Reinforced earth retaining wall in pluvial area and construction method of reinforced earth retaining wall

Abstract

The invention relates to a rainy region reinforced earth retaining wall and a construction method thereof.The rainy region reinforced earth retaining wall comprises a reinforced earth retaining wall body, a roadbed body, a waterproof and drainage system and a connecting system, the reinforced earth retaining wall body comprises concrete cap stones, a panel and a foundation, the cap stones are arranged on the upper portion of the panel, and the cast-in-place foundation is arranged on the lower portion of the panel; the subgrade body comprises a reinforced wrapping body, subgrade filler which is filled behind a wall in a layered manner, a subgrade bed surface layer and geogrids, the geogrids comprise panel connecting geogrids, wrapping type geogrids and end grouting mortar wrapping type geogrids, and the waterproof and drainage system comprises surface drainage, shallow drainage and internal drainage. The connecting system comprises a vertical connecting steel bar and a transverse connecting ring, and the vertical connecting steel bar downwards penetrates into the foundation from the interior of the face plate. The stability and durability of the reinforced earth retaining wall in a rainy area are improved, rib failure and structural damage caused by filler water accumulation are avoided, and the reinforced earth retaining wall is suitable for construction of highways, railways and other projects.

Description

Technical Field

[0001] The invention belongs to the technical field of reinforced earth retaining walls, and in particular relates to a reinforced earth retaining wall structure in rainy areas and a construction method thereof. Background Art

[0002] Reinforced earth retaining wall is a flexible composite structure widely used in infrastructure construction such as railways and highways. It is usually composed of fillers, reinforcement materials and wall panels. According to the different panel structures, reinforced earth retaining walls can be divided into prefabricated panel reinforced earth retaining walls, gabion reinforced earth retaining walls, modular reinforced earth retaining walls and wrapped reinforced earth retaining walls. The design of traditional reinforced earth retaining walls mainly relies on the anchoring friction generated when the reinforcement is subjected to load to transfer the lateral load force to the panel, thereby maintaining the overall stability of the fill. However, this structural form requires the panel to have high integrity and strength, otherwise it is easy to fail and affect the safety of the project. In recent years, in order to improve the stability of traditional structures, some schemes have adopted wrapped reinforced earth retaining walls, so that the inclusions replace the panels to bear the load, which improves the adaptability, but there are still certain limitations.

[0003] In rainy areas, long-term precipitation can easily lead to poor drainage of fillers. Softening of fillers will reduce the friction between the reinforcement and the soil, affecting the stability of the retaining wall. In addition, the direct contact between the concrete panel and the reinforcement may accelerate the rusting and electro-corrosion of the reinforcement due to rainwater erosion, leading to cracking of the panel and the formation of internal holes, further weakening the durability of the structure. At the same time, although the existing wrapped reinforced earth retaining wall reduces the stress on the panel to a certain extent, the construction process is relatively complicated, and it still faces the problems of reduced strength of the filler after long-term immersion in water and insufficient anchoring force of the reinforcement. Therefore, it is urgent to study a reinforced earth retaining wall structure suitable for rainy areas to improve drainage performance, enhance the tensile strength of the reinforcement, and optimize the connection method between the panel and the reinforcement, so as to improve the stability and durability of the overall structure. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a reinforced earth retaining wall in rainy areas and a construction method thereof, so as to solve the problems of poor drainage of filler, attenuation of tensile strength of reinforcement materials, enhanced contact electrocorrosion between steel bars and connecting reinforcements in the wall surface, etc. of traditional reinforced earth retaining walls in rainy environments. The present invention improves the stability and durability of the retaining wall by optimizing the wall structure, road base body, drainage system and connection method of the reinforced earth retaining wall.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A reinforced earth retaining wall for rainy areas, the reinforced earth retaining wall comprising a reinforced earth retaining wall body, a roadbed body, a drainage system and a connection system, wherein the reinforced earth retaining wall body comprises a concrete capstone (1.1), a panel (1.2) and a foundation (1.3), the upper part of the panel (1.2) is provided with a capstone (1.1) of concrete not less than C30, and the lower part of the panel (1.2) is provided with a cast-in-place foundation (1.3); the roadbed body comprises a reinforced inclusion (2.1), a roadbed filler (2.2) filled in layers behind the wall, an upper subgrade surface layer (2.3) and a geogrid (2.4) laid between the roadbed fillers, the roadbed filler (2.2) adopts a filler with good water permeability, the reinforced inclusion (2.1) adopts a permeable geobag filled with sand and gravel, and the geogrid (2.4) comprises a panel connecting geogrid (2.4. 1), a wrapped geogrid (2.4.2) and an end-injected mortar wrapped geogrid (2.4.3); the drainage system comprises surface drainage (3.1), shallow drainage (3.2) and internal drainage (3.3); the surface drainage (3.1) is sealed with 0.1m thick C30 fiber concrete, the shallow drainage (3.2) is a drain hole arranged on the panel (1.2), and the internal drainage (3.3) comprises a filter drainage pipe (3.3.1) and a drainage mat (3.3.2); the connection system comprises vertical connecting steel bars (4.1) and transverse connecting rings (4.2); the vertical connecting steel bars (4.1) are arranged at intervals inside the panel (1.2), and the vertical connecting steel bars (4.1) pass down into the reinforced concrete foundation (1.3) to achieve the connection between the panel (1.2) and the foundation (1.3).

