touch the milled end face with your hand or let it be contaminated by oil or other substances. Fourth, check the coaxiality of the PE600 pipe (the maximum misalignment amount is 10% of the pipe wall thickness). When the gap and misalignment amount between the two end faces do not meet the requirements, the workpieces to be welded should be re-clamped and milled, and the next operation can be carried out only after passing the inspection. Fifth, heating. Check whether the temperature of the heating plate is suitable at 210℃ - 230℃, and it is appropriate that the melting length at both end faces is 1 - 2mm. The red indicator light on the heating plate should be on or flashing. After the red indicator light on the heating plate first lights up, wait for another 10 minutes before using it to make the temperature of the entire heating plate uniform. Test the dragging pressure P0 of the system and record it. The dragging pressure of each weld joint needs to be measured; when the dragging pressure is too large, methods such as padding short pipes can be used to solve it. Place the heating plate with appropriate temperature on the frame, close the clamp, and set the system pressure P1. P1 = P0 + seam pressure. When the protrusions between the PE600 pipes are uniform and the height reaches the requirement, reduce the pressure to approximately the dragging pressure, and at the same time press the endothermic timing button to start recording the endothermic time. P2 = P0 + endothermic pressure (the endothermic pressure is almost zero). If the heating time is too short, it is easy to cause uneven heating of the pipe fittings, resulting in difficulty in butt joint; if the heating time is too long, the pipe fittings will be melted as a whole, and too much colloidal substance will appear and flow away.Sixth, switch, remove the heating plate, quickly let the two hot melt end faces stick together and pressurize. To ensure the quality of fusion butt joint, the shorter the switching cycle, the better. After the endothermic time is reached, quickly open the machine and remove the heating plate. When taking the heating plate, avoid collision with the molten end face; if it has occurred, the entire welding process should be restarted after the melted end face is completely cooled. Seventh, fusion butt joint, butt joint is the key to welding, the butt joint process should always be carried out under molten pressure, and the curling width should be 1 to 2 mm. Eighth, cooling, keep the butt joint pressure unchanged, let the interface cool slowly, and the cooling time is based on the stiffness of the curling edge when touched by hand and no heat can be felt. Quickly close the clamp, and within the specified time, quickly adjust the pressure to P3, and press the timer at the same time to record the cooling time. P3 = P0 + cooling pressure After the clamp is closed, the pressure should be increased evenly, not too fast or too slow, and should be completed within the specified time; in order to avoid false welding and virtual welding, this pressure should be maintained until the weld is completely cooled. Ninth, reduce the pressure to zero. After the docking is completed and the cooling time is reached, reduce the pressure to zero, open the clamp, remove the welded pipe (pipe fittings), move the docking machine, and prepare for the next interface connection. Before removing the pipe, the system pressure must be reduced to zero; if the welding machine needs to be moved, the hydraulic wire should be removed, and dust prevention work should be done at the joint in time.

[0036] Step 5, PE water collection well installation: PE water collection wells are available in 2-way, 3-way, and 4-way forms, and their functions are mainly in the following three aspects: the first aspect is to connect PE pipes in different directions, and generally a 3 / 4-way PE water collection well is used, which is mainly set at road intersections; the second aspect is to collect the road base drainage collected by the PE300 pipe, and generally a 2-way water collection well is installed, which is mainly set in a straight line; the third aspect is to collect the road surface drainage collected by the shallow "V" shaped ditch. First, the PE water collection well is installed. First, the PE water collection well is installed in the excavated foundation trench, and then the direction of the PE water collection well pipe mouth is adjusted after installation, and finally the level is used to measure and adjust the top elevation of the PE water collection well. Second, the PE water collection well is encapsulated. After the PE water collection is installed, the PE600 pipe is tightly installed and fixed to the PE water collection well port. Finally, C20 concrete is used for encapsulation.

