Hole slope excavation land acquisition red line control construction method

Abstract

The invention belongs to the field of slope excavation construction, and relates to a hole slope excavation land acquisition red line control construction method. According to the technical principle, active protection is carried out by anchoring and hardening the slope surface, arranging a slope toe at an opening line and additionally arranging an anchor bar pile and a retaining wall, effective control over a land acquisition red line can be achieved, smooth proceeding of engineering construction is guaranteed, land disputes and ecological damage are avoided, and reasonable utilization of land resources is guaranteed; according to the technology, the active protection foundation of the retaining wall is fully utilized, the land acquisition red line is ensured, strict control over the land acquisition red line is beneficial for maintaining legal use of land resources, and illegal land occupation is avoided. Meanwhile, the method has important significance in protecting the surrounding ecological environment and reducing the influence on the life of surrounding residents, and is widely popularized and applied in slope excavation.

Description

Technical Field

[0001] The invention belongs to the field of slope excavation construction, and relates to a construction method for controlling land acquisition red lines during tunnel entrance slope excavation. Background Art

[0002] The control of the land acquisition red line for slope excavation is a comprehensive task, which requires effective measures from both technical and management aspects. The existing technical measures usually take construction measures such as active protection of the slope by spraying anchors, slowing down the slope, cutting slopes and dissipating energy to adjust the opening line to the control range of the land acquisition red line. However, for complex geological conditions, changeable topography and landforms, and geology with strict construction requirements, such as loose slope deposits and piled soil slopes, the shortcomings of using this technology are: it is difficult to ensure the land acquisition red line, resulting in situations where the land acquisition red line is exceeded, thus causing a series of problems, such as land disputes, soil and water conservation, ecological damage, etc., affecting the progress of the project construction, and also having an important impact on the safety and quality of the project. Summary of the invention

[0003] In order to solve the problems of the prior art, the present invention provides a construction method for controlling the red line of land acquisition during the excavation of the side slope of the tunnel. The purpose of the present invention is to provide a construction method for controlling the red line of land acquisition during the excavation of the side slope of the tunnel in view of the shortcomings of the traditional technology. The technical principle of the invention is to realize the effective control of the red line of land acquisition by anchoring and hardening the slope surface, setting the foot of the slope at the opening line, and adding anchor piles + retaining walls for active protection, so as to ensure the smooth progress of engineering construction, avoid land disputes and ecological damage, and ensure the rational use of land resources.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A construction method for controlling the red line of land acquisition for excavation of a tunnel entrance slope comprises the following steps: S1: Add a composite retaining wall at the opening line for protection. The composite retaining wall adopts a stone-buried concrete structure with anchor piles inside. The lower part of the anchor piles is anchored to the foundation surface, and the upper part is anchored to the slope steel mesh to form a whole; S2: The slope surface from the opening line to the land acquisition red line, i.e. the upper slope of the retaining wall, is fully enclosed and protected by using the slope system anchor rod 21 and the mesh spray anchor method; S3: A drainage ditch shall be set up on the top of the slope within the land acquisition red line. The distance between the drainage ditch and the slope opening line shall not be less than 5m and greater than 10m. The drainage ditch shall be formed by composite geomembrane + mesh sprayed concrete.

[0005] The construction method for controlling the red line of land acquisition for excavation of the tunnel entrance slope includes the following steps for forming the composite retaining wall: (1) construction of the buried stone concrete retaining wall; and (2) construction of the anchor piles.

[0006] The construction method for controlling the red line of land acquisition for the excavation of the tunnel entrance slope, and the construction of the buried stone concrete retaining wall include the following steps: the foundation and the wall body are cast with C20 buried stone concrete; before the foundation is cast, the size and elevation of the foundation pit are checked, the debris is removed, the bottom of the foundation trench is leveled and compacted, and then the foundation is laid out, the reference line is pulled to lay out the foundation axis and the edge line, and the retaining wall is cast in layers, and the layered casting height is 100-150cm; The stone material is rough stone with a particle size of less than 30cm, and the burial rate is 25%; When pouring the wall, the retaining wall shall be divided in the long direction of the wall according to the drawing requirements, with a distance of 15m and a width of 20mm. The seams shall be filled with asphalt hemp tendons; the filling depth shall not be less than 15cm; The retaining wall is equipped with drainage pipes, which are PVC pipes and arranged in two rows. The diameter of the drainage pipe opening is 50mm. Each row of drainage pipes is arranged at a distance of 2.0m along the length direction of the retaining wall and at a distance of 2.0m along the height direction, in a plum blossom shape, and pre-buried in the wall at a slope of 5%; A crushed stone filter layer is set behind the wall, which is 550mm thick and 500mm wide. A clay compacted waterproof layer is set under the drainage hole behind the wall, which is 300mm thick and the same width as the width of the backfill behind the wall. The backfill behind the retaining wall is made of original soil. The backfill should be done while the wall is being built. The backfill must be compacted layer by layer, and the thickness of each layer is less than 300mm, and the compaction coefficient is greater than 0.97.

