CN107246267B

CN107246267B - Vertical shaft wall structure in bad stratum, construction device and construction method

Info

Publication number: CN107246267B
Application number: CN201710611082.7A
Authority: CN
Inventors: 董亚宁
Original assignee: Magang Group Holding Co Ltd
Current assignee: Magang Group Holding Co Ltd
Priority date: 2017-07-25
Filing date: 2017-07-25
Publication date: 2023-07-04
Anticipated expiration: 2037-07-25
Also published as: CN107246267A

Abstract

A vertical shaft wall structure in a poor stratum belongs to mine vertical shaft construction. The well shaft is arranged in a bad stratum, and is characterized in that a high-spraying curtain pile well wall structure is arranged at the neck section of the upper part of the vertical well, a positioning and targeting grouting section well wall structure and a well wall are arranged at the bedrock section, and the upper well wall structure and the lower well wall structure are concentric and have the same diameter and are tightly connected into a whole to protect the well wall; the well neck section high-spraying curtain pile well wall structure takes the center of a well shaft as a circle center, at least three circles of round-ring-shaped high-spraying curtain walls with sealed ends are arranged along the periphery of 0.6m of the rough diameter line of the well shaft, the positioning and targeting grouting well wall structure is provided with at least 8 positioning and targeting grouting sections perpendicular to the ground along the periphery of 2m of the rough diameter line of the well shaft, and the positioning and targeting grouting sections protect the well wall. The advantages are novel conception, simple structure, stability and reliability; the high-spraying curtain wall and the positioning targeting grouting section protect the well wall, enhance the bearing capacity and the deformation resistance, and have good water blocking effect; the construction is quick and convenient, the quick digging and building of the shaft are realized, the cost is saved, and the safe and smooth running of mine production is ensured.

Description

Vertical shaft wall structure in bad stratum, construction device and construction method

Technical Field

The invention belongs to the construction of mine vertical shafts, and particularly relates to a vertical shaft wall structure of a bad stratum and a construction method.

Background

Underground mining, a vertical shaft is an important lifting, ventilation, transportation, drainage and personnel safety channel for connecting underground with the earth surface, a shaft is directly connected with the earth surface and directly bears the whole load of a shaft lifting facility, and for this purpose, the shaft structure of the vertical shaft must be ensured to have enough bearing capacity and deformation resistance. Vertical shaft top-down: neck, well and bottom of the well. With the rapid development of the global mining industry, underground mining occupies a larger proportion, vertical shafts are deeper, and stratum passing through the vertical shafts is more complex. The poor stratum where the vertical shaft is positioned is represented by a thick water-containing backfill surface soil layer at the well neck section, and a water-rich layer at the well body section. The well neck structure comprises a well shaft surrounded by a circular well wall, and thick backfill surface soil layers are arranged on the periphery of the well wall. The backfill surface soil layer has complex structure, the surface soil is a clay layer or a mixed layer of clay, broken stone and ore, the soil body is loose, irregular and uneven, the compactness is low, a large number of pores are distributed, the strength is low, the bearing capacity is low, the water permeability is strong, the backfill surface soil layer has strong fluidity under the action of water and pressure water or power water, disasters such as water burst of a shaft and uneven settlement of a surface wellhead foundation are easily caused, the shaft facilities are damaged, or casualties seriously influence the smooth production. The poor aquifer of the bedrock section of the well body is a strong weathered layer, a apoplexy layer and a water-rich layer, wherein the strong weathered layer and the apoplexy layer belong to weak aquifers, the crack development degree is different, and the lower part is the strong aquifer. The raw rock components of the bad aquifer are mainly tuff, are changed into clay minerals such as kaolin and the like under the action of strong wind, are loose soil or are in a residual block shape, are disintegrated into loose shapes when being exposed to air or water, are permeable in cracks, have large water inflow, and cannot be excavated and supported in a shaft.

The conventional disposal method of the thick water-containing backfill surface soil layer of the vertical shaft neck is a soil replacement method or a freezing method, and the conventional method of the base rock section of the well body in the poor water-containing layer is a freezing method or a shaft working surface grouting method. The reinforced structure of the soil replacement method comprises the steps of firstly, completely excavating a thick water-containing backfill surface soil layer, pouring a well wall structure, and then, backfilling homogeneous soil in a layering manner, wherein the defects are that: the earth surface excavation area is large, and is limited by surrounding existing buildings, so that large-area excavation is difficult to perform; the construction period of layered backfilling homogeneous soil is long and the construction cost is high. The freezing method reinforcing structure is characterized in that one or two circles of freezing holes are drilled from the ground surface to the stable rock stratum or the bottom of a shaft by 10-20 m, freezing steel pipes are arranged in the freezing Kong Naquan holes, freezing stations are arranged on the ground surface, and refrigerating fluid is circularly conveyed to the bottoms of the freezing holes through the freezing steel pipes, so that surrounding rocks around the freezing shaft are reached, the aim of preventing water seepage and reinforcing the surrounding rocks is fulfilled, and the defects are that: the refrigerating system has long equipment construction period, high construction cost and high power consumption. The method for grouting the working surface of the shaft has the defects that the grouting pump has small power and grouting capacity, the grouting material consumes much water in a crack channel is difficult to block, the water inflow is still large after the shaft is excavated, and the crack water inflow drives surrounding rock to collapse to cause disasters. Practice shows that the three methods have the defects of long construction period, high construction cost and serious influence on production. It is imperative to find a more reasonable well wall structure.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a vertical shaft wall structure in a bad stratum and a construction method, and the vertical shaft wall structure is simple, stable, reliable and quick in construction, and can ensure the stability of a vertical shaft.

