Anti-sliding key structure, implementation method thereof and landslide treatment method

Abstract

The invention discloses an anti-sliding key structure which comprises a plurality of miniature steel pipe grouting piles and pressure grouting piles, each miniature steel pipe grouting pile comprises a first cement column, two miniature steel pipes welded side by side are arranged in each first cement column, and the bottoms of the miniature steel pipes are flush with the bottom of each first cement column. The invention further discloses an implementation method of the anti-sliding key structure. The implementation method comprises the following steps that a steel pipe pile hole and a pressure grouting hole are drilled in the rear edge position of a landslide; pouring cement paste into the steel pipe pile hole and the pressure grouting hole; two micro steel pipes welded side by side are pressed into the first cement column to the bottom end of the first cement column, and a micro steel pipe grouting pile is formed; and after the cement paste is solidified, an anti-sliding key structure is formed. The invention further discloses a landslide treatment method, 20-40 sets of anti-sliding key structures are implemented on the rear edge of the landslide, the distance between every two adjacent sets of anti-sliding key structures ranges from 4 m to 6 m, and the anti-sliding key structure sets are arranged in a V shape on the plane. The anti-sliding key structure can increase the depth of a sliding surface and reduce the sliding force and the deformation rate of a landslide.

Description

Technical Field

[0001] The invention belongs to the field of landslide control, and in particular relates to an anti-sliding key structure. The invention also relates to an implementation method of the anti-sliding key structure and a landslide control method. Background Art

[0002] Landslide is a common geological disaster, and the damage it causes is also very huge. At present, landslide control methods can be roughly divided into the following three categories: a. Interception and drainage: such as intercepting and diverting surface water outside the sliding body, collecting and dredging groundwater in the sliding body, etc. b. Change the mechanical equilibrium conditions of the landslide: such as reducing the slope of the slope, reducing the weight of the top of the slope and backfilling to counter-pressure the slope foot, or setting up retaining walls, anti-slide piles, anchor cables and other supporting structural measures at the slope foot and other appropriate locations; c. Change the properties of rock and soil: such as grouting, electrochemical reinforcement and other measures.

[0003] For large landslides, when retaining structures are used for control, anti-slide piles are usually used as a control method. This is mainly because anti-slide piles have better control effects. However, their project costs are generally very high, and the construction period is relatively long. Most of them are "rectangular" cross-section piles with better force effects, and most of them are manually excavated. However, when controlling landslides under deformation and creep conditions, the safety risks of manually excavated piles are very high.

[0004] Therefore, it is difficult to deal with some landslide rescue work with tight deadlines and great safety hazards. Especially in some landslides in a deformed creeping state, the construction of anti-slide piles is very dangerous and the safety of construction machinery and personnel cannot be guaranteed. Therefore, an emergency treatment method is urgently needed to slow down the deformation rate of the landslide during the sliding process. Summary of the invention

[0005] The purpose of the present invention is to provide an anti-sliding key structure, which can improve the sliding belt strength of the landslide, change the movement trajectory of the sliding body, and reduce the sliding force and deformation rate of the landslide.

[0006] Another object of the present invention is to provide a method for implementing an anti-slide key, which method can be constructed mechanically.

[0007] The third object of the present invention is to provide a landslide control method.

[0008] The technical solution adopted by the present invention is an anti-sliding key structure, including a plurality of micro steel pipe grouting piles and pressure grouting piles interspersed therein. The micro steel pipe grouting piles include a first cement column, in which two micro steel pipes welded side by side are arranged along the axial direction, and the bottom of the micro steel pipe is flush with the bottom of the first cement column; the diameter of the pressure grouting pile is not larger than that of the first cement column.

[0009] The present invention is also characterized in that: The interspersed arrangement is that several micro steel pipe grouting piles are longitudinally arranged in pairs, with no less than four pairs in each column, and each pair of micro steel pipe grouting piles are tangent to each other and tangent to the adjacent pair; a micro steel pipe grouting pile tangent to both the end pair of micro steel pipe grouting piles is also arranged at the end of the several longitudinally arranged pairs of micro steel pipe grouting piles; the pressure grouting piles are evenly distributed between two columns of micro steel pipe grouting piles.

