Construction method for vertical shaft neck section to pass through quaternary stratum

Abstract

According to the construction method for the vertical shaft neck section to pass through the quaternary stratum, the first sheet-pile construction is conducted at the preset range away from the to-be-constructed vertical shaft to form the first sheet-pile wall body, and then the sheet-pile construction is conducted at the lowest position of the slope face to form the second sheet-pile wall body, so that the lateral pressure of soil can be effectively resisted; a certain water stopping effect can be achieved while needed support is provided for engineering; then, a circle of groove is constructed around a wellhead of the vertical shaft to be constructed, reinforcing steel bars are bound in the groove to form a reinforcing steel bar network structure tightly attached to the vertical shaft to be constructed, a fixing cross rod is placed on the reinforcing steel bar network structure, one end of the fixing cross rod is bound on the reinforcing steel bars, and the other end of the fixing cross rod is fixedly erected on a derrick foundation; concrete anti-falling caps which are used for fixing the fixing transverse rods and the steel bar network structures and are integrally formed with the shaft are formed through pouring, so that the concrete anti-falling caps and the shaft form a whole, the shaft is further reinforced, and the whole well neck section is stably constructed.

Description

Technical Field

[0001] The present invention relates to the technical field of vertical shaft construction, and more particularly to a construction method for a vertical shaft neck section passing through a special stratum, and more particularly to a construction method for a vertical shaft neck section passing through a Quaternary stratum. Background Art

[0002] As an important underground engineering structure, vertical shaft plays an irreplaceable role in the fields of mineral resource mining. However, in the actual construction process, vertical shafts often encounter various complex geological conditions, such as Quaternary soft soil, expansive soil, fault zones and other special geological conditions, which put forward higher requirements on construction technology and safety management.

[0003] For example, when the vertical shaft construction was carried out in Chentaigou No. 2 return air shaft and south air intake shaft in Anshan City, Liaoning Province, the geological structure of the area was complex, the strata were unevenly distributed, and there were many special strata such as soft soil, gravel, and gushing water, which brought great challenges to the construction.

[0004] Therefore, there is an urgent need for a construction method that can solve the key technical problems in construction in special strata, resist the lateral pressure of the soil, provide the required support for the project, achieve a certain water-stopping effect, enhance the stability of the wellbore, improve construction efficiency and quality, and ensure the safe and smooth progress of the project, so as to ensure that the neck section of the vertical shaft passes through the Quaternary strata. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a construction method for a vertical shaft neck section through the Quaternary strata, so as to solve the problem that in the actual construction process, the vertical shaft often encounters various complex stratigraphic conditions, such as Quaternary soft soil, expansive soil, fault zones and other special stratigraphic conditions. These stratigraphic conditions put forward higher requirements on construction technology and safety management, and are easily affected by adverse effects such as lateral soil pressure.

[0006] The present invention provides a construction method for a vertical shaft neck section passing through a Quaternary stratum, which comprises:

[0007] The first sheet pile construction is carried out at a preset range from the shaft to be constructed, so that each sheet pile is driven into the soil one by one to form a first sheet pile wall with a continuous stroke;

[0008] Excavating rock and soil within the first sheet pile wall and outside the preset distance of the derrick foundation in the vertical shaft to be constructed, and sloping the excavated area according to a preset ratio to form a slope surface with a high outside and a low inside, and performing sheet pile construction at the lowest point of the slope surface to form a second sheet pile wall;

[0009] A circle of grooves is constructed around the wellhead of the vertical shaft to be constructed, steel bars are tied in the grooves to form a steel network structure close to the vertical shaft to be constructed, and a fixed cross bar is placed on the steel network structure, so that one end of the fixed cross bar is tied to the steel bar, and the other end is erected and fixed on the well frame foundation;

[0010] Concrete is poured between the shaft template and the shaft side wall of the shaft to be constructed, and between the shaft template and the groove to form a shaft, and a concrete anti-slip cap is cast and fixed to fix the fixed cross bar and the steel network structure and is integrally formed with the shaft.

