Structure for treating swelling soil slope slump and construction method

Abstract

The invention discloses a structure for treating swelling soil slope collapse and a construction method. The north leading dry weak expansive soil side slope is obviously damaged under the synergistic effect of freezing and thawing and water environments, the strength is reduced along with the increase of the freezing and thawing cycle times, the frost heaving deformation is large under partial working conditions, cracks are generated under the condition of large difference between the deformation and the strength, and the bank collapse phenomenon occurs. The structure comprises an original slope, PET bag reinforcing feet are arranged on the lower portion of a slope body of the original slope, the slope toe of the original slope is covered with a bidirectional geogrid, an anti-sliding key is nailed on the geogrid, the geogrid is covered with a covering layer, and the upper portion of the anti-sliding key is covered with the covering layer; the method is used for treating swelling soil slope collapse.

Description

Technical Field

[0001] The invention belongs to the field of geotechnical engineering, and particularly relates to a structure for controlling expansive soil slope landslide and a construction method. Background Art

[0002] The Heilongjiang Northern Nenjiang Water Diversion Project (hereinafter referred to as the "Northern Diversion Project") is located in western Heilongjiang Province, nestled in the heart of the Songnen Plain on the left bank of the middle reaches of the Nenjiang River. It is the largest damless water diversion project in Heilongjiang Province. The project diverts water from the main stream of the Nenjiang River to the Hongqipao Reservoir and the Daqing Reservoir, meeting the needs of Daqing's petrochemical production and urban life, while also providing agricultural water for 24 irrigation channels along the route. However, due to environmental factors such as dry-wet cycles and freeze-thaw cycles, the channel foundation is highly susceptible to freeze-thaw damage under hydrothermal conditions. Furthermore, because expansive soils contain a large number of hydrophilic minerals, they rapidly expand upon absorbing water, reducing their bearing capacity. Upon dehydration, their volume decreases significantly, potentially leading to cracks and landslides. Previous monitoring of a composite cross-section treatment method has shown good results in managing expansive soil slopes along the channel. However, the project is costly, necessitating the development of a rapid and cost-effective method for managing expansive soil slopes.

[0003] Previous studies have revealed that the weak expansive soil slopes of the North Diversion Canal suffer significant damage from the combined effects of freeze-thaw and water. Strength decreases with increasing freeze-thaw cycles, and under some conditions, frost heave deformation is significant. Large discrepancies between deformation and strength can lead to cracks and bank collapse. By investigating current expansive soil slope management technologies and considering the North Diversion Canal's function and site conditions, three less-costly methods were proposed: crushed stone, polyethylene rope + cover soil, and soil + PET sheeting. These methods were then tested and observed over a long period of time. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a structure for controlling the landslide of expansive soil slopes and a construction method.

[0005] The above purpose is achieved through the following technical solutions: A structure for controlling landslides on expansive soil slopes comprises: an original slope, a PET bag reinforcement foot provided at the lower part of the slope body of the original slope, a bidirectional geogrid covered at the slope toe of the original slope, anti-slip keys nailed to the geogrid, a covering layer covering the top of the anti-slip keys.

[0006] In the structure for controlling landslide of expansive soil slope, the anti-slip keys are wooden piles. After the anti-slip keys are constructed, when the geogrid is laid to the anti-slip key position, crushed stone with a thickness of 10 cm is laid above the geogrid.

[0007] In the structure for controlling landslide of expansive soil slopes, the anti-slip keys are wooden piles. After the anti-slip keys are constructed, polyethylene ropes are tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the polyethylene ropes are fixed to the anti-slip key.

[0008] The structure for controlling landslide of expansive soil slopes is described. The anti-slip keys are wooden piles. After the anti-slip keys are constructed, a soil layer is laid on the wooden piles, and a PET cloth is covered on the soil layer. A PET rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the anti-slip key PET rope is fixed.

