Construction method for high-fill roadbed in seasonal precipitation area

Abstract

The invention relates to a construction method for a high-fill roadbed in a seasonal precipitation area, belongs to the field of road engineering, and mainly solves the problem of structural stability caused by unsmooth drainage, non-uniform filling and waterproof failure of the roadbed in the precipitation area. Comprising the steps that transverse drainage blind ditches are arranged in the transverse axis direction of a roadbed, a graded broken stone layer is laid at the bottom and covered with a two-way stretching plastic drainage plate, and the transverse drainage blind ditches communicate with inverted-trapezoid longitudinal broken stone blind ditches; the filler particle size and the thickness of each layer during layered filling are controlled, the water content is adjusted to the optimal value through a rotary plow or atomized watering, and a road roller is adopted for rolling; after each layer is compacted, polypropylene geotextile is laid and lapped through hot melting welding, a polyethylene film is covered, and a double-sided tape is adopted for sealing; a concrete intercepting ditch is arranged at the top of the roadbed, the slope of the ditch bottom is consistent with that of the route longitudinal slope, and expansion joints are filled with asphalt batting. The method is suitable for construction of the high-fill roadbed in the seasonal precipitation area, and the impermeability and long-term stability of the roadbed are improved through comprehensive drainage control, layered compaction optimization and composite waterproof design.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and more specifically, to a method for constructing a high-fill roadbed in a seasonal precipitation area. Background Art

[0002] In the construction of high-fill roadbed in seasonal precipitation areas, the existing technology faces the following prominent problems: First, the roadbed base drainage system is easily affected by concentrated precipitation and fails. The traditional transverse drainage blind ditch adopts a single gravel layer structure, and the distribution range of graded gravel particle size is too large, resulting in uneven porosity distribution. Under the action of long-term seepage, the migration of fine particles is easy to cause pore blockage, and the drainage efficiency decreases significantly with the use time. At the same time, the spacing of the blind ditch lacks a dynamic hydrological calculation basis, and the fixed spacing is difficult to adapt to the peak flow demand under different precipitation intensities. During heavy rains, local water accumulation is prone to backflow, causing base softening. Secondly, the matching degree between the layered filling process parameters and the soil characteristics is insufficient, and the filling thickness and particle size control standards have not been effectively coordinated. When the natural moisture content of the filler fluctuates, the conventional turning or water replenishment methods lack real-time monitoring and dynamic regulation, and it is easy to have an interlayer moisture content gradient with the surface layer being too dry or the interior being too wet, resulting in uneven compaction distribution. The vibration rolling parameters (such as frequency and amplitude) are not set differently according to different filler types. When gravel soil and clay soil are rolled in the same mode, it is easy to cause coarse particle crushing or fine soil shear deformation, affecting the integrity of the structure. In addition, the construction quality stability of the waterproof layer is insufficient. The traditional geotextile overlap process relies on manual operation, the temperature and pressure control accuracy of hot-melt welding is low, the weld width and melting depth fluctuate greatly, and leakage channels are easily formed at the joints. The film covering adopts a single tape sealing method. The adhesive is prone to aging and failure under the action of temperature difference stress, and it is difficult to repair after the joint is peeled off. Finally, the durability of the intercepting ditch structure is poor. The shrinkage cracks caused by temperature stress in the cast-in-place concrete intercepting ditch cannot be effectively controlled, the deformation resistance of the expansion joint filling material is weak, and the asphalt hemp is easy to fall off under repeated dry-wet cycles, resulting in leakage in the ditch body. The construction accuracy of the ditch bottom slope depends on manual measurement, and the accumulation of elevation deviations is easy to form a local reverse slope, causing water accumulation and siltation in the ditch. The root causes of the above problems are: the drainage system has not established a multi-level filtration and dynamic diversion mechanism, the filling process parameters lack soil response adaptability, the waterproof layer lacks composite sealing technology, and the intercepting ditch prefabrication accuracy and joint waterproofing system are imperfect. The technical difficulties in solving these problems include: how to achieve a balance between the blind ditch drainage capacity and anti-clogging performance under complex geological conditions; how to build a linkage control model of filling layer moisture content-compaction degree-structural stability; how to improve the reliability and environmental adaptability of waterproof layer joint sealing; and how to achieve high-precision assembly of intercepting ditch prefabricated components and long-term waterproofing of expansion joints. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0004] In order to achieve these purposes and other advantages according to the present invention, a method for constructing a high fill roadbed in a seasonal precipitation area is provided, characterized in that it includes the following steps: Before the excavation of the roadbed base, a transverse drainage blind ditch with a spacing of 8-10m is set along the transverse axis of the roadbed. A 30cm thick graded gravel layer with a graded gravel particle size of 10-30mm is laid at the bottom of the transverse drainage blind ditch. A biaxially stretched plastic drainage board is laid above the graded gravel layer. The drainage flux of the biaxially stretched plastic drainage board is greater than 20cm 3 / s, the transverse drainage blind ditch is connected with the longitudinal gravel blind ditch on both sides of the roadbed. The cross section of the longitudinal gravel blind ditch is inverted trapezoidal shape, with a bottom width of 80cm, a top width of 120cm and a depth of 100cm; After the construction of the base drainage system is completed, the roadbed is filled by layered filling method, and the thickness of each layer does not exceed 50cm. The maximum particle size of the filler is controlled at 2 / 3 of the compacted thickness. When the natural moisture content of the filler exceeds the optimum moisture content ±2%, the moisture content is adjusted by using a rotary plow to turn it over or a sprinkler truck to atomize and replenish water. A 25t vibratory roller is used for rolling. The number of rolling passes is 1 static pressure, 6 vibration pressures, and 1 final pressure. The adjacent rolling wheel tracks overlap by 1 / 3 of the wheel width. After compaction, the roadbed surface forms a 2-4% cross slope; After each layer is filled and compacted, immediately lay 400g / m 2 Polypropylene filament needle-punched waterproof geotextile, the overlap width of the geotextile is not less than 50cm, the overlap is processed by hot melt welding, the welding temperature is controlled within the range of 280-300℃, the geotextile is covered with a polyethylene film with a thickness of 0.5mm, and the film seams are sealed with double-sided self-adhesive tape; After the roadbed is filled to the designed elevation, a concrete intercepting ditch is set at the top of the roadbed slope. The inner net width of the intercepting ditch is 40cm, the depth is 50cm, the slope of the ditch bottom is consistent with the longitudinal slope of the route and is not less than 0.3%. An expansion joint is set in the intercepting ditch every 15m, and the expansion joint is densely filled with asphalt hemp.

[0005] In traditional roadbed construction, the anti-clogging ability of the base drainage system is poor, the control accuracy of the moisture content and compaction degree of the filling layer is low, the sealing of the waterproof layer joints is unreliable, and the durability of the intercepting ditch structure is insufficient, which leads to the roadbed being prone to waterlogging, softening, interlayer slippage and water seepage damage in seasonal precipitation areas. The present invention significantly improves the anti-clogging ability and diversion efficiency of the base drainage system through the inverted trapezoidal cross-section design of the transverse drainage blind ditch and the longitudinal blind ditch, combined with the composite structure of the graded crushed stone layer and the drainage board; the layered filling process and dynamic adjustment of the moisture content ensure compaction uniformity; the stepped sealing process of the geotextile and the film enhances the reliability of the waterproof layer; the prefabricated intercepting ditch and the multi-layer waterproof design of the expansion joint extend the service life of the ditch body, and overall reduce the impact of seasonal precipitation on the stability of the roadbed.

[0006] Preferably, when laying the graded gravel layer at the bottom of the transverse drainage blind ditch, a layered paving process is adopted: first, graded gravel with a particle size of 20-30mm is laid on the base, the paving thickness is 15cm, and a 1.5t flat plate compactor is used for 3 times to form a lower filter layer; then, graded gravel with a particle size of 10-20mm is laid, the paving thickness is 15cm, and a 3t vibrating roller is used for static compaction for 2 times to form an upper supporting layer, and the biaxially stretched plastic drainage board is fixed to the surface of the upper supporting layer with a U-shaped anchor nail, the U-shaped anchor nail has an opening width of 50mm, a nail leg length of 300mm, and is arranged in a plum blossom shape with a spacing of 2m×2m, and the anchor nail is inserted into the upper supporting layer. The depth of the layer shall not be less than 250mm; a diversion trough is arranged at the connection node between the horizontal drainage blind ditch and the longitudinal gravel blind ditch. The diversion trough adopts C25 concrete prefabricated components, and the inner wall slope is 45°. A stainless steel filter with an aperture of 5mm is arranged at the water inlet of the diversion trough, and the bottom elevation of the diversion trough is 10cm lower than the bottom elevation of the horizontal drainage blind ditch; an inspection well is arranged every 30m in the longitudinal gravel blind ditch, and the inner diameter of the inspection well is 80cm. A water-permeable hole with a diameter of 10cm is arranged on the well wall, and the water-permeable holes are arranged in a 30cm×30cm matrix. A gravel filter layer with a thickness of 20cm and a gravel particle size of 40-60mm is laid at the bottom of the inspection well.