[0011] Optionally, the sheet piles in the first sheet pile wall and the second sheet pile wall are steel sheet piles, and two symmetrical isosceles trapezoidal locking openings are integrally formed on both sides of the steel sheet piles; and,

[0012] Two adjacent steel sheet piles in the first sheet pile wall and the second sheet pile wall are connected in pairs through the locking opening.

[0013] Optionally, the process of constructing the first sheet pile wall includes:

[0014] Selecting a first target address of a first sheet pile wall at a distance of 14-18 meters from the foundation of the shaft to be constructed; the first target address is a square with arc corners or a circle;

[0015] At the first target address, the sheet piles are aligned in pairs, and the sheet piles are driven completely into the ground one by one by a pile driver, so that the tops of all the sheet piles are flush with the ground to form a first sheet pile wall.

[0016] Optionally, the process of constructing the second sheet pile wall includes:

[0017] The area enclosed by the lowest point of the slope surface is taken as the second target address;

[0018] At the second target address, the sheet piles are aligned in pairs, and the sheet piles are driven completely into the ground one by one by a pile driver, so that the tops of all the sheet piles exceed the lowest point by 40-70 cm to form a second sheet pile wall.

[0019] Optionally, in the process of driving the sheet piles completely into the ground one by one by a pile driver,

[0020] The slope of the sheet pile is detected in real time. When the slope of the sheet pile exceeds 2%, it is adjusted by pulling it in line. If it cannot be adjusted, it is pulled out and reinserted. If there is large gravel underground, making it impossible to drive the sheet pile in, a boring machine is used to carry out boring construction, and the sheet pile is replaced with a spare sheet pile with a small vertical height.

[0021] Optionally, the preset ratio is 1:1.5 to 1:1.7.

[0022] Optionally, the depth of the pit formed by excavating the rock and soil is not more than five meters, and the bottom width is not less than three meters.

[0023] Optionally, the method further includes constructing the vertical shaft to be constructed downwards, and after the preset height of the upper part of the shaft of the vertical shaft to be constructed is completed, the method further includes:

[0024] Vibrate two adjacent sheet piles by vibrating hammer to reduce soil adhesion;

[0025] The sheet piles are pulled out in sequence by using a crane and a vibrating hammer; and the crane is gradually loaded with the vibration of the vibrating hammer;

[0026] The ground pile holes created by pulling out the sheet piles are backfilled with stone chips.

[0027] Optionally, the derrick foundation is a square derrick foundation, and during the process of placing the fixed crossbars on the steel network structure,

[0028] Two points are selected as vertical points at a preset interval on the edge of the square derrick foundation, the vertical points are used as the foot of the vertical line, and the points on the steel network structure are connected as the vertical lines of the edge, and the vertical lines on the two opposite sides of the square derrick foundation are symmetrical to each other;

[0029] The vertical line is used as a dividing line, and a fixed cross bar is placed at the dividing line, and the length of the fixed cross bar exceeds the outermost side wall of the shaft to be constructed by 3-4 meters; wherein,

[0030] The fixed cross bar is an I56b I-beam.

[0031] Optionally, the shaft template is hoisted by a hoisting machine.

