Retaining wall inverted filter structure and construction method thereof

Abstract

The invention provides a retaining wall inverted filter structure and a construction method thereof, and belongs to the field of building construction. According to the technical scheme, the retaining wall comprises a retaining wall body, an inverted filter body, a drainage pipeline, aerated water-permeable concrete blocks, backfill soil, an intercepting ditch and a drainage ditch, the inverted filter body is arranged on the retaining side of the retaining wall body, a plurality of water seepage pipes are arranged in the inverted filter body, and the aerated water-permeable concrete blocks are arranged on the outer side of the inverted filter body; backfill soil is arranged on the outer sides of the aerated water-permeable concrete blocks, and the lower ends of the water seepage pipes communicate with a drainage pipeline of the retaining wall body. The retaining wall has the beneficial effects that the inverted filter layer is arranged on the soil retaining side of the retaining wall body, and inverted filter drainage is achieved through the anti-crack leveling, waterproof material and polyurethane mortar interface in combination with the inner geotechnical cloth filter layer, the outer geotechnical cloth filter layer and the three-dimensional drainage pad; rainwater is guided and drained through the intercepting ditch, the water seepage pipe, the drainage pipeline and the drainage ditch, high-pressure cleaning of the detachable filter screen and a water level alarm are matched, and drainage and maintainability are improved.

Description

Technical Field

[0001] This invention relates to the field of building construction, and in particular to a retaining wall filter layer structure and its construction method. Background Technology

[0002] In retaining wall projects, the backfill soil behind the wall is easily affected by rainfall, surface runoff and seepage, which can lead to water accumulation and seepage pressure behind the wall. This results in an increase in the moisture content of the soil behind the wall, a decrease in shear strength, and the wall is subjected to more unfavorable combined water and soil pressure. In order to reduce the water pressure behind the wall and inhibit the migration of fine particles, filter layers and drainage facilities are commonly installed in the project, such as geotextiles, graded crushed stone filter layers, and drainage holes.

[0003] However, existing retaining wall reverse-filtration drainage systems still have several shortcomings in long-term service: on the one hand, traditional reverse-filtration materials and drainage channels are prone to clogging under conditions of backfill compaction, particle migration, and silt intrusion, resulting in a decrease in drainage capacity over time; on the other hand, unevenness, cracks, and seepage points in the back wall base may cause water concentration, local peeling, or damage at the interface between the reverse-filtration layer and the wall, thereby weakening the reverse-filtration and seepage prevention effects; in addition, if surface runoff is not effectively intercepted and discharged at the top of the wall, rainwater can directly enter the backfill soil behind the wall, causing fluctuations in moisture content and further exacerbating the drainage burden and safety risks. Therefore, it is necessary to provide a retaining wall reverse-filtration layer structure and its construction method that can take into account the back wall interface treatment, reverse-filtration drainage channel construction, and runoff interception and discharge organization at the top of the wall. Summary of the Invention

[0004] The purpose of this invention is to provide a retaining wall filter layer structure and construction method that improves drainage and maintainability by setting a filter layer on the retaining side of the main body of the retaining wall, using crack-resistant leveling, waterproof materials and polyurethane mortar interface, combined with inner and outer geotextile filter layers and three-dimensional drainage pad; and using intercepting ditch-seepage pipe-drainage pipe-drainage ditch to guide rainwater, combined with detachable filter screen high-pressure cleaning and water level alarm.

[0005] This invention is achieved through the following measures: A retaining wall filter layer structure and its construction method are characterized in that it includes a retaining wall body, a filter layer body, a drainage pipe, aerated permeable concrete blocks, backfill soil, intercepting ditch and drainage ditch. The retaining wall has a filter layer on the retaining side, and the filter layer has several drainage pipes inside. The filter layer has aerated permeable concrete blocks on the outside, and backfill soil is placed on the outside of the aerated permeable concrete blocks. The main body of the filter layer includes, in sequence, a crack-resistant cement mortar leveling layer, a cement-based penetrating crystalline waterproofing material, polyurethane mortar, an inner geotextile filter layer, a three-dimensional drainage pad, and an outer geotextile filter layer, all arranged on the retaining side base of the retaining wall. Several vertically arranged seepage pipes are installed between the three-dimensional drainage pad and the inner geotextile filter layer. The upper ends of the seepage pipes are connected to the intercepting ditch, and the lower ends are connected to the drainage pipes of the retaining wall. A water interception ditch is provided on one side of the top of the main body of the retaining wall, and a drainage ditch is provided on one side of the corner of the main body of the retaining wall. The drainage ditch is used to collect rainwater discharged from the drainage hole.

