CN111535342B - Method and device for reinforcing sandy cutting high slope by combining microorganisms and anchor cables - Google Patents

Abstract

The invention discloses a method and a device for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables, wherein the method comprises pile hole excavation, first pile hole grouting, second pile hole grouting, third pile hole grouting and third pile hole grouting; the device comprises a mixing device, an anchor rope and a drainage device. The construction of the invention is simpler, the application of the metal pipe pile effectively reduces the hole collapse risk, forms a composite slope reinforcement treatment system of the microorganism pile body, the metal hollow pipe pile, the anchor cable and the solidified sand body among the piles, effectively solves the problems of local damage of shallow layer and integral damage of deep part of the sandy slope, and compared with the existing microorganism solidification (MICP) technology, the invention effectively solves the uneven solidification phenomenon in the MICP technology by mixing and pouring the sand, the microorganism liquid and the nutrient solution, and effectively improves the strength of the solidified soil body.

Description

Method and device for reinforcing sandy cutting high slope by combining microorganisms and anchor cables

Technical Field

The invention relates to the field of foundation treatment construction, in particular to a method and a device for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables, which are mainly used for treating and reinforcing the sandy cutting high slope.

Background

At present, the commonly used method for treating the sandy slope mainly comprises square brushing load reduction, drainage and drainage, slope foot back pressure, slope body reinforcement and the like. The method for reinforcing rock strength includes prestressed anchor rod (cable) reinforcement, retaining wall and slide-resistant pile, pressure grouting, concrete spraying and grouting anti-seepage. But the prior sand cutting high slope treatment technology has the following problems:

(1) in the reinforcement treatment of the sandy side slope, as the sand layer is extremely loose and the construction is difficult, the hole forming difficulty is large, the deviation is easy, the block collapse and the hole collapse are easy to occur in the reinforcement construction of the slide-resistant pile and the anchor rope, and the treatment effect is seriously influenced;

(2) the sandy side slope is easy to generate a shallow local landslide and a deep integral landslide, the shallow local landslide is mainly treated by concrete spraying and grouting seepage prevention methods, but concrete grout is easy to block a grouting seepage passage in construction, so that the local strength is difficult to meet the design requirement; the deep integral landslide is reinforced by an anchor rod (lock), the adhesive force between an anchor rod cable and a sandy side slope body is provided by the friction force between cement paste and a hole wall, and the sandy hole wall is difficult to provide enough friction force and meet the reinforcement requirement of the high cutting sandy side slope;

(3) the cement, lime and other cementing materials used in the slope reinforcement construction can cause damage to the surrounding ecological environment, and the ecological environment is difficult to recover and high in cost after the reinforcement is completed.

Disclosure of Invention

The invention aims to provide a method for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables, which has the technical problems that: at present, in the reinforcement treatment of the sand cutting high slope, the problems of difficult construction operation, poor reinforcement effect, difficult recovery of damage to the natural environment and the like exist.

The principle of the invention is as follows:

the invention relates to a method for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables, a construction method for mixing, pouring sand, bacterial liquid and nutrient solution and pouring into piles in multiple times, and a set of device integrating microorganism mixing, pouring, piling, anchor cable and drainage is designed. And (3) providing cementing power for the sand piles and sand bodies among the piles by utilizing a microorganism induced calcium carbonate precipitation (MICP) technology, pouring to form the sand piles and reinforcing the sand bodies among the piles to form a composite sandy slope reinforcing system which is jointly formed by the metal hollow pipe piles, the sand piles in the microorganism curing pipes, the prestressed anchor cables and the sand bodies among the microorganism curing piles.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention discloses a method for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables, which comprises the following steps:

a. pile hole excavation, wherein a first row of pile holes and a second row of pile holes are manufactured on a soil foundation to be treated, metal hollow pipe piles are placed in the first row of pile holes and the second row of pile holes, anchor cables are placed in the first row of hollow pipe piles, and a drainage device is placed in the second row of hollow pipe piles;