[0007] The construction method for controlling the red line of land acquisition for the excavation of the tunnel entrance slope, the anchor pile construction comprises the following steps: The anchor pile is formed by welding a φ28mm steel bar. The diameter of the anchor pile is 84mm. The anchor pile is welded with the slope system anchor rod to form a whole. The slope system anchor rod is 6-12m long, with a horizontal spacing of 1.5-2.0m and a vertical spacing of 2-2.5m. The downward inclination angle of the anchor rod is 25 degrees. The anchor head of the lowest row of anchor rods is set at a height of 1.0m above the slope foot. The diameter of the slope system anchor rod is 25mm or 28mm. The lower part of the anchor pile is buried at least 3m deep into the foundation; the anchor piles are arranged in 2 rows horizontally, with a horizontal spacing of 1.0-1.5m and a vertical spacing of 1.5; On the retaining wall, 3-4 rows of anchor rods are set from bottom to top. The anchor rods pass through the retaining wall and enter the stable rock and soil layer. The mesh spraying anchor is installed by hanging steel mesh and spraying concrete. The size of the hanging steel mesh is ∅6@15cmx15cm, and C20 concrete is sprayed. The thickness of C20 concrete is 100mm.

[0008] The construction method for controlling the red line of land acquisition for excavation of the tunnel entrance slope, and the construction of the intercepting ditch include the following steps: After the intercepting ditch is excavated, a layer of geomembrane is laid along the trench of the intercepting ditch for anti-seepage, and then a layer of steel mesh is laid and concrete spraying construction is carried out. The distance between the intercepting ditch and the opening line shall not be less than 5m and greater than 10m.

[0009] Compared with the prior art, the invention has the following beneficial effects: the invention technology makes full use of the active protection principle of the retaining wall to ensure the land acquisition red line. The strict control of the land acquisition red line helps to maintain the legal use of land resources and avoid illegal occupation of land. At the same time, it is also of great significance to protect the surrounding ecological environment and reduce the impact on the lives of surrounding residents. It has been widely promoted and applied in slope excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0011] Figure 1 It is a schematic diagram of the structure of the present invention.

[0012] Figure 2 yes Figure 1 Schematic diagram of the structure at point A in the middle. DETAILED DESCRIPTION

[0013] The present invention is further described in detail below by examples, which are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0014] The technical solution of the present invention relates to a construction method for controlling the land acquisition red line of the excavation of a tunnel entrance slope, which is characterized in that a composite active protection structure of anchor piles + concrete retaining walls is arranged at the opening line position of the slope excavation, and the slope surface is anchored and fully enclosed for protection, thereby effectively supporting and stabilizing the soil, preventing geological disasters such as slope landslides and collapses, ensuring the stability of the slope, and controlling the range from the slope excavation opening line to the land acquisition red line to ensure the land acquisition red line.

[0015] A construction method for controlling the red line of land acquisition for excavation of a tunnel entrance slope comprises the following steps: S1: A composite retaining wall 1 is added at the opening line for protection. The composite retaining wall 1 adopts a stone-buried concrete structure with anchor piles arranged inside. The lower part of the anchor piles is anchored to the foundation surface, and the upper part is anchored to the slope steel mesh to form a whole. S2: The slope surface from the opening line to the land acquisition red line, i.e. the upper slope 2 of the retaining wall, is fully enclosed and protected by using the slope system anchor rod 21 and the mesh spraying anchor; S3: A drainage ditch 3 is set up on the top of the slope within the red line of land acquisition. The distance between the drainage ditch 3 and the slope opening line is not less than 5m and greater than 10m. The drainage ditch is formed by composite geomembrane + mesh sprayed concrete.