[0006] The invention also has the following specific features: The sidewalls of the seepage pipes are provided with seepage holes at equal intervals.

[0007] A filter screen is installed at the upper end of the seepage pipe. The filter screen is removable, and a high-pressure water pipe can be connected to the top of the seepage pipe to inject clean water to remove dirt from the seepage pipe and the three-dimensional drainage pad.

[0008] A water level alarm is installed on the upper part of the three-dimensional drainage pad. It can provide real-time warnings of excessively high water levels in the filter layer and provide timely warnings in case the filter layer's drainage function fails, thus ensuring safety.

[0009] A waterstop is installed at the lower end of the three-dimensional drainage pad, between the inner geotextile filter layer and the outer geotextile filter layer.

[0010] A construction method for a retaining wall filter layer structure as described above, characterized by comprising the following steps: S1. Clean the laitance, debris, and oil stains from the base layer of the retaining wall's main retaining side, and roughen it to a roughness Ra≥1.0mm. When cracks are >0.3mm, repair them with epoxy resin mortar. Before construction, moisten the base layer with water and control the moisture content to ≤9%. S2: Apply a layer of crack-resistant cement mortar leveling layer to the base layer of the main retaining wall on the retaining side; S3: After the crack-resistant cement mortar leveling layer is completed, apply cement-based penetrating crystalline waterproofing material in layers by spraying. S4: After the cement-based penetrating crystalline waterproofing material is applied, apply polyurethane mortar in layers, and apply the inner geotextile filter layer to the surface 1-2 hours after the polyurethane mortar is applied. S5: Install the seepage pipe, with a reserved connection length at the top of the seepage pipe for later connection with the intercepting ditch, and the bottom of the seepage pipe connected to the drainage pipe of the main body of the retaining wall. S6: Attach a three-dimensional drainage pad to the outside of the seepage pipe, and lay an outer layer of geotextile filter layer on the outside of the three-dimensional drainage pad. Install a water level alarm at the designated location of the three-dimensional drainage pad. S7: Construct aerated permeable concrete blocks on the outside of the three-dimensional drainage pad, and backfill soil in layers simultaneously during the construction of the aerated permeable concrete blocks. S8: Install intercepting ditch and drainage ditch, and connect the seepage pipe to the intercepting ditch to complete the construction. The intercepting ditch is set on the inner side of the top of the main retaining wall, and the drainage ditch is set at the corner of the main retaining wall and is used to collect rainwater discharged by the drainage pipe.

[0011] Under the influence of rainfall or seepage, moisture in the backfill soil behind the wall can enter the three-dimensional drainage pad through the outer geotextile filter layer, and be quickly dispersed using the three-dimensional drainage channels of the drainage pad. On the other hand, surface runoff on the top of the wall is collected by the intercepting ditch, guided by the seepage pipe connected to the intercepting ditch, and discharged through the connection between the lower end of the seepage pipe and the drainage pipe. Water from the drainage holes is collected by the drainage ditch at the corner of the wall and discharged in an organized manner. Through the above-mentioned organization, the probability of water stagnation and concentration on the back of the wall is reduced, and the impact of fine particles migrating with water on the drainage channels is reduced.

[0012] A filter screen is installed at the upper end of the seepage pipe, and the filter screen is removable. During maintenance, the filter screen can be removed, and a high-pressure water pipe can be connected to the top of the seepage pipe to inject clean water to flush the seepage pipe and the three-dimensional drainage pad, in order to remove any adhering or accumulated dirt. A water level alarm is used to alert maintenance personnel to abnormal water levels in the filter layer, facilitating timely checks on the patency of the intercepting ditch, seepage pipe, drain pipe, and drainage ditch, and to take unblocking measures.