b. grouting the pile holes in the first row for the first time, culturing microbial liquid and nutrient solution required by engineering, preparing fine sand, mixing the three into slurry, pouring the slurry into the hollow pipe piles in the first row after the mixing time meeting the requirement is met, pouring the slurry into the steel stranded wires of the anchoring sections of the anchor cables, curing to form pile bodies in the anchoring sections, beginning to enter soil bodies through liquid outlets in the hollow pipe piles and solidifying sand bodies among the piles, and simultaneously draining the pile holes in the second row through a drainage device;

c. grouting the secondary pile row holes for the first time, excavating a third pile row hole, placing hollow pipe piles and a drainage device, placing anchor cables in the secondary pile row holes, pouring grout into the secondary hollow pipe piles, pouring the grout into the anchor section steel strands of the anchor cables to immerse the anchor section steel strands, forming an anchor section pile body after curing, allowing microbial solution to enter a soil body through a liquid outlet in the hollow pipe piles and solidify inter-pile sand bodies, and performing drainage operation on the third pile row holes through the drainage device;

d. grouting the pile holes in the first row for the second time, pouring grout into the hollow pipe piles in the first row for the second time, pouring the grout into the hollow pipe piles in the first row to immerse the steel strands in the free sections of the anchor cables, curing to form free section pile bodies, allowing microbial liquid to enter soil bodies through liquid outlets in the hollow pipe piles and solidify sand bodies among the piles, and draining the pile holes in the third row through a drainage device;

e. secondary grouting of secondary row pile holes, namely pouring grout for the second time into the secondary row hollow pipe piles, pouring the grout to immerse the free section steel strand of the anchor cable, curing to form a free section pile body, allowing microbial liquid to enter a soil body through a liquid outlet in the hollow pipe piles and solidify inter-pile sand bodies, and simultaneously performing drainage operation on the third row pile holes through a drainage device;

f. grouting and forming the pile holes in the first row for three times, pouring grout into the hollow pipe piles in the first row for the third time to form tail pile bodies, piling and loading the piles to apply a pre-pressing load to promote the seepage of bacterial liquid in the hollow pipe piles in the first row to sand bodies among the piles, allowing microbial liquid to enter soil bodies through liquid outlets in the hollow pipe piles and solidify the sand bodies among the piles, and draining the pile holes in the third row through a drainage device;

after the grout is poured, maintaining to form a first row of formed pile microorganism solidified sand piles and performing anchoring operation;

g. thirdly grouting and forming secondary row pile holes, pouring grout for the third time into the secondary row hollow pipe piles to form tail pile bodies, piling and loading the piles to apply a pre-pressing load, enabling microbial bacteria liquid to enter soil bodies through liquid outlets in the hollow pipe piles and solidify sand bodies among the piles, and meanwhile, performing drainage operation on the third row pile holes through a drainage device;

after the grout is poured, curing to form secondary rows of formed microorganism solidified sand piles and performing anchoring operation;

and (3) forming a composite slope reinforcement treatment system of the microorganism solidified sand pile, the hollow pipe pile, the anchor rope and the sand body between the microorganism solidified sand piles through operations of pouring microorganism solidified slurry, forming a pile, maintaining and the like for three times, and repeating the operations to realize reinforcement treatment of the sandy cutting high slope.

Further, the bacteria in the microbial liquid are bacillus pasteurii; the concentration of urea in the nutrient solution is 0.35-0.55 mol/L, the concentration of calcium chloride is 0.25-0.3 mol/L, the concentration of sodium acetate is 0.1-0.25 mol/L, the concentration of ammonium chloride is 0.012-0.018 mol/L, and the concentration of yeast extract is 0.15 g/L; the sand is fine sand.

Furthermore, the temperature of the nutrient solution is 20-35 ℃, the construction environment temperature is 15-45 ℃, the mixing time of the microorganism slurry is 5-30 min and the microorganism slurry is used along with the mixing, the single hole pouring time of the slurry is not more than 30min, and the pre-pressing load and the drainage time are determined by the distance between two rows of pile holes and the permeability coefficient.