[0007] Because the graded gravel layer of the horizontal drainage blind ditch is easy to clog, the drainage board is not firmly fixed, the diversion node is easy to silt up, and the longitudinal blind ditch is difficult to maintain, which affects the long-term performance of the drainage system. The layered paving process in the present invention optimizes the pore distribution through particle size sorting, the U-shaped anchor nails enhance the fixing strength of the drainage board, the combination of the diversion trough and the inspection well improves the convenience of blind ditch system maintenance, and the gravel filter layer effectively intercepts fine particles, so that the drainage system maintains the designed flow for a long time.

[0008] Preferably, in the layered filling method, a composite filling process is adopted: when the filling layer is gravel soil, a 25 cm thick coarse aggregate layer is first laid, the maximum particle size of the filler is 3 / 4 of the thickness of the compacted layer, and a bulldozer is used to spread it and statically press it once to form a skeleton structure; then a 25 cm thick fine aggregate layer is laid, the maximum particle size of the filler is less than 10 mm, and a grader is used for fine leveling and a 3% sodium silicate solution accounting for 1.5% of the mass of the fine aggregate is sprayed, and the spraying amount is controlled at 2L / m 2; When the filling layer is clay, the horizontal strip filling method is adopted to divide the filling surface into parallel strips with a width of 8m. The filling time interval between adjacent strips is not less than 4 hours. Temporary retaining boards are set at the edges of the filling strips. The height of the retaining boards is 50cm, and a 10cm expansion joint is reserved between the boards. In the moisture content adjustment operation, a mobile soil moisture content rapid tester is used to conduct three tests before, during and after each layer of filling. The detection points are arranged at a density of 3 per square meter. When the deviation between the detection value and the optimal moisture content exceeds ±1.5%, the rotary plow turning and drying operation speed is controlled at 3km / h and the turning depth reaches 4 / 5 of the thickness of the filling layer, and the soil is sprinkled. The water truck atomization water replenishment adopts a fan-shaped nozzle with a spray angle of 60° and a spray pressure of 0.3MPa; when the vibratory roller is in operation, a high-frequency and low-amplitude mode is adopted in the gravel soil layer, with a vibration frequency of 35Hz and an amplitude of 1.2mm; a low-frequency and high-amplitude mode is adopted in the clay soil layer, with a vibration frequency of 28Hz and an amplitude of 2.0mm. The driving speed of the vibratory roller is maintained at a constant 2km / h; the cross slope of the roadbed surface is formed by an adjustable steel scraper, the length of the scraper is the same as the width of the roadbed, hydraulic lifting devices are arranged on both sides of the scraper, the lifting accuracy is controlled to ±1mm, and the welding height difference at the bottom of the scraper is a trapezoidal slope adjustment block of 3% of the thickness of the fill layer.

[0009] Since the filling process of gravel and clay soil is single, the moisture content is adjusted roughly, the rolling parameters are not adapted to the soil characteristics, and the cross slope forming accuracy is low, resulting in unstable filling structure. In the present invention, the gravel soil skeleton-fine grain grouting structure and the clay soil strip filling method are adapted to different soil characteristics respectively, the sodium silicate solution spraying enhances the stability of the fine grain layer, the differentiated rolling parameters reduce soil damage, and the adjustable scraper realizes precise control of the cross slope, which comprehensively improves the structural strength and drainage performance of the filling layer.

[0010] Preferably, in the adjustable steel scraper forming system, the scraper body is composed of an H-shaped steel welded frame and a 16Mn steel plate working surface. The length of the working surface is the same as the width of the roadbed, the steel plate thickness is 12mm, and the back is welded with reinforcing ribs with a spacing of 50cm; multi-stage adjustment devices are arranged on both sides of the scraper, including a coarse adjustment screw, a fine adjustment hydraulic cylinder and a laser slope sensor. The coarse adjustment screw adopts a trapezoidal thread with a pitch of 8mm and a stroke range of ±100mm. The fine adjustment hydraulic cylinder piston has a diameter of 40mm, a stroke of ±20mm, and a repeat positioning accuracy of ±0.1mm. During construction, two parallel laser reference lines are set up along the longitudinal direction of the roadbed. The spacing between the laser lines corresponds to the designed elevation difference at both ends of the scraper. The wavelength of the laser transmitter is 650nm, the power is 10mW, and the receiver sensitivity is ±0.5mm / 100m. The scraper operation adopts a three-stage Scraping process: The first scraping depth is 1 / 3 of the filling layer thickness, the scraper travel speed is 3m / min, the second scraping depth is 1 / 2 of the remaining thickness, the travel speed is 2m / min, and the final scraping adopts the vibration scraping mode, the vibration frequency is 25Hz, the amplitude is 0.5mm, and the travel speed is 1m / min; the bottom of the scraper is welded with a replaceable slope adjustment module, the module is made of cemented carbide, the blade angle is 45°, the module height difference is set in proportion to 3% of the filling layer thickness, and it is connected to the scraper body through T-slot bolts, and the bolt preload is controlled in the range of 15-18N·m; after the scraper is erected, a dynamic compaction detection device is used to monitor the scraping effect in real time. When the local compaction deviation exceeds 2%, the hydraulic cylinder is automatically triggered by the PLC control system for compensatory adjustment, and the adjustment response time is less than 0.3s.

[0011] The existing scraper system has insufficient adjustment accuracy, a single scraping process, easy wear of the slope adjustment module, and lack of dynamic compensation for compaction, which affects the surface flatness and drainage performance of the roadbed. The present invention uses a multi-stage adjustment device combined with a laser reference line to achieve millimeter-level slope control, a three-stage scraping process to eliminate filler rebound, and replaceable modules and dynamic compaction compensation to ensure that the surface flatness meets the standard and reduce the subsequent maintenance cost.

[0012] Preferably, in the laying process of the polypropylene filament needle-punched waterproof geotextile, a stepped composite sealing process is adopted: the overlapping parts of the geotextile are firstly subjected to surface pretreatment, and an electric wire brush is used to remove surface dust within a range of 10 cm on both sides of the center line of the overlapping seam, the brush wire diameter is 0.15 mm, and the brush head travels at a speed of 0.5 m / s; after pretreatment, double-pass hot-melt welding is adopted, the first welding temperature is 280°C, the welding pressure is 0.2 MPa, and a molten zone with a width of 3 cm is formed; the second welding temperature is 300°C, the welding pressure is 0.3 MPa, and a reinforced molten zone with a width of 5 cm is formed 5 cm away from the edge of the first weld, and a quick-setting modified asphalt coating is sprayed in the middle area of ​​the two welds, the coating thickness is 2 mm, and the spraying amount is 1.8 kg / m 2When the polyethylene film is laid, a strip of pressure-sensitive tape is set at an interval of 1m on the lower surface of the film. The tape width is 20mm and the bonding strength is greater than 1.5N / mm 2 A 30cm wide non-woven fabric reinforcement layer is first laid at the longitudinal joints of the film, and then double-sided self-adhesive tape is applied. The tape covers 15cm on both sides of the joint. The transverse joints of the film are welded by hot air. The welding temperature is 250℃, the wind pressure is 0.15MPa, and the welding gun moves at a speed of 0.8m / min to form a continuous weld with a width of 10mm. An anti-slip fixing belt is set every 2m between the geotextile and the film. The fixing belt is a rubber strip with a width of 10cm. The surface of the rubber strip is provided with air holes with a diameter of 5mm and a hole spacing of 15cm. The rubber strip is fixed to the roadbed surface by nailing. The nail length is 15cm, the nail cap diameter is 20mm, and the nail penetration depth is 12cm.