[0032] As can be seen from the above technical scheme, the construction method of the shaft neck section through the Quaternary stratum provided by the present invention first carries out the first sheet pile construction at a preset range from the shaft to be constructed, so that each sheet pile is driven into the first sheet pile wall with a continuous soil stroke one by one, and rock and soil are excavated within the first sheet pile wall and outside the preset distance of the derrick foundation in the shaft to be constructed, and the excavated area is sloped according to a preset ratio to form a slope surface with a high outside and a low inside, and sheet pile construction is carried out at the lowest point of the slope surface to form a second sheet pile wall, and the first sheet pile wall and the second sheet pile wall are constructed in steps, and are distributed underground from high to low when viewed from the outer circle to the inner circle, so that the lateral pressure of the soil can be effectively resisted, providing a good foundation for the project. The required support can also play a certain water-stopping effect. Then, a circle of grooves is constructed around the wellhead of the vertical shaft to be constructed, and steel bars are tied in the grooves to form a steel network structure that is close to the vertical shaft to be constructed, and a fixed cross bar is placed on the steel network structure, so that one end of the fixed cross bar is tied to the steel bar, and the other end is erected and fixed on the well frame foundation, and concrete is poured between the shaft template of the vertical shaft to be constructed and the side wall of the shaft, and between the shaft template and the groove to form a shaft, and a concrete anti-slip cap is formed by casting and fixing the fixed cross bar and the steel network structure, and integrally formed with the shaft, so that it forms a whole with the shaft, further reinforces the shaft, and ensures that the construction of the entire shaft neck section can be carried out steadily. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more clear and easy to understand. In the accompanying drawings:

[0034] Figure 1 It is a flow chart of a construction method of a vertical shaft neck section passing through a Quaternary stratum according to an embodiment of the present invention;

[0035] Figure 2 A top view of the structure involved in the construction method of a vertical shaft neck section passing through a Quaternary stratum according to an embodiment of the present invention;

[0036] Figure 3 A side view of a structure involved in a construction method for a vertical shaft neck section passing through a Quaternary stratum according to an embodiment of the present invention;

[0037] Figure 4 A top view of a process of forming a concrete anti-slip cap in a construction method for a vertical shaft neck section passing through a Quaternary stratum according to an embodiment of the present invention;

[0038] Figure 5 It is a schematic diagram of steel sheet piles in a construction method of a vertical shaft neck section passing through Quaternary strata according to an embodiment of the present invention.

[0039] Figure numerals: 1. first sheet pile wall; 2. second sheet pile wall; 3. derrick foundation; 4. groove; 5. steel network structure; 6. fixed cross bar; 7. shaft formwork; 8. shaft; 9. concrete anti-slip cap; 10. hoisting machine; 11. steel sheet pile. DETAILED DESCRIPTION

[0040] In the actual vertical shaft construction process, various complex stratum conditions are often encountered, such as Quaternary soft soil, expansive soil, fault zone and other special strata, which put forward higher requirements for construction technology and safety management. For example, when the return air shaft and the south air intake shaft are constructed, the regional geological structure is complex, the strata are unevenly distributed, and there are many special strata such as soft soil, gravel, and water gushing, which will bring great challenges to the construction.

[0041] In view of the above problems, the present invention provides a method for constructing a vertical shaft neck section through a Quaternary stratum. The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] In order to illustrate the construction method of the vertical shaft neck section through the Quaternary strata provided by the present invention, Figure 1-Figure 5 The embodiments of the present invention are exemplarily indicated.

[0043] The following description of exemplary embodiments is merely illustrative in nature and is not intended to limit the present invention and its application or use. Technologies and devices known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technologies and devices should be considered as part of the specification.

[0044] like Figure 1-Figure 5 As shown in the figure, the present invention provides a construction method for a vertical shaft neck section passing through a Quaternary stratum, comprising:

[0045] S1: Perform the first sheet pile construction at a preset range from the shaft to be constructed, so that each sheet pile is driven into the soil one by one to form a first sheet pile wall with a continuous stroke;

[0046] S2: excavating rock and soil within the first sheet pile wall and outside the preset distance of the derrick foundation in the vertical shaft to be constructed, and sloping the excavated area according to a preset ratio to form a slope surface with a high outside and a low inside, and performing sheet pile construction at the lowest point of the slope surface to form a second sheet pile wall;

[0047] S3: constructing a circle of grooves around the wellhead of the vertical shaft to be constructed, tying steel bars in the grooves to form a steel bar network structure close to the vertical shaft to be constructed, and placing fixed cross bars on the steel bar network structure, so that one end of the fixed cross bar is tied to the steel bar, and the other end is erected and fixed on the well frame foundation;

[0048] S4: pouring concrete between the shaft template and the shaft side wall of the shaft to be constructed, and between the shaft template and the groove to form a shaft, and forming a concrete anti-slip cap that is cast and fixed to the fixed cross bar and the steel network structure and is integrally formed with the shaft.

