CN116876580A - Anti-floating structure for construction of cyclone well and construction method thereof - Google Patents

Abstract

The invention provides a construction anti-floating structure of a cyclone well and a construction method thereof. The anti-floating structure is formed by constructing a support pile during construction of the cyclone well and comprises a plurality of buffer grooves formed by digging one side, adjacent to the wall of the cyclone well, of the support pile and fixed dowel bars reserved during binding of reinforcing steel bars of the wall of the cyclone well, wherein one part of the fixed dowel bars is used as main bars to be poured into the wall of the cyclone well, and the other part of the fixed dowel bars are inserted into the corresponding buffer grooves; according to the invention, when a foundation pit is excavated to the designed bottom elevation and the reinforcing steel bars of the cyclone well are bound, the pile body of the support pile is excavated in each pair of top elevation area, the inserted steel bars are reserved at the top of the buffer groove when the reinforcing steel bars of the cyclone well are bound, the uplift caused by overhigh water level in the construction process of the cyclone pool is prevented by using the uplift resistance and the dead weight of the support pile structure, a certain distance is reserved at the lower part of the buffer groove, the construction of the cyclone pool is prevented, the well wall is possibly cracked and damaged by post-construction settlement, and the support pile is used as an anti-floating structure in the construction period to generate an anti-floating effect.

Description

Anti-floating structure for construction of cyclone well and construction method thereof

Technical Field

The invention belongs to the field of construction of cyclone wells in metallurgical industry, and particularly relates to an anti-floating structure for construction of a cyclone well and a construction method thereof.

Background

In the construction process of steel mill construction in metallurgical industry, the cyclone well is one of the main water resource circulation systems in the steel mill, and the wastewater is filtered, separated and purified through the cyclone well, so that the water resource is fully utilized.

The construction of the cyclone well mainly adopts a forward construction method, and comprises three parts: deep foundation pit supporting part, earth and stone part and cyclone pool structure part. The method is mainly characterized in that the foundation pit is excavated deeply, the underground water is rich, the requirements of the stratum with high anti-floating water level on construction precipitation are high, foundation pit precipitation is started before earth excavation, and earth excavation and cyclone well structure construction can be carried out after the elevation of the underground water level meets the construction requirements.

In general, the dewatering water level of foundation pit construction is required to be reduced to-50 cm to-100 cm below the foundation pit, and the main structure of the cyclone well is designed to be designed and calculated in a certain range by increasing the dead weight of the main structure or directly increasing the gravity of water stored in the built well. Therefore, in the whole construction period, the pouring height of the main body structure of the well wall of the cyclone well is increased, the cyclone well gradually forms a whole, the foundation pit and the periphery of the foundation pit are required to be continuously subjected to water lowering and draining work, the water level of the foundation pit is ensured to be always kept between-50 cm and-100 cm at the bottom of the foundation pit, meanwhile, the load and the counterweight are temporarily increased through the bottom of the well when necessary, and the cyclone well is ensured not to generate larger buoyancy due to the rising of the underground water level in the construction process, so that the main body structure of the cyclone well floats upwards. However, in rainy season or rainstorm weather, the main structure of the cyclone well still floats due to the fact that the groundwater level is high or the water level in the well suddenly rises.

Disclosure of Invention

The invention provides a construction anti-floating structure of a cyclone well and a construction method thereof, aiming at the problems existing in the prior art.

In order to achieve the technical purpose, the invention provides an anti-floating structure for construction of a cyclone well, which is characterized in that: the anti-floating structure is formed by constructing a support pile during construction of the cyclone well and comprises a plurality of buffer grooves formed by digging one side, adjacent to the wall of the cyclone well, of the support pile and fixed dowel bars reserved during binding of reinforcing steel bars of the wall of the cyclone well, wherein one part of the fixed dowel bars is used as main bars to be poured into the wall of the cyclone well, and the other part of the fixed dowel bars are inserted into the corresponding buffer grooves; and the part inserted into the buffer groove is vertical to the part inserted into the wall of the cyclone well.

The invention has the preferable technical scheme that: the buffer grooves horizontally extend into the pile body of the support pile from one surface of the support pile adjacent to the wall of the cyclone well, the vertical section of each buffer groove is semicircular at the top and gradually-changed trapezoidal at the lower part, the diameter of the semicircle at the top is equal to the diameter d of the fixed dowel bar, the width of the gradually-changed trapezoidal upper section of the lower part of the buffer groove is d, and the width of the gradually-changed trapezoidal lower section of the buffer groove is d+10mm; the semicircular area and the gradual change trapezoid of the buffer groove are 2 d-3 d in overall height, and the buffer groove horizontally extends to the depth of 10 d-15 d in the pile body of the support pile.

The invention has the preferable technical scheme that: the fixed dowel bar is an inverted L-shaped dowel bar, the vertical part of the fixed dowel bar is fixed in the wall of the cyclone well and is used as a main dowel bar of the wall of the cyclone well, and the horizontal part of the fixed dowel bar is horizontally inserted into the buffer groove; the diameter d of the fixed dowel bar is larger than or equal to the design diameter of the main bar of the wall of the cyclone well.

The invention has the preferable technical scheme that: the buffer grooves are distributed at equal intervals along the vertical direction and the horizontal direction of the support pile, the vertical distance between every two adjacent buffer grooves is 2.5-5.0 m, and the horizontal distance is 1.2-4.8 m.

The invention further adopts the technical scheme that: the total number N of reserved fixed dowel bars is N, the horizontal reserved number of the single-circle fixed dowel bars is l, the horizontal spacing of the single-circle fixed dowel bars is determined according to the checking calculation of the groundwater anti-floating design, the sum of the dead weight of the constructed cyclone well and the total anti-floating force provided by the constructed dowel bars at any construction moment is ensured to be greater than or equal to the floating force generated by the constructed cyclone well structure, and the concrete checking calculation process is as follows:

n _i ＝πD _i /l _i

N＝n ₁ +n ₂ +....+n _i

f _s ×F _{floating i} ≤(n ₁ ×F _{Anti-floating 1} +...+n _i ×F _{Anti-floating i} )+G _i

f _s ×F _{Floating device} ≤N×F _{Anti-floating} +G

F _{Floating device} ＝γ _w ×V

Wherein: n is n _i Fixing the number of the dowel bars to a certain layer horizontally at a certain time for construction;