[0007] Preferably, the panel (1.2) is a 20cm-30cm cast-in-place concrete panel not less than C30, with a slope not steeper than 1:0.05. The lower part of the panel (1.2) is excavated with a foundation pit with a slope not steeper than 1:0.5, and a cast-in-place reinforced concrete foundation (1.3) and a crushed stone cushion layer are used.

[0008] Preferably, the cast-in-place reinforced concrete foundation (1.3) is 1m wide and 0.5m high, the crushed stone cushion layer is 2m wide and 0.5m high, and the slope of the foundation pit excavation line is not steeper than 1:0.5.

[0009] Preferably, the width of the reinforced inclusion (2.1) after filling is not less than 40 cm, the length of the filter layer reinforcement material is not less than 2 m, and the length of the top two layers is not less than 3.0 m. The sand and gravel filled in the geobag are required to be well graded, the content of fine particles with a particle size of less than 0.075 mm is less than 5%, and the permeability coefficient is not less than 10 -3 / cm / s, and the stacking slope of the reinforced inclusion (2.1) is the same as that of the integral cast-in-place panel (1.2).

[0010] Preferably, a waterproof layer is built into the gravel cushion layer for waterproof treatment.

[0011] Preferably, the geogrid (2.4) is a high-density polyethylene uniaxially stretched geogrid, with a layer spacing of not less than 0.3 m, an ultimate tensile strength of not less than 120 kN / m, and an elongation corresponding to the ultimate tensile strength of not more than 11.5%.

[0012] Preferably, the drainage hole has an outward drainage slope of not less than 4%, and a PVC drainage pipe is fixedly installed in the drainage hole, with the rear end located in the built-in drainage channel between the filter layer and the filler, connected by internal and external socket joints, the outer end of the drainage hole extends into the drainage hole by not less than 5 cm, and the inner end is inserted into the filter layer by not less than 10 cm.

[0013] Preferably, a closed-loop structural steel bar ring is arranged in the panel (1.2), extending to the rear side wall of the panel (1.2) to form an exposed end, the exposed end of the steel bar is connected to the galvanized steel bar, and the wrapped geogrid (2.4.2) and the panel connecting geogrid (2.4.1) respectively pass through the reinforced wrapping body (2.1) and the galvanized steel bar, fold back and wrap around the special plastic suture rod again to form a fixed knot.

[0014] Preferably, the end-cast mortar wrapped geogrid (2.4.3) is anchored with mortar through the gap between the rear end of the reinforcement and the soil, and the length of the cast mortar body should be no less than 15 times the diameter of the reinforcement.

[0015] On the other hand, the present invention also discloses a construction method of the reinforced earth retaining wall in rainy areas, comprising the following steps:

[0016] S1, compare and check the on-site construction situation with the design drawings, determine the appropriate construction method, carry out layout positioning, site cleaning, leveling and compaction to ensure that the installation of components and the laying requirements of geogrid 2.4 are met;

[0017] S2, excavate the foundation trench to the designed elevation, leaving a construction distance of no less than 50cm on both sides of the bottom of the foundation trench, determine whether to pile and the type of pile foundation according to the bearing capacity and settlement requirements, lay the crushed stone cushion layer and level and compact it, complete the foundation pouring, and set a closed waterproof layer on the side of the foundation close to the reinforcement structure;

[0018] S3. Perform quality inspection before laying the reinforcement to ensure that the maximum tensile force and the elongation under the maximum tensile force meet the design requirements, ensure that the laying site is flat and dense, use a winch to tension and tighten the bidirectional geogrid 2.4, give full play to the strength characteristics of the material, lay the geogrid 2.4, reserve the required length of the reverse part of the geogrid 2.4, stack the geobags according to the design and tamp them, connect the reverse part of the geogrid 2.4 with the laid geogrid 2.4 with a connecting rod, tighten the connected stress-bearing grid, and fix it with U-shaped nails every 1.5-2.0m;

