A beach-tideland road structure and its construction method

Abstract

The present invention discloses a coastal beach road structure and its construction method, belonging to the technical field of coastal beach road construction. It includes a sand layer, in which two rows of parallel wooden piles are inserted. The wooden piles on one side are tightly connected to each other. The two rows of parallel wooden piles form road boundary piles. There is a sand blowing and backfilling layer between the road boundary piles formed by parallel arrangement. The filling material of the sand blowing and backfilling layer is wet sand. The present invention uses wet sand as the road backfilling material, which not only fundamentally solves the problem that the roadbed becomes soft when encountering water, improves the bearing capacity of the road foundation, the gabion is filled with stones of comparable particle size, has better corrosion resistance than the traditional steel sheet pile, and the gabion can play a role in resisting sea waves due to its own weight and hardness. The roadbed uses geotextile and HDPE waterproof materials to isolate the sand layer from seawater, prevent the loss of the roadbed sand layer, ensure the integrity of the roadbed materials, and the construction method is simple, the construction period is short, and at the same time, it can meet the requirements for the passage of large materials and construction equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of beach road construction, and particularly relates to a beach road structure and a construction method thereof. Background Art

[0002] Wind power generation has been widely applied at home and abroad due to its advantages such as simple system, low construction difficulty, and short construction period. With the gradual maturity of wind power generation technology, the number of offshore wind farms and coastal wind farms is increasing year by year. Wind farms need to build internal roads for the installation of wind turbines. During the construction of the internal beach sections of coastal wind farms, there will be problems of continuous erosion by sea waves, resulting in increased construction difficulty and extended construction period.

[0003] In geological conditions where the foundation is soft and soaked by water bodies for a long time, such as in the sea, lakes, and rivers, and for engineering projects that need to bear the passage of large-scale mechanical equipment for a long time, in terms of geological conditions, the beach geomorphology is an area of long-term subsidence, so it is conducive to the accumulation of a large amount of substances. Due to the numerous rivers flowing into the sea along the coast, the sediment carried by the rivers accumulates at the estuaries and along the coast, and at the same time, the coast is continuously pushed outward. The material composition of the beach geomorphology is relatively fine and the structure is relatively loose, and it changes greatly under the action of hydrodynamic forces. If no corresponding protection measures are taken for the roadbed, it will be washed and eroded in a short period. And the so-called hydrodynamic forces mainly refer to the tide and waves, among which the influence of the tide is the most important. Therefore, effective road protection measures must be taken against the tide and sea waves during road construction in the beach geomorphology. Summary of the Invention

[0004] In order to overcome the technical problems in the background art, the present invention provides a beach road structure and a construction method thereof. The present invention uses wet sand as the backfill material for the road foundation to make the roadbed more firm. Stone cages are stacked in sequence on both sides of the road to prevent the impact of sea waves. Steel wires are transversely connected between the wooden piles to increase the lateral bearing capacity of the roadbed.

[0005] The technical solution adopted by the present invention to solve its technical problems is:

[0006] A beach road structure includes a sand layer. Two rows of parallel wooden piles are inserted into the sand layer. The wooden piles on one side are closely connected to each other. The two rows of parallel wooden piles form a road boundary pile. A sand backfill layer is provided between the two rows of parallel wooden piles that form the road boundary pile. The backfill material of the sand backfill layer is wet sand.

[0007] Further preferably, the sand-blowing backfill layer comprises a bottom geotextile, a first sand-blowing compaction layer, a middle anti-seepage membrane, a second sand-blowing compaction layer, and a top geotextile, which are arranged in sequence from bottom to top. The edges of the bottom geotextile, the middle anti-seepage membrane, and the top geotextile wrap around a wooden stake forming a road boundary stake and extend into the sand layer outside the road boundary stake.

[0008] Preferably, the middle anti-seepage membrane is made of HDPE plastic. Stone cage nets are provided on both sides above the middle anti-seepage membrane near the wooden stake, and the stone cage nets are filled with stones.

[0009] Preferably, every two adjacent wooden stakes arranged in parallel are horizontally connected at both ends by a steel wire rope passing through the gaps of the stone cage nets at an interval of 2m.

[0010] Preferably, the stone cage net is woven from galvanized steel wires, and the outer surface of the galvanized steel wires is wrapped with a PVC protective layer.

[0011] Preferably, a gravel layer is laid on the top of the sand-blowing backfill layer. The gravel layer comprises a first gravel layer and a second gravel layer. The second gravel layer is located above the first gravel layer. The maximum gravel particle size of the first gravel layer is 37.5mm, and the maximum gravel particle size of the second gravel layer is 25mm. The gravel layer has a slope, and the slope ratio is 1:50.

[0012] The present invention also provides a construction method for a beach road structure, which uses wet sand as the filling material for the sand-blowing backfill layer, and comprises the following steps:

[0013] S1. Road lofting: Ensure a wide field of vision. Professional surveyors use the real-time kinematic (RTK) technology to accurately find the reference points for the construction of wooden stakes.

[0014] S2. Road wooden stake construction: On the premise of accurate road lofting, drive evenly textured wooden stakes on both sides of the road. The wooden stakes on one side are closely connected to ensure that sundries will not be washed into the roadbed during high tide.