D _i for construction of the outer diameter of a cyclone well at a certain moment, the unit is: m;

l _i fixing the horizontal spacing of the dowel bars for construction at a certain moment;

n is the total number of fixed dowel bars of the cyclone well;

f _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating device} Buoyancy generated for the cyclone well structure, unit: kN;

F _{floating i} Buoyancy (kN) generated for constructing a swirl well structure at a certain moment;

F _{anti-floating} Providing anti-buoyancy for a single fixed dowel bar, unit: kN;

F _{anti-floating i} To be constructed at a certain momentTotal anti-buoyancy (kN) provided to a layer of fixed dowel bars;

g is the dead weight of the cyclone well in units of: kN;

G _i the dead weight (kN) of the cyclone well is used for constructing at a certain moment;

γ _w for water weight, 10KN/m is taken ³ ；

V is the inner volume of the outer edge contour of the cyclone well which is constructed and positioned below the underground water surface, and the unit is m ³ 。

The invention has the preferable technical scheme that: the diameter d of the fixed dowel bar and the horizontal depth h of the buffer groove, namely the horizontal depth h of the fixed dowel bar inserted into the buffer groove _Groove(s) Through groundwater anti-floating design calculation and dowel bar atress checking calculation, ensure that the dowel bar is not cut off or shear bending inefficacy is destroyed because of own shear strength is not enough, and not lead to relative frictional force to be too little and produce relative displacement because of the dowel bar inserts buffer tank degree of depth is not enough, the checking calculation process is as follows:

F _{anti-floating} ＝F _{Shearing resistance} +F _{Friction of}

F _{Shearing resistance} ＝0.25πd ² ×f _v

F _{Friction of} ＝f _rb ×s

s＝π×d×h _Groove(s) ×50％

h _Groove(s) ＝10d～15d

Wherein: f (F) _{Shearing resistance} Shear strength (kN) that can be provided for a single fixed dowel; f (F) _{Friction of} The limited friction force (kN) provided by the buffer slot portion inserted into the single fixed dowel bar; d is the diameter (m) of the fixed dowel bar; f (f) _v Designed value (kN/m) for shear strength of single fixed dowel bar ² ) The method comprises the steps of carrying out a first treatment on the surface of the s is the surface area (m ² ) 50% of the total surface area can be taken; f (f) _rb To fix the friction coefficient (kN/m) between the dowel bar and the inner wall of the buffer tank ² )；h _Groove(s) The horizontal depth (m) of the fixed dowel bar inserted into the buffer groove; which is a kind ofThe remainder is the same as above.

The invention has the preferable technical scheme that: the support pile adopts reinforced concrete filling piles; besides meeting the normal and stable setting requirements, the length of the support pile meets the pulling-resistant requirement transmitted to the pile body due to the buoyancy of groundwater in the construction process of the cyclone well, and is calculated specifically by the following formula:

f _s ×F _{floating device} -G≤(0.5×∑α _1j ×q _1jsi ×L _1j ×πZ _1j +G _{Pile 1} )+...+(0.5×∑α _ij ×q _ijsi ×L _ij ×πZ _ij +G _{Pile i} )

Wherein: alpha _ij The coefficient of the side rock-soil resistance of the j th layer of the ith support pile, q _ijsi Is the standard value (kPa) of limiting frictional resistance of the jth layer of side rock-soil layer of the ith support pile, L _ij The length (m) of the rock soil at the j-th layer side for the i-th support pile; z is Z _ij For the diameter of the rock-soil pile with the ith support pile positioned at the jth layer, G _{Pile i} The weight (kN) of the ith support pile is calculated.

In order to achieve the technical aim, the invention also provides a construction method of the anti-floating structure for the construction of the cyclone well, which is characterized by comprising the following specific steps:

s1, obtaining various construction parameters of the support pile and the cyclone well through corresponding project geotechnical engineering investigation reports, construction design drawings and engineering specifications of the support pile and the cyclone well, and calculating buoyancy F generated in the construction process of the cyclone well _{Floating device} The method comprises the steps of carrying out a first treatment on the surface of the Selecting steel bars with the diameter d being larger than or equal to the diameter of the main bars of the wall of the cyclone well as fixed dowel bars, and determining the total number N of the fixed dowel bars according to the following formula:

f _s ×F _{floating device} ≤N×F _{Anti-floating} +G

Wherein: f (f) _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating device} Buoyancy generated for the cyclone well structure, unit: kN;

F _{anti-floating} Providing anti-buoyancy for a single fixed dowel bar, unit: kN;

g is the dead weight of the cyclone well in units of: kN;

S2、determining the horizontal depth of the buffer groove, namely the depth h of inserting the fixed dowel into the buffer groove, according to the design calculation of groundwater anti-floating and the dowel stress checking calculation according to the fixed dowel selected in the step S1 _Groove(s) The method comprises the steps of carrying out a first treatment on the surface of the The joint bars are prevented from being sheared or broken by shearing bending failure due to insufficient shearing strength, and relative displacement caused by too small relative friction force due to insufficient depth of the joint bars inserted into the buffer grooves is avoided, so that the joint bars are broken by failure or the cyclone well floats upwards, and the construction of the cyclone well is further influenced; the checking and calculating process is as follows:

F _{anti-floating} ＝F _{Shearing resistance} +F _{Friction of}

F _{Shearing resistance} ＝0.25πd ² ×f _v

F _{Friction of} ＝f _rb ×s

s＝π×d×h _Groove(s) ×50％

h _Groove(s) ＝10d～15d

Wherein: f (F) _{Shearing resistance} Shear strength (kN) that can be provided for a single fixed dowel; f (F) _{Friction of} A limited friction force (kN) that can be provided for the single fixed dowel bar into the buffer channel portion; d is the diameter (m) of the fixed dowel bar; f (f) _v Designed value (kN/m) for shear strength of single fixed dowel bar ² ) The method comprises the steps of carrying out a first treatment on the surface of the s is the surface area (m ² ) 50% of the total surface area can be taken; f (f) _rb To fix the friction coefficient (kN/m) between the dowel bar and the inner wall of the buffer tank ² )；h _Groove(s) The horizontal depth (m) of the fixed dowel bar inserted into the buffer groove; n is the total number of fixed dowel bars of the cyclone well; the rest are the same as above;