A device for realizing a method for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables comprises a mixing device, the anchor cables and a drainage device; the mixing device is communicated with the top opening of the hollow pipe pile through a grouting pipe, a slurry valve and a high-pressure pump are arranged on the grouting pipe, and a plurality of seepage holes are formed in the circumferential wall of the hollow pipe pile; the drainage device is placed in the hollow tubular pile and used for discharging water in the pile hole.

Further, the mixing device comprises a mixing cylinder body, a mixing shaft is arranged in the mixing cylinder body, a mixing motor for driving the mixing shaft to rotate is arranged at the bottom of the mixing cylinder body, and a plurality of mixing blades are arranged on the mixing shaft; the mixing motor and the high-pressure pump are respectively and electrically connected with a power supply through a conductive cable; and the bottom of the mixing cylinder body is provided with a supporting leg caster.

Furthermore, the anchor cable comprises a guide head, a wire binding ring, a wire fixing ring, an anchoring section steel strand, a free section steel strand, an anchoring pier, an anchor backing plate and an anchor device.

Furthermore, the hollow pipe pile is made of metal materials, the bottom of the hollow pipe pile is conical, a protective cap is arranged at an opening at the top of the hollow pipe pile, a grouting opening is formed in the middle of the protective cap, steel strand avoidance holes are annularly arranged around the grouting opening, and a plurality of metal barbs are arranged on the outer circumferential wall of the hollow pipe pile; the diameter of the seepage hole is 0.1 cm-0.3 cm.

Further, the drainage device comprises a drainage pipe, a self-cleaning type water suction bottom valve and a drainage pump.

Further, the diameter of the hollow tubular pile is smaller than the aperture of the pile hole, and the diameter difference is 10 cm.

Compared with the prior art, the invention has the beneficial technical effects that:

(1) compared with the existing sand slope reinforcement treatment technology, the construction is simpler, the application of the metal tubular pile effectively reduces the hole collapse risk, a composite slope reinforcement treatment system of microorganism pile bodies, the metal hollow tubular pile, anchor cables and inter-pile solidified sand bodies is formed, and the problems of local shallow layer damage and integral deep part damage of the sand slope are effectively solved.

(2) Compared with the traditional slope reinforcement technology, the technology of utilizing the microorganism to induce the calcium carbonate precipitation (MICP) reduces the energy consumption and the pollution problem of cementing materials such as cement, lime and the like to the environment.

(3) Compared with the existing technology of microorganism reinforcement rock-soil Mass (MICP), the phenomenon of uneven reinforcement in the MICP technology is effectively solved through mixing and pouring of sand, bacterial liquid and nutrient solution, and the strength of reinforcing the side slope is effectively improved.

Drawings

The invention is further illustrated in the following description with reference to the drawings.

FIG. 1 is a flow chart of a method for reinforcing a sand cutting high slope by combining microorganisms and anchor cables according to the invention;

FIG. 2 is a schematic construction diagram of step a of the construction method of the present invention;

FIG. 3 is a schematic construction diagram of step b of the construction method of the present invention;

FIG. 4 is a schematic construction diagram of step c of the construction method of the present invention;

FIG. 5 is a schematic view of the construction of step d of the construction method of the present invention;

FIG. 6 is a schematic view of the construction of step e of the construction method of the present invention;

FIG. 7 is a schematic view of the construction of step f of the construction method of the present invention;

FIG. 8 is a g-step construction diagram of the construction method of the present invention;

FIG. 9 is a schematic view of the device for reinforcing a sand cut high slope by combining microorganisms and anchor cables according to the present invention;

fig. 10 is a partial enlarged view of fig. 9 at a;

fig. 11 is a partial enlarged view at B of fig. 9;

fig. 12 is a schematic view of a cable bolt structure;

fig. 13 is a schematic structural view of a hollow tubular pile;

FIG. 14 is a schematic top view of the protective cap;

fig. 15 is a schematic view of a drain structure.