A vertical shaft wall structure in a bad stratum comprises a shaft arranged in the bad stratum, and is characterized in that: the high-spraying curtain pile well wall structure arranged at the well neck section at the upper part of the vertical well, the positioning targeting grouting well wall structure arranged at the bedrock section and the well wall are concentric, have the same diameter and are tightly connected into a whole; the vertical shaft neck section high-spraying curtain pile well wall structure comprises a rock stratum excavated in a rough diameter line of a shaft, a well wall is poured between the clean diameter line of the shaft and the rough diameter line of the shaft, at least three circles of annular high-spraying curtain walls with sealed ends are arranged along the periphery of 0.6m of the rough diameter line of the shaft by taking the center of the shaft as a circle center, the distance between the two circles of high-spraying curtain walls is 1.2-2 m, the thickness of the high-spraying curtain walls is 800-1000 mm, and the depth is greater than the thickness of a thick water-containing backfill surface soil layer so as to protect the wall of the neck section of the well, and the bearing capacity, the deformation resistance and the waterproof capacity are enhanced; the poor aquifer positioning and targeting grouting vertical shaft wall structure of the bedrock section comprises positioning and targeting grouting drilling holes, orifice pipes and grouting sections which are arranged around a shaft, wherein the positioning and targeting grouting drilling holes are uniformly arranged in pairs and perpendicular to the ground outside the shaft along the circumference of a rough diameter line by 2m by taking the center of the shaft as the center of the shaft, and at least 8 positioning and targeting grouting drilling holes are arranged in the whole shaft; the orifice pipe is arranged in a positioning and targeting grouting drilling hole, cement slurry hydraulic pressure is injected from the targeting grouting drilling hole, the cement slurry hydraulic pressure is expanded into a bad water-bearing layer for the development of 5-10 m bedrock cracks around the drilling hole, the cement slurry is solidified into a grouting section, and the grouting section is layered in the bad water-bearing layer where the bedrock section is positioned so as to fill and plug the cracks, strengthen surrounding rocks, protect the bedrock section well wall, and strengthen the deformation resistance and the waterproof capacity; the well wall is composed of an inner wall and an outer wall, the outer wall is reinforced concrete with the thickness of not less than 300mm, and the inner wall is reinforced concrete with the thickness of not less than 600 mm.

The high-spraying curtain wall is formed by connecting high-spraying curtain piles on the same ring, wherein the high-spraying curtain piles are formed by injecting cement paste into preset high-spraying drilling holes by adopting a three-pipe high-pressure rotary spraying technology, solidifying the cement paste into cylindrical pile bodies, and mutually overlapping the pile bodies and the pile bodies on the same ring to form the annular high-spraying curtain wall.

Further improved, the high-spraying drilling hole is formed by drilling vertically downwards from the ground by a drilling machine, the depth is larger than the thickness of a thick water-containing backfill surface soil layer, and the diameter of the drilling hole is not smaller than 130mm; the cement slurry is injected into the high-injection drilling hole and expands to the periphery, the diameter of a pile is 800-1000 mm, and an overlapping connection area which is not smaller than 100mm is arranged between piles.

Further improved, two core drilling holes are symmetrically arranged in the high-spraying curtain wall area, the core drilling holes are drilled vertically downwards from the ground by a drilling machine, the depth of the core drilling holes is 5m greater than that of the high-spraying curtain wall pile, the diameter of each core drilling hole is 91mm, and the high-spraying quality is judged according to the taken out rock cores.

Further improved, at least one injection water hole is formed in the clean diameter line of the shaft, the injection water hole is drilled vertically downwards from the ground by a drilling machine, the depth of the injection water hole is 5m greater than that of a high-spraying curtain pile, the diameter of the drilling hole is 168mm, a water injection test is conducted on the drilling hole, and the water plugging effect of the high-spraying curtain wall is checked.

Further improved, the positioning targeting grouting drilling hole is vertically drilled downwards from the ground by a drilling machine after the positioning targeting grouting drilling hole is utilized, the depth of the positioning targeting grouting drilling hole is required to penetrate through the thickness of 10m at the lower end of a poor aquifer, and the drilling hole diameter is not less than 250mm.

Further improvement, the orifice pipe adopts a reducing structure form, wherein the vertical depth is 0-10 m, and the specification of the pipe is phi 219 multiplied by 6mm; the vertical depth is 10-30 m, and the specification of the pipe is phi 159 multiplied by 5mm.

Further improving, the grouting material of the grouting section selects clay cement slurry/superfine cement slurry according to the surrounding rock breaking degree and crack development condition of the stratum and the water consumption; grouting pressure is 2.5-4 times of hydrostatic pressure at the height position; the height of the section is 30-50 m, which is determined according to the condition of the exposed stratum.

Further improving, wherein the weight ratio of the clay cement slurry water ash is 1.2-1.5, and the weight ratio of the superfine cement slurry water ash is 0.8-1.0; the superfine cement paste is prepared by adding water, salt and triethanolamine into cement, wherein the adding amount of the triethanolamine is 0.5 per mill of the weight of the cement, and the adding amount of the salt is 5 per mill of the weight of the cement.

Further improvement, the cement is ordinary silicate P.O42.5; the water glass is 28 to 40Be; the sand content of clay is less than 5%.

Further improved, the grouting material is diffused 5-10 m to the outside of the barren diameter through 8 positioning targeting grouting drilling holes at the bad aquifer of the bedrock section, so as to block the cracks and strengthen the surrounding rock.

Further improved, the thickness of the concrete on the outer wall is not less than 300mm, the label is not less than C30, double-layer steel bars are arranged in the concrete, the diameter of the stressed bars is not less than 20mm, the stressed bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft, and the distance is 300mm.

Further improved, the thickness of the concrete on the inner wall is not less than 600mm, the number is not less than C30, single-layer steel bars are arranged in the concrete, the diameter of the stressed bars is not less than 20mm, the stressed bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft, and the distance is 300mm.

The device is characterized by comprising a cement tank, a water tank, a primary stirring barrel, a secondary stirring barrel, an operation table, a high-pressure grouting pump I, a high-pressure water pump, an air compressor, a drilling machine and a high-spraying trolley, and is arranged nearby or above a shaft; the cement tank and the water tank are respectively connected with a primary stirring barrel through a cement chute and a water pipe, the primary stirring barrel is connected with a secondary stirring barrel through a slurry pipe, the secondary stirring barrel is connected with a high-pressure grouting pump through a cement slurry pipe, and the high-pressure grouting pump I, the high-pressure water pump and the air compressor are respectively connected with a high-spraying trolley through a grouting high-pressure pipe, a high-pressure water pipe and a high-pressure air pipe; the cement tank, the water tank, the primary stirring barrel, the secondary stirring barrel, the high-pressure grouting pump I, the high-pressure water pump, the air compressor, the drilling machine and the high-spraying trolley are electrically connected with the operating platform through control cables.