s3, determining the number N of reserved fixed dowel bars and the depth h of the fixed dowel bars inserted into the buffer groove _Groove(s) The number and horizontal depth of the reserved buffer slots on the support piles can be determined, the size of a single reserved buffer slot is determined according to the diameter d of the selected fixed dowel bar, the buffer slot is of a structure with a semicircular upper part and a gradual trapezoid lower part, and the diameter of the semicircular upper part and the fixed dowel barThe diameter d is equal, the width of the upper section of the lower gradual change trapezoid is d, the width of the lower section is d+10mm, the height of the semicircular area of the buffer groove and the whole gradual change trapezoid is 2 d-3 d, and the buffer groove horizontally extends to the depth h in the pile body of the support pile _Groove(s) The method comprises the steps of carrying out a first treatment on the surface of the Then designing a layout scheme of the buffer grooves according to the vertical spacing of 2.5-5.0 m and the horizontal spacing of 1.2-4.8 m between two adjacent buffer grooves;

s4, after the layout parameters of the fixed dowel bars and the buffer grooves are well determined, starting to construct a cyclone well, firstly constructing a foundation pit supporting structure, after the construction of the foundation pit supporting structure is completed, performing foundation pit drainage and earth excavation, excavating to the designed shaft bottom elevation of the cyclone well, starting to construct a main structure of the cyclone well, positioning and paying off the buffer grooves on the supporting pile according to the parameters determined in the steps S1 to S3 before binding the well wall reinforcing steel bars, and performing buffer groove excavation by using a pneumatic pick or an electric hammer;

s5, after the buffer groove is dug, binding the corresponding area rotational flow well wall steel bars, and binding the fixed dowel bars, wherein the well wall part and the well wall main structure steel bars are bound together, and the inserted part is vertically inserted into the buffer groove to ensure that the fixed dowel bars are positioned at the semicircular position at the top of the buffer groove; and after the binding of the reinforcing steel bars is completed, the concrete pouring of the layer of cyclone well is completed.

The invention has the preferable technical scheme that: in the step S4, steel bars of the support piles are avoided when the buffer groove is dug, and residues and the like in the groove are cleaned up by blowing air by an air compressor or flushing by a water pipe after the buffer groove is dug, so that the smooth insertion of fixed dowel bars is ensured; in the step S5, the binding of the well wall part is firm, so that the fixed dowel bar is ensured not to loosen and move downwards in the concrete pouring process; in the construction process of the cyclone well in the step S5, checking calculation is carried out on the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the installed fixed dowel bars at each moment, when the sum of the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the constructed fixed dowel bars is smaller than the buoyancy generated by the constructed cyclone well structure, the adjustment is carried out by adding the number of the fixed dowel bars or replacing the large-diameter fixed dowel bars, so that the sum of the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the constructed fixed dowel bars at any moment in construction is ensured to be larger than or equal to the buoyancy generated by the constructed cyclone well structure, and the checking calculation process is as follows:

n _i ＝πD _i /l _i

f _s ×F _{floating i} ≤(n ₁ ×F _{Anti-floating 1} +...+n _i ×F _{Anti-floating i} )+G _i

F _{Floating i} ＝γ _w ×V _i

Wherein: n is n _i Fixing the number of the dowel bars to a certain layer horizontally at a certain time for construction;

D _i for construction of the outer diameter of a cyclone well at a certain moment, the unit is: m;

l _i fixing the horizontal spacing of the dowel bars for construction at a certain moment;

f _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating i} Buoyancy (kN) generated for constructing a swirl well structure at a certain moment;

F _{anti-floating i} The total anti-buoyancy (kN) is provided for constructing a certain layer of fixed dowel bars horizontally at a certain moment;

G _i the dead weight (kN) of the cyclone well is used for constructing at a certain moment;

γ _w for water weight, 10KN/m is taken ³ ；

V _i To construct the inner volume of the outer edge contour of the cyclone well which is constructed at a certain moment and is positioned below the underground water surface, the unit is m ³ 。

The invention has the preferable technical scheme that: and (S4) checking the length of the pile body of the support pile before construction of the foundation pit support structure in the step, wherein the length meets the pulling-resistant requirement of the pile body transmitted by the buoyancy of underground water, and ensures that the sum of the dead weight of the utilized support pile and the limit pulling-resistant force provided by the utilized support pile at any moment is larger than or equal to the difference between the buoyancy generated by the constructed cyclone well structure and the dead weight of the constructed cyclone well, and the concrete steps are as follows:

f _s ×F _{floating device} -G≤(0.5×∑α _1j ×q _1jsi ×L _1j ×πZ _1j +G _{Pile 1} )+...+(0.5×∑α _ij ×q _ijsi ×L _ij ×πZ _ij +G _{Pile i} )

Wherein: alpha _ij The coefficient of the side rock-soil resistance of the j th layer of the ith support pile, q _ijsi Is the standard value (kPa) of limiting frictional resistance of the jth layer of side rock-soil layer of the ith support pile, L _ij The length (m) of the rock soil at the j-th layer side for the i-th support pile; z is Z _ij For the diameter of the rock-soil pile with the ith support pile positioned at the jth layer, G _{Pile i} The weight (kN) of the ith support pile is calculated.

The buffer groove digging operation is simple, the technological requirement is low, and the construction cost is low; the reserved tie bar binding operation is simple, the technological requirements are low, and the construction cost is low; the reserved dowel bars are inserted into the buffer grooves, so that the operation is simple, the technological requirements are low, and the construction cost is low.

According to the anti-floating structure, through anti-floating design calculation and construction process, corresponding elevation and water level observation data of each cyclone well are constructed, in the process of pouring construction of the wall of the cyclone well, the height of the underground water level can rise along with the rise of pouring height, the problems of long precipitation period, large depth and large workload in the construction process of the cyclone well are overcome, and the construction precipitation water level requirement and the construction cost of a waterproof curtain in the whole construction process are reduced; the waste of groundwater resources is reduced; the corresponding measures of anti-floating by increasing pit bottom load, raft thickness, well wall thickness and the like in the construction process are reduced; not only shortens the construction period of precipitation and the intensity of precipitation, reduces the extra workload of precipitation and anti-floating, reduces the construction cost, but also effectively utilizes the support pile.

According to the invention, when a foundation pit is excavated to the designed bottom elevation and each pair of cyclone well wall reinforcing steel bars are bound, the pile body of the support pile is excavated and a buffer groove is reserved at the top of the buffer groove when each pair of cyclone well wall reinforcing steel bars are bound. The buffer tank lower part is reserved a certain distance to prevent the construction of the cyclone pool from being completed, the post-construction settlement possibly generates pulling crack damage to the well wall, and the support pile is utilized as an anti-floating structure during construction to generate an anti-floating effect.