[0010] The interspersed arrangement is that the micro steel pipe grouting piles form short rows of two in a row and long rows of three in a row, and the short rows and long rows are alternately arranged longitudinally. A micro steel pipe grouting pile is also arranged at the end of the outermost short row; there is the same spacing between adjacent two micro steel pipe grouting piles, and a pressure grouting pile (4) is arranged at the center of any three micro steel pipe grouting piles arranged in a "pin" shape.

[0011] The diameter of the first cement column is 700 - 800 mm, and the diameter of the pressure grouting pile is 120 - 150 mm.

[0012] The micro steel pipe uses a Q235 grade 273 steel pipe with a wall thickness of 12 mm, and the outer wall of the steel pipe is coated with a double-layer epoxy anti-corrosion paint layer.

[0013] The welding is L-shaped fillet welding, the weld length is not less than 100 mm, and the thickness is not less than 6 mm.

[0014] Another technical solution adopted by the present invention is the implementation method of the anti-slip key structure, including the following steps: Step 1: Drill steel pipe pile holes and pressure grouting holes at the position of the rear edge of the landslide. The bottom of the steel pipe pile hole enters the moderately weathered rock not less than 5.0 m, and the bottom of the pressure grouting hole enters the moderately weathered rock not less than 2.0 m; Step 2: Pour cement slurry into the steel pipe pile holes and pressure grouting holes to form the first cement column and the pressure grouting pile respectively; Step 3: Press two并排焊接的微型钢管 (并排焊接的微型钢管 can be translated as "two side-by-side welded micro steel pipes") into the first cement column to the bottom end of the first cement column to form micro steel pipe grouting piles; Step 4: Wait for the cement slurry to solidify to form an anti-slip key structure combined with micro steel pipe piles and pressure grouting.

[0015] Another feature of another technical solution of the present invention is: The pouring pressure of the cement slurry is not less than 3.5 Mpa.

[0016] The water-cement ratio of the cement slurry is 0.45:1, and it uses P.O42.5 ordinary Portland cement.

[0017] The third technical solution adopted by the present invention is a landslide control method, specifically, implementing 20 to 40 groups of anti-slip key structures at the rear edge of the landslide, the spacing between each adjacent group of anti-slip key structures is 4m to 6m, and the anti-slip key structure groups are arranged in a "V" shape on the plane.

[0018] The beneficial effects of the present invention are: 1. The present invention reinforces the rock and soil in the sliding zone of the landslide through anti-slip keys. During the implementation of the anti-slip keys, steel pipe pile holes and pressure grouting holes are first drilled on the landslide, and then pressure grouting is performed on the steel pipe pile holes and pressure grouting holes, so that cement slurry is squeezed into the gaps of the rock and soil to improve the shear strength of the landslide rock and soil itself, and finally the micro steel pipe grouting piles and pressure grouting pile groups form a solid and continuous whole with the surrounding rock and soil, thereby providing greater anti-slip force to reinforce the landslide body. The anti-slip keys are arranged at the rear edge of the landslide to reduce the sliding force, raise the depth of the sliding surface, and reduce the deformation rate of the landslide. When the deformation of the landslide slows down, permanent reinforcement structures such as anti-slip piles and drainage measures are implemented to ultimately ensure the elimination of landslide disasters.

[0019] 2. The anti-slip key structure of the present invention can be directly applied to deep and complex landslide control design projects. The anti-slip key structure of a combination of multiple groups of micro steel pipe grouting piles and pressure grouting is used to control the landslide. Mechanical construction can be carried out when arranging the anti-slip keys, which solves the problems of difficult manual excavation, long construction period and high safety risks of rectangular anti-slip piles commonly used in landslide control projects. Especially in the construction of landslide control in a creeping deformation state, it has great practical value and is of great importance to ensuring project quality and safety.

[0020] 3. The micro steel pipe grouting piles and pressure grouting piles of the present invention have the characteristics of small pile diameter, simple equipment, less disturbance to the surrounding rock and soil during the construction process, and flexible and changeable pile layout, which is conducive to use in some construction sites with poor conditions. In addition, this method has a fast construction speed, a small amount of work, and a short construction period, and is suitable for emergency rescue and disaster relief projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 (a) is a schematic diagram of the anti-sliding key structure of the present invention; Figure 1(b) is an enlarged view of the micro steel tube structure in 1(a); Figure 2 is a cross-sectional view of the arrangement of the anti-sliding key of the present invention; Figure 3 This is a diagram of the arrangement of tight anti-sliding keys according to Embodiment 5 of the present invention; Figure 4 This is the layout diagram of the non-tight anti-sliding key in Example 6 of the present invention.