[0037] Step 6, PE600 pipe 8 concrete encapsulation pouring: PE300 pipe water and shallow "V" ditch water flow into the PE600 main drainage pipe through the PE water collection well. PE600 pipe 8 is the main drainage pipe of this drainage system, which is mainly responsible for discharging PE300 pipe water and shallow "V" ditch water. First, the PE600 pipe concrete semi-encapsulation pouring, the hot-melt installed PE600 pipe is hoisted on the cast concrete cushion layer, and the center line is aligned after the hoisting is completed, so that the center line of the PE600 pipe coincides with the center line of the cushion layer, and the protective layer spacing between the left and right outer walls of the PE600 pipe is equal to 20cm. After the PE600 pipe centerline is adjusted to be qualified, the pipe is fixed on both sides. In order to prevent the PE600 pipe from being affected by the buoyancy of concrete during concrete pouring, causing the pipe body to float up and cause a reverse slope on the water surface, C20 concrete is first poured at a fixed point every 10m, and then semi-encapsulated pouring is performed. During semi-encapsulated pouring, the concrete submerges half of the pipe body diameter. Second, the PE600 pipe encapsulated concrete is poured for 7 minutes. When the semi-encapsulated concrete reaches the initial setting time, the remaining part is fully encapsulated and poured. After pouring and forming, the surface is manually smoothed. Finally, a "U" shape is made on the surface before the final setting of the concrete to facilitate the installation of the PE300 pipe. Third, the fully encapsulated concrete is cured. The poured concrete is covered with geotextiles and watered on time for curing. Prevent cracks from appearing on the concrete surface.

[0038] Step 7, Installation of PE300 Pipe 6: The PE300 pipe mainly collects the drainage of the road base. The accumulated water in the road base is collected from high to low according to the road cross slope into the PE300 pipe 6, and then flows into the PE300 pipe through the seepage holes of the PE300 pipe and is discharged into the PE sump and then collected into the PE600 pipe. First, punch holes in the PE300 pipe. First, punch holes in the PE300 pipe. The punching range is within 120° of the pipe body. Three holes are formed in each row. Each hole has a width of 0.5 cm and a length of 3 cm. The horizontal distance between holes is 10 cm and the vertical distance is 20 cm. A hand-held cutting machine is used for punching. Second, install the PE300 pipe. When installing the PE300 pipe, fix the side with punched holes downward in the cast U-shaped groove. When connecting the PE300 pipes, install a waterproof rubber gasket at the connecting end of every two pipes to make the connection of the pipes tight. Third, backfill the crushed stones 5 for the PE300 pipe. After the PE300 pipe is installed, first fill the crushed stones at points. First, use a mechanical and manual combined method to fill the crushed stones at points, which can ensure that the pipe body of the PE300 pipe does not shift during the filling of the crushed stones. Then use a loader to fill the crushed stones in other parts. The particle size of the filled crushed stones is required to be 2 cm - 3 cm crushed stones, and the thickness of the filled crushed stones is 20 - 30 cm. When filling the crushed stones mechanically, lower the height of the loader bucket. The free fall height of the crushed stones is controlled within 1 m. It is prohibited to pour the crushed stones in a high range during the filling of the crushed stones, as pouring in a high range will cause the pipe body to shift and affect the water flow surface slope. Fourth, compact the crushed stones for the PE300 pipe. After the filling of the crushed stones is completed, use manual labor to level and shape the top surface of the crushed stones. The crushed stones are leveled in a "V" shape, and the slope ratio is 1:6. Use a plate compactor to compact the leveled crushed stones, and the number of compaction passes is 3 times.

[0039] Step 8, Pour the shallow "V"-shaped groove 4: The shallow "V" groove mainly collects the surface water of the road. The surface water of the road is discharged into the shallow "V" groove through the road cross slope, and then collected by the shallow "V" groove and discharged into the PE sump, and finally discharged from the test site by the PE600 main drainage pipe. Pour a shallow "V"-shaped groove with a width of 1.5 m, a flowing water depth of 12.5 cm, and a thickness of 10 cm on the compacted crushed stone layer. The concrete type of the shallow "V"-shaped groove is C20.

[0040] The above details the solutions provided by the embodiments of the present invention. For general designers in the field, according to the idea of the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. The scope to be protected by the present invention is not limited to the technical solutions mentioned in this embodiment. Any technical solution inspired by the present invention falls within the protection scope of the present invention.