The invention has simple integral structure, low cost and simple and convenient construction process operation, and reduces the precipitation depth and the workload in the construction process of the cyclone well; corresponding anti-floating measures such as pit bottom load, raft thickness and well wall thickness are reduced in the construction process; not only shortens the construction period and reduces the construction cost, but also effectively utilizes the post of the support pile.

Drawings

FIG. 1 is a schematic cross-sectional view of the present invention;

FIG. 2 is a schematic top view of the present invention;

FIG. 3 is a schematic view of the anti-floating structure of the present invention;

FIG. 4 is a schematic vertical cross-section of a buffer tank according to the present invention;

FIG. 5 is a schematic transverse cross-sectional view of a buffer tank in accordance with the present invention.

In the figure: 1-a cyclone well wall, 2-supporting piles, 3-buffer grooves, 4-fixed dowel bars and 5-a cyclone well.

Detailed Description

The invention is further described below with reference to the drawings and examples. Fig. 1 to 5 are drawings of embodiments, which are drawn in a simplified manner, for the purpose of clearly and concisely illustrating embodiments of the present invention. The following technical solutions presented in the drawings are specific to embodiments of the present invention and are not intended to limit the scope of the claimed invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "vertical", "top", "bar diameter d", "2d to 3d", "10d to 15d", etc., are based on the directions or positional relationships shown in the drawings, or the directions or positional relationships in which the inventive product is conventionally put in use, or the directions or positional relationships as conventionally understood by those skilled in the art, are merely for convenience of description and simplicity of description, and are not intended to indicate or imply that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless explicitly stated and limited otherwise, the positions and numbers of the fixing dowels and the corresponding buffer grooves are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific position and number, and thus should not be construed as limiting the invention. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to specific circumstances.

The embodiment provides a whirl well construction anti-floating structure, as shown in fig. 1 to 5, anti-floating structure utilizes support stake 2 construction to form in whirl well 5 construction period, includes a plurality of dashpots 3 that dig to form in the side that support stake 2 is adjacent whirl well wall 1 and the fixed dowel 4 of reservation when the ligature of whirl well wall 1 reinforcing bar, dashpot 3 is all equidistantly laid along support stake 2 vertical direction and horizontal direction, and the vertical interval between two adjacent dashpots 3 is mostly 2.5 ~ 5.0m, and the horizontal interval is 1.2 ~ 4.8m. The buffer grooves 3 horizontally extend into the pile body of the support pile 2 from one surface of the support pile 2 adjacent to the cyclone well wall 1, the vertical section of each buffer groove 3 is semicircular at the top and gradually-changed trapezoidal at the lower part, the diameter of the semicircle at the top is equal to the diameter d of the fixed dowel bar 4, the width of the gradually-changed trapezoidal upper section at the lower part of the buffer groove 3 is d, and the width of the gradually-changed trapezoidal lower section is d+10mm; the semicircular area and the gradual change trapezoid of the buffer groove 3 are 2 d-3 d in overall height, and the buffer groove 3 horizontally extends to the depth of the pile body of the support pile 2 to be 10 d-15 d. One part of the fixed dowel bar 4 is used as a main bar to be poured into the wall of the cyclone well 5, the other part of the fixed dowel bar is inserted into the corresponding buffer groove 3, and the part inserted into the buffer groove 3 is in a vertical state with the part inserted into the wall 1 of the cyclone well. The fixed dowel bars 4 are inverted L-shaped dowel bars, the vertical parts of the fixed dowel bars are fixed in the cyclone well wall 1 to serve as main bars of the cyclone well wall 1, and the horizontal parts of the fixed dowel bars are horizontally inserted into the buffer grooves 3.

The embodiment provides a construction method for constructing an anti-floating structure of a cyclone well, which comprises the following specific steps:

s1, obtaining various construction parameters of the support pile and the cyclone well through corresponding project geotechnical engineering investigation reports, construction design drawings and engineering specifications of the support pile and the cyclone well, and calculating buoyancy F generated in the construction process of the cyclone well _{Floating device} The volume of the cyclone well occupying the underground water can be calculated only by adopting the outline schematic diagram of the cyclone well and the buried depth of the underground water, and then the buoyancy of the cyclone well can be calculated according to the Archimedes principle; specifically, the anti-pulling coefficient alpha of each support pile in each side rock-soil layer is determined through a corresponding project geotechnical engineering investigation report, and the ultimate frictional resistance standard value q of each support pile in each side rock-soil layer is determined _si And the field anti-floating water level; the self weight G of each support pile is obtained through the support pile and the construction drawing and the construction record of the cyclone well _Pile The cyclone well dead weight G and the cyclone well design height H; obtaining friction coefficient f between reserved dowel bars and inner wall of buffer groove through standard inquiry _rb The method comprises the steps of carrying out a first treatment on the surface of the The rationality of the parameters can be verified by field test; the allowable sedimentation value of the cyclone well and the structural stress of the wall of the cyclone well in the construction design stage can be obtained according to a construction diagram of the cyclone well; the waterproof curtain and the construction dewatering construction design are designed to be special for the construction diagram of the inherent cyclone well, can be directly obtained and used, and can be assisted with groundwater level monitoring and verification in the process; the parameters applied in the calculation process of the embodiment can be obtained through on-site investigation data or design drawing or specification inquiry. Fixing the diameter d of the dowel bar and the design value f of shear strength of the dowel bar _v Can be obtained according to the dowel bar factory nameplate. Firstly, determining the diameter d of a fixed dowel bar, wherein the diameter d of the fixed dowel bar is larger than or equal to the diameter of a main dowel bar of a wall of a cyclone well, and determining the total number N of the fixed dowel bars according to the selected fixed dowel bar by the following formula:

f _s ×F _{floating device} ≤N×F _{Anti-floating} +G

Wherein: f (f) _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating device} Is a cyclone well structureGenerated buoyancy, unit: kN;

F _{anti-floating} Providing anti-buoyancy for a single fixed dowel bar, unit: kN;

g is the dead weight of the cyclone well in units of: kN.