The construction device is characterized by comprising a primary slurry tank, a slurry storage tank, a clean water tank, a water glass tank, a cement tank, a slurry pump, a primary stirring tank, a secondary stirring tank, a high-pressure grouting pump II and a post drilling machine which are arranged in pairs, and is nearby a shaft; the primary pulp pool and the pulp storage pool are directly connected through pipelines; the first-stage stirring tank is connected with a cement tank through a pipeline, a slurry storage tank through a pipeline and a slurry pump, a clean water tank through a pipeline and a proper amount of cement, slurry and clean water are added; the second-stage stirring tank feeding hole is connected with the first-stage stirring tank discharging hole pipeline, the pipeline is connected with the water glass pool, water glass is added into cement slurry of the first-stage stirring tank, stirring is continued in the second-stage stirring tank, the second-stage stirring tank discharging hole is connected with the high-pressure grouting pump II, and the high-pressure grouting pump II injects cement slurry into a drilled hole under high pressure.

A construction method of a vertical shaft wall structure in a bad stratum comprises the following two stages:

the first-stage construction of the high-spraying curtain pile wall structure of the vertical shaft neck section comprises the following steps:

1. calibrating a construction line of a neck section of the vertical shaft:

(1) Calibrating a shaft center point on the earth surface according to the designed coordinates, and calibrating a shaft clear diameter line and a rough diameter line according to the shaft center point and the designed shaft clear diameter and supporting thickness;

(2) Arranging a first circle of high-spraying curtain pile drilling holes 0.6m outside the rough diameter line of the shaft, wherein the distance between the two drilling holes is not more than 0.9m;

(3) Arranging a second circle of high-spray curtain pile holes outside the first circle of high-spray curtain pile, wherein the distance between the two holes is not more than 0.9m, and the circle distance between the second circle and the first circle is not more than 1.2m;

(4) Arranging a third circle of high-spray curtain pile holes outside the second circle of high-spray curtain pile, wherein the distance between the two holes is not more than 0.9m, and the circle distance between the third circle and the second circle is not more than 1.2m;

2. setting a construction device, namely arranging a cement tank, a water tank, a primary stirring barrel, a secondary stirring barrel, a high-pressure grouting pump I, a high-pressure water pump, an air compressor, a grouting high-pressure pipe, a high-pressure water pipe, a high-pressure air pipe, a drilling machine, a high-spraying trolley and an operation table nearby near a shaft or above the shaft, and sequentially connecting related equipment;

3. the first circle of high-spraying curtain pile drilling rig is used for drilling holes at intervals, every other hole is drilled, the depth is larger than the thickness of the thick water-containing backfill surface soil layer, the drilling diameter is not larger than 130mm, the hole position deviation is not larger than 2cm, and the hole slope is not larger than 1%;

4. High-pressure rotary spraying first-circle high-spraying curtain wall isolating hole spraying

(1) Pulping according to a designed proportion, discharging quantitative cement from a cement tank through a cement chute, discharging quantitative water from a water tank through a water pipe, delivering the quantitative water to a first-stage stirring barrel with a high-speed stirrer, and after stirring for not less than 30 seconds, placing the prepared cement slurry into a second-stage stirring barrel with a slow-speed stirrer through a cement slurry pipe, and slowly stirring;

(2) The cement slurry in the high-pressure conveying secondary stirring barrel is communicated to a high-pressure grouting pump I through a cement slurry pipe, the cement slurry in the secondary stirring barrel is conveyed to a drill rod of a high-spraying trolley through a high-pressure grouting pipe by using the high-pressure grouting pump I, water is conveyed to the drill rod of the high-spraying trolley through a high-pressure water pipe by using a high-pressure water pump, and air is conveyed to the drill rod of the high-spraying trolley through a high-pressure air pipe by using an air compressor;

(3) The high-pressure injection is carried out to lower a drill rod of the high-injection trolley to the bottom of a high-injection drilling hole, and an operation table is connected to a high-pressure grouting pump I, a high-pressure water pump and an air compressor through control cables; starting an operation table, feeding slurry, gas and water meeting the requirements, wherein the specific gravity of cement slurry is not less than 1.5, the pressure is 0.2-1.0 Mpa, the water flow is 55-70L/min, the pressure of high-pressure water is 34-38 Mpa, the flow is 60-80L/min, the pressure of compressed air is 0.6-0.8 Mpa, the flow is 0.8-1.2 m < 3 >/min, and when cement slurry is discharged out of an orifice, lifting a drill rod from bottom to top according to a designed lifting mode and lifting speed until the cement slurry is lifted to a designed final spraying height of Cheng Ting, and solidifying the cement slurry into a cylindrical cement pile; then spraying the drilled holes between the two piles to form a high-spraying curtain wall with pile parts overlapped and connected into a whole;

5. Constructing a third circle of high-spraying curtain pile drilling holes according to the step 3;

6. performing high-pressure rotary spraying on the curtain wall with the third circle of high spraying according to the step 4;

7. constructing a second circle of high-spraying curtain pile drilling holes according to the step 3;

8. performing high-pressure rotary spraying on the second circle of high-spray curtain wall according to the step 4;

9. high spray quality inspection:

randomly selecting two positions at the central symmetry position of a shaft in the reinforcement range of the high-spraying curtain wall between the first circle and the third circle, constructing core drilling holes, drilling downwards from the ground by using a drilling machine, wherein the depth is 5m greater than the depth of a high-spraying curtain wall pile, the drilling diameter is 91mm, and judging the high spraying quality according to the taken out rock cores; after the construction is finished, the two core drilling holes are plugged by cement slurry through holes;

10. and (3) water injection test:

randomly selecting a position in the net diameter line of a shaft as a water injection hole, drilling downwards from the ground by using a drilling machine, wherein the depth is 5m greater than the depth of a high-spray curtain pile, the diameter of the drilled hole is 168mm, performing a water injection test on the drilled hole, and checking the water plugging effect of the high-spray curtain wall; after the pressure water injection test is finished, plugging the full hole of the constructed pressure water injection Kong Yongshui slurry;

11. and (5) dismantling the high-spraying curtain pile well wall construction device, and finishing the first-stage construction.