[0019] S4, fill the soil in layers and compact it by rolling, ensuring that the number of compaction passes meets the requirements; first fill the fill material within 2.0m of the adjacent panel and use a light compaction machine or manual tamping, and then conduct a compaction test after rolling, and then fill the fill material in other areas;

[0020] S5, during the laying process of the geogrid 2.4, the rear part of the geogrid 2.4 is anchored with mortar at intervals, a groove is dug on the rear end soil body where the geogrid 2.4 has been laid, the depth is 0.2-0.3m, and mortar is poured, and after the mortar is fully contacted and anchored with the soil filler, the next layer of filling is filled and compacted;

[0021] S6. When laying the drainage mat, fill in sections. Lay drainage pipes at intervals of 3-5 layers according to the groundwater development and rainfall conditions, ensure that the slope is not less than 2%, and lay drainage mats and connect them to drainage pipes according to the width of the roadbed surface. Connect the drainage pipes and drain pipes with waterproof plugs;

[0022] S7, carry out staggered construction according to the designed height, and repeat steps S3 to S6 until all reinforced fill construction is completed;

[0023] S8, after the deformation of the wrapped reinforcement body is stable, install the drainage hole PVC pipe according to the design requirements, insert the connecting steel bar vertically, cast the reinforced concrete panel as a whole by erecting the formwork, bury the closed-loop structural steel bar ring at the corresponding position, and connect the connecting grid buried in the roadbed filler body with galvanized steel bars;

[0024] S9, during the panel pouring construction, set an expansion joint every 15m~25m, with a width of 2cm~3cm, and fill the joint with asphalt hemp tendons or asphalt wood boards along the inner, outer and top sides of the wall, with a depth of not less than 0.2m, until the panel pouring is completed;

[0025] S10, construct concrete cap stone 1.1 and step concrete sealing layer. After the roadbed is filled, lay a 0.1m thick C30 fiber concrete sealing layer, and then fill the subgrade surface layer 2.3.

[0026] The present invention aims at the applicability problem of reinforced earth retaining walls in rainy areas, optimizes the design of filler drainage, prevents reinforcement failure and improves structural durability, and has the following beneficial effects:

[0027] (1) The present invention improves the drainage capacity of roadbed fillers in rainy environments by improving the drainage system. Fillers with good water permeability are used for layered filling, and combined with the surface drainage of the closed concrete of the base bed surface, the shallow drainage of the drainage holes reserved in the retaining wall panel, and the internal drainage of the filter drainage pipe and the drainage mesh mat, a three-dimensional drainage system is formed. The system can drain rainwater in time and reduce the impact of water accumulation, thereby controlling the impact of complex hydraulic environment on roadbed fillers and reinforcement materials and improving the stability of the retaining wall structure.

[0028] (2) The present invention adopts a structural design in which a reinforced enclosure is connected to a geogrid, so that the enclosure bears the horizontal component of the load, reduces the stress on the panel, and improves the overall safety of the structure. The enclosure acts as a traditional panel, while the real panel only serves as a structural component, avoiding direct load bearing and effectively reducing the risk of panel damage. At the same time, by pouring mortar at the end of the geogrid, the connection between the reinforcement and the soil is strengthened, the anchoring force and friction force are enhanced, the reinforcement can give full play to its tensile strength, and stable mechanical transmission is achieved, thereby improving the overall strength and durability of the reinforced earth retaining wall.

[0029] (3) In order to solve the problem of concrete panel deterioration in rainy environments, the present invention adopts a structural form of a steel ring inside the panel + geogrid buried in the roadbed filler to avoid direct contact between the panel connecting steel bars and the reinforcement inside the panel, and reduce the problem of enhanced electro-corrosion damage to the panel caused by contact between the steel bars and the tension bars inside the panel. This optimized design reduces the impact of rainwater on the durability of the structure, reduces the formation of cracks and holes, effectively improves the erosion resistance and long-term service performance of the reinforced earth retaining wall, and thus enhances the reliability and durability of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The reinforced earth retaining wall structure for rainy areas according to an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the connection between the surface drainage drain hole and the internal drainage reverse filtration drainage pipe according to an embodiment of the present invention;

[0032] Figure 3 It is a front view of a transverse connecting ring according to an embodiment of the present invention;

[0033] Figure 4 A top view of a transverse connecting ring according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the connection between the transverse connecting ring and the geogrid according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the anchoring of the wrapped geogrid end poured with mortar according to an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the segmented filling of the anti-filtration drainage pipe construction according to an embodiment of the present invention.