[0049] Step S1 is a process of performing the first sheet pile construction at a preset range from the shaft to be constructed, so that each sheet pile is driven into the soil one by one to form a first sheet pile wall 1 with a continuous stroke.

[0050] The process of constructing the first sheet pile wall includes:

[0051] S11: Selecting a first target address of the first sheet pile wall at a distance of 14-18 meters from the foundation 3 of the shaft to be constructed; that is, the preset range refers to a distance of 14-18 meters from the foundation 3 of the shaft to be constructed, and the first target address can be a square with arc angles or a circle;

[0052] S12: Align the sheet piles in pairs at the first target address, and use a pile driver to drive the sheet piles completely into the ground one by one, so that the tops of all the sheet piles are flush with the ground to form a first sheet pile wall 1.

[0053] In order to facilitate piling, and the default derrick foundation is often square, in this specific embodiment, the first target address is a square with rounded corners to facilitate piling. The reason for the rounded corners is that multiple sheet piles can be connected in sequence by tilting, and multiple sheet piles driven vertically into the ground are connected in pairs by tilting to form an arc-like shape. However, in actual operation, since the site is very large and many sheet piles are used, the inclination angle of the sheet piles at the arc corner is not large, thereby improving the side airtightness of the entire first sheet pile wall.

[0054] Step S2 is a process of excavating rock and soil within the first sheet pile wall 1 and outside the preset distance of the derrick foundation 3 in the vertical shaft to be constructed, and sloping the excavated area according to a preset ratio to form a slope surface with high outside and low inside, and performing sheet pile construction at the lowest point of the slope surface to form a second sheet pile wall 2;

[0055] The preset ratio is 1:1.5 to 1:1.7, that is, when excavating rock and soil, the ratio of the excavation width to the depth is between 1:1.5 and 1:1.7, so as to form a slope surface, and then pile construction is carried out at the lowest point of the slope surface. In a specific embodiment, the depth of the pit formed by excavating rock and soil is not greater than five meters, and the bottom width is not less than three meters, so as to form a slope surface.

[0056] The process of constructing the second sheet pile wall 2 includes:

[0057] The area enclosed by the lowest point of the slope surface is taken as the second target address;

[0058] At the second target address, the sheet piles are aligned in pairs, and the sheet piles are driven completely into the ground one by one by a pile driver, so that the top ends of all the sheet piles exceed the lowest point by 40-70 cm to form a second sheet pile wall.

[0059] like Figure 3 As shown, the overall piling depth of the second sheet pile wall is deeper than that of the first sheet pile wall. However, after the sheet piles of the first sheet pile wall are constructed, their tops are flush with the unmined ground, while the second sheet pile wall is constructed after the rock and soil excavation. Therefore, the second sheet pile wall is deeper and forms a stepped arrangement with the sheet piles in the first sheet pile wall. Since the sheet piles in the second sheet pile wall penetrate deeper into the rock and soil, the rock and soil in which they are located are harder, making it more difficult to carry out piling and pile pulling operations. In order to facilitate piling and pile pulling operations, the tops of each sheet pile in the constructed second sheet pile wall are about 40-70 cm higher than the lowest point of the slope surface, usually half a meter (50 cm) higher.