The construction and positioning targeting grouting vertical shaft wall structure method in the second stage is carried out according to the following steps

12. Calibrating a shaft center point on the earth surface according to the design coordinates by a calibration positioning targeting grouting vertical shaft wall structure construction line, and calibrating a shaft net diameter line and a waste diameter line according to the shaft center point and the designed shaft net diameter and supporting thickness; at least 8 positioning targeting injection holes which are vertical to the ground are symmetrically and uniformly arranged along the circumference of the outer 2m of the rough diameter line of the shaft, the diameter of each drilling hole is not less than 250mm, the depth of each drilling hole passes through the lower end 10m of the thickness of a poor aquifer, the serial numbers of the drilling holes are 1#, 2#, 3#, 4#, 5#, 6#, 7#, 8#, the 8 holes are divided into two groups, the first group is 1#, 3#, 5#, 7#, and the second group is 2#, 4#, 6#, 8 #. Firstly, constructing a first group of drilling holes, and simultaneously constructing 2/4 drilling holes according to the size of a field;

13. setting a grouting station at a proper nearby position on the ground, and arranging two sets of grouting systems in total, wherein the grouting systems comprise two cement tanks, a primary slurry tank, a slurry storage tank, a clean water tank, a water glass tank, two slurry pumps, two primary stirring tanks, two secondary stirring tanks and two grouting pumps;

14. the installation drilling machine performs field leveling according to the design requirement, an I-steel chassis is installed above the calibrated hole site, and the drilling machine and the drilling tower are installed on the chassis;

15. the drilling and hole-setting pipe adopts a drill with the diameter of 250mm to drill downwards for 40.5m, a hole pipe with a different-diameter structure with the length of 10m, the diameter of 219 multiplied by 6mm and the length of 30m and the diameter of 159 multiplied by 5mm is arranged downwards in the drilling, cement slurry with the cement weight ratio of 0.6:1 is injected into the hole pipe until the hole returns to slurry; maintaining for 24 hours, cleaning the mouth to the original depth, performing a pressurized water test, checking the consolidation quality, and grouting consolidation again if water leakage is found;

16. Setting a slurry stop plug, adopting a phi 133mm composite bit to drill down to a first grouting section without a core, and setting a KWS type slurry stop plug on a hole section;

17. the water pressure test is carried out by injecting water into the drill hole through the drill rod, and high-pressure grouting can be carried out after the water pressure test meets the design standard;

18. preparing cement clay slurry by high-pressure grouting according to a designed proportion, and grouting into a drill hole by high-pressure grouting through a drill rod to reach grouting set pressure, stabilizing for 20min, and ending grouting after reaching or approaching to a designed grouting amount;

19. sweeping, repeating the

steps

15, 16, 17 and 18 to enter a next grouting section for construction, wherein a KWS type grouting stop plug is arranged in a stable rock stratum at the upper part of the grouting section;

20. excavating a grouting section shaft from top to bottom in a section-by-section excavating shaft within a range of a rough diameter line designed by the shaft, wherein the excavating depth is not more than 4m each time;

21. pouring reinforced concrete on the outer wall of the shaft of the grouting section sequentially from top to bottom until reaching the bottom of the grouting section; the thickness of the concrete is not less than 300mm, the label is not less than C30, double-layer steel bars are arranged in the concrete, the diameter of the stressed steel bars is not less than 20mm, the stressed steel bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft with the interval of 300mm;

22. Pouring reinforced concrete on the inner wall of the shaft of the grouting section from bottom to top, and continuously pouring reinforced concrete on the inner wall of the shaft from bottom to top until the reinforced concrete reaches the surface of a wellhead; the thickness of the concrete is not less than 300mm, the label is not less than C30, double-layer steel bars are arranged in the concrete, the diameter of the stressed steel bars is not less than 20mm, the stressed steel bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft with the interval of 300mm;

23. and (5) removing the construction device, and finishing the second-stage construction.

Compared with the prior art, the device has the advantages of novel conception, simple structure, stability and reliability, and good water shutoff effect, and adopts the high-spraying curtain wall and the positioning targeting grouting to protect the well wall, enhance the bearing capacity and the deformation resistance; the construction is quick and convenient, the quick digging and building of the shaft can be realized, the cost is saved, and the safe and smooth production of mines is ensured.

Drawings

The invention is further illustrated in the following drawings.

FIG. 1 is a schematic plan view of a vertical well wall structure in a poor formation.

FIG. 2 is a schematic cross-sectional view of a vertical well wall structure in a poor formation.

FIG. 3 is a schematic diagram of the wall structure of a high-spraying curtain wall at the neck section of a vertical shaft.

FIG. 4 is a schematic cross-sectional view of a vertical shaft neck structure A-A of the high-spray curtain wall.

Fig. 5 is a schematic diagram of a high-jet drilling arrangement.

FIG. 6 is a schematic diagram of the construction equipment for the wall of the vertical shaft neck section high-spraying curtain wall.

FIG. 7 is a schematic plan view of a wall structure of a bedrock section poor aquifer positioning targeting grouting vertical shaft.

FIG. 8 is a schematic cross-sectional view of the B-B borehole wall structure of FIG. 5.

FIG. 9 is a schematic cross-sectional view of the orifice tube structure of FIG. 5.

Fig. 10 is a schematic view of the construction apparatus of fig. 5.

In the figure: 1. a vertical shaft; 1.1, a shaft center line; 2. A wellbore clear line; 3. A shaft rough diameter line; 4. An outer wall; 5. An inner wall; 6. Backfilling a surface soil layer; 7. Drilling holes on a first circle of high-spraying curtain piles; 8. Drilling holes on a third-circle high-spraying curtain pile; 9. Drilling holes on a second circle of high-spraying curtain piles; 10. A first circle of high-spraying curtain wall; 11. A third circle of high-spraying curtain wall; 12. A second circle of high-spraying curtain wall; 13. Core drilling; 14. A water injection hole; 15. a cement tank; 16. A cement chute; 17. A water tank; 18. A water pipe; 19. A first-stage stirring barrel; 20. A slurry pipe; 21. A secondary stirring barrel; 22. A cement slurry pipe; 23. An operation table; 24. A control cable; 25. A high-pressure grouting pump I; 26. A high pressure water pump; 27. An air compressor; 28. Grouting a high-pressure pipe; 29. A high pressure water pipe; 30. A high-pressure air duct; 31. Firstly, using a drilling machine; 32. A high spraying trolley; 33. Grouting and drilling; 34. An orifice tube; 35. Cement paste; 36. Grouting section; 37. A grout stop plug; 38. A drill rod; 39. A primary pulp pool; 40. A slurry reservoir; 41. A slurry pump; 42. A clean water tank; 43. A primary stirring tank; 44. A water glass pool; 45. A secondary stirring tank; 46. A high-pressure grouting pump II; 47. An aqueous formation; 48. And then using a drilling machine.