Claims

1. A construction method for a drainage side ditch in a test site, comprising the following steps: Step 1, surveying and setting out. Surveyors conduct on-site setting out. For straight sections, a drainage ditch center line elevation control point is determined at regular intervals of a distance S, and for curved sections, an elevation control point is determined at regular intervals of a distance S', where S > S'. Lime lines are used to connect the elevation control points pairwise as the central control line for foundation trench excavation; Step 2, excavating the foundation trench. The foundation trench excavation adopts a method of manual cooperation with machinery. Use a lime line spraying vehicle to accurately set out the excavation edge line of the drainage ditch foundation trench, and then use an excavator to excavate the foundation trench with the set-out edge line as the reference line; Step 3, pouring the cushion layer. Manually level the bottom surface of the excavated and formed foundation trench. Use a level to adjust the elevation during the base leveling. After the elevation is adjusted appropriately, pour the cushion layer; Step 4, hot melt installation of PE600 pipes. Sequentially cut the PE600 pipes, check the coaxiality of the PE600 pipes by centering, heat, switch, perform melt butt joint, cool, and reduce the pressure to zero; Step 5, installing the PE sump. First, install the PE sump in the already excavated and formed foundation trench, then adjust the pipe orifice direction of the PE sump after installation, and finally use a level to measure and adjust the top elevation of the PE sump. After the PE sump is installed qualifiedly, tightly install and fix the PE600 pipe to the through port of the PE sump; Step 6, pouring the concrete encasement for PE600 pipes. First, pour the semi-concrete encasement for the PE600 pipes. When the semi-concrete encasement reaches the initial setting time, then pour the remaining part for the full encasement. After pouring and forming, use manual plastering, and finally make a "U" shape on the surface before the concrete reaches the final setting; Step 7, installing PE300 pipes. Punch and install the PE300 pipes, and then backfill and compact the gravel; Step 8, pour a shallow "V"-shaped ditch on the compacted gravel layer.

2. The construction method for a drainage side ditch in a test site according to claim 1, wherein: In step 2, slope control is carried out during the foundation trench excavation, and the bottom width is less than the top width.

3. The construction method for a drainage side ditch in a test site according to claim 1, wherein: In step 4, the cutting method for PE600 pipes is as follows: Place the PE600 pipes in a flat position, place the hot melt connection end on the butt welding machine, open the machine frame, put in the milling cutter, rotate and lock the knob to fix the milling cutter on the machine frame. First, turn on the power switch of the milling cutter, then close the two ends of the pipes and apply appropriate pressure until continuous chips appear at both ends, then remove the pressure, wait for a moment, and then retract the movable frame and turn off the power of the milling cutter.

4. The construction method for a drainage side ditch in a test site according to claim 1, wherein: Adjusting the height of the milling cutter blades can achieve adjusting the chip thickness.

5. The construction method for a drainage side ditch in a test site according to claim 3, wherein: In step 4, the melt butt joint is the key to welding, and the butt joint process should always be carried out under the melt pressure.

6. The construction method for a drainage side ditch in a test site according to claim 5, wherein: In Step 4, during cooling, keep the butt joint pressure unchanged and let the interface cool slowly. The cooling time should be such that when touching the curled edge by hand, it feels hard and no heat is felt.

7. A construction method for a drainage side ditch in a test site according to claim 1, characterized in that: The water collected by the PE300 pipe and the water collected by the shallow "V" ditch flow into the PE600 main drainage pipe through the PE catch basin. The PE600 pipe is the main drainage pipe of the drainage system and is used to drain the water collected by the PE300 pipe and the shallow "V" ditch.

8. A construction method for a drainage side ditch in a test site according to claim 1, characterized in that: When casting the semi - wrapped concrete of the PE600 pipe, hoist the hot - melt installed PE600 pipe onto the already cast concrete cushion. After hoisting, align the center line to make the center line of the PE600 pipe coincide with the center line of the cushion.

9. A construction method for a drainage side ditch in a test site according to claim 8, characterized in that: During semi - wrapped casting, the concrete submerges half of the pipe body diameter.

10. A construction method for a drainage side ditch in a test site according to claim 9, characterized in that: After the full - wrapped casting of the PE600 pipe with concrete is completed, cover the cast concrete with geotextile and sprinkle water for curing on time to prevent cracks from appearing on the concrete surface.

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