[0013] The beneficial effects of this invention are as follows: This invention sets up a reverse filter layer on the retaining side of the main retaining wall. Through crack-resistant leveling, waterproof material and polyurethane mortar interface, combined with inner and outer geotextile filter layers and three-dimensional drainage pad, reverse filtration and drainage are achieved. Rainwater is guided and discharged through intercepting ditch-seepage pipe-drainage pipe-drainage ditch. With the addition of a detachable filter screen high-pressure cleaning and water level alarm, drainage and maintainability are improved. By sequentially setting a crack-resistant cement mortar leveling layer, a cement-based penetrating crystalline waterproof material, and a polyurethane mortar on the base layer of the retaining wall main body, the wall back interface has a crack-resistant, impermeable, and good bonding foundation, which is conducive to the stable adhesion and long-term effectiveness of the filter layer. The composite reverse filtration and drainage structure consisting of "inner geotextile filter layer - three-dimensional drainage pad - outer geotextile filter layer" forms a stable filtration and drainage channel, which helps to reduce the water pressure formed on the back of the wall by seepage. By connecting the intercepting ditch and the drainage pipe through vertical seepage pipes, the surface runoff on the top of the wall can be guided and discharged in an organized manner, reducing the probability of rainwater directly entering the backfill soil behind the wall and reducing the load on the reverse filter drainage system. The removable filter screen at the top of the seepage pipe and the high-pressure cleaning method facilitate the maintenance and unblocking of the seepage pipe and the three-dimensional drainage pad, thereby improving the maintainability of the drainage system. By setting up a water level alarm, an alarm can be triggered to indicate abnormal water levels in the filter layer, facilitating timely handling of risky conditions such as poor drainage. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 for Figure 1 Enlarged structural diagram of section A; Figure 3 for Figure 1 Enlarged structural diagram of section B; Figure 4 This is a schematic diagram of the seepage pipe in this invention; Figure 5 This is a schematic diagram of the three-dimensional drainage pad structure in this invention; Attached reference numerals: 1. Main body of retaining wall; 2. Main body of filter layer; 3. Drainage pipe; 4. Aerated permeable concrete block; 5. Backfill soil; 6. Intercepting ditch; 7. Drainage ditch; 8. Crack-resistant cement mortar leveling layer; 9. Cement-based penetrating crystalline waterproof material; 10. Polyurethane mortar; 11. Inner geotextile filter layer; 1101. Outer geotextile filter layer; 12. Three-dimensional drainage pad; 13. Seepage pipe; 14. Waterstop; 16. Filter screen; 17. Water level alarm; 18. Seepage hole. Detailed Implementation

[0015] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0016] Example 1 See Figures 1-5 A retaining wall filter layer structure and its construction method are characterized in that it includes a retaining wall body 1, a filter layer body 2, a drainage pipe 3, an aerated permeable concrete block 4, backfill soil 5, a water interception ditch 6, and a drainage ditch 7. The retaining wall body 1 has a filter layer body 2 on the retaining side. Several seepage pipes are installed inside the filter layer body. Aerated permeable concrete blocks 4 are installed on the outside of the filter layer body 2. Backfill soil 5 is installed on the outside of the aerated permeable concrete blocks 4. The filter layer body 2 includes, in sequence, a crack-resistant cement mortar leveling layer 8, a cement-based penetrating crystalline waterproof material 9, a polyurethane mortar 10, an inner geotextile filter layer 11, a three-dimensional drainage pad 12, and an outer geotextile filter layer 1101, all arranged on the retaining side base of the retaining wall body 1. Several vertically arranged seepage pipes 13 are provided between the three-dimensional drainage pad 12 and the inner geotextile filter layer 11. The upper end of each seepage pipe 13 is connected to a water interception ditch 6, and the lower end of each seepage pipe 13 is connected to a drainage pipe 3 of the retaining wall body 1. A water interception ditch 6 is provided on one side of the top of the main body 1 of the retaining wall, and a drainage ditch 7 is provided on one side of the corner of the main body 1 of the retaining wall. The drainage ditch 7 is used to collect rainwater discharged from the drainage hole.

[0017] The invention also has the following specific features: The sidewall of the seepage pipe 13 is provided with seepage holes 18 at equal intervals.

[0018] A filter screen 16 is provided at the upper end of the seepage pipe 13. The filter screen 16 is removable, and a high-pressure water pipe can be connected to the top of the seepage pipe 13 to inject clean water to remove dirt from the seepage pipe 13 and the three-dimensional drainage pad 12.

[0019] A water level alarm 17 is installed on the upper part of the three-dimensional drainage pad 12. It can provide real-time early warning of excessively high water levels in the filter layer and provide timely warning in case the drainage function of the filter layer fails, thus ensuring safety.

[0020] A waterstop 14 is provided at the lower end of the three-dimensional drainage pad 12, between the inner geotextile filter layer 11 and the outer geotextile filter layer 1101.