[0009] A construction method for controlling expansive soil slope collapse structure, the method comprising the following steps: S1. Pre-reinforce the original slope with anti-slide piles; S2, anti-slip key installation; S3, the construction process of the anti-slip key includes: construction preparation, measurement and layout - pile hole site leveling - locking plate construction - section excavation, hoisting - nailing of wooden piles; S4. The anti-slip keys are made of wooden stakes. The anti-slip keys must be aligned with the direction of gravity, and the anti-slip keys in the same row must be aligned to ensure the laying of further covering layers. S5. Geogrid construction; The construction process of the geogrid includes: testing and cleaning the underlying layer; manually laying the geogrid - overlapping and tying; Fixing - spreading the upper fill - geogrid wrapping - rolling - testing, repeating the process and laying in layers; S6. Lay the covering layer on the upper layer; S7. PET bag reinforcement foot construction: PET bag reinforcement feet are set at the lower part of the slope of the original slope. The PET bags are filled with sand or gravel and are placed at the foot of the slope.

[0010] The construction method for controlling the landslide structure of an expansive soil slope, wherein the construction process of the geogrid specifically includes: (1) Detect and clean the underlying layer; (2) Manual laying of geogrid: The geogrid is spliced ​​longitudinally using the overlap method. The grid width should be no less than 4 meters and the overlap width should be no less than 30 cm. (3) When installing and laying the grid on a flat and compacted site, its main force direction should be perpendicular to the direction of the slope. The grid should be laid flat, without wrinkles, and as tight as possible. After filling a layer of soil and before rolling, the grid should be tightened again manually or mechanically. The force should be uniform so that the grid is in a straight and stressed state in the soil. (4) When the geogrid is laid to the anti-slip key position, the anti-slip key anti-wrapping beam is reversed; after completion, the anti-wrapping beam and geogrid are fixed with "U"-shaped steel bars; (5) When laying geogrids close to the slope, the area required for backfilling should be reserved, and backfill sacks should be placed near the slope before filling. The backfilled geogrids should be fixed to the geogrids laid on the upper layer with "U"-shaped steel bars; (6) After the grid is laid and positioned, the covering layer should be laid in time, and the exposure time should not exceed 48 hours, or a continuous operation method of laying and backfilling should be adopted; first spread the filler at both ends, fix the grid, and then push it towards the middle; the order of rolling is first the two sides and then the middle.

[0011] In the construction method for controlling the collapse of an expansive soil slope, the covering layer is crushed stone, polyethylene rope or PET cloth.

[0012] The construction method for controlling landslide of an expansive soil slope is as follows: when the covering layer is PET cloth, after the anti-slip key is constructed, a soil layer is laid on the wooden piles, the soil layer is covered with PET cloth, and a PET rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the anti-slip key PET rope is fixed. Beneficial effects

[0013] 1. The expansive soil slope collapse structure of the present invention can be rationally utilized through experiments to act on the expansive soil slope using wooden piles and geogrids. This solves the problem of geogrids not participating in the overall slope anti-slip effect, effectively controlling the expansion and collapse of expansive soil slopes, achieving structural stability, economic rationality, and restoring the slope vegetation ecosystem. Furthermore, the present invention has low construction difficulty and is easy to implement.

[0014] 2. This invention rationally utilizes wood piles and geogrids to act on expansive soil on the slope, resolving the problem of geogrids not contributing to overall slope anti-slip performance. It effectively controls expansive soil slope expansion and collapse, achieving structural stability, economic rationality, and restoring the slope's vegetation ecosystem. Furthermore, this invention is easy to implement and requires minimal construction effort. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Attachment Figure 1 It is a structural schematic diagram of the present invention; Attachment Figure 2 It is a schematic structural diagram of the bidirectional geogrid of the present invention; Attachment Figure 3 This is a cross-sectional view of the arrangement of wooden piles; Attachment Figure 4 It is a schematic diagram of the arrangement of displacement monitoring points in the test section of the present invention.

[0016] In the figure: 1. Bidirectional geogrid; 2. Wooden piles; 3. Cover layer; 4. PET bag reinforcement feet. DETAILED DESCRIPTION

[0017] Reference Figure 1-Figure 4A structure for controlling landslide of expansive soil slopes comprises: an original slope, a PET bag reinforcement foot 4 is provided at the lower part of the slope of the original slope, a bidirectional geogrid 1 is covered at the toe of the slope of the original slope, an anti-slip key is nailed on the geogrid, and a covering layer 3 is covered above the geogrid, and the covering layer covers the upper part of the anti-slip key.