S2, determining the horizontal depth of the buffer groove, namely the depth h of inserting the fixed dowel into the buffer groove, according to the fixed dowel selected in the step S1 and according to groundwater anti-floating design calculation and dowel stress checking calculation _Groove(s) The method comprises the steps of carrying out a first treatment on the surface of the The joint bars are prevented from being sheared or broken by shearing bending failure due to insufficient shearing strength, and relative displacement caused by too small relative friction force due to insufficient depth of the joint bars inserted into the buffer grooves is avoided, so that the joint bars are broken by failure or the cyclone well floats upwards, and the construction of the cyclone well is further influenced; the checking and calculating process is as follows:

F _{anti-floating} ＝F _{Shearing resistance} +F _{Friction of}

F _{Shearing resistance} ＝0.25πd ² ×f _v

F _{Friction of} ＝f _rb ×s

s＝π×d×h _Groove(s) ×50％

h _Groove(s) ＝10d～15d

Wherein: f (F) _{Shearing resistance} Shear strength (kN) that can be provided for a single fixed dowel; f (F) _{Friction of} A limited friction force (kN) that can be provided for the single fixed dowel bar into the buffer channel portion; d is the diameter (m) of the fixed dowel bar; f (f) _v Designed value (kN/m) for shear strength of single fixed dowel bar ² ) The method comprises the steps of carrying out a first treatment on the surface of the s is the surface area (m ² ) 50% of the total surface area can be taken; f (f) _rb To fix the friction coefficient (kN/m) between the dowel bar and the inner wall of the buffer tank ² )；h _Groove(s) The horizontal depth (m) of the fixed dowel bar inserted into the buffer groove; n is the total number of fixed dowel bars of the cyclone well; the rest are the same as above.

S3, determining the number N of reserved fixed dowel bars and the depth h of the fixed dowel bars inserted into the buffer groove _Groove(s) After the defecationThe number and horizontal depth of the reserved buffer grooves on the support piles can be determined, the size of a single reserved buffer groove is determined according to the selected diameter d of the fixed dowel bars, the buffer groove is of a structure with a semicircular upper part and a gradual-change trapezoid lower part, the diameter of the semicircular upper part is equal to the diameter d of the fixed dowel bars, the width of the upper section of the gradual-change trapezoid of the lower part is d, the width of the lower section of the gradual-change trapezoid is d+10mm, the total height of the semicircular area and the gradual-change trapezoid of the buffer groove is 2 d-3 d, and the buffer groove horizontally extends to the depth h in the support pile body _Groove(s) The method comprises the steps of carrying out a first treatment on the surface of the And then designing a layout scheme of the buffer grooves according to the vertical spacing of 2.5-5.0 m and the horizontal spacing of 1.2-4.8 m between two adjacent buffer grooves.

S4, after the layout parameters of the fixed dowel bars and the buffer grooves are well determined, starting to construct a cyclone well, firstly constructing a foundation pit supporting structure, after the construction of the foundation pit supporting structure is completed, performing foundation pit drainage and earth excavation, excavating to the designed shaft bottom elevation of the cyclone well, starting to construct a main structure of the cyclone well, positioning and paying off the buffer grooves on the supporting pile according to the parameters determined in the steps S1 to S3 before binding the well wall reinforcing steel bars, and performing buffer groove excavation by using a pneumatic pick or an electric hammer; the steel bars of the support piles are avoided during the buffer groove digging, and residues and the like in the groove are cleaned up by blowing air by an air compressor or flushing by a water pipe after the buffer groove digging is completed, so that the fixed dowel bars are ensured to be inserted smoothly; the length of the pile body of the support pile is proved to meet the pulling-resistant requirement of transmitting the buoyancy of underground water to the pile body before the construction of the foundation pit support structure, so that the sum of the dead weight of the support pile to be utilized and the ultimate pulling-resistant force which can be provided by the support pile to be utilized at any moment is ensured to be larger than or equal to the difference between the buoyancy generated by the constructed cyclone well structure and the dead weight of the constructed cyclone well, and the method specifically comprises the following steps:

f _s ×F _{floating device} -G≤(0.5×∑α _1j ×q _1jsi ×L _1j ×πZ _1j +G _{Pile 1} )+...+(0.5×∑α _ij ×q _ijsi ×L _ij ×πZ _ij +G _{Pile i} )

Wherein: alpha _ij The coefficient of the side rock-soil resistance of the j th layer of the ith support pile, q _ijsi Is the standard value (kPa) of limiting frictional resistance of the jth layer of side rock-soil layer of the ith support pile, L _ij The length (m) of the rock soil at the j-th layer side for the i-th support pile; z is Z _ij For the diameter of the rock-soil pile with the ith support pile positioned at the jth layer, G _{Pile i} The weight (kN) of the ith support pile is calculated.

S5, after the buffer groove is dug, binding the wall steel bars of the cyclone well in the corresponding area, binding fixed dowel bars, binding the wall part of the well and the steel bars of the main structure of the wall of the well together, vertically inserting the inserted part into the buffer groove to ensure that the fixed dowel bars are positioned at the semicircular position of the top of the buffer groove, and completing concrete pouring of the cyclone well after the steel bars are bound; the well wall part is firmly bound, so that the fixed dowel bars cannot loosen and move downwards in the concrete pouring process; the construction layering of the cyclone well is used for carrying out concrete pouring, the pouring height of each layer is about 5m, in the construction process of the cyclone well, the total anti-buoyancy provided by the dead weight of each layer of constructed cyclone well and the installed fixed dowel bars is checked, when the sum of the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the constructed fixed dowel bars is smaller than the buoyancy generated by the constructed cyclone well structure, the fixed dowel bars are added or replaced by the large-diameter fixed dowel bars to carry out adjustment, the sum of the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the constructed fixed dowel bars at any construction moment is ensured to be larger than or equal to the buoyancy generated by the constructed cyclone well structure, and the checking process is as follows:

n _i ＝πD _i /l _i

f _s ×F _{floating i} ≤(n ₁ ×F _{Anti-floating 1} +...+n _i ×F _{Anti-floating i} )+G _i

F _{Floating i} ＝γ _w ×V _i

Wherein: n is n _i Fixing the number of the dowel bars to a certain layer horizontally at a certain time for construction;

D _i for construction of the outer diameter of a cyclone well at a certain moment, the unit is: m;

l _i fixing the horizontal spacing of the dowel bars for construction at a certain moment;

f _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating i} To be constructed at a certain momentBuoyancy (kN) generated by the cyclone well structure;

F _{anti-floating i} The total anti-buoyancy (kN) is provided for constructing a certain layer of fixed dowel bars horizontally at a certain moment;

G _i the dead weight (kN) of the cyclone well is used for constructing at a certain moment;

γ _w for water weight, 10KN/m is taken ³ ；

V _i To construct the inner volume of the outer edge contour of the cyclone well which is constructed at a certain moment and is positioned below the underground water surface, the unit is m ³ 。

The invention is further described below by referring to specific examples, wherein the examples are a cyclone well of a steelmaking unit of a certain steel mill, the outer diameter of the outer cylinder wall of the cyclone well is 35.2m, the inner diameter of the outer cylinder wall is 32m, the wall thickness is 1.6m, the depth is 35.2m, the stable burial depth of the underground water level is 9.50m actually measured during construction, the cyclone well is constructed by adopting a forward construction method, and the construction height of each cyclone well is 5.0m; the foundation pit support of the cyclone well adopts concrete row piles, the pile diameter is 1.0m, the pile length is 28.0m, 90 support piles are totally arranged, reinforced concrete crown beams are arranged at the top, the reinforced concrete crown beams are uniformly arranged along the outer side of the wall of the pile, and the center distance between every two adjacent piles is 1.2m.