Detailed Description

As can be seen from fig. 1, 2, 5, 6 and 9, the vertical shaft wall structure in the poor stratum comprises a shaft arranged in the poor stratum, a high-spraying curtain pile wall structure arranged at the neck section of the upper part of the vertical shaft, a positioning and targeting grouting wall structure arranged at the bedrock section and a wall, wherein the upper wall and the lower wall are concentric, have the same diameter and are tightly connected into a whole; the vertical shaft neck section high-spraying curtain pile well wall structure comprises the steps of excavating rock stratum in a rough diameter line 3 of a shaft, pouring a well wall between a shaft clean diameter line 2 and the shaft rough diameter line, taking a shaft center 1.1 as a circle center (not marked in the figure), arranging at least three circles of annular high-spraying curtain walls 10, 11 and 12 with sealed ends along the periphery of 0.6m of the shaft rough diameter line, wherein the distance between the two circles of high-spraying curtain walls is 1.5m, the thickness of the high-spraying curtain wall is 850mm, and the depth is greater than the thickness of a thick water backfill surface soil layer so as to protect the shaft neck section well wall, and enhance the bearing capacity, the deformation resistance and the waterproof capacity; the poor aquifer positioning and targeting grouting vertical shaft wall structure of the bedrock section is characterized in that positioning and targeting grouting drilling holes 33, orifice pipes 34 and grouting sections 36 are arranged around a shaft, the positioning and targeting grouting drilling holes are uniformly arranged in pairs and perpendicular to the ground outside the shaft along the circumference of the shaft rough diameter line by 2m by taking the shaft center as the center of the circle, and at least 8 positioning and targeting grouting drilling holes are arranged in the whole shaft; the orifice pipe is arranged in the positioning and targeting grouting drilling hole, cement slurry hydraulic pressure is injected from the targeting grouting drilling hole, the cement slurry hydraulic pressure is expanded into a bad water-bearing layer for the development of bedrock cracks around the drilling hole, the cement slurry is solidified into a grouting section, and the grouting section is arranged in the bad water-bearing layer where the bedrock section is positioned in a layered manner so as to fill and block the cracks, strengthen surrounding rock, protect the bedrock section well wall, and strengthen the deformation resistance and the waterproof capability; the well wall is composed of an inner wall 5 and an outer wall 4, wherein the outer wall is made of reinforced concrete with the thickness of 350mm, and the inner wall is made of reinforced concrete with the thickness of 700 mm.

As can be seen from fig. 1, 2 and 3, the high-spraying

curtain walls

10, 11 and 12 are formed by connecting high-spraying curtain piles on the same ring, the high-spraying curtain piles are formed by injecting cement paste into preset high-spraying holes by adopting a three-pipe high-pressure rotary spraying technology, solidifying the cement paste into cylindrical pile bodies, and overlapping the pile bodies and the pile bodies on the same ring to form a circular high-spraying curtain wall.

As can be seen from fig. 1, 2 and 3, the high-

jet drilling holes

7, 8 and 9 are formed by drilling vertically downwards from the ground by using a drilling machine 31, the depth is greater than the thickness of the thick water-containing backfill surface soil layer, and the drilling diameter is 150mm; cement slurry is sprayed into high-spraying holes and expands to the periphery, the diameter of a formed pile is 850mm, and a 120mm overlapping connection area is formed between piles.

As can be seen from fig. 1, 2 and 3, the two core drill holes 13 are symmetrically arranged in the high-spraying curtain wall area, and the core drill holes are drilled vertically downwards from the ground by using a drilling machine 31, the depth of the core drill holes is 5m greater than that of the high-spraying curtain wall pile, the diameter of the drilled holes is 91mm, and the high-spraying quality is judged according to the taken out core.

As can be seen from fig. 1, 2 and 3, the injection hole 14 is formed in the clean radial line of the shaft, and is formed by drilling vertically downwards from the ground by using a drilling machine 31, wherein the depth of the injection hole is greater than the depth of the high-spray curtain pile by 5m, the diameter of the drilling hole is 168mm, and the injection hole is subjected to a water injection test to check the water plugging effect of the high-spray curtain wall.

As can be seen from fig. 6, 7 and 9, the positioning targeting grouting drilling 33 is vertically drilled from the ground by a drilling machine 48, the depth of the drilling is 10m from the lower end of the poor aquifer, the upper part of the drilling diameter is 350mm, and the lower part of the drilling diameter is 145mm.

As can be seen from fig. 6, 7 and 9, the orifice tube 34 adopts a different diameter structure, wherein the vertical depth is 0-10 m, and the specification of the tube is phi 219 x 6mm; the vertical depth is 10-30 m, and the specification of the pipe is phi 159 multiplied by 5mm.

As can be seen from fig. 1, fig. 2, fig. 5, fig. 6 and fig. 9, the grouting material of the grouting section selects clay cement slurry/superfine cement slurry according to the surrounding rock breaking degree, crack development condition and water consumption of the stratum; grouting pressure is 3 times of hydrostatic pressure at the height position; the segment height is 45m, which depends on the condition of the exposed stratum.

The weight ratio of the cement slurry water ash of the clay is 1.35, and the weight ratio of the superfine cement slurry water ash is 0.9; the superfine cement paste is prepared by adding water, salt and triethanolamine into cement, wherein the adding amount of the triethanolamine is 0.5 per mill of the weight of the cement, and the adding amount of the salt is 5 per mill of the weight of the cement.

The cement adopted is ordinary silicate P.O42.5; the water glass is 28 to 40Be; the sand content of clay is less than 5%.

As can be seen from fig. 5, 6 and 9, the grouting material diffuses 8m outside the barren diameter through 8 positioning targeting grouting drilling holes 33 in the bad aquifer of the bedrock section, fills up the cracks and strengthens the surrounding rock.

As can be seen from fig. 2, 6 and 9, the thickness of the concrete on the outer wall is 350mm, the reference number is C30, double-layer steel bars are arranged in the concrete, the diameter of the stressed bars is 25mm, the stressed bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are 22mm, and the subsection ribs are arranged along the central line direction of the shaft, and the distance is 300mm.

As can be seen from fig. 2, 6 and 9, the thickness of the concrete on the inner wall is 700mm, the reference number is C30, single-layer steel bars are arranged in the concrete, the diameter of the stressed bars is 25mm, the stressed bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are 22mm, and the subsection ribs are arranged along the central line direction of the shaft, and the distance is 300mm.