[0021] A construction method for a retaining wall filter layer structure as described above, characterized by comprising the following steps: S1. Clean the loose slurry, debris, and oil stains from the base layer of the retaining wall main body 1 on the retaining side, and grind it rough to a roughness Ra≥1.0mm. When the crack is >0.3mm, repair it with epoxy resin mortar; before construction, sprinkle water to moisten the base layer and control the moisture content ≤9%; S2: Apply a layer of crack-resistant cement mortar leveling layer 8 to the base layer of the retaining wall main body 1 on the retaining side; S3: After the crack-resistant cement mortar leveling layer 8 is completed, apply cement-based penetrating crystalline waterproof material 9 in layers; S4: After the cement-based penetrating crystalline waterproofing material 9 is applied, polyurethane mortar 10 is applied in layers, and the inner geotextile filter layer 11 is applied to the surface 1-2 hours after the polyurethane mortar 10 is applied. S5: Install the seepage pipe 13. The top of the seepage pipe 13 is reserved for connection to the intercepting ditch 6 in the future. The bottom of the seepage pipe 13 is connected to the drainage pipe 3 of the retaining wall body 1. S6: Attach a three-dimensional drainage pad 12 to the outside of the seepage pipe 13, and lay an outer geotextile filter layer 1101 on the outside of the three-dimensional drainage pad 12. Set a water level alarm 17 at a designated position on the three-dimensional drainage pad 12. S7: Construct aerated permeable concrete blocks 4 on the outside of the three-dimensional drainage pad 12, and backfill soil 5 in layers simultaneously during the construction of aerated permeable concrete blocks 4. S8: Install intercepting ditch 6 and drainage ditch 7, and connect seepage pipe 13 to intercepting ditch 6 to complete the construction. Intercepting ditch 6 is set on the inner side of the top of retaining wall body 1, and drainage ditch 7 is set at the corner of retaining wall body 1 and is used to collect rainwater discharged by drainage pipe 3.

[0022] Under the influence of rainfall or seepage, moisture in the backfill soil behind the wall can enter the three-dimensional drainage pad through the outer geotextile filter layer, where it can be quickly dispersed using the three-dimensional drainage channels. Simultaneously, surface runoff at the top of the wall is collected by the intercepting ditch, guided by seepage pipes connected to the ditch, and discharged through the connection between the lower end of the seepage pipes and the drainage pipes. Water from the drainage holes is collected by the drainage ditch at the corner of the wall and discharged in an organized manner. This process reduces the probability of water stagnation and concentration behind the wall and minimizes the impact of fine particles migrating with the water on the drainage channels.

[0023] A filter screen is installed at the upper end of the seepage pipe, and the filter screen is removable. During maintenance, the filter screen can be removed, and a high-pressure water pipe can be connected to the top of the seepage pipe to inject clean water to flush the seepage pipe and the three-dimensional drainage pad, in order to remove any adhering or accumulated dirt. A water level alarm is used to alert maintenance personnel to abnormal water levels in the filter layer, facilitating timely checks on the patency of the intercepting ditch, seepage pipe, drain pipe, and drainage ditch, and to take unblocking measures.

[0024] Example 2 See Figures 1-5 A retaining wall filter layer structure and its construction method are characterized in that it includes a retaining wall body 1, a filter layer body 2, a drainage pipe 3, an aerated permeable concrete block 4, backfill soil 5, a water interception ditch 6, and a drainage ditch 7. The retaining wall body 1 has a filter layer body 2 on the retaining side. Several seepage pipes are installed inside the filter layer body. Aerated permeable concrete blocks 4 are installed on the outside of the filter layer body 2. Backfill soil 5 is installed on the outside of the aerated permeable concrete blocks 4. The preferred aerated permeable concrete block 4 is: 300–500 mm thick, C25 strength, permeability coefficient ≥0.3 mm / s, interconnected porosity 15%–25%, and is bonded with 1:6 dry-hard cement mortar. The filter layer body 2 includes a crack-resistant cement mortar leveling layer 8, a cement-based penetrating crystalline waterproof material 9, a polyurethane mortar 10, an inner geotextile filter layer 11, a three-dimensional drainage pad 12, and an outer geotextile filter layer 1101, which are sequentially arranged on the retaining side base layer of the retaining wall body 1. The preferred finishing structure of the outer geotextile filter layer 1101 at the intercepting ditch 6 is as follows: the upper end of the geotextile filter layer passes through the side wall of the intercepting ditch 6 and ends at the bottom of the intercepting ditch 6; the horizontal section of the geotextile filter layer in the intercepting ditch 6 is ≥150mm; and the geotextile filter layer is covered with 30mm of waterproof cement mortar. The three-dimensional drainage pad 12 is preferably 15mm thick, with a permeability ≥3000m / d and a tear strength ≥600N; a number of vertically arranged seepage pipes 13 are provided between the three-dimensional drainage pad 12 and the inner geotextile filter layer 11, the upper end of the seepage pipe 13 is connected to the intercepting ditch 6, and the lower end of the seepage pipe 13 is connected to the drainage pipe 3 of the retaining wall body 1; A water interception ditch 6 is provided on one side of the top of the main body 1 of the retaining wall, and a drainage ditch 7 is provided on one side of the corner of the main body 1 of the retaining wall. The drainage ditch 7 is used to collect rainwater discharged from the drainage hole.