[0013] The low sealing strength of geotextile overlap, easy peeling of film seams, and unreliable fixing methods lead to insufficient overall impermeability of the waterproof layer. The present invention forms multiple seals through double-pass gradient welding and modified asphalt coating, and the film seam reinforcement treatment inhibits peeling. The anti-slip fixing belt takes into account both displacement control and air permeability requirements, significantly improving the impermeability durability of the waterproof layer.

[0014] Preferably, in the construction of the concrete intercepting ditch, a prefabricated assembled structure is adopted: the intercepting ditch body is assembled from C30 reinforced concrete prefabricated trough sections with a length of 1.5m, mortise and tenon joints are arranged at both ends of the trough sections, the tenon length is 10cm, the mortise depth is 12cm, and the joints of adjacent trough sections are filled with water-expandable rubber strips with a thickness of 2cm; the ditch bottom slope control adopts an adjustable steel bracket system, the bracket columns are 1m apart, a hydraulic leveling device is arranged on the top of the column, the leveling accuracy is ±0.5mm, and a laser slope meter is installed on the bracket crossbeam to monitor the ditch bottom elevation in real time; the expansion joint construction adopts a three-layer waterproof structure, the first layer is laid with a butyl rubber waterstop with a width of 20cm, and a diameter is formed in the middle of the waterstop The second layer is filled with hot-melt modified asphalt to 2 / 3 of the seam depth. The third layer is pressed with a closed-cell polyethylene foam rod with a diameter of 8mm using a special caulking gun. Finally, the surface is coated with 2mm thick polyurethane sealant. A diversion rib is set every 3m on the inner wall of the intercepting ditch. The rib height is 30cm, the thickness is 10cm, and the inclination angle is 45°. A 5cm diameter drainage hole is opened at the bottom of the rib. A PVC diversion pipe is inserted into the hole. The diversion pipe extends 20cm outside the ditch. An anti-filtration structure is set at the junction of the ditch and the roadbed. A 30cm thick gravel layer, a 20cm thick coarse sand layer and a 5cm thick permeable geotextile are laid from the inside to the outside. The permeability coefficient of the geotextile is greater than 1×10 -2 cm / s, gravel particle size 5-10mm, coarse sand particle size 0.5-1mm.

[0015] Due to the poor construction accuracy of cast-in-place intercepting ditches, failure of expansion joint waterproofing, insufficient diversion structure, and unreasonable design of anti-filter layer, leakage and siltation of ditches occur. In the present invention, the mortise and tenon joints of the prefabricated groove sections and the water-expanding rubber ensure the assembly accuracy, the diversion ribs and PVC pipes optimize the water flow path, the three-layer expansion joint waterproofing system resists deformation stress, and the anti-filter structure prevents siltation, which improves the drainage efficiency and structural life of the intercepting ditch as a whole.

[0016] Preferably, in the adjustable steel support system, the steel support is composed of an H-shaped steel column, a channel steel beam and a spherical hinged base. A square steel plate base with a side length of 40 cm is welded at the bottom of the column, and M30 anchor bolt holes are set at the four corners of the base; the hydraulic leveling device includes a double-acting hydraulic jack, a laser receiving target and a pressure sensor. The jack piston has a diameter of 80 mm and a stroke of 50 mm. The pressure sensor has a range of 0-10 MPa and an accuracy level of 0.5. During the leveling operation, a laser transmitter is set up at intervals of 5 m along the longitudinal direction of the ditch body. The transmitter wavelength is 635 nm, the output power is 5 mW, and the slope control The control signal is linked to the hydraulic jack through the PLC controller to form a closed-loop control system; the three-level leveling method is adopted when installing the bracket: first, the ±20mm coarse adjustment is carried out through the anchor bolts, then the ±5mm fine adjustment is carried out through the spherical hinged base, and finally the hydraulic jack is started to implement ±1mm fine adjustment; after the leveling is completed, a chloroprene rubber buffer pad is set between the beam and the prefabricated slot section, the cushion layer has a thickness of 15mm, a hardness of 60 Shore A, and a compression permanent deformation of less than 15%; when the bracket system is accepted, a total station is used to re-measure the three-dimensional coordinates, and the plane position deviation is controlled within ±3mm, and the elevation deviation does not exceed ±2mm.

[0017] The existing support system has low leveling efficiency, manual reliance on accuracy, and cumulative installation deviations of prefabricated components, which affect the slope control and structural stability of the intercepting ditch. The present invention uses a three-level leveling method combined with laser closed-loop control to achieve high-precision slope adjustment, a buffer pad to absorb construction vibration, and a total station re-measurement to ensure the installation quality of the support system, providing a reliable foundation for the long-term stable operation of the intercepting ditch.

[0018] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0020] The present invention provides a method for constructing a high-fill roadbed in a seasonal precipitation area, which is characterized by comprising the following steps: Before the excavation of the roadbed base, a transverse drainage blind ditch with a spacing of 8-10m is set along the transverse axis of the roadbed. A 30cm thick graded gravel layer with a graded gravel particle size of 10-30mm is laid at the bottom of the transverse drainage blind ditch. A biaxially stretched plastic drainage board is laid above the graded gravel layer. The drainage flux of the biaxially stretched plastic drainage board is greater than 20cm 3 / s, the transverse drainage blind ditch is connected with the longitudinal gravel blind ditch on both sides of the roadbed. The cross section of the longitudinal gravel blind ditch is inverted trapezoidal shape, with a bottom width of 80cm, a top width of 120cm and a depth of 100cm; After the construction of the base drainage system is completed, the roadbed is filled by layered filling method, and the thickness of each layer does not exceed 50cm. The maximum particle size of the filler is controlled at 2 / 3 of the compacted thickness. When the natural moisture content of the filler exceeds the optimum moisture content ±2%, the moisture content is adjusted by using a rotary plow to turn it over or a sprinkler truck to atomize and replenish water. A 25t vibratory roller is used for rolling. The number of rolling passes is 1 static pressure, 6 vibration pressures, and 1 final pressure. The adjacent rolling wheel tracks overlap by 1 / 3 of the wheel width. After compaction, the roadbed surface forms a 2-4% cross slope; After each layer is filled and compacted, immediately lay 400g / m 2 Polypropylene filament needle-punched waterproof geotextile, the overlap width of the geotextile is not less than 50cm, the overlap is processed by hot melt welding, the welding temperature is controlled within the range of 280-300℃, the geotextile is covered with a polyethylene film with a thickness of 0.5mm, and the film seams are sealed with double-sided self-adhesive tape; After the roadbed is filled to the designed elevation, a concrete intercepting ditch is set at the top of the roadbed slope. The inner net width of the intercepting ditch is 40cm, the depth is 50cm, the slope of the ditch bottom is consistent with the longitudinal slope of the route and is not less than 0.3%. An expansion joint is set in the intercepting ditch every 15m, and the expansion joint is densely filled with asphalt hemp.

[0021] Specifically, when the base drainage system is constructed, the spacing of the lateral drainage blind ditch can be set to 8m, 9m or 10m, which is determined according to the on-site hydrogeological survey data. The thickness of the graded gravel layer is 30cm, and the layered paving process is adopted. The lower 15cm is paved with gravel with a particle size of 20-30mm, and the upper 15cm is paved with gravel with a particle size of 10-20mm. The biaxially oriented plastic drainage board can be made of commercially available HDPE material products, and the drainage flux is greater than 20cm 3 / s, fixed to the gravel layer surface by U-shaped anchor nails, the anchor nail opening width is 50mm, the nail leg length is 300mm, and it is arranged in a plum blossom shape with a spacing of 2m×2m. The cross section of the longitudinal gravel blind ditch is inverted trapezoidal, with a bottom width of 80cm, a top width of 120cm, and a depth of 100cm. A C25 concrete diversion trough is set at the connection with the transverse blind ditch, and a stainless steel filter with an aperture of 5mm is installed at the water inlet of the diversion trough. The bottom elevation of the trough is 10cm lower than the bottom of the transverse blind ditch.

[0022] For the construction equipment, an excavator can be selected for the blind ditch excavation, and a plate compactor is used to compact the gravel layer. The graded gravel material can be sourced from local stone quarries and complies with the aggregate standards for highway engineering. The biaxial geotextile drain can be purchased from professional building material suppliers, and the anchor nails are made of hot-dip galvanized steel. The precast components of the diversion channel are processed in the factory and transported to the site for installation, with the concrete strength grade being C25.