As can be seen from fig. 4, the construction device for the well wall structure of the high-spraying curtain pile at the neck section of the vertical well comprises a cement tank 15, a water tank 17, a primary stirring barrel 19, a secondary stirring barrel 21, an operation table 23, a high-pressure grouting pump i 25, a high-pressure water pump 26, an air compressor 27, a drilling machine and a 31 high-spraying trolley 32, and is arranged nearby or above the well; the cement tank and the water tank are respectively connected with a primary stirring barrel through a cement chute 16 and a water pipe 18, the primary stirring barrel is connected with a secondary stirring barrel through a slurry pipe 20, the secondary stirring barrel is connected with a high-pressure grouting pump I through a cement slurry pipe 22, and the high-pressure grouting pump I, the high-pressure water pump and the air compressor are respectively connected with a high-spraying trolley through a slurry high-pressure pipe 28, a high-pressure water pipe 29 and a high-pressure air pipe 30; the cement tank, the water tank, the primary stirring barrel, the secondary stirring barrel, the high-pressure grouting pump I, the high-pressure water pump, the air compressor, the drilling machine and the high-spraying trolley are electrically connected with the operation table through the control cable 24.

As can be seen from FIG. 8, the construction device for the wall structure of the bedrock section poor aquifer positioning and targeting grouting vertical shaft is characterized by comprising a primary slurry tank 39, a slurry storage tank 40, a clean water tank 42, a water glass tank 44, a cement tank 15, a slurry pump 41, a primary stirring tank 43, a secondary stirring tank 45 and a high-pressure grouting pump II 46 which are arranged in pairs, wherein the construction device is arranged nearby a shaft; the primary pulp pool and the pulp storage pool are directly connected through pipelines; the first-stage stirring tank is connected with a cement tank through a pipeline, a slurry storage tank through a pipeline and a slurry pump, a clean water tank through a pipeline and a proper amount of cement, slurry and clean water are added; the second-stage stirring tank feeding hole is connected with the first-stage stirring tank discharging hole pipeline, the pipeline is connected with the water glass pool, water glass is added into cement slurry of the first-stage stirring tank, stirring is continued in the second-stage stirring tank, the second-stage stirring tank discharging hole is connected with the high-pressure grouting pump II, and the high-pressure grouting pump II injects cement slurry into a drilled hole under high pressure.

1. calibrating a construction line of a neck section of the vertical shaft:

2. the construction device is arranged to arrange a cement tank, a water tank, a primary stirring barrel, a secondary stirring barrel, a high-pressure grouting pump I, a high-pressure water pump, an air compressor, a grouting high-pressure pipe, a high-pressure water pipe, a high-pressure air pipe, a drilling machine, a high-spraying trolley and an operation table nearby near a shaft or above the shaft and sequentially connect related equipment.

4. High-pressure jet grouting a first circle of high-jet curtain wall isolating holes:

(2) The cement slurry in the high-pressure conveying secondary stirring barrel is communicated to a high-pressure grouting pump I through a cement slurry pipe, the cement slurry in the secondary stirring barrel is conveyed to a drill rod of a high-pressure spraying trolley through the high-pressure grouting pipe by using the high-pressure grouting pump, water is conveyed to the drill rod of the high-pressure spraying trolley through the high-pressure water pipe by using the high-pressure water pump, and air is conveyed to the drill rod of the high-pressure spraying trolley through the high-pressure air pipe by using the air compressor;

(3) The high-pressure injection is carried out to lower a drill rod of the high-injection trolley to the bottom of a high-injection drilling hole, and an operation table is connected to a high-pressure grouting pump I, a high-pressure water pump and an air compressor through control cables; starting an operation table, feeding slurry, gas and water meeting the requirements, wherein the specific gravity of cement slurry is not less than 1.5, the pressure is 0.60Mpa, the water flow is 60min, the pressure of high-pressure water is 36Mpa, the flow is 70/min, the pressure of compressed air is 0.7Mpa, the flow is 1.0m3/min, and when the cement slurry exits from an orifice, lifting a drill rod from bottom to top according to a designed lifting mode and lifting speed until the cement slurry is lifted to a designed final spraying height of Cheng Ting, and solidifying the cement slurry into a cylindrical cement pile; then spraying the drilled holes between the two piles to form a high-spraying curtain wall with pile parts overlapped and connected into a whole;

9. high spray quality inspection:

10. and (3) water injection test:

19. sweeping the mouth, repeating the

steps

18, 19 and 20, entering the construction of the next grouting section, and arranging a KWS type grouting stopper in a stable rock stratum at the upper part of the grouting section;

20. excavating a grouting section shaft from top to bottom in a section-by-section excavating shaft within the range of a rough diameter line designed by the shaft, wherein the excavating depth is not more than 3.5m each time;

21. pouring reinforced concrete on the outer wall of the shaft of the grouting section, and pouring reinforced concrete on the outer wall of the shaft from top to bottom until reaching the bottom of the grouting section; the concrete is marked as C30, the thickness is 350mm, double-layer steel bars are arranged in the concrete, the diameter of the stressed bars is 25mm, and the stressed bars are arranged along the periphery of a shaft with the spacing of 300mm; the diameters of the subsection ribs are not smaller than 22mm, and the subsection ribs are arranged along the central line direction of the shaft with the interval of 300mm;

22. Pouring reinforced concrete on the inner wall of the shaft of the grouting section from bottom to top, and continuously pouring reinforced concrete on the inner wall of the shaft from bottom to top until the reinforced concrete reaches the surface of a wellhead; the concrete is marked with a C30, the thickness is 700mm, double-layer steel bars are arranged in the concrete, the diameter of the stressed steel bars is 25mm, and the stressed steel bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 22mm, and the subsection ribs are arranged along the central line direction of the shaft with the interval of 300mm;