Description of reference numerals: 1. sand bodies between piles; 1-1, pile holes are arranged at the head row; 1-2, secondary row pile holes; 1-3, a third row of pile holes; 2. hollow pipe piles; 2-1, seepage holes; 2-2, metal barbs; 2-3, a protective cap; 3. an anchor cable; 3-1, a guide head; 3-2, a wire harness loop; 3-3, a wire fixing ring; 3-4, anchoring section steel strand wires; 3-5, free section steel strand; 3-6, anchoring piers; 3-7, anchor backing plate; 3-8, an anchorage device; 4. a drainage device; 4-1, a drain pipe; 4-2, self-cleaning water absorption bottom valve; 4-3, draining pump; 5. solidifying the sand pile by microorganisms; 5-1, anchoring section pile bodies; 5-1, free section pile body; 5-3, a tail section pile body; 6. pre-pressing load; 7. a grouting pipe; 8. a mud valve; 9. a high pressure pump; 10. a mixing cylinder; 11. a mixing shaft; 12. a mixing motor; 13. a mixing blade; 14. a power source; 15. the leg truckles.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and the detailed description.

As shown in fig. 1 to 8, the present embodiment discloses a method for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables, which includes the following steps:

a. pile holes are excavated, as shown in fig. 2, a first row of pile holes 1-1 and a second row of pile holes 1-2 are formed in the soil foundation to be treated, metal hollow pipe piles 2 are placed in the first row of pile holes 1-1 and the second row of pile holes 1-2, anchor cables 3 are placed in the first row of hollow pipe piles 2, and drainage devices 4 are placed in the second row of hollow pipe piles 2.

b. The pile holes in the first row are firstly grouted, as shown in fig. 3, microbial liquid and nutrient solution required by engineering are cultured, fine sand is prepared, the three are mixed to prepare slurry, the slurry is poured into the hollow pipe pile 2 in the first row after the mixing time meeting the requirement is met, the slurry is poured into the steel strand wires in the anchoring section of the anchor cable 3, the pile body 5-1 in the anchoring section is formed after maintenance, the microbial liquid starts to enter the soil body through the liquid outlet in the hollow pipe pile 3 and solidifies sand bodies 1 among the piles, and meanwhile, drainage operation is carried out on the pile holes 1-2 in the second row through the drainage device 4.

c. And (3) grouting the secondary row of pile holes for the first time, excavating a third row of pile holes 1-3, placing hollow tubular piles 2 and a drainage device 4, placing anchor cables 3 in the secondary row of pile holes 1-2, pouring grout into the secondary row of hollow tubular piles 2, pouring the grout into the anchor section steel strands of the anchor cables 3, curing to form anchor section pile bodies 5-1, allowing microbial solution to enter a soil body through a liquid outlet in the hollow tubular piles 3 and solidify sand bodies 1 among the piles, and draining the third row of pile holes 1-3 through the drainage device 4.

d. And (3) performing secondary grouting on the pile holes in the first row, pouring grout for the second time into the hollow tubular piles 2 in the first row as shown in fig. 5, pouring the grout to immerse the steel strands in the free sections of the anchor cables 3, curing to form free section pile bodies 5-2, allowing microbial liquid to enter soil bodies through liquid outlets in the hollow tubular piles 3 and solidify inter-pile sand bodies 1, and draining the pile holes 1-3 in the third row through a drainage device 4.

e. And (3) secondary grouting of the secondary row of pile holes, as shown in fig. 6, pouring grout for the second time into the secondary row of hollow tubular piles 2, pouring the grout into the hollow tubular piles 2 to immerse the free section steel strands of the anchor cables 3, curing to form free section pile bodies 5-2, allowing microbial liquid to enter soil bodies through liquid outlets in the hollow tubular piles 3 and solidify inter-pile sand bodies 1, and draining the third row of pile holes 1-3 through a drainage device 4.

f. And (3) performing three-time grouting forming on the first row of pile holes, as shown in fig. 7, pouring grout for the third time into the first row of hollow pipe piles 2 to form tail-section pile bodies 5-3, piling and loading the piles to apply a pre-pressing load 6 to promote the seepage of bacteria liquid in the first row of hollow pipe piles 2 to inter-pile sand bodies 1, allowing the microorganism bacteria liquid to enter soil bodies through liquid outlets on the hollow pipe piles 3 and solidify the inter-pile sand bodies 1, and simultaneously performing drainage operation on the third row of pile holes 1-3 through a drainage device 4.