[0018] The anti-slip key is a wooden pile 2. After the anti-slip key is constructed, when the geogrid is laid to the anti-slip key position, crushed stone with a thickness of 10 cm is laid above the geogrid.

[0019] The anti-slip key is made of wooden stakes. After the anti-slip key is constructed, a polyethylene rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the polyethylene rope is fixed to the anti-slip key.

[0020] The anti-slip key is made of wooden piles. After the construction of the anti-slip key is completed, a soil layer is laid on the wooden piles, and a PET cloth is covered on the soil layer. A PET rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the anti-slip key PET rope is fixed.

[0021] When the covering layer is gravel, the construction method for controlling the landslide structure of the expansive soil slope is characterized in that the method comprises the following steps: S1. Pre-reinforce the original slope with anti-slide piles; S2, anti-slip key installation; S3, the construction process of the anti-slip key includes: construction preparation, measurement and layout - pile hole site leveling - locking plate construction - section excavation, hoisting - nailing of wooden piles; S4. The anti-slip keys are made of wooden stakes. The anti-slip keys must be aligned with the direction of gravity, and the anti-slip keys in the same row must be aligned to ensure the laying of the next gravel layer. S5. After the anti-slip key construction is completed, 10 cm thick crushed stone is laid on top of the geogrid to cover the top of the wooden piles; S6. Geogrid construction; The construction process of the geogrid includes: testing and cleaning the underlying layer; manually laying the geogrid - overlapping, tying, fixing - spreading the upper fill - geogrid wrapping - rolling - testing, repeating the process and laying in layers; S7, laying gravel on the upper layer; S8, PET bag reinforced foot construction.

[0022] PET bag reinforcement feet are set at the bottom of the original slope. PET bags are filled with sand or gravel and placed at the slope foot.

[0023] The construction process of the geogrid specifically includes: (1) Detect and clean the underlying layer; (2) Manual laying of geogrid: The geogrid is spliced ​​longitudinally using the overlap method. The grid width should be no less than 4 meters and the overlap width should be no less than 30 cm. (3) When installing and laying the grid on a flat and compacted site, its main force direction should be perpendicular to the direction of the slope. The grid should be laid flat, without wrinkles, and as tight as possible. After filling a layer of soil and before rolling, the grid should be tightened again manually or mechanically. The force should be uniform so that the grid is in a straight and stressed state in the soil. (4) When the geogrid is laid to the anti-slip key position, the anti-slip key anti-wrapping beam is reversed; after completion, the anti-wrapping beam and geogrid are fixed with "U"-shaped steel bars; (5) When laying geogrids close to the slope, the area required for backfilling should be reserved, and backfill sacks should be placed near the slope before filling. The backfilled geogrids should be fixed to the geogrids laid on the upper layer with "U"-shaped steel bars; (6) After the grid is laid and positioned, gravel should be laid in time, and the exposure time should not exceed 48 hours, or a continuous operation method of laying and backfilling should be adopted; first spread the filler at both ends, fix the grid, and then push it towards the middle; the order of rolling is first the two sides and then the middle.

[0024] When the covering layer is polyethylene rope, the construction method for controlling the landslide structure of the expansive soil slope is characterized in that the method comprises the following steps: S1. Pre-reinforce the original slope with anti-slide piles; S2, anti-slip key installation; S3, the construction process of the anti-slip key includes: construction preparation, measurement and layout - pile hole site leveling - locking plate construction - section excavation, hoisting - nailing of wooden piles; S4. The anti-slip keys are made of wooden stakes. The anti-slip keys must be aligned with the direction of gravity, and the anti-slip keys in the same row must be aligned to ensure the further installation of the polyethylene rope; S5. After the anti-slip key is constructed, polyethylene rope is installed on the side close to the slope surface; S6. Geogrid construction; The construction process of the geogrid includes: testing and cleaning the underlying layer; manually laying the geogrid - overlapping, tying, fixing - spreading the upper fill - geogrid wrapping - rolling - testing, repeating the process and laying in layers; S7, cover the upper layer with soil and plant grass; S8, PET bag reinforced foot construction; PET bag reinforcement feet are set at the bottom of the original slope. PET bags are filled with sand or gravel and placed at the slope foot.