[0022] Figure 5 This is a plane distribution diagram of the anti-sliding key in landslide control in Example 7 of the present invention; Figure 6It is a plan view of the arrangement of anti-sliding keys in landslide control in Example 7 of the present invention; In the figure: 1. micro steel pipe, 2. first cement column, 3. welding rod, 4. pressure grouting pile, 5. sliding surface, 6. anti-slip key. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1 An anti-sliding key structure of a combination of micro steel pipe piles and pressure grouting, as shown in FIG1 (a), is composed of a plurality of micro steel pipe grouting piles and pressure grouting piles 4 that jointly form an anti-sliding key 6. The micro steel pipe grouting pile comprises a first cement column 2, in which two micro steel pipes 1 welded side by side are arranged axially, and the bottom of the micro steel pipe 1 is flush with the bottom of the first cement column 2. The pressure grouting pile 4 is also a cement column, and its diameter is not greater than that of the first cement column 2. The micro steel pipe grouting pile and the pressure grouting pile are vertically arranged at the rear edge of the landslide body, and the micro steel pipe 1 and the pressure grouting pile 4 pass through the sliding surface 5 of the landslide, with one part above the sliding surface 5 and the other part below the sliding surface 5.

[0025] When the anti-slip key 6 is implemented, first, holes are drilled in the ground at the rear edge of the landslide body to drill out steel pipe pile holes and pressure grouting holes, and then pressure grouting operations are performed on the steel pipe pile holes and pressure grouting holes to squeeze cement slurry into the gaps in the rock and soil body to improve the shear strength of the landslide rock and soil body itself, forming a first cement column 2 and a pressure grouting pile 4 respectively, and then two micro steel pipes 1 welded side by side are pressed in from the axis of the first cement column 2 until the bottom of the first cement column 2, and the cement is solidified overnight to form micro steel pipe grouting piles and pressure grouting piles. The pile group formed by the micro steel pipe grouting piles and the pressure grouting piles forms a solid and continuous whole with the surrounding rock and soil, thereby providing greater anti-slip force, thereby reinforcing the landslide body. The anti-slip key is arranged at the rear edge of the landslide, which can reduce the sliding force, raise the sliding surface depth, and reduce the deformation rate of the landslide. Figure 2 shown.

[0026] Example 2 An anti-sliding key structure of a combination of micro steel pipe piles and pressure grouting, as shown in FIG1 (a), is composed of a plurality of micro steel pipe grouting piles and pressure grouting piles 4 that jointly form an anti-sliding key 6. The micro steel pipe grouting pile comprises a first cement column 2, in which two micro steel pipes 1 welded side by side are arranged axially, and the bottom of the micro steel pipe 1 is flush with the bottom of the first cement column 2. The pressure grouting pile 4 is also a cement column, and its diameter is not greater than that of the first cement column 2. The micro steel pipe grouting pile and the pressure grouting pile are vertically arranged at the rear edge of the landslide body, and the micro steel pipe 1 and the pressure grouting pile 4 pass through the sliding surface 5 of the landslide, with one part above the sliding surface 5 and the other part below the sliding surface 5.

[0027] The welding form of two micro steel pipes is shown in Figure 1 (b). The two micro steel pipes are placed side by side and welded with welding rod 3 using L-shaped circumferential welding. The weld length after welding is not less than 100 mm and the weld thickness is not less than 6 mm. The micro steel pipe is made of Q235 grade 273 steel pipe with a wall thickness of 12 mm. Welding rod 3 uses E43 welding rod, and the outer wall of the micro steel pipe is coated with a double-layer epoxy anti-corrosion paint anti-corrosion layer.