[0060] More specifically, in this embodiment, the sheet piles in the first sheet pile wall 1 and the second sheet pile wall 2 are steel sheet piles, in order to improve the hardness of the sheet piles and facilitate pile driving and pulling. Two symmetrical isosceles trapezoidal locking openings are formed integrally on both sides of the steel sheet piles; and the two adjacent steel sheet piles in the first sheet pile wall and the second sheet pile wall are connected in pairs through the locking openings. Since each steel sheet pile has symmetrically arranged vertical strip-shaped locking openings with isosceles trapezoidal cross sections on both sides, the locking buckles of two adjacent steel sheet piles are arranged relative to each other, so that the side edges of the locking buckles on the adjacent steel sheet piles are directly and tightly connected to each other, thereby improving the airtightness of the direct connection between the sheet piles and the sheet piles, and further effectively reinforcing the soil and preventing water. The shape of the main part of the steel sheet pile except the locking buckles on both sides is not specifically limited, and can be an ordinary rectangular steel plate, or a steel plate with the same shape as the locking buckles with isosceles trapezoidal cross sections on both sides, but with a larger specification and isosceles trapezoidal cross section. No limitation is made here, such as Figure 5 As shown, in this specific embodiment, a steel sheet pile 11 whose main body is an isosceles trapezoidal cross section is used, so as to further enhance its buffering force for intercepting soil and water.

[0061] More specifically, in the process of driving the sheet piles completely into the ground one by one by a pile driver,

[0062] The slope of the sheet piles is detected in real time. When the slope of the sheet piles exceeds 2%, they are adjusted by pulling them in line. If they cannot be adjusted, they are pulled out and driven back in. If there are large pieces of gravel underground that make it impossible to drive the sheet piles in, a boring machine is used to conduct boring construction, and the sheet piles are replaced with spare sheet piles with a small vertical height to improve the stability of the overall first sheet pile wall and the second sheet pile wall.

[0063] In a particularly specific embodiment, the first circle of sheet piles is a first sheet pile wall made of 9m high steel plates, which are constructed around the derrick and within 15m beyond the well foundation frame to form the first sheet pile wall. After the first circle of sheet piles is constructed, the rock and soil 1m beyond the derrick foundation is excavated, the depth does not exceed 5m, the bottom width is not less than 3m, and the slope is 1:1.6. At the same time, a special construction plan can be prepared and submitted to the owner and the supervision unit for approval before implementation. Then the second circle of sheet piles is constructed. The second circle of sheet piles uses 12m high steel plates and is constructed at the bottom of the excavation pit. After the second circle of sheet piles is constructed, the second sheet pile wall is formed, and then the wellbore neck section can be formally excavated. The length and width of the steel sheet piles during the second circle of sheet piles are determined according to the derrick model, and the steel sheet pile specifications are 575mm×10mm×12m. If large pieces of gravel appear during the construction process and the steel sheet piles cannot be driven in, a boring machine must be used to drill holes and the sheet piles must be replaced with small-sized spare sheet piles of 400mm×10mm×12m.

[0064] Step S3 is a process of constructing a circle of grooves around the wellhead of the vertical shaft to be constructed, tying steel bars in the grooves to form a steel network structure that is close to the vertical shaft to be constructed, and placing fixed cross bars on the steel network structure, so that one end of the fixed cross bar is tied to the steel bar and the other end is set and fixed on the well frame foundation.

[0065] That is Figure 4 As shown, after the sheet pile wall is piled, the neck section of the Quaternary stratum is constructed. Before the neck section is constructed, the upper wellhead part of the well to be constructed needs to be reinforced to ensure the quality of the subsequent neck section construction. A concrete anti-slip cap is used for reinforcement. First, step S3 is required, that is, a circle of grooves 4 (wellhead widening surface) is constructed around the wellhead of the vertical shaft to be constructed, and steel bars are tied in the grooves 4 (wellhead widening surface) to form a steel network structure 5 that is close to the vertical shaft to be constructed, and a fixed cross bar 6 is placed on the steel network structure, so that one end of the fixed cross bar is tied to the steel bar, and the other end is erected and fixed on a preset derrick foundation 3.

[0066] Among them, the derrick foundation is a square derrick foundation. In the process of placing fixed cross bars on the steel network structure,

[0067] Two points are selected as vertical points at preset intervals on the edge of the square derrick foundation, and the vertical points are used as the foot of the vertical line. The points on the steel network structure are connected as the vertical lines of the edges, and the vertical lines on the two opposite sides of the square derrick foundation are symmetrical to each other; the vertical lines are used as dividing lines, and fixed cross bars are placed at the dividing lines, and the length of the fixed cross bars exceeds the outermost side wall of the shaft to be constructed by 3-4 meters; wherein the fixed cross bars are I56b I-beams, thereby enhancing stability.