[0037] Figure numbers: 1.1-capstone; 1.2-panel; 1.3-foundation; 2.1-reinforced inclusion; 2.2-layered roadbed filler behind the wall; 2.3-surface of the base bed; 2.4-geogrid; 2.4.1-panel connection geogrid; 2.4.2-wrapped geogrid; 2.4.3-end-cast mortar wrapped geogrid; 3.1-surface drainage; 3.2-shallow drainage; 3.3-internal drainage; 3.3.1-filter drainage pipe; 3.3.2-drainage mat; 4.1-vertical connecting steel bars; 4.2-horizontal connecting rings. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the present invention.

[0039] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0040] like Figure 1-5As shown, this embodiment discloses a reinforced earth retaining wall for rainy areas, and the reinforced earth retaining wall includes a reinforced earth retaining wall body, a roadbed body, a drainage system and a connection system. The reinforced earth retaining wall body includes a concrete capstone 1.1, a panel 1.2 and a foundation 1.3. The upper part of the panel 1.2 is provided with a capstone 1.1 of not less than C30 concrete. The capstone 1.1 is used to reinforce the top of the panel 1.2, improve the structural stability, and prevent water erosion and the influence of external loads. A cast-in-place foundation 1.3 is provided at the lower part of the panel 1.2. The foundation 1.3 provides support force to ensure the overall stability of the retaining wall and reduce deformation that may be caused by foundation settlement. Panel 1.2 is a 20cm-30cm cast-in-place concrete panel not less than C30, with a slope not steeper than 1:0.05. The lower part of panel 1.2 is excavated with a slope not steeper than 1:0.5, and a reinforced concrete foundation 1.3 with a width of 1m*height of 0.5m and a crushed stone cushion with a width of 2m*height of 0.5m are used. The lower part of the crushed stone cushion can be determined by calculation according to the bearing capacity of the foundation and the settlement requirements, without piling or with cement mixing piles, CFG piles, concrete cast-in-place piles, etc. A waterproof layer is built in on the crushed stone cushion for waterproofing treatment, and finally the foundation pit will be backfilled, and the slope of the foundation pit excavation line is not steeper than 1:0.5.

[0041] The roadbed body 2 includes a reinforced inclusion 2.1, a roadbed filler 2.2 filled in layers behind the wall, an upper base surface layer 2.3 and a geogrid 2.4 laid between the roadbed fillers. The roadbed filler 2.2 uses fillers with good water permeability. Filler 2.2 helps to improve the drainage performance of the filling soil and reduce the softening problem of the filler caused by long-term water accumulation. The reinforced inclusion 2.1 is filled with sand and gravel in permeable geobags. The width after filling is not less than 40cm. The length of the anti-packing and anti-filtering layer reinforcement is not less than 2m and is fixed with special plastic suture rods. The length of the top two layers of anti-packing is not less than 3.0m. The width of the reinforced inclusion is not less than 0.4m. The sand and gravel filled in the geobags are required to be well graded, the content of fine particles with a particle size of less than 0.075mm is less than 5%, and the permeability coefficient is not less than 10 -3 / cm / s, the stacking slope of the reinforced inclusion 2.1 is the same as that of the integral cast-in-place panel 1.2. The reinforced inclusion 2.1 plays the role of drainage and filtration to prevent the loss of filler particles, while ensuring that moisture can be discharged smoothly to avoid the influence of long-term water accumulation on the stability of the reinforcement connection.

[0042] Geogrid 2.4 includes panel-connected geogrid 2.4.1, wrapped geogrid 2.4.2 and end-injected mortar wrapped geogrid 2.4.3. Wrapped geogrid 2.4.2 and end-injected mortar wrapped geogrid 2.4.3 are arranged in layers and intervals in the roadbed filler as structural grids, and use their tensile strength to offset the horizontal component of the load, so that the panel is not subject to the load. Panel-connected geogrid 2.4.1 is only used as a structural structure, thereby reducing the soil pressure acting on panel 1.2, improving the overall stability of the panel, and meeting the requirements for small deformation control of the panel. Geogrid 2.4 can use high-density polyethylene uniaxial tensile geogrid, with a layer spacing of not less than 0.3m, an ultimate tensile strength of not less than 120kN / m, and an elongation corresponding to the ultimate tensile strength of not more than 11.5%. End-cast mortar wrapped geogrid 2.4.3 Mortar anchoring is performed through the interval between the rear end of the reinforcement and the soil. The length of the cast mortar body should be no less than 15 times the diameter of the reinforcement. The specific parameters such as the anchoring length and diameter should be determined by calculation according to the actual engineering requirements in rainy areas. After the geogrid is laid in layers for roadbed filling, a groove is dug at the rear of the reinforcement and cement mortar is poured to make the reinforcement fully contact with the filling soil, thereby improving the friction between the reinforcement and the soil. This can solve the problem of reduced friction between the filling and reinforcement interface in rainy areas, which leads to reduced or failed connection strength between the reinforcement and the soil.