[0028] Example 3 An anti-sliding key structure of a combination of micro steel pipe piles and pressure grouting, as shown in FIG1 (a), is composed of a plurality of micro steel pipe grouting piles and pressure grouting piles 4 that jointly form an anti-sliding key 6. The micro steel pipe grouting pile comprises a first cement column 2, in which two micro steel pipes 1 welded side by side are arranged axially, and the bottom of the micro steel pipe 1 is flush with the bottom of the first cement column 2. The pressure grouting pile 4 is also a cement column, and its diameter is not greater than that of the first cement column 2. The micro steel pipe grouting pile and the pressure grouting pile are vertically arranged at the rear edge of the landslide body, and the micro steel pipe 1 and the pressure grouting pile 4 pass through the sliding surface 5 of the landslide, with one part above the sliding surface 5 and the other part below the sliding surface 5.

[0029] The welding form of two micro steel pipes is shown in Figure 1 (b). The two micro steel pipes are placed side by side and welded with welding rod 3 using L-shaped circumferential welding. After welding, the weld length is not less than 100 mm and the weld thickness is not less than 6 mm. The micro steel pipe is made of Q235 grade 273 steel pipe with a wall thickness of 12 mm. Welding rod 3 is E43 welding rod, and the outer wall of the micro steel pipe is coated with double-layer epoxy anticorrosive paint for corrosion protection. The bottom end of the micro steel pipe 1 is conically closed to form a conical pile tip, and the pile tip length is not less than 30 cm. Fine stone concrete is poured in the micro steel pipe.

[0030] Example 4 An anti-sliding key structure of a combination of micro steel pipe piles and pressure grouting, as shown in FIG1 (a), is composed of a plurality of micro steel pipe grouting piles and pressure grouting piles 4 that jointly form an anti-sliding key 6. The micro steel pipe grouting pile comprises a first cement column 2, in which two micro steel pipes 1 welded side by side are arranged axially, and the bottom of the micro steel pipe 1 is flush with the bottom of the first cement column 2. The pressure grouting pile 4 is also a cement column, and its diameter is not greater than that of the first cement column 2. The micro steel pipe grouting pile and the pressure grouting pile are vertically arranged at the rear edge of the landslide body, and the micro steel pipe 1 and the pressure grouting pile 4 pass through the sliding surface 5 of the landslide, with one part above the sliding surface 5 and the other part below the sliding surface 5.

[0031] The first cement column 2 and the pressure grouting pile 4 are cast with cement paste having a water-cement ratio of 0.45, and the cement paste uses P.O42.5 ordinary Portland cement.

[0032] The welding form of two micro steel pipes is shown in Figure 1 (b). The two micro steel pipes are placed side by side and welded with welding rod 3 using L-shaped circumferential welding. After welding, the weld length is not less than 100 mm and the weld thickness is not less than 6 mm. The micro steel pipe is made of Q235 grade 273 steel pipe with a wall thickness of 12 mm. Welding rod 3 is E43 welding rod, and the outer wall of the micro steel pipe is coated with double-layer epoxy anticorrosive paint for corrosion protection. The bottom end of the micro steel pipe 1 is conically closed to form a conical pile tip, and the pile tip length is not less than 30 cm. Fine stone concrete is poured in the micro steel pipe.

[0033] Example 5 An anti-sliding key structure of a combination of micro steel pipe piles and pressure grouting, wherein a plurality of micro steel pipe grouting piles and pressure grouting piles are interlaced to form an anti-sliding key 6. A single micro steel pipe grouting pile comprises a first cement column 2, in which two micro steel pipes 1 welded side by side are arranged axially, and the bottom of the micro steel pipe 1 is flush with the bottom of the first cement column; the pressure grouting pile 4 is also a cement column, and its diameter is not greater than that of the first cement column 2. The micro steel pipe grouting pile and the pressure grouting pile are vertically arranged at the rear edge of the landslide body, and the micro steel pipe 1 and the pressure grouting pile pass through the sliding surface 5 of the landslide, with one part above the sliding surface 5 and the other part below the sliding surface 5.

[0034] The anti-slip key 6 is interspersed in a manner that a plurality of micro steel pipe grouting piles are arranged longitudinally in pairs, and each row has no less than four pairs, and each pair of micro steel pipe grouting piles is tangent to each other and to the adjacent pair; a micro steel pipe grouting pile tangent to the pair of micro steel pipe grouting piles at the end is also arranged at the end of the plurality of micro steel pipe grouting piles arranged longitudinally in pairs; the pressure grouting piles are evenly distributed between the two rows of micro steel pipe grouting piles. According to actual needs, pressure grouting piles can also be arranged on both sides of the plurality of micro steel pipe grouting piles arranged longitudinally in pairs.