[0015] S3. Subgrade surface cleaning: After the construction of wooden stakes is completed, arrange construction workers to clean the sundries washed onto the beach by the tide. The cleaned sundries are uniformly recycled and shall not be discarded randomly.

[0016] S4. Laying the bottom geotextile: After the subgrade cleaning is completed, lay the bottom geotextile on the bottom of the sand layer. Adopt the manual rolling method. The cloth surface should be flat and have appropriate deformation allowance. During the sewing process, continuous sewing should be carried out and the overlapping dimension should not be less than 150mm. Spot sewing is not allowed. During the laying process, the wooden stakes inserted into the sand layer are wrapped together, and the cloth surface outside the wooden stakes is buried in the sand layer for fixation.

[0017] S5. Blowing sand and leveling and compacting the first sand-blowing and compacting layer: On the premise that the bottom geotextile is laid intact without breakage or unsealing, prepare a sand pumping pump and plastic hoses of appropriate length. The initial sand-blowing construction needs to be completed within a short period. Select a sand-blowing pump with a large flow rate and high corrosion resistance. When the sand-blowing reaches the corresponding elevation, use a bulldozer to level and pre-compress. Ensure uniformity during the leveling and pre-compression process. After leveling, use a vibratory roller to compact. The compaction process is static pressure - weak vibration rolling - strong vibration rolling. Use a 15T vibratory roller for static pressure once. After completion, carry out vibration rolling. When rolling, start slowly and then speed up, start with weak vibration and then strong vibration. First, carry out weak vibration rolling once, then carry out strong vibration three times, and finally carry out static pressure once;

[0018] S6. Compaction degree detection of the first sand-blowing and compacting layer: After compaction to the designed elevation, invite a third-party testing agency to conduct compaction degree detection. When the compaction degree ≥ K95 and CBR ≥ 4, the acceptance passes and subsequent construction can be carried out. Otherwise, it is regarded as unqualified and sand-blowing and compaction need to be carried out again;

[0019] S7. Laying the middle anti-seepage membrane: After the first sand-blowing and compacting layer meets the compaction degree requirements, lay the middle anti-seepage membrane on the road surface. The middle anti-seepage membrane is an HDPE plastic anti-seepage film. When laying, completely cover the first sand-blowing and compacting layer and the wooden piles. The lap width of the joints of the middle anti-seepage membrane is not less than 20 cm. During the laying process, wrap the wooden piles inserted into the sand layer together. The anti-seepage membrane outside the wooden piles is buried in the sand layer for fixation;

[0020] S8. Stacking gabion nets and transverse tie bars: The gabion nets are made of galvanized steel wires, and a layer of PVC protective layer is wrapped on the surface of the galvanized steel wires. The gabion nets are purchased in advance according to the stacking length and quantity and organized for construction by construction personnel on site. After filling the stones and covering the gabion nets, the construction personnel need to level the top of the stones before continuing the construction. During the covering process of the gabion nets, first fix them with covering clips, and then tie them at the adjacent joints at both ends. When tying, tie a binding wire every 25 cm at the intersection of the gabion net cover and the net box frame. During the stacking process of the gabion nets, use stainless steel wire ropes to horizontally connect the wooden piles at both ends every 2 m. Tighten and tie the wire ropes firmly. The wire ropes pass through the gaps between the gabion nets;

[0021] S9. Sandblasting and Compaction of the Second Sandblasting Compaction Layer: After the gabion mesh is stacked, start the sandblasting and compaction of the second sandblasting compaction layer. On the premise that the middle anti-seepage membrane is laid intact without breakage or cracks, prepare the sand suction pump and plastic hoses of appropriate length. The initial sandblasting construction needs to be completed in a short period of time. Select a sandblasting pump with a large flow rate and high corrosion resistance. When the sandblasting reaches the corresponding elevation, use a bulldozer to level and pre-compress. Ensure uniformity during the leveling and pre-compression process. After leveling, use a vibratory roller to compact. The compaction process is static pressure - weak vibration rolling - strong vibration rolling. Use a 15T vibratory roller for static pressure once. After completion, carry out vibration rolling. When rolling, start slowly and then speed up, start with weak vibration and then strong vibration. First, carry out weak vibration rolling once, then carry out strong vibration three times, and finally carry out static pressure once;

[0022] S10. Compaction Degree Detection of the Second Sandblasting Compaction Layer: Invite a third-party testing agency to conduct compaction degree detection. When the compaction degree ≥ K95 and CBR ≥ 4, the acceptance is passed and subsequent construction can be carried out. Otherwise, it is regarded as unqualified and sandblasting and compaction need to be carried out again;

[0023] S11. Laying the Top Geotextile: Lay the top geotextile on the second sandblasting compaction layer. Adopt the manual rolling method. The cloth surface should be flat and leave appropriate deformation allowance. During the sewing process, continuous sewing should be carried out and the overlapping size should not be less than 150mm. Spot sewing is not allowed. During the laying process, wrap the wooden stakes inserted into the sand layer. The cloth surface outside the wooden stakes is buried into the sand layer for fixation;