Claims

1. The vertical shaft wall structure in the bad stratum comprises a shaft arranged in the bad stratum, and is characterized in that the high-spraying curtain pile wall structure arranged at the shaft neck section at the upper part of the vertical shaft, the positioning targeting grouting wall structure arranged at the bedrock section and the wall are concentric, have the same diameter and are tightly connected into a whole; the high-spraying curtain pile well wall structure is characterized in that rock stratum is excavated in a rough radial line (3) of a shaft, a well wall is poured between a clean radial line (2) of the shaft and the rough radial line of the shaft, at least three circles of annular high-spraying curtain walls with closed ends are arranged along the periphery of 0.6m of the rough radial line of the shaft by taking the center of the shaft as the circle center, the distance between the two circles of high-spraying curtain walls is 1.2-2 m, the thickness of the high-spraying curtain walls is 800-1000 mm, and the depth is greater than the thickness of a thick water backfilling surface soil layer; the positioning and targeting grouting well wall structure is characterized in that positioning and targeting grouting drilling holes (33), orifice pipes (34) and grouting sections (36) are formed around a shaft, and 8 positioning and targeting grouting drilling holes perpendicular to the ground are uniformly formed in pairs at least outside the circumference 2m of a rough radial line of the shaft by taking the center of the shaft as the center of the shaft; the method comprises the steps that an orifice pipe is arranged in a positioning target grouting drilling hole, cement slurry hydraulic pressure is injected from the target grouting drilling hole, the cement slurry hydraulic pressure is expanded to a poor water-bearing layer for 5-10 m bedrock fracture development around the drilling hole, the cement slurry is solidified into a grouting section, and the grouting section is layered in the poor water-bearing layer where the bedrock section is located; the well wall consists of an inner wall and an outer wall, wherein the outer wall is reinforced concrete with the thickness of not less than 300mm, and the inner wall is reinforced concrete with the thickness of not less than 600 mm;

The high-spraying curtain wall is formed by connecting high-spraying curtain piles on the same ring, the high-spraying curtain piles are formed by spraying cement paste into preset high-spraying drilling holes by adopting a three-pipe high-pressure rotary spraying technology, solidifying the cement paste into cylindrical pile bodies, and mutually overlapping the pile bodies and the pile bodies of the same ring to form a circular high-spraying curtain wall;

the construction device for the well wall structure of the high-spraying curtain pile at the well neck section comprises a cement tank (15), a water tank (17), a primary stirring barrel (19), a secondary stirring barrel (21), an operation table (23), a high-pressure grouting pump I (25), a high-pressure water pump (26), an air compressor (27), a drilling machine (31) and a high-spraying trolley (32), and is arranged nearby or above a well shaft; the cement tank and the water tank are respectively connected with a primary stirring barrel through a cement chute (16) and a water pipe (18), the primary stirring barrel is connected with a secondary stirring barrel through a slurry pipe (20), the secondary stirring barrel is connected with a high-pressure grouting pump I through a cement slurry pipe (22), and the high-pressure grouting pump I, the high-pressure water pump and the air compressor are respectively connected with a high-spraying trolley through a grouting high-pressure pipe (28), a high-pressure water pipe (29) and a high-pressure air pipe (30); the cement tank, the water tank, the primary stirring barrel, the secondary stirring barrel, the high-pressure grouting pump I, the high-pressure water pump, the air compressor, the drilling machine and the high-spraying trolley are electrically connected with the operating platform through control cables (24).

2. The vertical well wall structure in the poor stratum according to claim 1, wherein the Gao Penzuan holes (7), (8) and (9) are drilled vertically downwards from the ground by a drilling machine (31), the depth is larger than the thickness of a thick water-containing backfill surface soil layer, and the drilling diameter is not smaller than 130mm; the cement slurry is injected into the high-injection drilling holes and expands to the periphery, the diameter of the formed piles is 800-1000 mm, and an overlapping connection area which is not smaller than 100mm is arranged between the piles.

3. The vertical well wall structure in the poor stratum according to claim 1, wherein the positioning targeting grouting drilling hole (33) is vertically drilled downwards from the ground by a drilling machine (48), the depth of the drilling hole passes through the thickness of 10m at the lower end of the poor aquifer, the upper part of the drilling hole diameter is 250mm, and the lower part diameter is 150mm; a different-diameter orifice pipe is arranged in the positioning targeting grouting drilling hole, wherein the vertical depth is 0-10 m, and the specification of the pipe is phi 219 multiplied by 6mm; the vertical depth is 10-30 m, and the specification of the pipe is phi 159 multiplied by 5mm.

4. The wall structure of a vertical well in a poor stratum according to claim 1, wherein the grouting material of the grouting section is clay cement slurry/superfine cement slurry; grouting pressure is 2.5-4 times of hydrostatic pressure at the height position; the grouting material is diffused 8m from the poor water-bearing layer of the bedrock section to the outside of the barren diameter through 8 positioning targeting grouting drill holes, is solidified into a grouting section with the height of 30-50 m, and is arranged in the poor water-bearing layer of the bedrock section.

5. The vertical well wall structure in an unfavorable stratum according to claim 1, wherein the number of concrete marks on the outer wall is not less than C30, double-layer steel bars are arranged in the concrete, the diameter of the stressed bars is not less than 20mm, and the stressed bars are arranged along the periphery of a well shaft at intervals of 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft, and the distance is 300mm.

6. The vertical well wall structure in an unfavorable stratum according to claim 1, wherein the number of concrete marks on the inner wall is not less than C30, single-layer steel bars are arranged in the concrete, the diameter of the stressed bars is not less than 20mm, and the stressed bars are arranged along the periphery of a well shaft at intervals of 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft, and the distance is 300mm.

7. The vertical shaft wall structure in the poor stratum according to claim 1, wherein the positioning and targeting grouting vertical shaft wall structure construction device comprises a post-use drilling machine (48), a primary slurry tank (39), a slurry storage tank (40), a clean water tank (42), a water glass tank (44) and cement tanks (15), a slurry pump (41), a primary stirring tank (43), a secondary stirring tank (45) and a high-pressure grouting pump II (46) which are arranged in pairs, and are arranged nearby a shaft; the primary pulp pool and the pulp storage pool are directly connected through pipelines; the first-stage stirring tank is connected with a cement tank through a pipeline, a slurry storage tank through a pipeline and a slurry pump, a clean water tank through a pipeline and a proper amount of cement, slurry and clean water are added; the second-stage stirring tank feeding hole is connected with the first-stage stirring tank discharging hole pipeline, the pipeline is connected with the water glass pool, water glass is added into cement slurry of the first-stage stirring tank, stirring is continued in the second-stage stirring tank, the second-stage stirring tank discharging hole is connected with the high-pressure grouting pump II, and the high-pressure grouting pump II injects cement slurry into a drilled hole under high pressure.