And after the grout is poured, maintaining to form the pile microorganism solidified sand piles 5 which are formed in the first row and performing anchoring operation.

g. And (3) grouting and forming the secondary row of pile holes for three times, as shown in fig. 8, grouting slurry for the third time into the secondary row of hollow pipe piles 2 to form end-section pile bodies 5-3, piling and loading the formed piles to apply a pre-pressing load 6, allowing the microbial liquid to enter a soil body through a liquid outlet on the hollow pipe piles 3 and solidify sand bodies 1 among the piles, and draining the third row of pile holes 1-3 through a drainage device 4. And after the grout is poured, curing to form secondary rows of formed microorganism solidified sand piles 5 and performing anchoring operation.

And (3) forming a composite slope reinforcement treatment system of the microorganism solidified sand pile 5, the hollow pipe pile 2, the anchor cable 3 and the microorganism solidified inter-pile sand body 1 by pouring microorganism solidified slurry, forming a pile, maintaining and the like for three times, and repeating the operation to realize reinforcement treatment of the sandy cutting high slope.

Culturing microbial liquid and nutrient solution required by engineering, preparing fine sand, and mixing the three to prepare slurry, wherein the weight mixture ratio of the microbial liquid to the nutrient solution to the fine sand is 1: 25: 72. wherein the bacteria in the microbial liquid are Bacillus pasteurianus, and the concentration OD of the Bacillus pasteurianus in the microbial liquid₆₀₀1.2. The bacillus pasteurii has the function of reinforcing loose sand and has good cementing effect. The concentration of urea in the nutrient solution is 0.35-0.55 mol/L, the concentration of calcium chloride is 0.25-0.3 mol/L, the concentration of sodium acetate is 0.1-0.25 mol/L, the concentration of ammonium chloride is 0.012-0.018 mol/L, and the concentration of yeast extract is 0.15 g/L; the sand is fine sand.

In this embodiment, the concentration of urea is preferably 0.45mol/L, the concentration of calcium chloride is preferably 0.27mol/L, the concentration of sodium acetate is preferably 0.20mol/L, and the concentration of ammonium chloride is preferably 0.015 mol/L. Laboratory tests show that the concentration is most favorable for the calcium carbonate precipitation reaction induced by the microorganisms.

The temperature of the nutrient solution is 20-35 ℃, the temperature of the construction environment is 15-45 ℃, and the temperature condition of the microorganism induced calcium carbonate precipitation reaction is effectively ensured to be met. The mixing time of the microorganism slurry is 5min to 30min and the slurry is used along with the mixing, the single-hole pouring time of the slurry is not more than 30min, the microorganism liquid, the nutrient solution and the fine sand are fully mixed, the microorganism induced calcium carbonate precipitation reaction is promoted to be fully carried out, and the calcium carbonate precipitation is ensured to be generated in the pile holes and between the piles.

The pre-pressing load and the drainage time are determined by the distance between two rows of pile holes and the permeability coefficient, and the skilled person can understand that the calculation can be carried out according to Darcy's law to solve the problem.

As shown in fig. 9, a irrigation and drainage anchor cable device for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables comprises a mixing device, an anchor cable 3 and a drainage device 4. The mixing device is communicated with the top opening of the hollow pipe pile 2 through a grouting pipe 7, a slurry valve 8 and a high-pressure pump 9 are arranged on the grouting pipe 7, a plurality of seepage holes 2-1 are formed in the circumferential wall of the hollow pipe pile 2, and microbial bacteria liquid and nutrient solution in slurry after pile forming by pouring can flow into soil through the seepage holes 2-1. A drainage device 4 is placed in the hollow tubular pile 2 for draining water in the pile hole.