[0024] S12. Gravel Laying, Leveling and Compaction: Lay two layers of gravel, the first gravel layer at the bottom and the second gravel layer on the top. First, lay the first gravel layer and then carry out compaction. After compaction, the thickness of the first gravel layer reaches 15cm. The maximum particle size of the gravel in the first gravel layer is 37.5mm. After passing the corresponding tests, carry out the construction of the second gravel layer. After compaction, the thickness reaches 15cm. The maximum particle size of the gravel in the second gravel layer is 25mm. The slope ratio of the gravel-compacted road surface is 1:50;

[0025] S13. Inspection of Compaction Degree: After the gravel layer is compacted to the design elevation, invite a third-party unit for testing. If the compaction degree of the first gravel layer reaches ≥ K98, CBR ≥ 55 and the thickness reaches 15cm, the test is qualified. If the compaction degree of the second gravel layer reaches ≥ K98, CBR ≥ 100 and the thickness reaches 15cm, the test is qualified, and it meets the traffic conditions.

[0026] Preferably, in step S2, before driving the wooden stakes, use the water jetting method to impact the sand layer at the corresponding wooden stake points with a high-pressure water gun to make it loose, reduce the sinking resistance of the wooden stakes, and then quickly insert the wooden stakes until the depth reaches the requirement. If the sea water level is higher than the wooden stake construction area and the wooden stake points are underwater, the construction personnel should drive a small boat and carry out the wooden stake construction in sequence along a straight line according to the positions and densities of the previously constructed wooden stakes.

[0027] Preferably, in step S8, the gabion net is formed by twisting galvanized steel wires wrapped with PVC, and the length of the double-wire twisted part is not less than 50 mm.

[0028] The beneficial effects of the present invention are as follows:

[0029] 1. The present invention uses wet sand as the road backfill material, which not only fundamentally solves the problem of the roadbed becoming soft when encountering water, improves the bearing capacity of the road foundation, and the gabion net is filled with crushed stones of equivalent particle size, which has better corrosion resistance than traditional steel sheet piles. Moreover, due to its own weight and hardness, the gabion can play a role in resisting sea waves. The roadbed uses geotextiles and HDPE waterproof materials to isolate the sand layer and seawater, prevent the loss of the roadbed sand layer, and ensure the integrity of the roadbed materials.

[0030] 2. During the construction process of this construction method, it is not necessary to frequently maintain the road foundation, and the entire construction process is simple, only requiring a small amount of mechanical equipment, which guarantees the project duration and can also meet the requirements for the passage of large materials and construction equipment. Description of the Drawings

[0031] Figure 1 It is a cross-sectional schematic diagram of a beach road structure of the present invention;

[0032] Figure 2 It is a schematic flow chart of the construction method of a beach road structure of the present invention.

[0033] Components and numbers in the figure:

[0034] 1 - sand layer; 2 - wooden pile; 3 - bottom geotextile; 4 - middle anti-seepage membrane; 5 - top geotextile; 6 - first sand blowing and compaction layer; 7 - second sand blowing and compaction layer; 8 - gabion net; 9 - steel wire rope; 10 - first gravel layer; 11 - second gravel layer. Detailed Embodiments

[0035] The following embodiments are used to illustrate a beach road structure and its construction method of the present invention. The present invention uses wet sand as the road foundation filling material to make the roadbed more firm, stacks gabions on both sides of the road in sequence to prevent the impact of sea waves, and horizontally connects the wooden piles with steel wire ropes to increase the lateral bearing capacity of the roadbed.

[0036] As Figure 1 shown, the present invention provides a beach road structure, including a sand layer 1, two rows of parallel wooden piles 2 are inserted on the sand layer 1, the wooden piles 2 on one side are closely connected, the two rows of parallel wooden piles 2 form a road boundary stake, and there is a sand blowing backfill layer between the two rows of parallel wooden piles 2 that form the road boundary stake, and the filling material of the sand blowing backfill layer is wet sand.

[0037] The wooden piles 2 arranged in parallel are in the direction of road extension. The wooden piles 2 arranged in parallel form the road boundary piles. The roadbed is between the wooden piles 2. The wooden piles 2 are closely connected so that sundries will not be washed into the roadbed during high tide. The roadbed is composed of a sand blowing backfill layer formed by backfilling wet sand. The wet sand fundamentally solves the problem that the roadbed becomes soft when encountering water, and improves the bearing capacity of the road foundation.

[0038] Specifically, the sand blowing backfill layer includes a bottom geotextile 3, a first sand blowing compaction layer 6, a middle anti-seepage membrane 4, a second sand blowing compaction layer 7, and a top geotextile 5 arranged in sequence from bottom to top. The edges of the bottom geotextile 3, the middle anti-seepage membrane 4, and the top geotextile 5 wrap around the wooden piles 2 that form the road boundary piles and extend into the sand layer 1 outside the road boundary piles.