[0023] During the working process, first, the transverse blind ditches are excavated at the designed spacing, the graded gravel is laid and compacted in layers, and then the drain plates are installed and the anchor nails are fixed. The diversion channels are installed at the nodes of the longitudinal and transverse blind ditches, and the stainless steel filter screen can prevent debris from entering. After the construction is completed, the drainage efficiency of the blind ditches is verified through a water injection test to ensure smooth water flow without blockage.

[0024] When using the layered filling method for subgrade filling, the thickness of each filling layer can be controlled at 40 cm, 45 cm, or 50 cm, and the maximum particle size of the filler does not exceed 2 / 3 of the thickness of the compacted layer. When the natural moisture content of the filler exceeds the optimum moisture content by ±2%, a rotary tiller can be used for sunning or a water truck can be used for atomizing water for adjustment. For the rolling operation, a 25-ton vibratory roller is used, with 1 static pass, 6 vibratory passes, and 1 final pass, and the adjacent wheel tracks overlap by 1 / 3 of the wheel width. When filling with sandy gravel soil, the vibration frequency is set at 35 Hz and the amplitude is 1.2 mm; when filling with cohesive soil, the vibration frequency is adjusted to 28 Hz and the amplitude is 2.0 mm. The cross slope of the subgrade surface is formed by an adjustable steel scraper, and adjustment blocks with a height difference of 3% of the filling layer thickness are welded at the bottom of the scraper.

[0025] The filler can be selected from the on-site excavated soil or the purchased improved soil, and the maximum particle size needs to be controlled through a screening test. The operating speed of the rotary tiller for sunning can be set at 3 km / h, and the tillage depth reaches 4 / 5 of the filling layer thickness. The atomizing water supply of the water truck uses a fan-shaped nozzle with a spraying angle of 60° and a pressure of 0.3 MPa. When the roller is compressing, the traveling speed is kept constant at 2 km / h to ensure uniform compaction. The scraper adjustment device can be connected to a laser slope sensor to calibrate the cross slope in real time.

[0026] During construction, first, the coarse-grained material is paved to form a skeleton structure, and after static compaction, the fine-grained material is laid and sodium silicate solution is sprayed. After each layer of filling is completed, a dynamic compaction detector is used for random inspection, and the density of the inspection points is 3 per square meter. The inspection data is real-time fed back to the control system. When the local deviation exceeds 2%, the scraper hydraulic compensation device is automatically triggered, and the adjustment response time is less than 0.3 s.

[0027] When laying the polypropylene filament needle-punched waterproof geotextile, the unit area mass of the polypropylene filament needle-punched waterproof geotextile is 400 g / m 2The overlap width can be set to 50cm, 55cm or 60cm. The overlap is hot-melt welded, the welding temperature can be set to 280℃, 290℃ or 300℃, and the welding pressure is 0.2-0.3MPa. The polyethylene film is 0.5mm thick, and the joints are sealed with double-sided self-adhesive tape. A 30cm wide non-woven fabric reinforcement layer is added to the longitudinal joints. The anti-slip fixing belt is made of rubber strips with 5mm diameter air holes on the surface. It is fixed to the roadbed surface by nailing. The nail length is 15cm and the nail penetration depth is 12cm.

[0028] Geotextiles can be made of polypropylene filament needle-punched products, and films can be HDPE anti-seepage membranes. Hot-melt welding equipment can be automatic crawling welders with a welding speed of 0.5m / s. Self-adhesive tapes can be made of butyl rubber with a bonding strength greater than 1.5N / mm 2 The rubber strip can be made of EPDM material, and the nails can be galvanized steel nails with a spacing of 2m.

[0029] During construction, first clean the dust on the overlapped surface of the geotextile, then perform double-pass hot-melt welding to form 3cm and 5cm wide molten strips, and spray quick-setting modified asphalt coating in the middle. After the film is laid, the longitudinal joints are taped and hot-air welded, and the transverse joints are sealed with double-sided tape. The anti-slip fixing tape is installed at 2m intervals, and the nails are driven vertically into the roadbed. The air holes of the rubber strips are staggered with the film joints.

[0030] The net width of the inner side of the concrete intercepting ditch is 40cm, the depth is 50cm, and the slope of the bottom of the ditch can be set to 0.3%, 0.35% or 0.4%. The expansion joint spacing is 15m, filled with asphalt hemp, and the hemp needle penetration is 60-80. The prefabricated trough section uses C30 reinforced concrete, the length is 1.5m, the length of the tenon joint is 10cm, the depth of the mortise is 12cm, and the joint is filled with water-expanding rubber strips. The height of the diversion rib is 30cm, the inclination angle is 45°, and the bottom is installed with a 5cm diameter PVC diversion pipe with a length of 20cm.

[0031] The prefabricated trough section can be prefabricated in the factory, with a concrete strength grade of C30 and a steel bar protective layer thickness of 25mm. The expansion rate of the water-expandable rubber strip is ≥150%, and the width of the butyl rubber waterstop is 20cm. The filter layer is laid from the inside to the outside with 30cm gravel, 20cm coarse sand and 5cm permeable geotextile, with a gravel particle size of 5-10mm and a coarse sand particle size of 0.5-1mm.

[0032] During installation, the position of the prefabricated trench section is measured with a total station, and the hydraulic leveling device is used to adjust the slope of the trench bottom to the design value. For expansion joint construction, first lay the water stop belt, pour hot melt asphalt to 2 / 3 of the joint depth, then press in the closed-cell polyethylene foam rod, and finally apply polyurethane sealant. After the diversion ribs and PVC pipes are installed, the filter layer is backfilled and compacted, and the permeability coefficient of the permeable geotextile is greater than 0.01cm / s.

[0033] In another technical solution, when laying the graded gravel layer at the bottom of the transverse drainage blind ditch, a layered paving process is adopted: first, graded gravel with a particle size of 20-30mm is laid on the base, the paving thickness is 15cm, and a 1.5t flat plate rammer is used to compact it 3 times to form a lower filter layer; then, graded gravel with a particle size of 10-20mm is laid, the paving thickness is 15cm, and a 3t vibratory roller is used to statically press 2 times to form an upper supporting layer. The biaxially stretched plastic drainage board is fixed to the surface of the upper supporting layer with U-shaped anchor nails. The U-shaped anchor nails have an opening width of 50mm and a nail leg length of 300mm. They are arranged in a plum blossom shape with a spacing of 2m×2m, and the anchor nails are inserted into the upper The depth of the supporting layer shall not be less than 250mm; a diversion trough is arranged at the connection node between the horizontal drainage blind ditch and the longitudinal gravel blind ditch. The diversion trough adopts C25 concrete precast components, and the inner wall slope is 45°. A stainless steel filter with an aperture of 5mm is arranged at the water inlet of the diversion trough, and the bottom elevation of the diversion trough is 10cm lower than the bottom elevation of the horizontal drainage blind ditch; an inspection well is arranged every 30m in the longitudinal gravel blind ditch, and the inner diameter of the inspection well is 80cm. A water-permeable hole with a diameter of 10cm is arranged on the well wall, and the water-permeable holes are arranged in a 30cm×30cm matrix. A gravel filter layer with a thickness of 20cm and a gravel particle size of 40-60mm is laid at the bottom of the inspection well.

[0034] The implementation of this technical solution can effectively improve the comprehensive performance of the drainage system. A lower layer of 20-30mm diameter gravel is set at the bottom of the horizontal drainage blind ditch, and a stable filtering structure is formed by flat tamping to intercept fine particles in the seepage; the upper layer of 10-20mm diameter gravel is formed into a dense supporting layer by static pressure, and cooperates with the lower layer to achieve graded filtration and reduce the risk of pore blockage. The U-shaped anchor nails are arranged in a plum blossom shape to fix the drainage board. The design of the opening width of 50mm and the nail leg length of 300mm forms a mechanical bite. The constraint condition of the insertion depth of not less than 250mm can resist the displacement caused by water scouring and ensure the long-term stable operation of the drainage board.