The mixing device includes mixing barrel 10, is provided with in the mixing barrel 10 and mixes axle 11, and the bottom of mixing barrel 10 is provided with the mixing motor 12 that 11 pivoted of drive mixing axle were provided with, and power connected mode is particularly, and the drive shaft and the internal thread steel pipe of mixing motor 12 are connected, and the lower extreme of mixing axle 11 is fixed with the external screw thread steel pipe, external screw thread steel pipe and internal thread steel pipe arc cooperation threaded connection to realize that mixing motor 12 transmits power to mixing axle 11. It should be noted that the rotation direction of the driving shaft of the mixing motor 12 is opposite to the thread turning direction of the steel pipe, so as to prevent the external thread steel pipe and the internal thread steel pipe from being unscrewed mutually. A plurality of mixing blades 13 are welded on the mixing shaft 11; the mixing motor 12 and the high-pressure pump 9 are respectively electrically connected with a power supply 14 through conducting cables. In order to ensure that the device is movable and convenient to construct, the bottom of the mixing cylinder body 10 is provided with supporting leg casters 15.

As shown in fig. 10 to 12, the anchor cable 3 comprises a guide head 3-1, a wire harness ring 3-2, a wire fixing ring 3-3, an anchoring section steel strand 3-4, a free section steel strand 3-5, an anchoring pier 3-6, an anchor backing plate 3-7 and an anchor device 3-8. Specifically, the guide head 3-1 is a carbon steel cap body with a pointed head, a steel strand central through hole is formed in the cap body, and the guide head is used as a protective sleeve arranged at the front end of a steel strand when a steel strand pulling machine pulls the steel strand. The wire binding ring 3-2 is formed by winding an iron wire with the diameter of 16mm, is not less than two turns and is matched with the wire fixing ring 3-3 for use, and the anchoring force of the steel strand is improved. The wire fixing ring 3-3 is a carbon steel or plastic ring with reserved steel strand holes, so that the steel strands are reliably separated and uniformly distributed in the holes to be fully stressed. The steel strand is processed and manufactured, forms an anchor cable steel strand bundle together with a guide head 3-1, a strand ring 3-2 and a wire fixing ring 3-3, is placed in a hollow tubular pile 2, and is subjected to step grouting and conventional prestressed anchor cable anchoring construction.

As shown in fig. 13 and 14, the hollow tubular pile 2 is made of a metal material, and the bottom is tapered to facilitate insertion into the pile hole. The outer circumferential wall of the hollow tubular pile 2 is provided with a plurality of metal barbs 2-2, and the metal barbs 2-2 can be embedded into the inter-pile sand body 1 to form stable connection. The top opening of the hollow tubular pile 2 is provided with a protective cap 2-3, the middle part of the protective cap 2-3 is provided with a grouting port, steel strand avoidance holes are annularly arranged around the grouting port, and the protective cap 2-3 and the hollow tubular pile 2 are connected in a socket-and-spigot manner. It should be noted that the protective caps 2-3 are placed immediately after the anchor cable 3 is placed.

The diameter of the seepage hole 10 is 0.1 cm-0.3 cm, which is most beneficial to the seepage of mixed slurry and has little influence on the strength of the hollow pipe pile 2. The diameter of the hollow tubular pile 2 is smaller than the aperture of the pile hole, and the diameter difference is 10cm, so that the hollow tubular pile 2 is ensured to be smoothly placed into the pile hole.