[0068] Then, step S4 is performed, in which concrete is poured between the shaft template and the side wall of the shaft to be constructed, and between the shaft template and the groove to form a shaft 8, and a concrete anti-slip cap 9 is cast and fixed to fix the fixed cross bar and the steel network structure, and is integrally formed with the shaft. The concrete anti-slip cap 9 is integrally formed with the shaft 8 to enhance the stability of the shaft, and the fixed cross bar of the I-beam is also cast inside to further increase the stability of the shaft.

[0069] During pouring, the shaft template is in a hoisting state, that is, the shaft template 7 is hoisted by a hoisting machine 10 to facilitate pouring of the shaft.

[0070] In addition, the method further includes S5: constructing the vertical shaft to be constructed downwards, and after the preset height of the upper part of the shaft of the vertical shaft to be constructed is completed, the method further includes:

[0071] S51: vibrating two adjacent sheet piles by a vibrating hammer to reduce soil adhesion;

[0072] S52: performing pile extraction processing by means of a crane and a vibrating hammer to sequentially extract the sheet piles; and the crane is gradually loaded with the vibration of the vibrating hammer;

[0073] S53: Use stone chips to backfill the ground pile holes formed by pulling out the sheet piles to restore the original appearance of the ground.

[0074] In a specific embodiment, for example, after the construction of the upper 20m of the wellbore is completed, the construction of the Quaternary stratum is completed, and the steel sheet piles need to be removed for reuse. Before removing the steel sheet piles, the sequence of pile pulling methods, pile pulling time and soil hole treatment should be carefully studied. Otherwise, due to the vibration of the pile pulling and the excessive soil brought by the pile pulling, the ground settlement and displacement may be caused, which may cause damage to the completed surface structure and affect the safety of the adjacent derrick foundation.

[0075] Pile extraction method:

[0076] This project uses a vibrating hammer to pull out the piles: using the forced vibration generated by the vibrating hammer to disturb the soil, destroy the cohesion of the soil around the steel sheet pile to overcome the resistance to pulling out the piles, and rely on the additional lifting force to pull out the piles. Things to note when pulling out the piles:

[0077] ① Vibration and pulling: When pulling out the pile, you can first use a vibrating hammer to vibrate the lock of the steel sheet pile to reduce the adhesion of the soil, and then pull it out while vibrating. For steel sheet piles that are difficult to pull out, you can first use a vibrating hammer to vibrate the pile down 100mm to 300mm, and then alternately vibrate and pull it out with the vibrating hammer. Sometimes, in order to fill the soil hole after pulling out the pile in time, when the sheet pile is pulled to a height slightly higher than the foundation bottom plate, stop pulling out, and vibrate with a vibrating hammer for a few minutes to try to fill the soil hole partially.

[0078] ② The crane should be gradually loaded as the vibrating hammer is started. The lifting force is generally slightly smaller than the compression limit of the shock absorber spring.

[0079] ③The power supply for the vibratory hammer is 1.2 to 2.0 times the rated power of the vibratory hammer itself.

[0080] ④ For steel sheet piles with large pull-out resistance, use intermittent vibration method, with each vibration lasting 15 minutes, and the continuous vibration of the vibrating hammer shall not exceed 1.5 hours.

[0081] (6) Steel sheet pile hole treatment

[0082] The pile hole left after the pile is pulled out must be backfilled in time. The backfilling method is the filling method. The material used in the filling method is stone chips.

[0083] (7) Number of steel sheet piles

[0084] The total length of the two layers of steel sheet piles is 225m, the specifications of the steel sheet piles are 575mm×10mm×12m(9m), and a total of 391 pieces are required.