[0035] The diversion trough uses precast concrete components with a 45° inner wall slope, combined with a bottom elevation 10cm lower than the blind ditch, to form a natural hydraulic gradient and accelerate the water flow to the longitudinal blind ditch. The 5mm stainless steel filter at the water inlet can prevent debris with a particle size greater than 5mm from entering the drainage system, reducing the probability of siltation. The inspection wells set up at intervals of 30m in the longitudinal blind ditch can realize water level monitoring and local dredging through the permeable holes arranged in a 30cm×30cm matrix. The 20cm thick gravel filter layer at the bottom selectively lays gravels with a particle size of 40-60mm, which can balance permeability and interception efficiency and extend the maintenance cycle. The overall solution achieves the synergistic effect of improving drainage efficiency and reducing operation and maintenance costs through material grading optimization, structural hierarchical design and the setting of maintainability nodes. The layered filtration structure delays the attenuation of system performance. The combined design of the diversion trough and the inspection well enables the drainage network to have self-cleaning capabilities, providing reliable guarantees for the long-term stability of the roadbed in seasonal precipitation areas.

[0036] In another technical solution, a composite filling process is used in the layered filling method: when the filling layer is gravel soil, a 25 cm thick coarse aggregate layer is first laid, and the maximum particle size of the filler is 3 / 4 of the thickness of the compacted layer. A bulldozer is used to spread and statically press once to form a skeleton structure; then a 25 cm thick fine aggregate layer is laid, and the maximum particle size of the filler is less than 10 mm. A grader is used for fine leveling and a 3% sodium silicate solution accounting for 1.5% of the mass of the fine aggregate is sprayed, and the spraying amount is controlled at 2L / m 2 ; When the filling layer is clay, the horizontal strip filling method is adopted to divide the filling surface into parallel strips with a width of 8m. The filling time interval between adjacent strips is not less than 4 hours. Temporary retaining boards are set at the edges of the filling strips. The height of the retaining boards is 50cm, and a 10cm expansion joint is reserved between the boards. In the moisture content adjustment operation, a mobile soil moisture content rapid tester is used to conduct three tests before, during and after each layer of filling. The detection points are arranged at a density of 3 per square meter. When the deviation between the detection value and the optimal moisture content exceeds ±1.5%, the rotary plow turning and drying operation speed is controlled at 3km / h and the turning depth reaches 4 / 5 of the thickness of the filling layer, and the soil is sprinkled. The water truck atomization water replenishment adopts a fan-shaped nozzle with a spray angle of 60° and a spray pressure of 0.3MPa; when the vibratory roller is in operation, a high-frequency and low-amplitude mode is adopted in the gravel soil layer, with a vibration frequency of 35Hz and an amplitude of 1.2mm; a low-frequency and high-amplitude mode is adopted in the clay soil layer, with a vibration frequency of 28Hz and an amplitude of 2.0mm. The driving speed of the vibratory roller is maintained at a constant 2km / h; the cross slope of the roadbed surface is formed by an adjustable steel scraper, the length of the scraper is the same as the width of the roadbed, hydraulic lifting devices are arranged on both sides of the scraper, the lifting accuracy is controlled to ±1mm, and the welding height difference at the bottom of the scraper is a trapezoidal slope adjustment block of 3% of the thickness of the fill layer.

[0037] The implementation of this technical solution can improve the structural stability of the filling layer and the level of construction quality control. When filling gravel soil, first lay a 25cm thick coarse aggregate layer (maximum particle size is 3 / 4 of the compaction layer thickness), form a skeleton structure through static pressure, and enhance the interlayer shear resistance; then lay a 25cm thick fine aggregate layer (maximum particle size is less than 10mm), spray 3% sodium silicate solution (dosage is 1.5% of the mass of fine aggregate), and use its cementation effect to fill the skeleton pores to form a composite stable structure. The clay soil is filled in horizontal strips with a width of 8m. The 4-hour construction interval between adjacent strips combined with the setting of a 50cm high retaining wall can effectively control lateral deformation, and a 10cm expansion joint is reserved to avoid cracks caused by temperature stress.

[0038] The moisture content is regulated by a dynamic monitoring system with three detection points per square meter. When the deviation exceeds ±1.5%, the rotary plow is turned at a speed of 3km / h to a depth of 4 / 5 of the thickness of the filling layer to ensure a uniform moisture content gradient; the atomization water supply adopts a 60° fan-shaped nozzle (pressure 0.3MPa) to achieve fine water particle distribution. The vibratory roller adopts a 35Hz / 1.2mm high-frequency low-amplitude mode in the gravel layer to reduce the crushing of coarse particles; the clay layer adopts a 28Hz / 2.0mm low-frequency high-amplitude mode to enhance the density of fine-grained soil, and a constant speed of 2km / h ensures rolling uniformity.

[0039] The adjustable steel scraper is precisely formed into a 2-4% cross slope through a hydraulic lifting device with an accuracy of ±1mm, combined with a trapezoidal slope adjustment block with a fill layer thickness of 3%. During the construction process, the differentiated application of the gravel soil skeleton-fine-grained grouting structure and the clay soil strip filling method, combined with the dynamic adjustment of vibration parameters, significantly reduces the risk of interlayer shear failure. The cementing and curing effect of the sodium silicate solution and the precise control of the cross slope synergistically improve the overall drainage performance of the roadbed, providing technical support for the long-term stability of the high-fill roadbed in seasonal precipitation areas.

[0040] In another technical solution, in the adjustable steel scraper forming system, the scraper body is composed of an H-shaped steel welded frame and a 16Mn steel plate working surface. The length of the working surface is the same as the width of the roadbed. The steel plate thickness is 12mm, and the back is welded with reinforcing ribs with a spacing of 50cm. Multi-stage adjustment devices are arranged on both sides of the scraper, including a coarse adjustment screw, a fine adjustment hydraulic cylinder and a laser slope sensor. The coarse adjustment screw adopts a trapezoidal thread with a pitch of 8mm and a stroke range of ±100mm. The fine adjustment hydraulic cylinder piston has a diameter of 40mm, a stroke of ±20mm, and a repeat positioning accuracy of ±0.1mm. During construction, two parallel laser reference lines are set up along the longitudinal direction of the roadbed. The spacing between the laser lines corresponds to the designed elevation difference at both ends of the scraper. The wavelength of the laser transmitter is 650nm, the power is 10mW, and the receiver sensitivity is ±0.5mm / 100m. The scraper operation adopts three Segmented scraping process: the first scraping depth is 1 / 3 of the filling layer thickness, the scraper travel speed is 3m / min, the second scraping depth is 1 / 2 of the remaining thickness, the travel speed is 2m / min, and the final scraping adopts the vibration scraping mode, the vibration frequency is 25Hz, the amplitude is 0.5mm, and the travel speed is 1m / min; the bottom of the scraper is welded with a replaceable slope adjustment module, the module is made of cemented carbide, the blade angle is 45°, the module height difference is set in proportion to 3% of the filling layer thickness, and it is connected to the scraper body through T-slot bolts, and the bolt preload is controlled in the range of 15-18N·m; after the scraper is erected, a dynamic compaction detection device is used to monitor the scraping effect in real time. When the local compaction deviation exceeds 2%, the hydraulic cylinder is automatically triggered by the PLC control system for compensation adjustment, and the adjustment response time is less than 0.3s.

[0041] The implementation of this technical solution can significantly improve the surface forming accuracy and construction efficiency of the roadbed. The working surface composed of the H-shaped steel welded frame and the 12mm thick 16Mn steel plate, combined with the reinforced rib design with a spacing of 50cm on the back, ensures the structural stability of the scraper under vibration conditions. In the multi-stage adjustment device, the coarse adjustment screw (trapezoidal thread pitch 8mm) achieves rapid positioning within the range of ±100mm, and the fine adjustment hydraulic cylinder (piston diameter 40mm) completes fine adjustment with a repeatable positioning accuracy of ±0.1mm, forming a closed-loop control with the laser slope sensor (wavelength 650nm, sensitivity ±0.5mm / 100m) to ensure the consistency of the scraper elevation with the designed slope.

[0042] In the three-stage scraping process, the first scraping speed is 3m / min to scrape 1 / 3 of the thickness of the filling layer (such as 50cm layer thickness corresponds to 16.7mm) to initially level the surface; the second scraping speed is 2m / min to scrape 1 / 2 of the remaining thickness to refine the flatness; the final 1m / min vibration scraping (25Hz / 0.5mm) eliminates material rebound. The replaceable carbide module (blade 45°) is fixed by T-slot bolts, and the height difference is set in proportion to 3% of the thickness of the filling layer (such as 50cm layer thickness corresponds to 15mm module height difference), and the preload force is 15-18N·m to ensure the stability of the module to meet different cross slope requirements.