The project dowel bar is made of threaded reinforcing steel bars with the brand number of HRB400 and the diameter of 40mm, one bar planting point is arranged at every 1 support pile on the horizontal interval, 45 steel bar planting points are counted in a single circle, the vertical interval is 5m consistent with the construction height of each steel bar, 7 steel bar planting points are counted in total, and the total number of the steel bar planting points is 315. The depth of the embedded bars extending into the buffer groove is 15 times of the embedded bar diameter of 600mm, the friction coefficient of the embedded bars and reinforced concrete is 0.7, and the design of groundwater anti-floating and the stress of the reinforced bars are proved as follows:

n=45×7=315 roots

F _{Floating device} ＝γ _w ×V＝10*3.14*17.6 ² *(35.2-9.5)＝249970.1kN

F _{Shearing resistance} ＝0.25πd ² ×f _v ＝0.25*3.14*0.04 ² *400*1000＝502.4kN

F _{Friction of} ＝f _rb ×s＝0.7*400*3.14*0.04*0.3*50％＝5.2kN

G＝3.14*(17.6 ² -16 ² )*35.2*25＝148549.6kN

F _{Anti-floating} ＝315*(502.4+5.2)＝159894.0kN

F _{Anti-floating} +G＝159894+148549.6＝308443.6kN

F _{Floating device} *1.2＝249970.1*1.2＝299964.1kN

308443.6kN >299964.1kN, and the groundwater anti-floating design and the steel bar stress checking calculation meet the requirements.

According to the geological survey data and the construction record of the supporting piles, the pulling-resistant requirement of the supporting piles of the project is checked and calculated, and the concrete steps are as follows.

The maximum anti-buoyancy force required to be provided by the support piles is 1.2 x 249970.1-148549.6 = 151414.5kN

Single support piles can provide a pullout resistance of 3.14 x 0.5 x 28 x 24+0.3 x 5000= 2027.5kN;

the top of the supporting pile is provided with a reinforced concrete crown beam, and the total pulling resistance provided by the corresponding supporting pile group is 90 x 2027.5= 182475kN according to the integral consideration

182475kN is more than 151414.5kN, and the pull-out resistance checking calculation of the support pile meets the requirements.

The embodiment performs anti-floating by using the support piles during construction of the cyclone well, and theoretical calculation is feasible and is verified by field application: the ground water is dynamically adjusted, the ground water drop head height is synchronously increased while the construction is upward along with the construction of the cyclone well, only the ground water is ensured to be 0.5m below the current construction working surface, the ground water pumping workload can be greatly reduced, and the ground water pumping can be expected to be avoided to be nearly 100 tens of thousands of times during the construction period of the project; meanwhile, the project is not provided with an anti-floating pile/an anti-floating anchor rod or independent auxiliary anti-floating measures such as increasing dead weight by deliberately increasing the wall thickness of the cyclone well, and only the pile is supported by the cyclone well and anti-floating is carried out by adopting the structure and the corresponding construction method, so that the anti-floating cost is saved by approximately 500 ten thousand yuan; in addition, the field monitoring data is not abnormal, and the project is finished in the construction of the main body and is ready for production.

The foregoing description is of one embodiment of the invention and is thus not to be taken as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of the invention should be assessed as that of the appended claims.

Claims (10)

1. The utility model provides a whirl well construction anti-floating structure which characterized in that: the anti-floating structure is formed by constructing a supporting pile (2) during construction of a cyclone well (5), and comprises a plurality of buffer grooves (3) formed by digging one side, adjacent to the cyclone well wall (1), of the supporting pile (2) and fixed dowel bars (4) reserved during reinforcement binding of the cyclone well wall (1), wherein one part of the fixed dowel bars (4) is used as a main dowel bar to be poured into the wall of the cyclone well (5), the other part of the fixed dowel bars are inserted into the corresponding buffer grooves (3), and the part inserted into the buffer grooves (3) is in a vertical state with the part inserted into the cyclone well wall (1).

2. The cyclone well construction anti-floating structure according to claim 1, wherein: the buffer grooves (3) horizontally extend into the pile body of the support pile (2) from one surface of the support pile (2) adjacent to the cyclone well wall (1), the vertical section of each buffer groove (3) is semicircular at the top and gradually-changed trapezoid at the lower part, the diameter of the semicircle at the top is equal to the diameter d of the fixed dowel bar (4), the width of the upper section of the gradually-changed trapezoid at the lower part of the buffer groove (3) is d, and the width of the lower section of the gradually-changed trapezoid is d+10mm; the semicircular area and the gradual change trapezoid of the buffer groove (3) are 2 d-3 d in overall height, and the buffer groove (3) horizontally extends to the depth of the pile body of the support pile (2) to be 10 d-15 d.

3. The cyclone well construction anti-floating structure according to claim 1 or 2, wherein: the fixed dowel bars (4) are inverted L-shaped dowel bars, the vertical parts of the fixed dowel bars are fixed in the cyclone well wall (1) and serve as main dowel bars of the cyclone well wall (1), and the horizontal parts of the fixed dowel bars are horizontally inserted into the buffer grooves (3); the diameter d of the fixed dowel bar (4) is larger than or equal to the design diameter of the main bar of the cyclone well wall (1).

4. The cyclone well construction anti-floating structure according to claim 1 or 2, wherein: the buffer grooves (3) are uniformly distributed along the vertical direction and the horizontal direction of the support pile (2), the vertical distance between two adjacent buffer grooves (3) is 2.5-5.0 m, and the horizontal distance is 1.2-4.8 m.