As shown in fig. 15, the drain device 4 includes a drain pipe 4-1, a self-cleaning type suction foot valve 4-2, and a drain pump 4-3.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims (8)

1. A method for reinforcing a sandy cutting high slope by combining microorganisms and anchor cables is characterized by comprising the following steps:

a. pile holes are excavated, a first row of pile holes (1-1) and a second row of pile holes (1-2) are manufactured on the soil foundation to be treated,

metal hollow pipe piles (2) are placed in the first row of pile holes (1-1) and the second row of pile holes (1-2), anchor cables (3) are placed in the first row of hollow pipe piles (2), and water drainage devices (4) are placed in the second row of hollow pipe piles (2);

b. grouting a first row of pile holes for the first time, culturing microbial liquid and nutrient solution required by engineering, preparing fine sand, mixing the three into slurry, pouring the slurry into the first row of hollow pipe piles (2) after the mixing time meeting the requirement is met, pouring the slurry into the anchoring section steel strand of the anchor rope (3), curing to form an anchoring section pile body (5-1), allowing the microbial liquid to enter a soil body through a liquid outlet on the hollow pipe piles (2) and solidify inter-pile sand bodies (1), and draining the second row of pile holes (1-2) through a drainage device (4);

c. grouting a secondary pile row hole for the first time, excavating a third pile row hole (1-3), placing a hollow pipe pile (2) and a drainage device (4), placing an anchor rope (3) in the secondary pile row hole (1-2), pouring grout into the secondary hollow pipe pile (2), pouring the grout into an anchoring section steel strand of the anchor rope (3), forming an anchoring section pile body (5-1) after maintenance, allowing microbial bacteria liquid to enter a soil body through a liquid outlet on the hollow pipe pile (2) and solidify inter-pile sand bodies (1), and draining the third pile row hole (1-3) through the drainage device (4);

d. grouting the pile holes in the first row for the second time, pouring grout into the hollow pipe piles (2) in the first row for the second time, pouring the grout into the free-section steel strands of the immersed anchor cables (3), curing to form free-section pile bodies (5-2), allowing microbial liquid to enter soil bodies through liquid outlets in the hollow pipe piles (2) and solidify inter-pile sand bodies (1), and draining the pile holes (1-3) in the third row through a drainage device (4);

e. secondary grouting of secondary row pile holes, namely, grouting slurry for the second time into a secondary row hollow pipe pile (2), grouting the slurry to immerse a free section steel strand of the anchor cable (3), forming a free section pile body (5-2) after maintenance, allowing microbial liquid to enter a soil body through a liquid outlet on the hollow pipe pile (2) and solidify inter-pile sand bodies (1), and simultaneously, performing drainage operation on a third row of pile holes (1-3) through a drainage device (4);

f. grouting and forming the pile holes in the first row for three times, pouring grout into the hollow pipe piles (2) in the first row for the third time to form tail-section pile bodies (5-3), piling and loading the piles to apply a pre-pressing load (6) to promote the seepage of bacteria liquid in the hollow pipe piles (2) in the first row to sand bodies (1) among the piles, allowing the microorganism bacteria liquid to enter soil bodies through liquid outlets in the hollow pipe piles (2) and solidify the sand bodies (1) among the piles, and draining the pile holes (1-3) in the third row through a drainage device (4);

after the grout is poured, the grout is cured to form a first row of formed microorganism solidified sand piles (5) and anchoring operation is carried out;

g. thirdly grouting and forming secondary row pile holes, pouring grout for the third time into the secondary row hollow pipe piles (2) to form tail-section pile bodies (5-3), piling and loading the piles to apply a pre-pressing load (6), enabling microbial bacteria liquid to enter soil bodies through liquid outlets on the hollow pipe piles (2) and solidify sand bodies (1) among the piles, and meanwhile, draining the third row pile holes (1-3) through a drainage device (4);

after the grout is poured, curing to form secondary rows of formed microorganism solidified sand piles (5) and performing anchoring operation;

and pouring microorganism curing slurry, forming a pile and maintaining for three times to form a composite slope reinforcement treatment system of the microorganism curing sand pile (5), the hollow pipe pile (2), the anchor cable (3) and the microorganism curing inter-pile sand body (1), and repeating the operations to realize reinforcement treatment of the sandy cutting high slope.