[0043] The dynamic compaction detection device collects surface density data in real time. The PLC system automatically triggers hydraulic compensation when the deviation exceeds 2%. The 0.3s response time effectively corrects local unevenness. The laser reference line guidance and vibration scraping work together to control the error of the formed cross slope within ±1mm. The wear resistance of the carbide module extends the service life, and the modular design supports rapid replacement and reduces maintenance costs. The overall system achieves precise control of the surface flatness and drainage slope of the high fill roadbed through the integration of mechanical structure optimization and intelligent control.

[0044] In another technical solution, in the laying process of the polypropylene filament needle-punched waterproof geotextile, a stepped composite sealing process is adopted: the overlapping parts of the geotextile are firstly subjected to surface pretreatment, and an electric wire brush is used to remove surface dust within a range of 10 cm on both sides of the center line of the overlapping seam, the brush wire diameter is 0.15 mm, and the brush head travels at a speed of 0.5 m / s; after pretreatment, double-pass hot-melt welding is adopted, the first welding temperature is 280°C, the welding pressure is 0.2 MPa, and a molten zone with a width of 3 cm is formed, the second welding temperature is 300°C, the welding pressure is 0.3 MPa, and a reinforced molten zone with a width of 5 cm is formed 5 cm away from the edge of the first weld, and a quick-setting modified asphalt coating is sprayed in the middle area of ​​the two welds, the coating thickness is 2 mm, and the spraying amount is 1.8 kg / m 2 When the polyethylene film is laid, a strip of pressure-sensitive tape is set at an interval of 1m on the lower surface of the film. The tape width is 20mm and the bonding strength is greater than 1.5N / mm 2A 30cm wide non-woven fabric reinforcement layer is first laid at the longitudinal joints of the film, and then double-sided self-adhesive tape is applied. The tape covers 15cm on both sides of the joint. The transverse joints of the film are welded by hot air. The welding temperature is 250℃, the wind pressure is 0.15MPa, and the welding gun moves at a speed of 0.8m / min to form a continuous weld with a width of 10mm. An anti-slip fixing belt is set every 2m between the geotextile and the film. The fixing belt is a rubber strip with a width of 10cm. The surface of the rubber strip is provided with air holes with a diameter of 5mm and a hole spacing of 15cm. The rubber strip is fixed to the roadbed surface by nailing. The nail length is 15cm, the nail cap diameter is 20mm, and the nail penetration depth is 12cm.

[0045] The implementation of this technical solution can effectively improve the sealing reliability and structural durability of the waterproof layer. The overlapping parts of the geotextile are pretreated with an electric wire brush (brush wire diameter 0.15mm, travel speed 0.5m / s) to remove surface dust and form a rough interface to enhance welding bonding. In double-pass hot-melt welding, the first pass at 280℃ / 0.2MPa forms a 3cm wide molten zone to achieve basic sealing, and the second pass at 300℃ / 0.3MPa forms a 5cm wide reinforced molten zone at a 5cm offset position, improving the shear resistance of the weld through the temperature gradient; a 2mm thick quick-setting modified asphalt coating (dosage 1.8kg / m 2 ), forming a flexible transition layer to make up for the difference in thermal expansion between the hot-melt material and the geotextile.

[0046] When laying polyethylene film, the longitudinal seams are reinforced with a 30cm wide non-woven fabric and double-sided self-adhesive tape (covering 15cm on each side) to disperse the stress concentration at the seams; the transverse seams are welded by 250℃ hot air to form a 10mm continuous weld (wind pressure 0.15MPa, welding speed 0.8m / min) to ensure the transverse tensile strength. The 20mm wide pressure-sensitive tape (bonding strength > 1.5N / mm2) is set at intervals of 1m on the lower surface of the film. 2 ), provide uniform adhesion and prevent film bulging. Rubber fixing belts (width 10cm, air hole diameter 5mm / spacing 15cm) are installed every 2m between geotextile and film, and nails (length 15cm, nail penetration depth 12cm) are anchored to a depth exceeding 1 / 4 of the thickness of the filling layer, which not only limits the displacement of materials, but also releases water vapor between layers through air holes to avoid water pressure accumulation.

[0047] The overall process significantly reduces the risk of leakage through stepped sealing (mechanical cleaning-hot melt welding-flexible filling), differentiated joint treatment (longitudinal reinforcement / transverse welding) and breathable fixing design. The elastic compensation effect of the modified asphalt coating and the water vapor diversion ability of the air pores work together to extend the service life of the waterproof system in a dry-wet cycle environment, providing long-term anti-seepage protection for the roadbed in seasonal precipitation areas.

[0048] In another technical solution, a prefabricated assembled structure is used in the construction of the concrete intercepting ditch: the main body of the intercepting ditch is assembled from 1.5m long C30 reinforced concrete prefabricated trough sections, mortise and tenon joints are set at both ends of the trough sections, the tenon length is 10cm, the mortise depth is 12cm, and the joints of adjacent trough sections are filled with 2cm thick water-expandable rubber strips; the ditch bottom slope control adopts an adjustable steel bracket system, the bracket columns are 1m apart, a hydraulic leveling device is set on the top of the column, the leveling accuracy is ±0.5mm, and a laser slope meter is installed on the bracket crossbeam to monitor the ditch bottom elevation in real time; the expansion joint construction adopts a three-layer waterproof structure, the first layer is laid with a butyl rubber waterstop with a width of 20cm, and the middle of the waterstop is formed The semicircular protrusion with a diameter of 15 cm is poured with hot-melt modified asphalt to 2 / 3 of the seam depth in the second layer. The third layer is pressed with a closed-cell polyethylene foam rod with a diameter of 8 mm using a special caulking gun, and finally the surface is coated with 2 mm thick polyurethane sealant; diversion ribs are set every 3 m on the inner wall of the intercepting ditch. The rib height is 30 cm, the thickness is 10 cm, and the inclination angle is 45°. A drainage hole with a diameter of 5 cm is opened at the bottom of the rib. A PVC diversion pipe is inserted into the hole, and the diversion pipe extends 20 cm outside the ditch body; an anti-filtration structure is set at the junction of the ditch body and the roadbed. From the inside to the outside, a 30 cm thick gravel layer, a 20 cm thick coarse sand layer and a 5 cm thick permeable geotextile are laid in sequence. The permeability coefficient of the geotextile is greater than 1×10 -2 cm / s, gravel particle size 5-10mm, coarse sand particle size 0.5-1mm.

[0049] The implementation of this technical solution can significantly improve the structural stability and drainage reliability of the intercepting ditch. The prefabricated assembled trough section adopts a 1.5m length and mortise and tenon joint (10cm for the tenon and 12cm for the mortise), and is equipped with a 2cm thick water-expanding rubber strip to fill the joint. It can be quickly positioned during assembly and form a dynamic seal. The rubber expansion rate ≥150% after contact with water can compensate for construction errors and reduce the risk of leakage. The adjustable steel support system is supported by 1m-spaced columns, and the hydraulic leveling device with an accuracy of ±0.5mm combined with real-time monitoring by a laser slope meter ensures that the slope error of the ditch bottom is less than 0.3%, avoiding local reverse slope water accumulation.

[0050] In the three-layer waterproof structure of the expansion joint, the semicircular protrusion of the butyl rubber water stop (diameter 15cm) adapts to the expansion and contraction deformation, the hot-melt modified asphalt is poured to 2 / 3 of the joint depth to provide flexible filling, the closed-cell polyethylene foam rod (diameter 8mm) is used as the backing material, and the surface 2mm polyurethane sealant has an elastic recovery rate of >90%, forming a graded waterproof system that effectively resists temperature stress and foundation settlement. The combined design of the diversion rib (30cm high, 45° inclination) and the PVC diversion pipe (5cm diameter, 20cm extension) can guide the water flow to reduce the impact of turbulence, and the drainage hole is 5cm higher than the bottom of the ditch to prevent sediment backflow.

[0051] The anti-filtration structure adopts a three-layer gradation of 30cm gravel (5-10mm), 20cm coarse sand (0.5-1mm) and 5cm permeable geotextile (permeability coefficient>0.01cm / s). The gravel layer intercepts large particles, the coarse sand layer refines and filters, and the geotextile prevents the loss of fine soil. The three work together to control the infiltration rate and avoid silting of blind ditches. The factory production of prefabricated trough sections ensures the concrete strength (C30) and the thickness of the steel bar protective layer (25mm). The on-site assembly efficiency is increased by more than 50% compared with cast-in-place, and the waste of templates is reduced. The overall solution achieves long-term drainage and low-maintenance operation of the intercepting ditch through modular design, precise slope control and composite waterproofing system, and adapts to the complex hydrological conditions in seasonal precipitation areas.