8. The vertical well wall structure in an unfavorable stratum according to claim 1, wherein the construction method of the vertical well wall structure in the unfavorable stratum is carried out in two stages:

1) Calibrating a construction line of a neck section of the vertical shaft:

2) Setting a construction device, namely arranging a cement tank, a water tank, a primary stirring barrel, a secondary stirring barrel, a high-pressure grouting pump I, a high-pressure water pump, an air compressor, a grouting high-pressure pipe, a high-pressure water pipe, a high-pressure air pipe, a drilling machine, a high-spraying trolley and an operation table nearby near a shaft or above the shaft, and sequentially connecting related equipment;

3) Drilling holes at intervals by a drilling machine for constructing a first circle of high-spraying curtain pile, wherein the depth of each hole is greater than the thickness of a thick water-containing backfill surface soil layer, the drilling diameter is not greater than 130mm, the deviation of the hole position is not greater than 2cm, and the slope of the hole is not greater than 1%;

4) High-pressure jet grouting a first circle of high-jet curtain wall isolating holes:

(3) The high-pressure injection is carried out to lower a drill rod of the high-injection trolley to the bottom of a high-injection drilling hole, and an operation table is connected to a high-pressure grouting pump I, a high-pressure water pump and an air compressor through control cables; starting an operation table, feeding slurry, gas and water meeting the requirements, wherein the specific gravity of cement slurry is not less than 1.5, the pressure is 0.20-1.0 Mpa, the water flow is 55-70L/min, the pressure of high-pressure water is 34-38 Mpa, the flow is 60-80L/min, the pressure of compressed air is 0.6-0.8 Mpa, the flow is 0.8-1.2 m < 3 >/min, and when cement slurry is discharged out of an orifice, lifting a drill rod from bottom to top according to a designed lifting mode and lifting speed until the cement slurry is lifted to a designed final spraying height of Cheng Ting, and solidifying the cement slurry into a cylindrical cement pile; then spraying the drilled holes between the two piles to form a high-spraying curtain wall with pile parts overlapped and connected into a whole;

5) Constructing a third circle of high-spraying curtain pile drilling holes according to the step 3;

6) Step 4, high-pressure rotary spraying is performed on the third high-spray curtain wall;

7) Constructing a second circle of high-spraying curtain pile drilling holes according to the step 3;

8) Step 4, performing high-pressure jet grouting on the second circle of high-spray curtain wall;

9) And (3) high spray quality inspection:

10 Pressure water injection test):

11 Removing the high-spraying curtain pile well wall construction device, and finishing the first-stage construction;

the construction positioning and targeting grouting vertical shaft wall structure method in the second stage is carried out according to the following steps:

12 Calibrating a shaft center point on the earth surface according to the designed coordinates by calibrating a positioning targeting grouting vertical shaft wall structure construction line, and calibrating a shaft net diameter line and a rough diameter line according to the shaft center point, the designed shaft net diameter and the designed supporting thickness; at least 8 positioning targeting injection holes which are vertical to the ground are symmetrically and uniformly arranged along the circumference of the outer 2m of the rough diameter line of the shaft, the diameter of each drilling hole is not less than 250mm, the depth of each drilling hole passes through the lower end 10m of the thickness of a poor aquifer, the serial numbers of the drilling holes are 1#, 2#, 3#, 4#, 5#, 6#, 7#, 8#, the 8 holes are divided into two groups, the first group is 1#, 3#, 5#, 7#, and the second group is 2#, 4#, 6#, 8 #. Firstly, constructing a first group of drilling holes, and simultaneously constructing 2/4 drilling holes according to the size of a field;

13 Setting a grouting station at a proper nearby position on the ground, and setting two sets of grouting systems, wherein the grouting systems comprise two cement tanks, a primary slurry tank, a slurry storage tank, a clean water tank, a water glass tank, two slurry pumps, two primary stirring tanks, two secondary stirring tanks and two grouting pumps;

14 Performing field leveling according to design requirements by installing a drilling machine, installing an I-steel chassis above a calibrated hole site, and installing the drilling machine and a drilling tower on the chassis;

15 Drilling a hole pipe with a diameter of 250mm, downwards drilling by adopting a drill bit with the diameter of 250mm for 40.5m, arranging a hole pipe with a different diameter structure with the length of 10m, the diameter of 219 multiplied by 6mm, the length of 30m and the diameter of 159 multiplied by 5mm in the hole, and injecting cement slurry with the cement weight ratio of 0.6:1 into the hole pipe until the hole returns to slurry; maintaining for 24 hours, cleaning the mouth to the original depth, performing a pressurized water test, checking the consolidation quality, and grouting consolidation again if water leakage is found;

16 Setting a slurry stop plug, adopting a phi 133mm composite bit to drill down to a first grouting section in a coreless manner, and setting a KWS type slurry stop plug on a hole section;

17 Water is injected into a drill hole through a drill rod in a pressurized water test, and high-pressure grouting can be performed after the pressurized water test meets the design standard;

18 Preparing cement clay slurry according to a designed proportion by high-pressure grouting, and grouting into a drill hole by a drill rod under high pressure to reach grouting set pressure and stable for 20min, wherein the grouting is finished after reaching or approaching to the designed grouting amount;

19 Step 18, 19 and 20, and then entering the next grouting section for construction, wherein the KWS type grouting plug is arranged in the stable rock stratum at the upper part of the grouting section;

20 Excavating the grouting section shaft from top to bottom in a range of a rough diameter line designed for the shaft in a successive and sectional manner, wherein the excavation depth is not more than 4m each time;

21 Pouring reinforced concrete on the outer wall of the shaft of the grouting section from top to bottom, and pouring reinforced concrete on the outer wall of the shaft until the bottom of the grouting section; the concrete label is not less than C30, the thickness is not less than 300mm, double-layer steel bars are arranged in the concrete, the diameter of the stressed steel bars is not less than 20mm, the stressed steel bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft with the interval of 300mm;

22 Pouring reinforced concrete on the inner wall of the shaft of the grouting section from bottom to top, and continuously pouring reinforced concrete on the inner wall of the shaft from bottom to top until the reinforced concrete reaches the surface of a wellhead; the concrete label is not less than C30, the thickness is not less than 600mm, double-layer steel bars are arranged in the concrete, the diameter of the stressed steel bars is not less than 20mm, the stressed steel bars are arranged along the periphery of a shaft, and the spacing is 300mm; the diameters of the subsection ribs are not smaller than 20mm, and the subsection ribs are arranged along the central line direction of the shaft with the interval of 300mm;

23 And (3) removing the construction device on the inner wall of the grouting section shaft, and finishing the construction of the second stage.