[0085] This will reduce damage to the land.

[0086] As described above, the construction method of the shaft neck section provided by the present invention through the Quaternary strata is the first in China to create and implement the step-type sheet pile method construction process (first pile construction of the first sheet pile wall, and then excavation of the slope to construct the second sheet pile wall). When constructing the shaft neck section in metal and non-metal mines, a steel sheet pile plus anti-slip structure construction process is adopted to quickly pass the construction under special stratum conditions, and the shaft quality is fully guaranteed, and safe construction is ensured; compared with the previous ordinary construction methods, it has achieved a safe construction process with fast construction, low investment, and guaranteed shaft quality, which not only improves economic benefits, but also has certain social benefits. The construction of special stratum shaft neck sections in domestic metal and non-metal mines has a leading construction technology level, and more specifically, it has the following advantages:

[0087] 1) High strength and good stability: Sheet piles are made of high-strength steel, can withstand large loads and external forces, have high bending and torsional strength, and can effectively resist vibrations and impacts caused by earthquakes, wind and other natural disasters.

[0088] 2) Convenient and fast construction: Sheet piles can quickly enter the soil or rock through vibration or striking. The construction process is simple, fast and flexible, not affected by weather factors, which helps to shorten the construction period.

[0089] 3) Easy to detect and control quality: During the sheet pile construction process, on-site detection technology and remote monitoring system can be used for quality monitoring to ensure the construction quality.

[0090] 4) Recyclable: Sheet piles can be recycled and reused to reduce resource consumption and environmental pollution.

[0091] 5) Wide adaptability: Sheet piles are suitable for various complex geological conditions, such as soft soil, sand, silt, rock, etc., and have strong adaptability.

[0092] 6) Good waterproof performance: The closed structure of the sheet pile provides good waterproof performance and is suitable for construction in deep water.

[0093] 7) Can form cofferdams of various shapes: Sheet piles can be used to form cofferdams of different shapes as needed, suitable for a variety of engineering needs.

[0094] 8) Multiple reuse: Sheet piles have high durability and can be reused many times in different projects.

[0095] In summary, in special strata, sheet piles can provide sufficient stability and support while adapting to changing geological conditions. The first and second sheet pile walls formed can effectively resist the lateral pressure of the soil, provide the required support for the project, and also have a certain water-stopping effect. Recycling can reinforce the soil, prevent water, and ensure the safety and efficiency of construction. After use, the steel sheet piles can be pulled out one by one through equipment such as a vibrating hammer, and can be repeatedly used in multiple construction sites. The concrete anti-slip cap in this embodiment is integrally formed with the wellbore to enhance the stability of the wellbore, and the fixed cross bar of the I-beam is also cast inside to further increase the stability of the wellbore.

[0096] As described above with reference to the accompanying drawings, the construction method of the vertical shaft neck section passing through the Quaternary strata proposed by the present invention is described by way of example. However, those skilled in the art should understand that various improvements can be made to the construction method of the vertical shaft neck section passing through the Quaternary strata proposed by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A construction method for a vertical shaft neck section passing through a Quaternary stratum, characterized in that: include: The first sheet pile construction is carried out at a preset range from the shaft to be constructed, so that each sheet pile is driven into the soil one by one to form a first sheet pile wall with a continuous stroke; Excavating rock and soil within the first sheet pile wall and outside the preset distance of the derrick foundation in the vertical shaft to be constructed, and sloping the excavated area according to a preset ratio to form a slope surface with a high outside and a low inside, and performing sheet pile construction at the lowest point of the slope surface to form a second sheet pile wall; A circle of grooves is constructed around the wellhead of the vertical shaft to be constructed, steel bars are tied in the grooves to form a steel network structure close to the vertical shaft to be constructed, and a fixed cross bar is placed on the steel network structure, so that one end of the fixed cross bar is tied to the steel bar, and the other end is erected and fixed on the well frame foundation; Concrete is poured between the shaft template and the shaft side wall of the shaft to be constructed, and between the shaft template and the groove to form a shaft, and a concrete anti-slip cap is cast and fixed to fix the fixed cross bar and the steel network structure and is integrally formed with the shaft.