[0039] The sand blowing backfill layer is divided into a first sand blowing compaction layer 6 and a second sand blowing compaction layer 7, which are separated by the middle anti-seepage membrane 4. The two layers are respectively sand blown and compacted, making the bearing capacity of the roadbed higher. The bottom geotextile 3 is laid on the roadbed, and the top geotextile 5 is laid on the second sand blowing compaction layer 7. The bottom geotextile 3, the middle anti-seepage membrane 4, and the top geotextile 5 wrap around and cover the wooden piles 2 on both sides, and the extended parts are buried along the wooden piles 2 into the sand layer 1 for fixation to prevent being carried away by the sea waves. The geotextile is composed of synthetic fibers and is a kind of permeable material, which plays a role in filtering and draining in the roadbed and protects the road foundation sand; the middle anti-seepage membrane 4 is made of HDPE plastic material, and its main component is high-density polyethylene. In addition to having the same effects as the geotextile, it mainly plays a role in preventing water seepage and permeation. On the other hand, it has excellent organic chemical stability, excellent anti-aging, anti-ultraviolet, and anti-decomposition abilities, and the material has a long service life.

[0040] Specifically, the middle anti-seepage membrane 4 is made of HDPE plastic, and wire cages 8 are provided on both sides of its upper part close to the wooden piles 2, and the wire cages 8 are filled with stones.

[0041] The wire cages 8 filled with stones are part of the road foundation. Horizontally, they can be used to resist the impact of sea waves, and vertically, they can bear the road surface pressure. Moreover, the wire cages 8 are simple to manufacture, low in cost, convenient for transportation, and simple in construction. Only need to transport the net to the construction site and assemble it into a cage-like structure according to the site conditions.

[0042] Specifically, every 2 m of the wooden piles 2 arranged in parallel are horizontally connected at both ends by a steel wire rope 9 passing through the gaps of the wire cages 8.

[0043] To increase the lateral bearing capacity of the roadbed, the horizontal steel wire rope 9 will pass through the middle anti-seepage membrane 4 and the bottom geotextile 3. Since the geotextile and the anti-seepage membrane have good ductility, they will not be broken, but only local holes will exist. And the middle anti-seepage membrane 4 is outside the wire cage 8. During sand blowing backfill, the wet sand sinks to the bottom of the roadbed and between the wire cages 8 on both sides. Therefore, the holes in the anti-seepage membrane caused by the steel wire rope 9 can be ignored.

[0044] Specifically, the gabion mesh 8 is woven from galvanized steel wires, and the outer surface of the galvanized steel wires is wrapped with a PVC protective layer.

[0045] Specifically, a gravel layer is laid on the top of the sand backfill layer. The gravel layer includes a first gravel layer 10 and a second gravel layer 11. The second gravel layer 11 is located above the first gravel layer 10. The maximum gravel particle size of the first gravel layer 10 is 37.5 mm, and the maximum gravel particle size of the second gravel layer 11 is 25 mm. The gravel layer has a slope with a slope ratio of 1:50 to ensure good road drainage performance.

[0046] As Figure 2 shown, the present invention also provides a construction method for a beach road structure, which uses wet sand as the filling material for the sand backfill layer, and includes the following steps:

[0047] S1. Road layout: Ensure a wide field of vision. Professional surveyors use real-time kinematic (RTK) technology to accurately find the reference points for the construction of the wooden piles 2.

[0048] S2. Construction of road wooden piles 2: On the premise of accurate road layout, drive uniformly textured wooden piles 2 on both sides of the road. The wooden piles 2 on one side are closely connected to ensure that sundries will not be washed into the roadbed during high tide.

[0049] Specifically, on the premise of accurate road layout, drive two rows of uniformly textured wooden piles 2 with a diameter of 120 mm on both sides of the road. The depth of the wooden piles 2 buried in the soil is about 4.5 m. The wooden piles 2 on one side of the road are closely connected to ensure that sundries will not be washed into the roadbed during high tide. The length, diameter, and buried depth of the wooden piles 2 are adjusted according to the actual site conditions.

[0050] S3. Cleaning of the roadbed surface: After the construction of the wooden piles 2 is completed, arrange construction workers to clean the sundries washed onto the beach by the tide. The cleaned sundries are uniformly recycled and shall not be discarded randomly.

[0051] S4. Laying the bottom geotextile 3: After the roadbed cleaning is completed, lay the bottom geotextile 3 at the bottom of the sand layer 1. Use the manual rolling method. The cloth surface should be flat and have appropriate deformation allowance. During the sewing process, continuous sewing should be carried out and the overlapping size should not be less than 150 mm. Spot sewing is not allowed. During the laying process, the wooden piles 2 inserted into the sand layer 1 are wrapped together, and the cloth surface outside the wooden piles 2 is buried in the sand layer 1 for fixation.

[0052] Specifically, after the geotextile is purchased by the subcontractor, it should be first taken to the laboratory of a third-party testing agency for testing. Only after it is confirmed that the breaking strength of the geotextile reaches 12 KN / m and the data such as thickness and width meet the standards and are approved by the supervisor can it be used.