[0035] like Figure 3 The cross-sectional view of an anti-sliding key is shown, and the anti-sliding key is composed of 11 micro steel pipe grouting piles and 8 pressure grouting piles. The 11 micro steel pipe grouting piles are closely distributed, and 10 of them are distributed in a rectangular array of two columns and five rows. The two micro steel pipe grouting piles in each row are tangent to each other, and the two micro steel pipe grouting piles in the rear row are tangent to the micro steel pipe grouting piles in the front row respectively. The 11th micro steel pipe grouting pile is located at the end of the width of the rectangular array, and it is tangent to the two micro steel pipe grouting piles at the end at the same time. The 8 pressure grouting piles are adjacent to the micro steel pipe grouting piles, of which 4 are evenly distributed in the gap formed between the two columns of micro steel pipe grouting piles, and the other 2 are distributed on both sides of the micro steel pipe grouting piles at the end, and the last 2 are distributed on the outside of the rectangular array in the length direction.

[0036] In actual use, the number of rows of micro steel pipe grouting piles can be increased or decreased according to the site conditions. It is also possible to flexibly add pressure grouting piles outside two rows of micro steel pipe grouting piles.

[0037] The welding form of two micro steel pipes is shown in Figure 1(b). The two micro steel pipes are placed side by side, and the two micro steel pipes are welded with electrode 3 by L-shaped circumferential welding. After welding, the weld length is not less than 100 mm, and the weld thickness is not less than 6 mm. The micro steel pipes are made of Q235 grade 273 steel pipes with a wall thickness of 12 mm. Electrode 3 uses E43 electrode, and the outer wall of the micro steel pipe is coated with double-layer epoxy anti-corrosion paint for anti-corrosion. The bottom end of the micro steel pipe 1 is made into a conical closure to form a conical pile tip, the pile tip length is not less than 30 cm, and fine aggregate concrete is poured into the micro steel pipe. The first cement column 2 and the pressure grouting pile 4 are prepared with a cement slurry with a water-cement ratio of 0.45, and the cement slurry uses P.O42.5 ordinary portland cement.

[0038] Example 6 An anti-sliding key structure combined with micro steel pipe piles and pressure grouting is composed of a number of micro steel pipe grouting piles and pressure grouting piles arranged alternately to form an anti-sliding key 6. The first cement column 2 of the micro steel pipe grouting pile has two micro steel pipes 1 welded side by side along the axial direction inside, and the bottom of the micro steel pipe 1 is flush with the bottom of the first cement column 2; the pressure grouting pile 4 is also a cement column, and its diameter is not greater than that of the first cement column 2. The micro steel pipe grouting piles and the pressure grouting piles are vertically arranged at the trailing edge of the landslide, and the micro steel pipes and the pressure grouting piles pass through the landslide sliding surface 5, part of them are above the sliding surface 5, and the other part is below the sliding surface 5, as Figure 2 shown.

[0039] The interlaced arrangement method of the anti-sliding key 6 is that the micro steel pipe grouting piles form short rows of two in a row and long rows of three in a row, and the short rows and the long rows are alternately arranged longitudinally. A micro steel pipe grouting pile is also arranged at the end of the outermost short row; there is the same spacing between two adjacent micro steel pipe grouting piles, and a pressure grouting pile is arranged at the center of any three micro steel pipe grouting piles arranged in a "pin" shape.

[0040] As Figure 4 shown in a cross-sectional view of an anti-sliding key, the anti-sliding key is jointly composed of 8 micro steel pipe grouting piles and 7 pressure grouting piles. The 8 micro steel pipe grouting piles are dispersedly arranged at the same spacing, with a total of 4 rows. The first row is one at the end, the second row has two, the third row has three, and the fourth row has two. A pressure grouting pile is arranged at the center of any three micro steel pipe grouting piles arranged in a "pin" shape.

[0041] In actual use, the number of rows of micro steel pipe grouting piles can be increased.