[0025] The sidewall of the seepage pipe 13 is provided with seepage holes 18 at equal intervals so that seepage water can enter the seepage pipe 13 and be discharged downward. The diameter of the seepage pipe 13 is 50mm and the opening rate of the seepage pipe 13 is 30%.

[0026] A filter screen 16 is provided at the upper end of the seepage pipe 13. The filter screen 16 is removable, and a high-pressure water pipe can be connected to the top of the seepage pipe 13 to inject clean water to remove dirt from the seepage pipe 13 and the three-dimensional drainage pad 12.

[0027] A water level alarm 17 is installed on the upper part of the three-dimensional drainage pad 12. It can provide real-time early warning of excessively high water levels in the filter layer and provide timely warning in case the drainage function of the filter layer fails, thus ensuring safety.

[0028] A waterstop 14 is provided at the lower end of the three-dimensional drainage pad 12, between the inner geotextile filter layer 11 and the outer geotextile filter layer 1101, to reduce the mixing of mud and water into the three-dimensional drainage pad 12 and form a sealed node.

[0029] The intercepting ditch 6 and the drainage ditch 7 are preferably located as follows: the intercepting ditch 6 is located on the inner side of the top of the retaining wall body 1 and is 100mm lower than the top of the retaining wall. The internal width of the intercepting ditch 6 is ≥200mm and the longitudinal slope is 0.3%. The drainage ditch 7 is located at the corner of the retaining wall body 1. The internal width of the drainage ditch 7 is ≥200mm and the longitudinal slope is 0.3%.

[0030] Example 3 See Figures 1-5 A construction method using a retaining wall filter layer structure, characterized by the following steps: S1. Clean the loose slurry, debris, and oil stains from the base layer of the retaining wall main body 1 on the retaining side, and grind it rough to a roughness Ra≥1.0mm. When the crack is >0.3mm, repair it with epoxy resin mortar; before construction, sprinkle water to moisten the base layer and control the moisture content ≤9%; S2: Apply crack-resistant cement mortar leveling layer 8 in layers to the base layer of the retaining wall main body 1 on the retaining side. Preferably, the thickness of the crack-resistant cement mortar leveling layer 8 is 15–20 mm. After construction, cover with moisture-retaining material and cure for ≥5 days. S3: After the crack-resistant cement mortar leveling layer 8 is completed, apply cement-based penetrating crystalline waterproof material 9 in layers; Preferably, the cement-based penetrating crystalline waterproofing material 9 has a thickness of 2mm, a spraying pressure of 0.3–0.5MPa, and a curing period of ≥3 days; S4: After the cement-based penetrating crystalline waterproofing material 9 is applied, polyurethane mortar 10 is applied in layers, and the inner geotextile filter layer 11 is applied to the surface 1-2 hours after the polyurethane mortar 10 is applied. Preferably, the polyurethane mortar 10 has a thickness of 10mm and a flatness error of ≤3mm / 2m.