5. The cyclone well construction anti-floating structure according to claim 1, wherein: the total number N is reserved for the fixed dowel bars (4), the reserved number of the horizontal fixed dowel bars to a single circle is N, the horizontal spacing of the single circle fixed dowel bars is l, which is determined according to the anti-floating design checking calculation of underground water, so that the sum of the dead weight of a constructed cyclone well and the total anti-floating force provided by the constructed dowel bars at any time in construction is ensured to be greater than or equal to the floating force generated by the constructed cyclone well structure, and the specific checking calculation process is as follows:

n _i ＝πD _i /l _i

N＝n ₁ +n ₂ +....+n _i

f _s ×F _{floating i} ≤(n ₁ ×F _{Anti-floating 1} +...+n _i ×F _{Anti-floating i} )+G _i

f _s ×F _{Floating device} ≤N×F _{Anti-floating} +G

F _{Floating device} ＝γ _w ×V

Wherein: n is n _i Fixing the number of the dowel bars to a certain layer horizontally at a certain time for construction;

D _i for construction of the outer diameter of a cyclone well at a certain moment, the unit is: m;

l _i fixing the horizontal spacing of the dowel bars for construction at a certain moment;

n is the total number of fixed dowel bars of the cyclone well;

f _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating device} Buoyancy generated for the cyclone well structure, unit: kN;

F _{floating i} Buoyancy (kN) generated for constructing a swirl well structure at a certain moment;

F _{anti-floating} Providing anti-buoyancy for a single fixed dowel bar, unit: kN;

F _{anti-floating i} The total anti-buoyancy (kN) is provided for constructing a certain layer of fixed dowel bars horizontally at a certain moment;

g is the dead weight of the cyclone well in units of: kN;

G _i the dead weight (kN) of the cyclone well is used for constructing at a certain moment;

γ _w for water weight, 10KN/m is taken ³ ；

V is the inner volume of the outer edge contour of the cyclone well which is constructed and positioned below the underground water surface, and the unit is m ³ 。

6. The cyclone well construction anti-floating structure according to claim 1, wherein: the diameter d of the fixed dowel bar (4) and the horizontal depth of the buffer groove (3), namely the horizontal depth h of the fixed dowel bar inserted into the buffer groove _Groove(s) Through groundwater anti-floating design calculation and dowel bar atress checking calculation, ensure that the dowel bar is not cut off or shear bending inefficacy is destroyed because of own shear strength is not enough, and not lead to relative frictional force to be too little and produce relative displacement because of the dowel bar inserts buffer tank degree of depth is not enough, the checking calculation process is as follows:

F _{anti-floating} ＝F _{Shearing resistance} +F _{Friction of}

F _{Shearing resistance} ＝0.25πd ² ×f _v

F _{Friction of} ＝f _rb ×s

s＝π×d×h _Groove(s) ×50％

h _Groove(s) ＝10d～15d

Wherein F is _{Shearing resistance} Shear strength (kN) that can be provided for a single fixed dowel; f (F) _{Friction of} The limited friction force (kN) provided by the buffer slot portion inserted into the single fixed dowel bar; d is the diameter (m) of the fixed dowel bar; f (f) _v Designed value (kN/m) for shear strength of single fixed dowel bar ² ) The method comprises the steps of carrying out a first treatment on the surface of the s is the surface area (m ² ) 50% of the total surface area can be taken; f (f) _rb To fix the friction coefficient (kN/m) between the dowel bar and the inner wall of the buffer tank ² )；h _Groove(s) Is fixed and insertedHorizontal depth (m) of rib insertion into buffer channel; the rest are the same as above.

7. The cyclone well construction anti-floating structure according to claim 1, wherein: the support pile adopts reinforced concrete filling piles; besides meeting the normal and stable setting requirements, the length of the support pile meets the pulling-resistant requirement transmitted to the pile body due to the buoyancy of groundwater in the construction process of the cyclone well, and is calculated specifically by the following formula:

f _s ×F _{floating device} -G≤(0.5×∑α _1j ×q _1jsi ×L _1j ×πZ _1j +G _{Pile 1} )+...+(0.5×∑α _ij ×q _ijsi ×L _ij ×πZ _ij +G _{Pile i} )

Wherein: alpha _ij The coefficient of the side rock-soil resistance of the j th layer of the ith support pile, q _ijsi Is the standard value (kPa) of limiting frictional resistance of the jth layer of side rock-soil layer of the ith support pile, L _ij The length (m) of the rock soil at the j-th layer side for the i-th support pile; z is Z _ij For the diameter of the rock-soil pile with the ith support pile positioned at the jth layer, G _{Pile i} The weight (kN) of the ith support pile is calculated.

8. A construction method of a cyclone well construction anti-floating structure as claimed in any one of claims 1 to 5, characterized by comprising the following specific steps:

s1, obtaining various construction parameters of the support pile and the cyclone well through corresponding project geotechnical engineering investigation reports, construction design drawings and engineering specifications of the support pile and the cyclone well, and calculating buoyancy F generated in the construction process of the cyclone well _{Floating device} The method comprises the steps of carrying out a first treatment on the surface of the Selecting steel bars with the diameter d being larger than or equal to the diameter of the main bars of the wall of the cyclone well as fixed dowel bars, and determining the total number N of the fixed dowel bars according to the following formula:

f _s ×F _{floating device} ≤N×F _{Anti-floating} +G

Wherein: f (f) _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating device} Buoyancy generated for the cyclone well structure, unit: kN;

F _{anti-floating} Providing anti-buoyancy for a single fixed dowel bar, unit: kN;

g is the dead weight of the cyclone well in units of: kN;

s2, determining the horizontal depth of the buffer groove, namely the depth h of inserting the fixed dowel into the buffer groove, according to the fixed dowel selected in the step S1 and according to groundwater anti-floating design calculation and dowel stress checking calculation _Groove(s) The method comprises the steps of carrying out a first treatment on the surface of the The joint bars are prevented from being sheared or broken by shearing bending failure due to insufficient shearing strength, and relative displacement caused by too small relative friction force due to insufficient depth of the joint bars inserted into the buffer grooves is avoided, so that the joint bars are broken by failure or the cyclone well floats upwards, and the construction of the cyclone well is further influenced; the checking and calculating process is as follows:

F _{anti-floating} ＝F _{Shearing resistance} +F _{Friction of}

F _{Shearing resistance} ＝0.25πd ² ×f _v

F _{Friction of} ＝f _rb ×s

s＝π×d×h _Groove(s) ×50％

h _Groove(s) ＝10d～15d

Wherein F is _{Shearing resistance} Shear strength (kN) that can be provided for a single fixed dowel; f (F) _{Friction of} A limited friction force (kN) that can be provided for the single fixed dowel bar into the buffer channel portion; d is the diameter (m) of the fixed dowel bar; f (f) _v Designed value (kN/m) for shear strength of single fixed dowel bar ² ) The method comprises the steps of carrying out a first treatment on the surface of the s is the surface area (m ² ) 50% of the total surface area can be taken; f (f) _rb To fix the friction coefficient (kN/m) between the dowel bar and the inner wall of the buffer tank ² )；h _Groove(s) The horizontal depth (m) of the fixed dowel bar inserted into the buffer groove; n is the total number of fixed dowel bars of the cyclone well; the rest are the same as above;

s3, determining the number N of reserved fixed dowel bars and the depth h of the fixed dowel bars inserted into the buffer groove _Groove(s) The number and horizontal depth of the reserved buffer slots on the support piles can be determined,the size of a single reserved buffer groove is determined according to the diameter d of the selected fixed dowel bar, the buffer groove is of a structure with a semicircular upper part and a gradual change trapezoid lower part, the diameter of the semicircular upper part is equal to the diameter d of the fixed dowel bar, the width of the upper section of the gradual change trapezoid lower part is d, the width of the lower section of the gradual change trapezoid is d+10mm, the semicircular area of the buffer groove and the overall height of the gradual change trapezoid are 2 d-3 d, and the buffer groove horizontally extends to the depth h in the supporting pile body _Groove(s) The method comprises the steps of carrying out a first treatment on the surface of the Then designing a layout scheme of the buffer grooves according to the vertical spacing of 2.5-5.0 m and the horizontal spacing of 1.2-4.8 m between two adjacent buffer grooves;

s4, after the layout parameters of the fixed dowel bars and the buffer grooves are well determined, starting to construct a cyclone well, firstly constructing a foundation pit supporting structure, after the construction of the foundation pit supporting structure is completed, performing foundation pit drainage and earth excavation, excavating to the designed shaft bottom elevation of the cyclone well, starting to construct a main structure of the cyclone well, positioning and paying off the buffer grooves on the supporting pile according to the parameters determined in the steps S1 to S3 before binding the well wall reinforcing steel bars, and performing buffer groove excavation by using a pneumatic pick or an electric hammer;

s5, after the buffer groove is dug, binding the corresponding area rotational flow well wall steel bars, and binding the fixed dowel bars, wherein the well wall part and the well wall main structure steel bars are bound together, and the inserted part is vertically inserted into the buffer groove to ensure that the fixed dowel bars are positioned at the semicircular position at the top of the buffer groove; and after the binding of the reinforcing steel bars is completed, the concrete pouring of the layer of cyclone well is completed.

9. The construction method for constructing the anti-floating structure of the cyclone well as claimed in claim 8, which is characterized by comprising the following specific steps: in the step S4, steel bars of the support piles are avoided when the buffer groove is dug, and residues and the like in the groove are cleaned up by blowing air by an air compressor or flushing by a water pipe after the buffer groove is dug, so that the smooth insertion of fixed dowel bars is ensured; in the step S5, the binding of the well wall part is firm, so that the fixed dowel bar is ensured not to loosen and move downwards in the concrete pouring process; in the construction process of the cyclone well in the step S5, checking calculation is carried out on the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the installed fixed dowel bars at each moment, when the sum of the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the constructed fixed dowel bars is smaller than the buoyancy generated by the constructed cyclone well structure, the adjustment is carried out by adding the number of the fixed dowel bars or replacing the large-diameter fixed dowel bars, so that the sum of the dead weight of the constructed cyclone well and the total anti-buoyancy provided by the constructed fixed dowel bars at any moment in construction is ensured to be larger than or equal to the buoyancy generated by the constructed cyclone well structure, and the checking calculation process is as follows:

n _i ＝πD _i /l _i

f _s ×F _{floating i} ≤(n ₁ ×F _{Anti-floating 1} +...+n _i ×F _{Anti-floating i} )+G _i

F _{Floating i} ＝γ _w ×V _i

Wherein: n is n _i Fixing the number of the dowel bars to a certain layer horizontally at a certain time for construction;

D _i for construction of the outer diameter of a cyclone well at a certain moment, the unit is: m;

l _i fixing the horizontal spacing of the dowel bars for construction at a certain moment;

f _s 1.2 is taken as an anti-floating safety calculation coefficient;

F _{floating i} Buoyancy (kN) generated for constructing a swirl well structure at a certain moment;

F _{anti-floating i} The total anti-buoyancy (kN) is provided for constructing a certain layer of fixed dowel bars horizontally at a certain moment;

G _i the dead weight (kN) of the cyclone well is used for constructing at a certain moment;

γ _w for water weight, 10KN/m is taken ³ ；

V _i To construct the inner volume of the outer edge contour of the cyclone well which is constructed at a certain moment and is positioned below the underground water surface, the unit is m ³ 。

10. The construction method for constructing an anti-floating structure for a cyclone well according to claim 8, wherein the construction method comprises the following steps: and (S4) checking the length of the pile body of the support pile before construction of the foundation pit support structure in the step, wherein the length meets the pulling-resistant requirement of the pile body transmitted by the buoyancy of underground water, and ensures that the sum of the dead weight of the utilized support pile and the limit pulling-resistant force provided by the utilized support pile at any moment is larger than or equal to the difference between the buoyancy generated by the constructed cyclone well structure and the dead weight of the constructed cyclone well, and the concrete steps are as follows:

f _s ×F _{floating device} -G≤(0.5×∑α _1j ×q _1jsi ×L _1j ×πZ _1j +G _{Pile 1} )+...+(0.5×∑α _ij ×q _ijsi ×L _ij ×πZ _ij +G _{Pile i} )

Wherein: alpha _ij The coefficient of the side rock-soil resistance of the j th layer of the ith support pile, q _ijsi Is the standard value (kPa) of limiting frictional resistance of the jth layer of side rock-soil layer of the ith support pile, L _ij The length (m) of the rock soil at the j-th layer side for the i-th support pile; z is Z _ij For the diameter of the rock-soil pile with the ith support pile positioned at the jth layer, G _{Pile i} The weight (kN) of the ith support pile is calculated.