[0052] In another technical solution, in the adjustable steel support system, the steel support is composed of an H-shaped steel column, a channel steel beam and a spherical hinged base. A square steel plate base with a side length of 40 cm is welded at the bottom of the column, and M30 anchor bolt holes are set at the four corners of the base; the hydraulic leveling device includes a double-acting hydraulic jack, a laser receiving target and a pressure sensor. The jack piston has a diameter of 80 mm and a stroke of 50 mm. The pressure sensor has a range of 0-10 MPa and an accuracy level of 0.5. During the leveling operation, a laser transmitter is set up at intervals of 5 m along the longitudinal direction of the ditch body. The transmitter wavelength is 635 nm, the output power is 5 mW, and the slope is The control signal is linked to the hydraulic jack through the PLC controller to form a closed-loop control system; the three-level leveling method is adopted when installing the bracket: first, the ±20mm coarse adjustment is carried out through the anchor bolts, then the ±5mm fine adjustment is carried out through the spherical hinged base, and finally the hydraulic jack is started to implement ±1mm fine adjustment; after the leveling is completed, a chloroprene rubber buffer pad is set between the beam and the prefabricated slot section, the cushion layer has a thickness of 15mm, a hardness of 60 Shore A, and a compression permanent deformation of less than 15%; when the bracket system is accepted, a total station is used to re-measure the three-dimensional coordinates, and the plane position deviation is controlled within ±3mm, and the elevation deviation does not exceed ±2mm.

[0053] The implementation of this technical solution can ensure the precise installation and long-term stable operation of the intercepting ditch support system. The combined structure of the H-shaped steel column and the channel steel beam, combined with the 40cm square steel plate base and M30 anchor bolts at the bottom, forms an anti-overturning rigid support system. In the three-level leveling method, the anchor bolts are roughly adjusted by ±20mm to quickly eliminate the foundation deviation, the spherical hinge base is finely adjusted by ±5mm to compensate for the installation angle error, and the hydraulic jack is fine-tuned by ±1mm (piston diameter 80mm, stroke 50mm). The PLC receives the laser transmitter (wavelength 635nm, spacing 5m) signal to achieve closed-loop control, and finally the ditch bottom slope error is controlled within ±0.5mm, meeting the 0.3% slope design accuracy requirement.

[0054] The hydraulic leveling system integrates a pressure sensor (range 0-10MPa, accuracy 0.5 level) to monitor the jack load in real time to avoid overpressure damage to the prefabricated slot section. The 15mm thick chloroprene rubber cushion (hardness 60A, compression deformation <15%) set between the beam and the slot section can absorb construction vibration and temperature deformation, and reduce stress transmission to the prefabricated components. The bracket acceptance adopts the three-dimensional coordinate re-measurement of the total station, and the dual control standards of plane deviation ±3mm and elevation deviation ±2mm to ensure the linear smoothness of the slot section after assembly.

[0055] The overall system improves the efficiency of traditional manual leveling by more than 3 times through modular leveling technology and intelligent feedback mechanism, while reducing the dependence on operator experience. The buffer pad and spherical articulation design extend the service life of the bracket system under dynamic loads, and the total station acceptance data provides an accurate benchmark for later maintenance. This technical solution takes into account both construction efficiency and quality controllability, laying the foundation for the long-term reliability of the drainage function of the intercepting ditch.

[0056] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A method for constructing high fill roadbed in seasonal precipitation areas, characterized in that: The following steps are involved: Before the excavation of the roadbed base, a transverse drainage blind ditch with a spacing of 8-10m is set along the transverse axis of the roadbed. A 30cm thick graded gravel layer with a graded gravel particle size of 10-30mm is laid at the bottom of the transverse drainage blind ditch. A biaxially stretched plastic drainage board is laid above the graded gravel layer. The drainage flux of the biaxially stretched plastic drainage board is greater than 20cm 3 / s, the transverse drainage blind ditch is connected with the longitudinal gravel blind ditch on both sides of the roadbed. The cross section of the longitudinal gravel blind ditch is inverted trapezoidal shape, with a bottom width of 80cm, a top width of 120cm and a depth of 100cm; After the construction of the base drainage system is completed, the roadbed is filled by layered filling method, and the thickness of each layer does not exceed 50cm. The maximum particle size of the filler is controlled at 2 / 3 of the compacted thickness. When the natural moisture content of the filler exceeds the optimum moisture content ±2%, the moisture content is adjusted by using a rotary plow to turn it over or a sprinkler truck to atomize and replenish water. A 25t vibratory roller is used for rolling. The number of rolling passes is 1 static pressure, 6 vibration pressures, and 1 final pressure. The adjacent rolling wheel tracks overlap by 1 / 3 of the wheel width. After compaction, the roadbed surface forms a 2-4% cross slope; After each layer is filled and compacted, immediately lay 400g / m 2 Polypropylene filament needle-punched waterproof geotextile, the overlap width of the geotextile is not less than 50cm, the overlap is processed by hot melt welding, the welding temperature is controlled within the range of 280-300℃, the geotextile is covered with a polyethylene film with a thickness of 0.5mm, and the film seams are sealed with double-sided self-adhesive tape; After the roadbed is filled to the designed elevation, a concrete intercepting ditch is set at the top of the roadbed slope. The inner net width of the intercepting ditch is 40cm, the depth is 50cm, the slope of the ditch bottom is consistent with the longitudinal slope of the route and is not less than 0.3%. An expansion joint is set in the intercepting ditch every 15m, and the expansion joint is densely filled with asphalt hemp.

2. The method for constructing high-fill roadbed in seasonal precipitation areas according to claim 1, characterized in that: When laying the graded gravel layer at the bottom of the transverse drainage blind ditch, a layered paving process is adopted: first, graded gravel with a particle size of 20-30mm is laid on the base, the paving thickness is 15cm, and a 1.5t flat plate tamping is used for 3 times to form a lower filter layer; then, graded gravel with a particle size of 10-20mm is laid, the paving thickness is 15cm, and a 3t vibrating roller is used for static compaction for 2 times to form an upper supporting layer. The biaxially stretched plastic drainage board is fixed to the surface of the upper supporting layer with U-shaped anchor nails. The U-shaped anchor nails have an opening width of 50mm and a nail leg length of 300mm. They are arranged in a plum blossom shape with a spacing of 2m×2m, and the anchor nails are inserted into the upper supporting layer. The depth is not less than 250mm; a diversion trough is set at the connection node between the horizontal drainage blind ditch and the longitudinal gravel blind ditch. The diversion trough adopts C25 concrete precast components, and the inner wall slope is 45°. A stainless steel filter with an aperture of 5mm is set at the water inlet of the diversion trough, and the bottom elevation of the diversion trough is 10cm lower than the bottom elevation of the horizontal drainage blind ditch; an inspection well is set every 30m in the longitudinal gravel blind ditch. The inner diameter of the inspection well is 80cm, and the well wall is provided with a diameter of 10cm. The water permeable holes are arranged in a 30cm×30cm matrix. A gravel filter layer with a thickness of 20cm is laid at the bottom of the inspection well, and the gravel particle size is 40-60mm.

3. The method for constructing high fill roadbed in seasonal precipitation area according to claim 1, characterized in that: In the layered filling method, a composite filling process is used: when the filling layer is gravel soil, a 25cm thick coarse aggregate layer is first laid, and the maximum particle size of the filler is 3 / 4 of the thickness of the compacted layer. A bulldozer is used to spread and statically press once to form a skeleton structure; then a 25cm thick fine aggregate layer is laid, and the maximum particle size of the filler is less than 10mm. A grader is used for fine leveling and a 3% sodium silicate solution accounting for 1.5% of the mass of the fine aggregate is sprayed, and the spraying amount is controlled at 2L / m 2 ; When the filling layer is clay, the horizontal strip filling method is adopted to divide the filling surface into parallel strips with a width of 8m. The filling time interval between adjacent strips is not less than 4 hours. Temporary retaining boards are set at the edges of the filling strips. The height of the retaining boards is 50cm, and a 10cm expansion joint is reserved between the boards. In the moisture content adjustment operation, a mobile soil moisture content rapid tester is used to conduct three tests before, during and after each layer of filling. The detection points are arranged at a density of 3 per square meter. When the deviation between the detection value and the optimal moisture content exceeds ±1.5%, the rotary plow turning and drying operation speed is controlled at 3km / h and the turning depth reaches 4 / 5 of the thickness of the filling layer, and the soil is sprinkled. The water truck atomization water replenishment adopts a fan-shaped nozzle with a spray angle of 60° and a spray pressure of 0.3MPa; when the vibratory roller is in operation, a high-frequency and low-amplitude mode is adopted in the gravel soil layer, with a vibration frequency of 35Hz and an amplitude of 1.2mm; a low-frequency and high-amplitude mode is adopted in the clay soil layer, with a vibration frequency of 28Hz and an amplitude of 2.0mm. The driving speed of the vibratory roller is maintained at a constant 2km / h; the cross slope of the roadbed surface is formed by an adjustable steel scraper, the length of the scraper is the same as the width of the roadbed, hydraulic lifting devices are arranged on both sides of the scraper, the lifting accuracy is controlled to ±1mm, and the welding height difference at the bottom of the scraper is a trapezoidal slope adjustment block of 3% of the thickness of the fill layer.