[0043] The drainage system 3 includes surface drainage 3.1, shallow drainage 3.2 and internal drainage 3.3. The surface drainage 3.1 is sealed with 0.1m thick C30 fiber concrete to separate the surface layer of the subgrade from the bottom layer of the subgrade and the roadbed body, which plays a waterproof role in preventing some rainfall infiltration. The shallow drainage 3.2 is a drainage hole set on the panel 1.2. The shallow drainage 3.2 can effectively guide the shallow water on the rear side of the panel 1.2 to drain out, reduce the accumulation of water on the rear side of the panel 1.2, and prevent water pressure from damaging the panel 1.2. The internal drainage 3.3 includes a filter drainage pipe 3.3.1 and a drainage mat 3.3.2. The filter drainage pipe 3.3.1 and the drainage mat 3.3.2 together constitute an internal drainage system, so that deep water can be discharged smoothly through the reinforced inclusion 2.1, avoiding the filler 2.2 from affecting the structural stability due to long-term water accumulation. The drainage hole has an outward drainage slope of not less than 4%. A PVC drainage pipe is fixedly installed in the drainage hole. The rear end is located in the filter layer and connected to the built-in drainage channel of the filler through the inner and outer socket joints. The outer end of the drainage hole extends into the drainage hole by not less than 5 cm, and the inner end is inserted into the filter layer by not less than 10 cm. The water in the shallow part of the filler can be directly discharged through the drainage pipe. The problem of deep drainage of the filler is solved by setting the filter layer drainage pipe 3.3.1 and the drainage mat 3.3.2 to form a deep drainage channel. The rainwater infiltration is absorbed and discharged by the drainage channel set inside the filler. The drainage pipe inside the soil also has an outward drainage slope of not less than 4%. It is set to a 0.2m~0.4m graded crushed stone filter layer, covered with non-woven fabric, and arranged at intervals of about 1.2m~1.5m. If the base bed is the same length as the station roadbed, the drainage mat can be appropriately increased to enhance the water-repellent capacity. The three-dimensional drainage system consisting of surface drainage 3.1, shallow drainage 3.2 and internal drainage 3.3 can solve the problem of difficult drainage of fillers in rainy areas, control the impact of complex hydraulic environment on roadbed fillers and reinforcement materials, and achieve good drainage and filtration requirements.

[0044] The connection system 4 includes vertical connecting steel bars 4.1 and transverse connecting rings 4.2. The vertical connecting steel bars are arranged inside the panel 1.2 and pass through the reinforced concrete foundation 1.3 to realize the connection between the panel 1.2 and the foundation 1.3. The vertical fixation of the connecting steel bars increases the overall stability of the panel and the foundation. The vertical connecting steel bars 4.1 ensure the stable connection between the panel 1.2 and the foundation 1.3, and prevent the panel 1.2 from being displaced due to the load. The transverse connecting rings 4.2 are used to enhance the overall shear resistance of the retaining wall, so that the various components of the retaining wall can be stably connected, and the overall deformation resistance of the structure is improved.

[0045] In order to ensure the connection between the panel 1.2 and the roadbed soil 2, a closed-loop structural steel bar ring is set inside the panel, extending to the rear side wall of the panel to form an exposed end, and the exposed end of the steel bar is connected to the galvanized steel bar. The wrapped geogrid 2.4.2 and the panel connection earth grid 2.4.1 pass through the reinforced wrapping and the galvanized steel bar, respectively, and then fold back and surround the special plastic suture rod again to form a fixed knot. The transverse connection ring avoids direct contact between the panel connection steel bar and the reinforcement material inside the panel, and reduces the problem of increased electro-corrosion damage to the panel caused by the contact between the steel bar and the tension bar inside the panel.

[0046] On the basis of the traditional reinforced earth retaining wall, this structure adopts the form of transverse steel rings inside the panel + geogrids buried in the roadbed filler to avoid direct contact between the panel connecting steel bars and the reinforcement inside the panel, reducing the electro-corrosion effect of the two under long-term immersion in rainy areas. At the same time, by adding surface, shallow and deep three-dimensional drainage systems, water can be quickly discharged from the roadbed body, reducing the impact of water on the reinforced earth retaining wall, and mortar anchors are used at the rear end of the reinforcement to enhance the anchoring force and friction between the reinforcement and the soil, so that the reinforcement maintains and better exerts its own strength, thereby improving the integrity of the reinforced earth retaining wall.