2. The construction method of a vertical shaft neck section passing through a Quaternary stratum according to claim 1, characterized in that: The sheet piles in the first sheet pile wall and the second sheet pile wall are steel sheet piles, and two symmetrical isosceles trapezoidal locking openings are integrally formed on both sides of the steel sheet piles; and Two adjacent steel sheet piles in the first sheet pile wall and the second sheet pile wall are connected in pairs through the locking opening.

3. The construction method of a vertical shaft neck section passing through a Quaternary stratum as claimed in claim 2, characterized in that: The process of constructing the first sheet pile wall includes: Selecting a first target address of a first sheet pile wall at a distance of 14-18 meters from the foundation of the shaft to be constructed; the first target address is a square with arc corners or a circle; At the first target address, the sheet piles are aligned in pairs, and the sheet piles are driven completely into the ground one by one by a pile driver, so that the tops of all the sheet piles are flush with the ground to form a first sheet pile wall.

4. The construction method of a vertical shaft neck section passing through a Quaternary stratum as claimed in claim 3, characterized in that: The process of constructing the second sheet pile wall includes: The area enclosed by the lowest point of the slope surface is taken as the second target address; At the second target address, the sheet piles are aligned in pairs, and the sheet piles are driven completely into the ground one by one by a pile driver, so that the tops of all the sheet piles exceed the lowest point by 40-70 cm to form a second sheet pile wall.

5. The construction method of a vertical shaft neck section passing through a Quaternary stratum as claimed in claim 4, characterized in that: In the process of driving the sheet piles completely into the ground one by one by a pile driver, The slope of the sheet pile is detected in real time. When the slope of the sheet pile exceeds 2%, it is adjusted by the pulling method. If it cannot be adjusted, it is pulled out and re-driven in. If there is large gravel underground, making it impossible to drive the sheet pile in, a boring machine is used to carry out boring construction, and the sheet pile is replaced with a spare sheet pile whose vertical height is less than that of the current construction sheet pile.

6. The construction method of a vertical shaft neck section passing through a Quaternary stratum according to claim 1, characterized in that: The preset ratio is 1:1.5 to 1:1.

7.

7. The construction method of a vertical shaft neck section passing through a Quaternary stratum as claimed in claim 6, characterized in that: The depth of the pit formed by excavating rock and soil shall not exceed five meters, and the bottom width shall not be less than three meters.

8. The method for constructing a vertical shaft neck section through a Quaternary stratum according to claim 1, characterized in that: The method further includes constructing the vertical shaft to be constructed downwards, and after the preset height of the upper part of the shaft of the vertical shaft to be constructed is completed, the method includes: Vibrate two adjacent sheet piles by vibrating hammer to reduce soil adhesion; The sheet piles are pulled out in sequence by using a crane and a vibrating hammer; and the crane is gradually loaded with the vibration of the vibrating hammer; The ground pile holes created by pulling out the sheet piles are backfilled with stone chips.

9. The method for constructing a vertical shaft neck section through a Quaternary stratum according to claim 1, characterized in that: The derrick foundation is a square derrick foundation. During the process of placing fixed cross bars on the steel network structure, Two points are selected as vertical points at a preset interval on the edge of the square derrick foundation, the vertical points are used as the foot of the vertical line, and the points on the steel network structure are connected as the vertical lines of the edge, and the vertical lines on the two opposite sides of the square derrick foundation are symmetrical to each other; The vertical line is used as a dividing line, and a fixed cross bar is placed at the dividing line, and the length of the fixed cross bar exceeds the outermost side wall of the shaft to be constructed by 3-4 meters; wherein, The fixed cross bar is an I56b I-beam.

10. The method for constructing a vertical shaft neck section through a Quaternary stratum according to claim 1, characterized in that: The shaft template is hoisted by a hoisting machine.

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