[0053] S5. Blowing sand and compaction of the first layer 6: On the premise that the bottom geotextile 3 is laid intact without breakage or slit, prepare a sand pumping pump and a plastic hose of appropriate length. The initial blowing sand construction needs to be completed in a short period of time. Select a sand pumping pump with a large flow rate and high corrosion resistance. When the blowing sand reaches the corresponding elevation, use a bulldozer to level and pre-compress. Ensure uniformity during the leveling and pre-compression process. After leveling, use a vibratory roller to compact. The compaction process is static pressure - weak vibration rolling - strong vibration rolling. Use a 15T vibratory roller for static pressure once. After completion, carry out vibration rolling. When rolling, start slowly and then speed up, start with weak vibration and then strong vibration. First, carry out weak vibration rolling once, then carry out strong vibration three times, and finally carry out static pressure once.

[0054] Specifically, for blowing sand, it is generally required that the content of particles with a particle size above 0.05mm in the blown filling material should exceed 50%, and the content of particles with a particle size less than 0.005mm should be less than 15%. The maximum speed of the roller is 3km / h. Start and stop evenly, and do not start suddenly, stop abruptly, or turn around midway. During normal rolling, the wheel tracks overlap by 1 / 3 of the wheel.

[0055] S6. Compaction degree detection of the first layer 6 of blowing sand and compaction: After compaction to the designed elevation, invite a third-party testing agency to conduct compaction degree detection. When the compaction degree ≥ K95 and CBR ≥ 4, the acceptance is passed and subsequent construction can be carried out. Otherwise, it is regarded as unqualified and blowing sand and compaction need to be carried out again.

[0056] Specifically, during the compaction process, sprinkle an appropriate amount of water to increase the compaction degree.

[0057] S7. Laying the middle anti-seepage membrane 4: After the first layer 6 of blowing sand and compaction meets the compaction degree requirements, lay the middle anti-seepage membrane 4 on the road surface. The middle anti-seepage membrane 4 is an HDPE plastic anti-seepage film. When laying, completely cover the first layer 6 of blowing sand and compaction and the wooden piles 2. The lap width of the joints of the middle anti-seepage membrane 4 is not less than 20cm. During the laying process, wrap the wooden piles 2 inserted into the sand layer 1 together. The anti-seepage membrane outside the wooden piles 2 is buried into the sand layer 1 for fixation.

[0058] Specifically, the middle anti-seepage membrane 4 further strengthens the waterproof property of the roadbed. When laying, completely cover the sand and the wooden piles 2 to avoid artificial wrinkles. When the temperature is relatively low, try to lay it flat and tighten it. Outside the wooden piles 2, the plastic film should be wrapped vertically along the wooden piles 2 and buried into the sand layer 1 for fixation.

[0059] S8. Stacked gabion mesh 8 and transverse tie bars: The gabion mesh is woven from galvanized steel wire, and the surface of the galvanized steel wire is wrapped with a layer of PVC protective layer. The gabion mesh 8 is purchased in advance according to the stacking length and quantity and transported to the site, and then construction workers are organized to weave it on site. After the gabion mesh 8 is filled with stones and covered, the construction workers need to level the top of the stones before continuing the construction. During the covering process of the gabion mesh 8, first fix it with a covering clip, and then tie it at the adjacent knots at both ends. When tying, tie a binding wire every 25 cm at the intersection of the gabion mesh 8 cover and the cage frame. During the stacking process of the gabion mesh 8, use stainless steel wire ropes 9 to horizontally connect the two end wooden piles 2 every 2 m. Tighten and tie the wire ropes 9 firmly, and the wire ropes 9 pass through the gaps between the gabion meshes 8.

[0060] Specifically, due to the location in the beach-tidal flat area, the galvanized steel wire has a diameter of 4 mm and is wrapped with a layer of PVC protective layer on the surface. The gabion mesh 8 is purchased in advance according to the stacking length and quantity. After being transported to the site, construction workers are organized to weave it into gabion mesh boxes of 2 m × 1 m × 1 m on site. The stones filled should not be stones with sharp corners or thin edges to prevent wearing the gabion mesh 8 itself. The stones themselves should be solid, not easily broken, and not easily weathered.

[0061] S9. Sand blowing and compaction of the second sand blowing and compaction layer 7: After the stacking of the gabion mesh 8 is completed, start the sand blowing and compaction of the second sand blowing and compaction layer 7. On the premise that the middle anti-seepage membrane 4 is laid intact without breakage or cracks, prepare a sand pumping pump and a plastic hose of appropriate length. The early sand blowing construction needs to be completed in a short period of time. Select a sand pumping pump with a large flow rate and high corrosion resistance. When the sand blowing reaches the corresponding elevation, use a bulldozer to level and pre-compress. Ensure uniformity during the leveling and pre-compression process. After leveling, use a vibratory roller for compaction. The compaction process is static pressure - weak vibration rolling - strong vibration rolling. Use a 15T vibratory roller for static pressure once. After completion, carry out vibration rolling. When rolling, start slowly and then speed up, start with weak vibration and then strong vibration. First, carry out weak vibration rolling once, then carry out strong vibration three times, and finally carry out static pressure once.

[0062] The detailed construction process and requirements of the second sand blowing and compaction layer 7 are the same as those of the first sand blowing and compaction layer 6, and will not be elaborated here.

[0063] S10. Compaction degree detection of the second sand blowing and compaction layer 7: Invite a third-party testing agency to conduct compaction degree detection. When the compaction degree ≥ K95 and CBR ≥ 4, the acceptance is passed and subsequent construction can be carried out; otherwise, it is regarded as unqualified and sand blowing and compaction need to be carried out again.