[0016] The steps of forming the composite retaining wall 1 include: (1) construction of buried stone concrete retaining wall The foundation and wall are cast with C20 buried stone concrete; before casting the foundation, first check the size and elevation of the foundation pit, remove debris, and level and tamp the bottom of the foundation trench (tamp twice with a vertical electric tamping machine) to ensure that there are no large protrusions at the bottom of the trench. Then, lay out the foundation, pull the reference line to lay out the foundation axis and edge line, and cast the retaining wall in layers, with a layered casting height of 100 to 150 cm.

[0017] The stone material should be rough stone with a particle size of less than 30cm. The rough stone should be washed clean and should not contain a large amount of soil. The burial rate is 25%.

[0018] When pouring the wall, the retaining wall shall be divided into joints in the long direction of the wall according to the requirements of the drawings, with a joint distance of 15m. The joint width is 20mm, and the joint is filled with asphalt hemp tendons; the filling depth is not less than 15cm.

[0019] The retaining wall is provided with drainage pipes 11, which are PVC pipes and arranged in two rows. The diameter of the pipe opening of the drainage pipes 11 is 50 mm. Each row of drainage pipes 11 is arranged at a spacing of 2.0 m in the length direction of the retaining wall and 2.0 m in the height direction, arranged in a plum blossom shape, and pre-buried in the wall body at a slope of 5%. The first drainage pipe is arranged at 35 mm from the natural ground, and the subsequent drainage pipes are arranged according to the above requirements, that is, the drainage pipes 11 are arranged at a spacing of 2.0 m in the length direction of the retaining wall and 2.0 m in the height direction, arranged in a plum blossom shape, and pre-buried in the wall body at a slope of 5%.

[0020] A crushed stone filter layer is set behind the wall, with a thickness of 550mm and a width of 500mm. A clay compacted waterproof layer is set under the drainage hole behind the wall, with a thickness of 300mm and a width equal to the width of the backfill behind the wall. The backfill behind the retaining wall is made of original soil (crushed stone soil), and organic matter or other debris shall not be mixed in the backfill. Backfilling should be done while the wall is being built. The backfill must be compacted layer by layer, with each layer thickness less than 300mm and a compaction coefficient greater than 0.97.

[0021] (2) Anchor pile construction The anchor pile 12 is formed by welding three φ28mm steel bars, the diameter of the anchor pile 12 is 84mm, the anchor pile 12 is welded with the slope system anchor rod 21 to form a whole, the slope system anchor rod 21 is 6-12m long, the horizontal spacing is 1.5-2.0m, the vertical spacing is 2-2.5m, the anchor rod downward angle is 25 degrees, and the anchor head of the lowest row of anchor rods is set at a height of 1.0m above the slope foot. The diameter of the slope system anchor rod 21 is 25mm or 28mm; The lower part of the anchor pile is buried at a depth of not less than 3m into the foundation; the anchor piles are arranged in two rows horizontally, with a horizontal spacing of 1.0-1.5m and a vertical spacing of 1.5.

[0022] On the retaining wall, 3-4 rows of anchor rods are set from bottom to top. The anchor rods pass through the retaining wall and enter the stable rock and soil layer, connecting the retaining wall with the rear rock and soil body, "pulling" the retaining wall to prevent further displacement of the retaining wall. The mesh spray anchor adopts the method of installing the steel mesh 22 and spraying concrete. The size of the steel mesh 22 is ∅6@15cmx15cm, spraying C20 concrete, and the thickness of C20 concrete is 100mm; (3) Construction of intercepting ditch 3 The intercepting ditch is formed by composite geomembrane + mesh sprayed concrete. After the intercepting ditch 3 is excavated, a layer of geomembrane is laid along the trench of the intercepting ditch 3 for anti-seepage, and then a layer of steel mesh is laid, and concrete spraying is carried out. The size of the intercepting ditch 3 is 0.6mx0.6m, and the distance between the intercepting ditch 3 and the opening line is not less than 5m and greater than 10m.