[0047] In another embodiment, a construction method of the reinforced earth retaining wall in rainy areas is disclosed, comprising the following steps:

[0048] S1, compare and check the on-site construction situation with the design drawings, determine the appropriate construction method, carry out layout positioning, site cleaning, leveling and compaction to ensure that the installation of components and the laying requirements of geogrid 2.4 are met;

[0049] S2, excavate the foundation trench to the designed elevation, leaving a construction distance of no less than 50cm on both sides of the bottom of the foundation trench, determine whether to pile and the type of pile foundation according to the bearing capacity and settlement requirements, lay the crushed stone cushion layer and level and compact it, complete the foundation pouring, and set a closed waterproof layer on the side of the foundation close to the reinforcement structure;

[0050] S3, before laying the reinforcement, conduct a quality inspection to ensure that the maximum tensile force and the elongation under the maximum tensile force meet the design requirements, ensure that the laying site is flat and dense, and use a winch to tension and tighten the bidirectional geogrid 2.4 to give full play to the strength characteristics of the material. When laying the geogrid 2.4, reserve the required length of the reverse part of the geogrid 2.4, stack the geobags according to the design and tamp them, connect the reverse part of the geogrid 2.4 with the connecting rod, tighten the connected stress grid, and fix it with U-shaped nails (wire diameter 1cm, single leg length 15cm, inner diameter 5cm) every 1.5-2.0m.

[0051] S4, fill the soil in layers and roll it densely to ensure that the number of compaction times meets the requirements; first fill the filler within 2.0m of the adjacent panel and use light compaction machinery or manual tamping, conduct a compaction test after rolling, and then fill the filler in other areas.

[0052] S5, during the laying process of the geogrid 2.4, the rear part of the geogrid 2.4 is anchored with mortar at intervals, a groove is dug on the rear end soil body where the geogrid 2.4 has been laid, the depth is 0.2-0.3m, and mortar is poured, and after the mortar is fully contacted and anchored with the soil filler, the next layer of filling is filled and compacted;

[0053] S6. When laying the drainage mat, fill in sections. Lay drainage pipes at intervals of 3-5 layers according to the groundwater development and rainfall conditions, ensure that the slope is not less than 2%, and lay drainage mats and connect them to drainage pipes according to the width of the roadbed surface. Connect the drainage pipes and drain pipes with waterproof plugs;

[0054] S7, carry out staggered construction according to the designed height, and repeat steps S3 to S6 until all reinforced fill construction is completed.

[0055] S8. After the deformation of the wrapped reinforced body is stable, install the drainage hole PVC pipe according to the design requirements, insert the connecting steel bars vertically, cast the reinforced concrete panel as a whole in the formwork, bury the closed-loop structural steel bar ring at the corresponding position, and connect the connecting grid buried in the roadbed filler body through galvanized steel bars.

[0056] S9, during the panel pouring construction, set an expansion joint every 15m~25m, with a width of 2cm~3cm, and fill the joint with asphalt hemp tendons or asphalt wood boards along the inner, outer and top sides of the wall, with a depth of not less than 0.2m until the panel pouring is completed.

[0057] S10, construct concrete cap stone 1.1 and step concrete sealing layer. After the roadbed is filled, lay a 0.1m thick C30 fiber concrete sealing layer, and then fill the subgrade surface layer 2.3.

[0058] In summary, the present invention discloses a reinforced earth retaining wall for rainy areas and a construction method thereof. The reinforced earth retaining wall comprises a reinforced earth retaining wall body, a road base body, a drainage system and a connection system. The wall part adopts a structure of a concrete cap stone 1.1, a panel 1.2 and a foundation 1.3, so that the panel 1.2 does not directly bear the load, improves the structural stability, and enhances the overall shear resistance through vertical connection steel bars 4.1 and horizontal connection rings 4.2. The road base body 2 adopts a reinforced wrapping body 2.1 and a layered filling material 2.2 with good water permeability, and combines the layout of a geogrid 2.4 to improve the bonding force and stability between the reinforcement material and the filling material. At the same time, the present invention constructs a three-dimensional drainage system 3, which is composed of a surface drainage 3.1, a shallow drainage 3.2 and an internal drainage 3.3, so that the moisture inside the filling material can be effectively discharged, avoiding the influence of long-term immersion on the reinforcement material and the filling material, thereby ensuring the long-term stability of the retaining wall. The present invention uses the innovative design of the wrapped geogrid 2.4.2 and the end-injected mortar wrapped geogrid 2.4.3 to enable the reinforcement to fully exert its tensile strength, improve the overall bearing capacity of the retaining wall, and avoid direct contact between the panel 1.2 and the reinforcement by pre-embedded steel rings, reduce the impact of water erosion and electrical erosion, and improve the durability of the retaining wall. At the same time, the construction method of the present invention clarifies the key steps of foundation treatment, panel installation, reinforcement laying, filler compaction and drainage system layout, ensuring that the retaining wall can remain stable under complex hydraulic environments, and the construction process is efficient and standardized, suitable for a variety of foundation bearing conditions.