4. The method for constructing high fill roadbed in seasonal precipitation area according to claim 3, characterized in that: In the adjustable steel scraper forming system, the scraper body is composed of an H-shaped steel welded frame and a 16Mn steel plate working surface. The length of the working surface is the same as the width of the roadbed. The steel plate thickness is 12mm, and the back is welded with a reinforcing rib with a spacing of 50cm. Multi-stage adjustment devices are arranged on both sides of the scraper, including a coarse adjustment screw, a fine adjustment hydraulic cylinder and a laser slope sensor. The coarse adjustment screw adopts a trapezoidal thread with a pitch of 8mm and a stroke range of ±100mm. The fine adjustment hydraulic cylinder piston has a diameter of 40mm, a stroke of ±20mm, and a repeat positioning accuracy of ±0.1mm. During construction, two parallel laser reference lines are set up along the longitudinal direction of the roadbed. The spacing between the laser lines corresponds to the designed elevation difference at both ends of the scraper. The wavelength of the laser transmitter is 650nm, the power is 10mW, and the receiver sensitivity is ±0.5mm / 100m. The scraper operation adopts a three-stage scraping and leveling method. Process: The first scraping depth is 1 / 3 of the thickness of the filling layer, the scraper travel speed is 3m / min, the second scraping depth is 1 / 2 of the remaining thickness, the travel speed is 2m / min, and the final scraping adopts the vibration scraping mode, the vibration frequency is 25Hz, the amplitude is 0.5mm, and the travel speed is 1m / min; the bottom of the scraper is welded with a replaceable slope adjustment module, the module is made of cemented carbide, the blade angle is 45°, the module height difference is set proportionally to 3% of the filling layer thickness, and it is connected to the scraper body by T-slot bolts, and the bolt preload is controlled in the range of 15-18N·m; after the scraper is erected, a dynamic compaction detection device is used to monitor the scraping effect in real time. When the local compaction deviation exceeds 2%, the hydraulic cylinder is automatically triggered by the PLC control system for compensatory adjustment, and the adjustment response time is less than 0.3s.

5. The method for constructing high fill roadbed in seasonal precipitation area according to claim 1, characterized in that: In the laying process of the polypropylene filament needle-punched waterproof geotextile, a stepped composite sealing process is adopted: the surface of the overlapped part of the geotextile is first pretreated, and the surface dust is removed within 10 cm on both sides of the center line of the overlapped seam using an electric wire brush, the brush wire diameter is 0.15 mm, and the brush head travels at a speed of 0.5 m / s; after pretreatment, double-pass hot-melt welding is adopted, the first welding temperature is 280°C, the welding pressure is 0.2 MPa, and a molten zone with a width of 3 cm is formed, the second welding temperature is 300°C, the welding pressure is 0.3 MPa, and a reinforced molten zone with a width of 5 cm is formed 5 cm away from the edge of the first weld, and a quick-setting modified asphalt coating is sprayed in the middle area of ​​the two welds, the coating thickness is 2 mm, and the spraying amount is 1.8 kg / m 2 When the polyethylene film is laid, a strip of pressure-sensitive tape is set at an interval of 1m on the lower surface of the film. The tape width is 20mm and the bonding strength is greater than 1.5N / mm 2 A 30cm wide non-woven fabric reinforcement layer is first laid at the longitudinal joints of the film, and then double-sided self-adhesive tape is applied. The tape covers 15cm on both sides of the joint. The transverse joints of the film are welded by hot air. The welding temperature is 250℃, the wind pressure is 0.15MPa, and the welding gun moves at a speed of 0.8m / min to form a continuous weld with a width of 10mm. An anti-slip fixing belt is set every 2m between the geotextile and the film. The fixing belt is a rubber strip with a width of 10cm. The surface of the rubber strip is provided with air holes with a diameter of 5mm and a hole spacing of 15cm. The rubber strip is fixed to the roadbed surface by nailing. The nail length is 15cm, the nail cap diameter is 20mm, and the nail penetration depth is 12cm.

6. The method for constructing high fill roadbed in seasonal precipitation area according to claim 1, characterized in that: In the construction of the concrete intercepting ditch, a prefabricated assembled structure is adopted: the main body of the intercepting ditch is assembled from C30 reinforced concrete prefabricated ditch sections with a length of 1.5m, mortise and tenon joints are set at both ends of the ditch sections, the tenon length is 10cm, the mortise depth is 12cm, and the joints of adjacent ditch sections are filled with water-expanding rubber strips with a thickness of 2cm; the slope control of the ditch bottom adopts an adjustable steel bracket system, the bracket columns are 1m apart, a hydraulic leveling device is set on the top of the column, the leveling accuracy is ±0.5mm, and a laser slope meter is installed on the bracket crossbeam to monitor the elevation of the ditch bottom in real time; the expansion joint construction adopts a three-layer waterproof structure, the first layer is laid with a butyl rubber waterstop with a width of 20cm, and a diameter of 15 is formed in the middle of the waterstop The second layer is poured with hot-melt modified asphalt to 2 / 3 of the seam depth. The third layer is pressed with a closed-cell polyethylene foam rod with a diameter of 8mm using a special caulking gun, and finally the surface is coated with 2mm thick polyurethane sealant; diversion ribs are set every 3m on the inner wall of the intercepting ditch. The rib height is 30cm, the thickness is 10cm, and the inclination angle is 45°. A 5cm diameter drainage hole is opened at the bottom of the rib. A PVC diversion pipe is inserted into the hole. The diversion pipe extends 20cm outside the ditch body; an anti-filtration structure is set at the junction of the ditch body and the roadbed. A 30cm thick gravel layer, a 20cm thick coarse sand layer and a 5cm thick permeable geotextile are laid from the inside to the outside. The permeability coefficient of the geotextile is greater than 1×10 -2 cm / s, gravel particle size 5-10mm, coarse sand particle size 0.5-1mm.

7. The method for constructing high-fill roadbed in seasonal rainfall areas according to claim 1, characterized in that: In the adjustable steel support system, the steel support is composed of an H-shaped steel column, a channel steel beam and a spherical hinged base. A square steel plate base with a side length of 40 cm is welded at the bottom of the column, and M30 anchor bolt holes are set at the four corners of the base; the hydraulic leveling device includes a double-acting hydraulic jack, a laser receiving target and a pressure sensor. The jack piston has a diameter of 80 mm and a stroke of 50 mm. The pressure sensor has a range of 0-10 MPa and an accuracy level of 0.

5. During the leveling operation, a laser transmitter is set up at intervals of 5 m along the longitudinal direction of the ditch. The transmitter wavelength is 635 nm, the output power is 5 mW, and the slope control signal A closed-loop control system is formed by linking the PLC controller with the hydraulic jack. A three-level leveling method is used during bracket installation: first, a coarse adjustment of ±20mm is performed through the anchor bolts, then a fine adjustment of ±5mm is performed through the spherical hinged base, and finally, the hydraulic jack is started to implement a fine adjustment of ±1mm. After leveling, a chloroprene rubber cushion is set between the beam and the prefabricated slot section. The cushion layer has a thickness of 15mm, a hardness of 60 Shore A, and a compression permanent deformation of less than 15%. During the acceptance of the bracket system, a total station is used for three-dimensional coordinate re-measurement, and the plane position deviation is controlled within ±3mm, and the elevation deviation does not exceed ±2mm.