[0042] The welding form of two micro steel pipes is shown in Figure 1 (b). The two micro steel pipes are placed side by side and welded with welding rod 3 using L-shaped circumferential welding. After welding, the weld length is not less than 100 mm and the weld thickness is not less than 6 mm. The micro steel pipe is made of Q235 grade 273 steel pipe with a wall thickness of 12 mm. Welding rod 3 is E43 welding rod, and the outer wall of the micro steel pipe is coated with double-layer epoxy anticorrosive paint for corrosion protection. The bottom end of the micro steel pipe 1 is conically closed to form a conical pile tip, and the pile tip length is not less than 30 cm. Fine stone concrete is poured in the micro steel pipe. The first cement column 2 and the pressure grouting pile 4 are prepared with cement slurry with a water-cement ratio of 0.45, and the cement slurry uses P.O42.5 ordinary Portland cement.

[0043] The present invention also provides an implementation method of the anti-sliding key structure, which is specifically implemented according to the following steps: Step 1: Drill steel pipe pile holes and pressure grouting holes at the rear edge of the slope. The bottom of the steel pipe pile hole enters the medium weathered rock by no less than 5.0m, and the hole diameter is 700-800mm; the bottom of the pressure grouting hole enters the medium weathered rock by no less than 2.0m, and the hole diameter is 120-150mm; Step 2: pouring cement slurry into the steel pipe pile hole and the pressure grouting hole at a grouting pressure of not less than 3.5 MPa to form a first cement column 2 and a pressure grouting pile 4 respectively; Step 3: Press two micro steel pipes 1 welded side by side into the first cement column 2 to the bottom end of the first cement column 2 to form a micro steel pipe pile.

[0044] Step 4: After the cement slurry solidifies, an anti-sliding key structure of the micro steel pipe pile and pressure grouting is formed.

[0045] The present invention also provides a method for controlling landslides, and the anti-slip key structure is implemented specifically according to the following steps: 20 to 40 groups of anti-slip key structures are implemented at the rear edge of the landslide, with a spacing of 4m to 6m between each group of anti-slip keys, and the arrangement is in a "V" shape on the plane.

[0046] Example 7 The landslide on the south side of the Libi Coal Mine Coal Preparation Plant was deformed and creeped due to extreme rainfall in the summer of 2021, with a maximum deformation rate of 5cm / d. In order to slow down the deformation rate of the landslide as soon as possible, a combination of emergency and permanent management methods was adopted. Emergency management uses anti-sliding keys composed of micro steel pipe piles and pressure grouting that can be mechanically constructed, and arranges them at the rear edge of the landslide to reduce the sliding force, raise the depth of the sliding surface, and reduce the deformation rate. When the deformation of the landslide slows down, permanent reinforcement structures and drainage measures mainly based on anti-sliding piles and prestressed anchor cables are implemented to ultimately ensure the elimination of landslide disasters.

[0047] like Figure 5 and 6As shown in the figure, 31 groups of anti-slip key structures are arranged at the rear edge of the landslide, with a spacing of 6m between each group. The anti-slip key groups are arranged in a "V" shape on the plane. Each group of anti-slip keys consists of 7-22 micro steel pipe grouting piles and 8-22 pressure grouting piles. During implementation, the length of the micro steel pipe grouting pile end entering the medium weathering layer is not less than 7.0m, and the pressure grouting pile end entering the medium weathering rock layer is not less than 2.0m. The pressure grouting hole and the steel pipe pile hole can be constructed at the same time. Grouting is carried out in the pressure grouting hole and the steel pipe pile hole to make them a whole, that is, an anti-slip key, which bears the anti-slip force. Micro steel pipe grouting piles and anti-slip keys with a large number of grouting piles are arranged in the middle of the landslide, and micro steel pipe grouting piles and anti-slip keys with a small number of grouting piles are arranged on both sides. After the overall anti-slip key group is implemented, the deformation rate of the landslide slows down significantly, and the maximum rate monitored is 0.89mm / d, which provides safety guarantee for the construction of anti-slip piles in the front of the landslide.