[0059] The technical solution of the present invention overcomes the problems of insufficient drainage capacity, easy failure of reinforcement materials and structural damage caused by uneven stress on panels of traditional reinforced earth retaining walls in rainy environments, ensuring the stability, durability and construction reliability of reinforced earth retaining walls in rainy areas. The implementation of the present invention is of great significance for improving the safety of roads, railways and various infrastructure projects, can effectively adapt to the requirements of complex hydraulic environments, and provides the industry with an efficient, stable and economical reinforced earth retaining wall design solution.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reinforced earth retaining wall for rainy areas, characterized in that: The reinforced earth retaining wall comprises a reinforced earth retaining wall body, a roadbed body, a drainage system and a connection system, wherein the reinforced earth retaining wall body comprises a concrete capstone (1.1), a panel (1.2) and a foundation (1.3), the upper part of the panel (1.2) is provided with a capstone (1.1) of not less than C30 concrete, and the lower part of the panel (1.2) is provided with a cast-in-place foundation (1.3); the roadbed body comprises a reinforced enclosure (2.1), a roadbed filler (2.2) filled in layers behind the wall, an upper base bed surface layer (2.3) and a geogrid (2.4) laid between the roadbed fillers, the roadbed filler (2.2) adopts a filler with good water permeability, the reinforced enclosure (2.1) adopts a permeable geobag filled with sand and gravel, and the geogrid (2.4) comprises a panel connection geogrid (2.4.1), an enclosure type geogrid (2.4.2), a geogrid (2.4.3) and a geogrid (2.4.4) arranged between the roadbed fillers. A geogrid (2.4.2) and an end-injected mortar-wrapped geogrid (2.4.3); the drainage system comprises surface drainage (3.1), shallow drainage (3.2) and internal drainage (3.3); the surface drainage (3.1) is sealed with 0.1 m thick C30 fiber concrete, the shallow drainage (3.2) is a drain hole arranged on the panel (1.2), and the internal drainage (3.3) comprises a filter drainage pipe (3.3.1) and a drainage mat (3.3.2); the connection system comprises vertical connecting steel bars (4.1) and transverse connecting rings (4.2); the vertical connecting steel bars (4.1) are arranged at intervals inside the panel (1.2), and the vertical connecting steel bars (4.1) pass down into the reinforced concrete foundation (1.3) to achieve the connection between the panel (1.2) and the foundation (1.3).

2. The reinforced earth retaining wall according to claim 1, characterized in that: The panel (1.2) is a 20cm-30cm cast-in-place concrete panel not less than C30, with a slope not steeper than 1:0.

05. The lower part of the panel (1.2) is excavated with a foundation pit with a slope not steeper than 1:0.5, and a cast-in-place reinforced concrete foundation (1.3) and a crushed stone cushion layer are used.

3. The reinforced earth retaining wall according to claim 2, characterized in that: The cast-in-place reinforced concrete foundation (1.3) is 1m wide and 0.5m high, the crushed stone cushion is 2m wide and 0.5m high, and the slope of the foundation pit excavation line is not steeper than 1:0.

5.

4. The reinforced earth retaining wall according to claim 3, characterized in that: The reinforced inclusion (2.1) has a width of not less than 40 cm after filling, a length of the filter layer reinforcement material inverted not less than 2 m, and a length of the top two layers inverted not less than 3.0 m. The sand and gravel filled in the geotextile bag is required to be well graded, with a fine particle content of less than 0.075 mm and a permeability coefficient of not less than 10 -3 / cm / s, and the stacking slope of the reinforced inclusion (2.1) is the same as that of the integral cast-in-place panel (1.2).

5. The reinforced earth retaining wall according to claim 4, characterized in that: A water-proof layer is built in the crushed stone cushion layer for water-proof treatment.