[0064] S11. Laying the top geotextile 5: Lay the top geotextile 5 on the second sand blowing and compaction layer 7. Use the manual rolling method. The cloth surface should be flat and have an appropriate deformation allowance. During the stitching process, continuous stitching should be carried out and the overlapping dimension should not be less than 150 mm. Spot stitching is not allowed. During the laying process, the wooden stakes 2 inserted into the sand layer 1 should be wrapped together. The cloth surface outside the wooden stakes 2 should be buried in the sand layer 1 for fixation.

[0065] The specific operations and precautions are the same as those of the bottom geotextile 3, and will not be elaborated here.

[0066] S12. Laying, leveling and compacting the gravel: Lay two layers of gravel, the first gravel layer 10 at the bottom and the second gravel layer 11 at the top. First lay the first gravel layer 10 and then compact it. After compaction, the thickness of the first gravel layer 10 reaches 15 cm. The maximum particle size of the gravel in the first gravel layer 10 is 37.5 mm. After passing the corresponding tests, carry out the construction of the second gravel layer 11. After compaction, the thickness reaches 15 cm. The maximum particle size of the gravel in the second gravel layer 11 is 25 mm. The road surface slope ratio of the compacted gravel on the road surface is 1:50.

[0067] S13. Inspecting the compaction degree: After the gravel layer is compacted to the design elevation, conduct third-party unit inspections. If the compaction degree of the first gravel layer 10 reaches ≥K98, CBR≥55 and the thickness reaches 15 cm, the inspection is qualified. If the compaction degree of the second gravel layer 11 reaches ≥K98, CBR≥100 and the thickness reaches 15 cm, the inspection is qualified and it meets the traffic conditions.

[0068] In another embodiment, the above construction method further includes:

[0069] In step S2, before driving the wooden stakes 2, use the water jetting method to impact the sand layer 1 at the corresponding positions of the wooden stakes 2 with a high-pressure water gun to make it loose, reduce the sinking resistance of the wooden stakes 2, and then quickly insert the wooden stakes 2 until the depth reaches the requirement. If the sea water level is higher than the construction area of the wooden stakes 2 and the positions of the wooden stakes 2 are underwater, the construction personnel should drive a small boat and carry out the construction of the wooden stakes 2 in sequence along a straight line according to the positions and densities of the previously constructed wooden stakes 2.

[0070] In another embodiment, the above construction method further includes:

[0071] In step S8, the gabion mesh 8 is completed by twisting the galvanized steel wires wrapped with PVC. The length of the double-wire twisted part is not less than 50 mm.

[0072] Specifically, the gabion mesh 8 is completed by twisting the galvanized steel wires wrapped with PVC. The anti-corrosion layer of the wires in the double-wire twisted part will not be damaged. The twisted wires have mesh openings, and the minimum diameter of the stones should be greater than the maximum size of the mesh openings.

[0073] Materials and equipment used:

[0074] The model and quantity of materials and equipment should be determined according to the actual construction volume on site (see Table 1 below for equipment names)

[0075] Table 1

[0076]

[0077]

[0078] Quality Control:

[0079] Quality Management Procedures

[0080] After each process is completed, self-inspection must be completed first, and self-inspection materials must be prepared. The project department will be notified for re-inspection, and finally the supervision engineer will accept and approve it. Only after signing and approval can the next process be entered. When a third-party testing unit intervenes, the corresponding construction can only be carried out after the third-party test report comes out and is reviewed and approved by the supervision unit.

[0081] Quality Assurance System

[0082] This section of mudflat road is the only access road for on-site construction and is the only way for large-scale machinery and equipment to enter the site for subsequent construction. Its quality issues are directly related to the progress of subsequent construction. During the construction process, inspection and acceptance should be strictly carried out in accordance with quality requirements. In order to complete the construction tasks with quality and quantity, our department has established a quality management system network. The lower level in the network system must be responsible to the upper level. If a construction quality accident occurs, our department will investigate the accident. After obtaining the investigation results, we will punish the relevant personnel in accordance with the project management system to ensure the quality of the project.

[0083] Project safety measures

[0084] 1. Implement comprehensive quality management, clarify the job functions of quality inspectors at all levels, strengthen internal quality inspection work, strictly control construction technology and materials, and strive for pre-control.

[0085] 2. According to the overall plan, project volume and construction period requirements, arrange the delivery of materials reasonably.

[0086] Construction survey plane control

[0087] Before construction, the measurement control points provided by the owner are re-measured. According to the coordinate points and level point elevations, a site control network is established, and a special area is set up to control the measurement elevation. After the control network is established, the construction site is marked. According to the leveling points and construction accuracy requirements provided by the owner, several water level monitoring points can be set up in the site during high tide. The elevation of the wooden piles is fixed, and the changes in the sea tide water level can be checked at any time according to the height of the wooden piles exposed above the water surface.