2. The method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to claim 1, wherein the method comprises the following steps: the bacteria in the microbial liquid are bacillus pasteurii; the concentration of urea in the nutrient solution is 0.35-0.55 mol/L, the concentration of calcium chloride is 0.25-0.3 mol/L, the concentration of sodium acetate is 0.1-0.25 mol/L, the concentration of ammonium chloride is 0.012-0.018 mol/L, and the concentration of yeast extract is 0.15 g/L; the sand is fine sand.

3. The method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to claim 1, wherein the method comprises the following steps: the temperature of the nutrient solution is 20-35 ℃, the construction environment temperature is 15-45 ℃, the mixing time of the microorganism slurry is 5-30 min and the microorganism slurry is used along with the mixing, the single hole pouring time of the slurry is not more than 30min, and the pre-pressing load and the drainage time are determined by the distance between two rows of pile holes and the permeability coefficient.

4. A device for realizing the method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to any one of claims 1 to 3, which is characterized in that: comprises a mixing device, an anchor cable (3) and a drainage device (4); the mixing device is communicated with the top opening of the hollow pipe pile (2) through a grouting pipe (7), a slurry valve (8) and a high-pressure pump (9) are arranged on the grouting pipe (7), and a plurality of seepage holes (2-1) are formed in the circumferential wall of the hollow pipe pile (2); the drainage device (4) is placed in the hollow tubular pile (2) and is used for draining water in a pile hole;

the anchor cable (3) comprises a guide head (3-1), a wire binding ring (3-2), a wire fixing ring (3-3), an anchoring section steel strand (3-4), a free section steel strand (3-5), an anchoring pier (3-6), an anchor backing plate (3-7) and an anchor device (3-8);

the guide head (3-1) is a carbon steel cap body with a pointed head, and a steel strand central through hole is formed in the carbon steel cap body; the wire binding ring (3-2) is wound by iron wires with the diameter of 16 mm; the wire fixing ring (3-3) is a carbon steel or plastic ring with reserved steel strand holes and is used for reliably separating the steel strands; the plurality of wire binding rings (3-2) and the wire fixing rings (3-3) are alternately arranged on the steel strands (3-4) of the anchoring section of the anchor cable (3).

5. The device for implementing the method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to any one of claims 1 to 3, wherein the method comprises the following steps: the mixing device comprises a mixing cylinder body (10), a mixing shaft (11) is arranged in the mixing cylinder body (10), a mixing motor (12) for driving the mixing shaft (11) to rotate is arranged at the bottom of the mixing cylinder body (10), and a plurality of mixing blades (13) are arranged on the mixing shaft (11); the mixing motor (12) and the high-pressure pump (9) are respectively and electrically connected with a power supply (14) through a conducting cable; and the bottom of the mixing cylinder body (10) is provided with a supporting leg caster (15).

6. The device for implementing the method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to any one of claims 1 to 3, wherein the method comprises the following steps: the hollow pipe pile (2) is made of metal materials, the bottom of the hollow pipe pile is conical, a protective cap (2-3) is arranged at the opening of the top of the hollow pipe pile, a grouting opening is formed in the middle of the protective cap (2-3), steel strand avoidance holes are annularly arranged around the grouting opening, and a plurality of metal barbs (2-2) are arranged on the outer circumferential wall of the hollow pipe pile (2); the diameter of the seepage hole (2-1) is 0.1 cm-0.3 cm.

7. The device for implementing the method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to any one of claims 1 to 3, wherein the method comprises the following steps: the drainage device (4) comprises a drainage pipe (4-1), a self-cleaning type water suction bottom valve (4-2) and a drainage pump (4-3).

8. The device for implementing the method for reinforcing the sand cutting high slope by combining the microorganisms and the anchor cables according to any one of claims 1 to 3, wherein the method comprises the following steps: the diameter of the hollow tubular pile (2) is smaller than the aperture of the pile hole, and the diameter difference is 10 cm.

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