[0031] S5: Install the seepage pipe 13. The top of the seepage pipe 13 is reserved for connection to the intercepting ditch 6 in the future. The bottom of the seepage pipe 13 is connected to the drainage pipe 3 of the retaining wall body 1. Preferably, seepage holes 18 are provided at equal intervals on the side wall of the seepage pipe 13; a filter screen 16 is provided at the upper end of the seepage pipe 13, the filter screen 16 can be removed, and a high-pressure water pipe can be connected to the top of the seepage pipe 13 to inject clean water to remove dirt from the seepage pipe 13 and the three-dimensional drainage pad 12. S6: Attach a three-dimensional drainage pad 12 to the outside of the seepage pipe 13, and lay an outer geotextile filter layer 1101 on the outside of the three-dimensional drainage pad 12. Set a water level alarm 17 at a designated position on the three-dimensional drainage pad 12. Preferably, the three-dimensional drainage pad 12 has a thickness of 15 mm, a permeability ≥3000 m / d, and a tear strength ≥600 N. Preferably, a waterstop 14 is provided at the lower end of the three-dimensional drainage pad 12, between the inner geotextile filter layer 11 and the outer geotextile filter layer 1101. S7: Construct aerated permeable concrete blocks 4 on the outside of the three-dimensional drainage pad 12, and backfill soil 5 in layers simultaneously during the construction of aerated permeable concrete blocks 4. Preferably, the aerated permeable concrete blocks 4 are 300–500 mm thick, have a strength of C25, a permeability coefficient ≥0.3 mm / s, and a connected porosity of 15%–25%, and are bonded using 1:6 dry-hard cement mortar; the backfill soil 5 has a compaction degree ≥93%; S8: Install intercepting ditch 6 and drainage ditch 7, and connect the seepage pipe 13 to the intercepting ditch 6 to complete the construction. The intercepting ditch 6 is located on the inner side of the top of the retaining wall body 1, and the drainage ditch 7 is located at the corner of the retaining wall body 1 and is used to collect rainwater discharged by the drainage pipe 3. Preferably, the intercepting ditch 6 is 100mm lower than the top of the retaining wall, the internal width of the intercepting ditch 6 is ≥200mm, and the longitudinal slope is 0.3%; the internal width of the drainage ditch 7 is ≥200mm, and the longitudinal slope is 0.3%.

[0032] Preferably, the upper end of the geotextile filter layer passes through the side wall of the intercepting ditch 6 and ends at the bottom of the intercepting ditch 6. The horizontal section of the geotextile filter layer in the intercepting ditch 6 is ≥150mm. The geotextile filter layer is covered with 30mm of waterproof cement mortar.

[0033] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.

Claims

1. A retaining wall filter structure, characterised in that, The retaining wall body, the anti-filter layer body, the drainage pipeline, the aerated pervious concrete block, the backfill, the water interception ditch and the drainage ditch are included. The retaining wall body is provided with the anti-filter layer body on the retaining side, and the anti-filter layer body is internally provided with a plurality of water seepage pipes. The retaining wall body is provided with the water seepage pipe, and the water seepage pipe is internally provided with the filter screen. The water level alarm is arranged on the upper part of the three-dimensional drainage pad.

2. The retaining wall reverse filter structure and its construction method according to claim 1, characterized in that, The water stop belt is arranged on the lower end of the three-dimensional drainage pad and between the inner geotextile filter layer and the outer geotextile filter layer.

3. The retaining wall reverse filter structure and its construction method according to claim 2, characterized in that, The method comprises the following steps:

4. The retaining wall reverse filter structure and construction method thereof according to claim 3, wherein S1, cleaning the floating slurry, sundries and oil stains on the retaining side of the retaining wall body, polishing to roughness Ra≥1.0mm, and repairing the cracks with epoxy resin mortar when the cracks are greater than 0.3mm; 5. The retaining wall reverse filter structure and its construction method according to claim 4, wherein S2, layering and batch scraping the anti-crack cement mortar leveling layer on the retaining side of the retaining wall body; 6. A method of constructing a retaining wall filter structure as claimed in any one of claims 1 to 5, characterised in that, S3, layering and spraying the cement-based permeable crystalline waterproof material after the anti-crack cement mortar leveling layer is constructed; S4, layering and batch scraping the polyurethane mortar after the cement-based permeable crystalline waterproof material is constructed, and the inner geotextile filter layer is pasted on the surface of the polyurethane mortar after 1-2 hours of construction; S5, installing the water seepage pipe, reserving the connecting length at the top end of the water seepage pipe for subsequent communication with the water interception ditch, and connecting the bottom end of the water seepage pipe with the drainage pipeline of the retaining wall body; S6, pasting the three-dimensional drainage pad on the outer side of the water seepage pipe, laying the outer geotextile filter layer on the outer side of the three-dimensional drainage pad, and arranging the water level alarm at the specified position of the three-dimensional drainage pad; S7, laying the aerated pervious concrete block on the outer side of the three-dimensional drainage pad, and simultaneously layering the backfill during the laying process of the aerated pervious concrete block; S8, installing the water interception ditch and the drainage ditch, connecting the water seepage pipe with the water interception ditch, and completing the construction. ​ ​ ​

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