[0088] Road construction quality control (see Table 2 below)

[0089] Table 2 Quality Inspection Standards

[0090]

[0091] In summary, the present invention uses wet sand as the road backfill material, which not only fundamentally solves the problem of the roadbed softening when encountering water, improves the bearing capacity of the road foundation, fills the gabion with crushed stones of appropriate particle size, has better corrosion resistance than the traditional steel sheet pile, and because of its own weight and hardness, the gabion can play a role in resisting sea waves. The geotextile and HDPE waterproof material are used in the roadbed to isolate the sand layer and seawater, prevent the loss of the roadbed sand layer, and ensure the integrity of the roadbed material.

[0092] During the construction process of this construction method, it is not necessary to frequently maintain the road foundation, and the entire construction process is simple, only requiring a small amount of mechanical equipment, which guarantees the project duration and can also meet the requirements for the passage of large materials and construction equipment.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A beachfront road structure, comprising a sand layer (1), characterized in that: Two rows of parallel wooden piles (2) are inserted into the sand layer (1). The wooden piles (2) on one side are closely connected to each other. The two rows of parallel wooden piles (2) form road boundary stakes. A sand filling layer is arranged between the road boundary stakes. The filling material of the sand filling layer is wet sand. The sand filling layer includes a bottom geotextile (3), a first sand compaction layer (6), a middle anti-seepage membrane (4), a second sand compaction layer (7), and a top geotextile (5) arranged in sequence from bottom to top. The edges of the bottom geotextile (3), the middle anti-seepage membrane (4), and the top geotextile (5) wrap the wooden piles (2) forming the road boundary stakes and extend into the sand layer (1) outside the road boundary stakes.

2. The beach-tideland road structure according to claim 1, wherein: The middle anti-seepage membrane (4) is made of HDPE plastic. Wire cages (8) are arranged on both sides above it near the wooden piles (2). The wire cages (8) are filled with stones.

3. The beach-tidal-flat road structure according to claim 2, characterized in that: For the parallel wooden piles (2), every 2 m, the two end wooden piles (2) are transversely connected by a steel wire rope (9) passing through the gaps of the wire cages (8).

4. The beach road structure according to claim 3, characterized in that: The wire cage (8) is woven from galvanized steel wires, and the outer surface of the galvanized steel wires is wrapped with a PVC protective layer.

5. A beach road structure according to claim 4, characterized in that: A gravel layer is paved on the top of the sand filling layer. The gravel layer includes a first gravel layer (10) and a second gravel layer (11). The second gravel layer (11) is located above the first gravel layer (10). The maximum gravel particle size of the first gravel layer (10) is 37.5 mm, and the maximum gravel particle size of the second gravel layer (11) is 25 mm. The gravel layer has a slope, and the slope ratio is 1:

50.