[0023] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A construction method for controlling the red line of land acquisition for excavation of tunnel entrance slope, characterized in that: The steps include: S1: Add a composite retaining wall at the opening line for protection. The composite retaining wall adopts a stone-buried concrete structure with anchor piles inside. The lower part of the anchor piles is anchored to the foundation surface, and the upper part is anchored to the slope steel mesh to form a whole; S2: The slope surface from the opening line to the land acquisition red line, i.e. the upper slope of the retaining wall, is fully enclosed and protected by using the slope system anchor rod 21 and the mesh spray anchor method; S3: A drainage ditch shall be set up on the top of the slope within the land acquisition red line. The distance between the drainage ditch and the slope opening line shall not be less than 5m and greater than 10m. The drainage ditch shall be formed by composite geomembrane + mesh sprayed concrete.

2. The construction method for controlling the red line of land acquisition for excavation of tunnel entrance slope according to claim 1 is characterized in that: The steps for forming the composite retaining wall include: (1) construction of the buried stone concrete retaining wall; (2) construction of the anchor piles.

3. The construction method for controlling the red line of land acquisition for excavation of tunnel entrance slope according to claim 2 is characterized in that: The construction of the buried stone concrete retaining wall includes the following steps: the foundation and the wall are cast with C20 buried stone concrete; before the foundation is cast, the size and elevation of the foundation pit are checked, the debris is removed, the bottom of the foundation trench is leveled and compacted, and then the foundation is laid out, the reference line is drawn to lay out the foundation axis and edge line, and the retaining wall is cast in layers, with a layered casting height of 100 to 150 cm; The stone material is rough stone with a particle size of less than 30cm, and the burial rate is 25%; When pouring the wall, the retaining wall shall be divided into joints in the long direction of the wall according to the requirements of the drawings, with a joint distance of 15m, a joint width of 20mm, and asphalt hemp tendons to fill the joints; the filling depth shall not be less than 15cm; The retaining wall is equipped with drainage pipes, which are PVC pipes and arranged in two rows. The diameter of the drainage pipe opening is 50mm. Each row of drainage pipes is arranged at a distance of 2.0m along the length direction of the retaining wall and at a distance of 2.0m along the height direction, in a plum blossom shape, and pre-buried in the wall at a slope of 5%; A crushed stone filter layer is set behind the wall, which is 550mm thick and 500mm wide. A clay compacted waterproof layer is set under the drainage hole behind the wall, which is 300mm thick and the same width as the width of the backfill behind the wall. The backfill behind the retaining wall is made of original soil. The backfill should be done while the wall is being built. The backfill must be compacted layer by layer, and the thickness of each layer is less than 300mm, and the compaction coefficient is greater than 0.

97.

4. The construction method for controlling the red line of land acquisition for excavation of tunnel entrance slope according to claim 3 is characterized in that: The construction of anchor piles includes the following steps: The anchor pile is formed by welding a φ28mm steel bar. The diameter of the anchor pile is 84mm. The anchor pile is welded with the slope system anchor rod to form a whole. The slope system anchor rod is 6-12m long, with a horizontal spacing of 1.5-2.0m and a vertical spacing of 2-2.5m. The downward inclination angle of the anchor rod is 25 degrees. The anchor head of the lowest row of anchor rods is set at a height of 1.0m above the slope foot. The diameter of the slope system anchor rod is 25mm or 28mm. The lower part of the anchor pile is buried at least 3m deep into the foundation; the anchor piles are arranged in 2 rows horizontally, with a horizontal spacing of 1.0-1.5m and a vertical spacing of 1.5; On the retaining wall, 3-4 rows of anchor rods are set from bottom to top. The anchor rods pass through the retaining wall and enter the stable rock and soil layer. The mesh spraying anchor is installed by hanging steel mesh and spraying concrete. The size of the hanging steel mesh is ∅6@15cmx15cm, and C20 concrete is sprayed. The thickness of C20 concrete is 100mm.

5. The construction method for controlling the red line of land acquisition for excavation of tunnel entrance slope according to claim 4 is characterized in that: The construction of the intercepting ditch includes the following steps: After the intercepting ditch is excavated, a layer of geomembrane is laid along the trench of the intercepting ditch for anti-seepage, and then a layer of steel mesh is laid and concrete spraying construction is carried out. The distance between the intercepting ditch and the opening line shall not be less than 5m and greater than 10m.

Images