6. The reinforced earth retaining wall according to claim 5, characterized in that: The geogrid (2.4) is a high-density polyethylene uniaxially stretched geogrid, with a layer spacing of not less than 0.3 m, an ultimate tensile strength of not less than 120 kN / m, and an elongation corresponding to the ultimate tensile strength of not more than 11.5%.

7. The reinforced earth retaining wall according to claim 6, characterized in that: The drainage hole has an outward drainage slope of not less than 4%, and a PVC drainage pipe is fixedly installed in the drainage hole, with the rear end located in the built-in drainage channel of the filter layer and the filler, connected by internal and external socket joints, the outer end of the drainage hole extends into the drainage hole by not less than 5 cm, and the inner end is inserted into the filter layer by not less than 10 cm.

8. The reinforced earth retaining wall according to claim 7, characterized in that: A closed-loop structural steel bar ring is arranged in the panel (1.2) and extends to the rear side wall of the panel (1.2) to form an exposed end. The exposed end of the steel bar is connected to the galvanized steel bar. The wrapped geogrid (2.4.2) and the panel connecting geogrid (2.4.1) pass through the reinforced wrapping body (2.1) and the galvanized steel bar respectively, fold back and surround the special plastic sewing rod again to form a fixed knot.

9. The reinforced earth retaining wall according to claim 8, wherein: The end-cast mortar body wrapped geogrid (2.4.3) is anchored by mortar between the rear end of the reinforcement and the soil, and the length of the cast mortar body should be no less than 15 times the diameter of the reinforcement.

10. A construction method for a reinforced earth retaining wall in rainy areas according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, compare and check the on-site construction situation with the design drawings, determine the appropriate construction method, carry out layout positioning, site cleaning, leveling and compaction to ensure that the installation of components and the laying requirements of geogrid 2.4 are met; S2, excavate the foundation trench to the designed elevation, leaving a construction distance of no less than 50cm on both sides of the bottom of the foundation trench, determine whether to pile and the type of pile foundation according to the bearing capacity and settlement requirements, lay the crushed stone cushion layer and level and compact it, complete the foundation pouring, and set a closed waterproof layer on the side of the foundation close to the reinforcement structure; S3. Perform quality inspection before laying the reinforcement to ensure that the maximum tensile force and the elongation under the maximum tensile force meet the design requirements, ensure that the laying site is flat and dense, use a winch to tension and tighten the bidirectional geogrid 2.4, give full play to the strength characteristics of the material, lay the geogrid 2.4, reserve the required length of the reverse part of the geogrid 2.4, stack the geobags according to the design and tamp them, connect the reverse part of the geogrid 2.4 with the laid geogrid 2.4 with a connecting rod, tighten the connected stress-bearing grid, and fix it with U-shaped nails every 1.5-2.0m; S4, fill the soil in layers and compact it by rolling, ensuring that the number of compaction passes meets the requirements; first fill the fill material within 2.0m of the adjacent panel and use a light compaction machine or manual tamping, and then conduct a compaction test after rolling, and then fill the fill material in other areas; S5, during the laying process of the geogrid 2.4, the rear part of the geogrid 2.4 is anchored with mortar at intervals, a groove is dug on the rear end soil body where the geogrid 2.4 has been laid, the depth is 0.2-0.3m, and mortar is poured, and after the mortar is fully contacted and anchored with the soil filler, the next layer of filling is filled and compacted; S6. When laying the drainage mat, fill in sections. Lay drainage pipes at intervals of 3-5 layers according to the groundwater development and rainfall conditions, ensure that the slope is not less than 2%, and lay drainage mats and connect them to drainage pipes according to the width of the roadbed surface. Connect the drainage pipes and drain pipes with waterproof plugs; S7, carry out staggered construction according to the designed height, and repeat steps S3 to S6 until all reinforced fill construction is completed; S8, after the deformation of the wrapped reinforcement body is stable, install the drainage hole PVC pipe according to the design requirements, insert the connecting steel bar vertically, cast the reinforced concrete panel as a whole by erecting the formwork, bury the closed-loop structural steel bar ring at the corresponding position, and connect the connecting grid buried in the roadbed filler body with galvanized steel bars; S9, during the panel pouring construction, set an expansion joint every 15m~25m, with a width of 2cm~3cm, and fill the joint with asphalt hemp tendons or asphalt wood boards along the inner, outer and top sides of the wall, with a depth of not less than 0.2m, until the panel pouring is completed; S10, construct concrete cap stone 1.1 and step concrete sealing layer. After the roadbed is filled, lay a 0.1m thick C30 fiber concrete sealing layer, and then fill the subgrade surface layer 2.3.

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