6. The construction method of a beach road structure according to claim 5, characterized in that: Using wet sand as the filling material for the sand filling layer includes the following steps: S1. Road layout: Ensure a wide field of vision. Professional surveyors use real-time kinematic carrier phase differential technology to accurately find the reference points for the construction of the wooden piles (2). S2. Construction of road wooden piles (2): On the premise of accurate road layout, drive evenly textured wooden piles (2) on both sides of the road. The wooden piles (2) on one side are closely connected to each other to ensure that sundries will not be washed into the roadbed during high tide. S3. Cleaning of the roadbed surface: After the construction of the wooden piles (2) is completed, arrange construction personnel to clean the sundries washed onto the beach by the tide. The cleaned sundries are uniformly recycled and not discarded randomly. S4. Laying the bottom geotextile (3): After the roadbed is cleaned, lay the bottom geotextile (3) at the bottom of the sand layer (1). Use the manual rolling method. The cloth surface should be flat and have appropriate deformation allowance. During the sewing process, continuous sewing should be carried out and the overlapping dimension should not be less than 150 mm. Spot sewing is not allowed. During the laying process, the wooden piles (2) inserted into the sand layer (1) are also wrapped, and the cloth surface outside the wooden piles (2) is buried in the sand layer (1) for fixation. S5. Blowing sand and compaction of the first sand-blowing compaction layer (6): On the premise that the bottom geotextile (3) is laid intact without breakage or unsealing, prepare a sand pumping pump and a plastic hose of appropriate length. The initial sand-blowing construction needs to be completed within a short period of time. Select a sand-blowing pump with a large flow rate and high corrosion resistance. When the sand-blowing reaches the corresponding elevation, use a bulldozer to level and pre-compress. Ensure uniformity during the leveling and pre-compression process. After leveling, use a vibratory roller for compaction. The compaction process is static pressure - weak vibration rolling - strong vibration rolling. Use a 15T vibratory roller for static pressure once. After completion, carry out vibration rolling. When rolling, start slowly and then speed up, start with weak vibration and then strong vibration. Conduct weak vibration rolling once, then conduct strong vibration three times, and finally conduct static pressure once; S6. Compaction degree detection of the first sand-blowing compaction layer (6): After compaction to the designed elevation, invite a third-party testing agency to conduct compaction degree detection. When the compaction degree ≥ K95 and CBR ≥ 4, the acceptance is passed and subsequent construction can be carried out. Otherwise, it is regarded as unqualified and sand-blowing compaction needs to be carried out again; S7. Laying the middle anti-seepage membrane (4): After the first sand-blowing compaction layer (6) meets the compaction degree requirements, lay the middle anti-seepage membrane (4) on the road surface. The middle anti-seepage membrane (4) is an HDPE plastic anti-seepage film. When laying, completely cover the first sand-blowing compaction layer (6) and the wooden piles (2). The lap width of the joints of the middle anti-seepage membrane (4) is not less than 20 cm. During the laying process, wrap the wooden piles (2) inserted into the sand layer (1) together. The anti-seepage membrane outside the wooden piles (2) is buried into the sand layer (1) for fixation; S8. Stacking gabion nets (8) and transverse tie bars: The gabion nets are made of galvanized steel wires, and a layer of PVC protective layer is wrapped on the surface of the galvanized steel wires. The gabion nets (8) are purchased in advance according to the stacking length and quantity and then organized for construction on-site by construction personnel. After filling the stones, after covering the gabion nets (8), the construction personnel need to level the top of the stones before continuing the construction. During the covering process of the gabion nets (8), first fix them with covering clips, and then tie them at the adjacent joints at both ends. When tying, tie a binding wire every 25 cm at the intersection of the covering of the gabion nets (8) and the net box frame. During the stacking process of the gabion nets (8), use stainless steel steel wires (9) to horizontally connect the two ends of the wooden piles (2) every 2 m. Tighten and tie the steel wires (9) firmly. The steel wires (9) pass through the gaps between the gabion nets (8); S9. Sandblasting and Compaction of the Second Sandblasting Compaction Layer (7): After the gabion mesh (8) is stacked, start the sandblasting and compaction of the second sandblasting compaction layer (7). On the premise that the middle anti-seepage membrane (4) is laid intact without breakage or cracks, prepare a sand pumping pump and a plastic hose of appropriate length. The initial sandblasting construction needs to be completed in a short period of time. Select a sandblasting pump with a large flow rate and high corrosion resistance. When the sandblasting reaches the corresponding elevation, use a bulldozer to level and pre-compress. Ensure uniformity during the leveling and pre-compression process. After leveling, use a vibratory roller for compaction. The compaction process is static pressure - weak vibration rolling - strong vibration rolling. Use a 15T vibratory roller for static pressure once. After completion, perform vibration rolling. When rolling, start slowly and then speed up, start with weak vibration and then strong vibration. Perform weak vibration rolling once, then perform strong vibration three times, and finally perform static pressure once; S10. Compaction Degree Detection of the Second Sandblasting Compaction Layer (7): Invite a third-party testing agency to conduct compaction degree detection. When the compaction degree ≥ K95 and CBR ≥ 4, the acceptance is passed and subsequent construction can be carried out. Otherwise, it is regarded as unqualified and sandblasting and compaction need to be carried out again; S11. Laying the Top Geotextile (5): Lay the top geotextile (5) on the second sandblasting compaction layer (7). Adopt the manual rolling laying method. The surface of the cloth should be flat and leave an appropriate deformation margin. During the sewing process, continuous sewing should be carried out and the overlapping size should not be less than 150mm. Spot sewing is not allowed. During the laying process, wrap the wooden stakes (2) inserted into the sand layer (1) together. The cloth surface outside the wooden stakes (2) is buried in the sand layer (1) for fixation; S12. Laying, Leveling and Compacting Gravel: Lay two layers of gravel, the first gravel layer (10) below and the second gravel layer (11) above. First lay the first gravel layer (10) and then compact it. After compaction, the thickness of the first gravel layer (10) reaches 15cm. The maximum particle size of the gravel in the first gravel layer (10) is 37.5mm. After passing the corresponding tests, carry out the construction of the second gravel layer (11). After compaction, the thickness reaches 15cm. The maximum particle size of the gravel in the second gravel layer (11) is 25mm. The slope ratio of the road surface gravel-compacted road surface is 1:50; S13. Inspection of Compaction Degree: After the gravel layer is compacted to the design elevation, conduct third-party unit testing. If the compaction degree of the first gravel layer (10) reaches ≥ K98, CBR ≥ 55 and the thickness reaches 15cm, the test is qualified. If the compaction degree of the second gravel layer (11) reaches ≥ K98, CBR ≥ 100 and the thickness reaches 15cm, the test is qualified, and it meets the traffic conditions.

7. The construction method of a beach-tideland road structure according to claim 6, characterized in that: In step S2, before driving the wooden stakes (2) in, use the water jet method to impact the sand layer (1) at the corresponding positions of the wooden stakes (2) with a high-pressure water gun to make it loose, reducing the sinking resistance of the wooden stakes (2). Then quickly insert the wooden stakes (2) until the depth reaches the requirement. If the sea water level is higher than the construction area of the wooden stakes (2) and the positions of the wooden stakes (2) are underwater, the construction personnel should drive a small boat and sequentially carry out the construction of the wooden stakes (2) along a straight line according to the positions and densities of the previously constructed wooden stakes (2).

8. The construction method of a beach-tideland road structure according to claim 6, characterized in that: In the step S8, the gabion mesh (8) is formed by twisting galvanized steel wires wrapped with PVC, and the length of the double-wire twisting part is not less than 50 mm.

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