[0025] The construction process of the geogrid specifically includes: (1) Detect and clean the underlying layer; (2) Manual laying of geogrid: The geogrid is spliced ​​longitudinally using the overlap method. The grid width should be no less than 4 meters and the overlap width should be no less than 30 cm. (3) When installing and laying the grid on a flat and compacted site, its main force direction should be perpendicular to the direction of the slope. The grid should be laid flat, without wrinkles, and as tight as possible. After filling a layer of soil and before rolling, the grid should be tightened again manually or mechanically. The force should be uniform so that the grid is in a straight and stressed state in the soil. (4) When the geogrid is laid to the anti-slip key position, the anti-slip key anti-wrapping beam is reversed; after completion, the anti-wrapping beam and geogrid are fixed with "U"-shaped steel bars; (5) When laying geogrids close to the slope, the area required for backfilling should be reserved, and backfill sacks should be placed near the slope before filling. The backfilled geogrids should be fixed to the geogrids laid on the upper layer with "U"-shaped steel bars; (6) After the grid is laid and positioned, it should be covered with soil in time. The exposed time should not exceed 48 hours, or a continuous operation method of laying and backfilling should be adopted; first spread the filler at both ends, fix the grid, and then push it towards the middle; the order of rolling is first the two sides and then the middle.

[0026] When the covering layer is PET cloth, the construction method for treating the landslide structure of the expansive soil slope is characterized in that the method comprises the following steps: S1. Pre-reinforce the original slope with anti-slide piles; S2, anti-slip key installation; S3, the construction process of the anti-slip key includes: construction preparation, measurement and layout - pile hole site leveling - locking plate construction - section excavation, hoisting - nailing of wooden piles; S4. The anti-slip keys are made of wooden stakes. The anti-slip keys must be aligned with the direction of gravity, and the anti-slip keys in the same row must be aligned to ensure the further installation of the polyethylene rope; S5. After the anti-slip key is constructed, polyethylene rope is installed on the side close to the slope surface; S6. Geogrid construction; The construction process of the geogrid includes: testing and cleaning the underlying layer; manually laying the geogrid - overlapping, tying, fixing - spreading the upper fill - geogrid wrapping - rolling - testing, repeating the process and laying in layers; S7, cover the upper layer with soil and plant grass; S8, PET bag reinforced foot construction; PET bag reinforcement feet are set at the bottom of the original slope. PET bags are filled with sand or gravel and placed at the slope foot.

[0027] The construction process of the geogrid specifically includes: (1) Detect and clean the underlying layer; (2) Manual laying of geogrid: The geogrid is spliced ​​longitudinally using the overlap method. The grid width should be no less than 4 meters and the overlap width should be no less than 30 cm. (3) When installing and laying the grid on a flat and compacted site, its main force direction should be perpendicular to the direction of the slope. The grid should be laid flat, without wrinkles, and as tight as possible. After filling a layer of soil and before rolling, the grid should be tightened again manually or mechanically. The force should be uniform so that the grid is in a straight and stressed state in the soil. (4) When the geogrid is laid to the anti-slip key position, the anti-slip key anti-wrapping beam is reversed; after completion, the anti-wrapping beam and geogrid are fixed with "U"-shaped steel bars; (5) When laying geogrids close to the slope, the area required for backfilling should be reserved, and backfill sacks should be placed near the slope before filling. The backfilled geogrids should be fixed to the geogrids laid on the upper layer with "U"-shaped steel bars; (6) After the grid is laid and positioned, it should be covered with soil in time. The exposed time should not exceed 48 hours, or a continuous operation method of laying and backfilling should be adopted; first spread the filler at both ends, fix the grid, and then push it towards the middle; the order of rolling is first the two sides and then the middle.