[0048] The present invention adopts micro steel pipe grouting piles, performs pressure grouting after drilling and then presses into micro steel pipes to reinforce the landslide rock and soil around the steel pipes, and then performs pressure grouting between the micro steel pipe grouting piles to squeeze the slurry into the gaps of the rock and soil to improve the anti-slip performance of the landslide rock and soil itself, and finally forms a solid and continuous whole with the rock and soil around the pile body, thereby providing a greater anti-slip force to reinforce the landslide body. In addition, the use of this governance method can also play a role in raising the sliding surface to a certain extent, thereby reducing the volume of the sliding body and reducing the degree of harm of the landslide. Compared with other technologies combined with micro piles, this method makes more full use of the advantages of micro pile technology, is easy to construct, and is effective in governance.

Claims

1. Anti-sliding key structure, characterized in that: It includes a number of micro-steel pipe grouting piles and pressure grouting piles (4) arranged alternately. The micro-steel pipe grouting pile includes a first cement column (2). Inside the first cement column (2), two micro-steel pipes (1) welded side by side are arranged along its axial direction. The bottom of the micro-steel pipe (1) is flush with the bottom of the first cement column (2). The diameter of the pressure grouting pile (4) is not greater than that of the first cement column (2).

2. The anti-sliding key structure according to claim 1, characterized in that: The way of the alternate arrangement is that a number of micro-steel pipe grouting piles are longitudinally arranged in pairs, and each column has no less than four pairs. Each pair of micro-steel pipe grouting piles is tangent to each other and tangent to the adjacent pair. At the end of the longitudinally arranged micro-steel pipe grouting piles in pairs, there is also a micro-steel pipe grouting pile tangent to both micro-steel pipe grouting piles at the end pair. The pressure grouting piles (4) are evenly distributed between two columns of micro-steel pipe grouting piles.

3. The anti-sliding key structure according to claim 1, characterized in that: The way of the alternate arrangement is that the micro-steel pipe grouting piles form short rows with two in a row and long rows with three in a row. The short rows and long rows are alternately arranged longitudinally. At the end of the outermost short row, there is also a micro-steel pipe grouting pile. There is the same spacing between two adjacent micro-steel pipe grouting piles. A pressure grouting pile (4) is provided at the center of any three micro-steel pipe grouting piles arranged in a "pin" shape.

4. The anti-sliding key structure according to claim 1, characterized in that: The diameter of the first cement column (2) is 700 - 800 mm, and the diameter of the pressure grouting pile (4) is 120 - 150 mm.

5. The anti-sliding key structure according to claim 1, characterized in that: The micro-steel pipe (1) is a Q235 grade 273 steel pipe with a wall thickness of 12 mm, and the outer wall of the steel pipe is coated with a double-layer epoxy anti-corrosion paint layer.

6. The anti-sliding key structure according to claim 1, characterized in that: The welding is L-shaped circumferential welding, the weld length is not less than 100 mm, and the thickness is not less than 6 mm.

7. The implementation method of the anti-sliding key structure according to any one of claims 1 to 6, characterized in that: It includes the following steps: Step 1: Drill steel pipe pile holes and pressure grouting holes at the trailing edge of the landslide. The bottom of the steel pipe pile hole enters the moderately weathered rock not less than 5.0 m, and the bottom of the pressure grouting hole enters the moderately weathered rock not less than 2.0 m. Step 2: Pour cement slurry into the steel pipe pile holes and pressure grouting holes to form the first cement column (2) and the pressure grouting pile (4) respectively. Step 3: Press two micro-steel pipes (1) welded side by side into the first cement column (2) to the bottom end of the first cement column (2) to form a micro-steel pipe grouting pile. Step 4: Wait for the cement slurry to solidify to form an anti-slide key structure combined with micro-steel pipe piles and pressure grouting.

8. The method for implementing the anti-sliding key structure according to claim 7, characterized in that: The pouring pressure of the cement slurry is not less than 3.5 Mpa.

9. The method for implementing the anti-sliding key structure according to claim 7, characterized in that: The water-cement ratio of the cement slurry is 0.45:1, and it uses P.O42.5 ordinary Portland cement.

10. A landslide control method, characterized in that: Using the implementation method of the anti-slide key structure described in any one of claims 7 - 8, specifically, 20 - 40 groups of anti-slide key structures are implemented at the trailing edge of the landslide. The spacing between adjacent groups of anti-slide key structures is 4 m - 6 m, and the layout form of the anti-slide key structure groups is in a "V" shape on the plane.

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