Claims

1. A structure for controlling expansive soil slope collapse, characterized by: The invention comprises: an original slope, a PET bag reinforcement foot is provided at the lower part of the slope of the original slope, a bidirectional geogrid is covered at the toe of the slope of the original slope, an anti-slip key is nailed on the geogrid, a covering layer is covered above the geogrid, and the covering layer covers the upper part of the anti-slip key.

2. The structure for controlling expansive soil slope collapse according to claim 1, wherein: The anti-slip keys are made of wooden piles. After the anti-slip key construction is completed, when the geogrid is laid to the anti-slip key position, 10 cm thick crushed stone is laid above the geogrid.

3. The structure for controlling expansive soil slope collapse according to claim 1, wherein: The anti-slip key is made of wooden stakes. After the anti-slip key is constructed, a polyethylene rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the polyethylene rope is fixed to the anti-slip key.

4. The structure for controlling expansive soil slope collapse according to claim 1, wherein: The anti-slip key is made of wooden piles. After the anti-slip key is constructed, a soil layer is laid on the wooden piles, and a PET cloth is covered on the soil layer. A PET rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the anti-slip key PET rope is fixed.

5. A construction method for controlling expansive soil slope collapse according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1. Pre-reinforce the original slope with anti-slide piles; S2, anti-slip key installation; S3, the construction process of the anti-slip key includes: construction preparation, measurement and layout - pile hole site leveling - locking plate construction - section excavation, hoisting - nailing of wooden piles; S4. The anti-slip keys are made of wooden stakes. The anti-slip keys must be aligned with the direction of gravity, and the anti-slip keys in the same row must be aligned to ensure the laying of further covering layers. S5. Geogrid construction; The construction process of the geogrid includes: testing and cleaning the underlying layer; manually laying the geogrid - overlapping and tying; Fixing - spreading the upper fill - geogrid wrapping - rolling - testing, repeating the process and laying in layers; S6. Lay the covering layer on the upper layer; S7. PET bag reinforcement foot construction: PET bag reinforcement feet are set at the lower part of the slope of the original slope. The PET bags are filled with sand or gravel and are placed at the foot of the slope.

6. The construction method for controlling expansive soil slope collapse structure according to claim 5, characterized in that: The construction process of the geogrid specifically includes: (1) Detect and clean the underlying layer; (2) Manual laying of geogrid: The geogrid is spliced ​​longitudinally using the overlap method. The grid width should be no less than 4 meters and the overlap width should be no less than 30 cm. (3) When installing and laying the grid on a flat and compacted site, its main force direction should be perpendicular to the direction of the slope. The grid should be laid flat, without wrinkles, and as tight as possible. After filling a layer of soil and before rolling, the grid should be tightened again manually or mechanically. The force should be uniform so that the grid is in a straight and stressed state in the soil. (4) When the geogrid is laid to the anti-slip key position, the anti-slip key anti-wrapping beam is reversed; after completion, the reversed beam and geogrid are fixed with "U"-shaped steel bars; (5) When laying geogrids close to the slope, the area required for backfilling should be reserved, and backfill sacks should be placed near the slope before filling. The backfilled geogrids should be fixed to the geogrids laid on the upper layer with "U"-shaped steel bars; (6) After the grid is laid and positioned, the covering layer should be laid in time, and the exposure time should not exceed 48 hours, or a continuous operation method of laying and backfilling should be adopted; first spread the filler at both ends, fix the grid, and then push it towards the middle; the order of rolling is first the two sides and then the middle.

7. The construction method for controlling expansive soil slope collapse structure according to claim 5, characterized in that: The covering layer is crushed stone or polyethylene rope or PET cloth.

8. The construction method for controlling expansive soil slope collapse structure according to claim 5, characterized in that: When the covering layer is PET cloth, after the anti-slip key construction is completed, a soil layer is laid on the wooden piles, and the PET cloth is covered on the soil layer. A PET rope is tied on the side close to the slope. When the geogrid is laid to the anti-slip key position, the anti-slip key PET rope is fixed.

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