CN117888531A - Pulling-pressing combined slow-bonding post Zhang Kang pile pulling and construction process thereof - Google Patents

Abstract

The application relates to a pulling-pressing combined type post Zhang Kang pile pulling and construction process thereof in the field of underground foundations, which comprises the following steps: pile body; the pile body is internally provided with composite steel bars and anchoring steel bars which are arranged up and down, and the top ends of the composite steel bars penetrate out from the top of the pile body; the connector is used for connecting the composite steel bar and the anchoring steel bar; the composite steel bar comprises a twisted steel bar for prestressed concrete, and a slow bonding layer and a protective pipe layer are sequentially laminated on the outer surface of the twisted steel bar. The uplift pile can effectively protect the twisted steel, the twisted steel has larger rust allowance compared with a steel strand, the durability and the anti-floating effect of the uplift pile can be ensured, and the formed composite steel reinforcement cage is not easy to bend and twist and deform, so that the consumption of the steel is reduced, and the cost is reduced.

Description

Pulling-pressing combined slow-bonding post Zhang Kang pile pulling and construction process thereof

Technical Field

The application relates to the field of underground foundations, in particular to a pile pulling pile Zhang Kang after pulling and pressing combined slow bonding and a construction process thereof.

Background

At present, anti-floating piles, anti-floating anchor rods, prestressed concrete anti-pulling piles and the like are arranged under building foundations to balance buoyancy generated by underground water; some engineering structures such as: wind power foundation, tower crane foundation, etc., the superstructure receives great horizontal load generally, leads to its basic cushion cap to receive great eccentric moment, and the effect of eccentric moment makes the stake foundation of cushion cap below regard neutral axle as the boundary, receives the pull out while pressing.

The conventional anti-pulling pile is of a reinforced concrete structure, and the reinforced concrete anti-pulling pile is a foundation pile with three-level crack control grade which allows cracks to appear according to the technical Specification of building pile foundations (JGJ 94-2008). However, the problems are: 1. if the control of pile body cracks is poor, corrosive gas and underground water can be caused to directly contact with the longitudinal stressed main bars through the cracks, so that the bars are corroded, and the durability and the reliability of the foundation pile in the designed service life are threatened. 2. In order to meet the checking calculation of the pile body cracks, on the premise of meeting the tensile bearing capacity of the pile body positive section, the reinforcement arrangement rate of the longitudinal main reinforcements of the pile body is required to be increased, so that the strength of the longitudinal stressed main reinforcements cannot be fully exerted, and the reinforcement is wasted.

The anti-floating anchor rod also comprises a common anti-floating anchor rod and a prestressed anti-floating anchor rod. The common anti-floating anchor rod is a full-bonding tension anti-floating anchor rod. The problems are: 1. the common anti-floating anchor rod grouting body is the only anti-corrosion protection layer, and the grouting body is easy to crack when being pulled, so that hidden danger exists in durability. 2. The common anchor rod grouting has the defect of construction quality. 3. The common anchor rod uses HRB400 grade steel bars, the tensile strength of the steel bars is low, and the steel consumption is large. The problems of the prestressed anti-floating anchor are as follows: 1. the nodes are complex, the construction procedures are numerous, and the cost is high. 2. Post grouting is needed for the inner sleeve (transition pipe) of the bottom plate, construction is difficult, compaction is difficult, and a leakage channel is easy to form. 3. The anchor head exposed out of the bottom plate surface has the problem of corrosion, the thickness of the building surface layer is increased, the clean height of the basement is affected, or the embedded depth of the basement is increased, and the manufacturing cost is increased. 4. The anchor sealing is added with a procedure, which is labor-and time-consuming. 5. The floor can be stretched only after pouring (20 days), the construction period is increased, and the manufacturing cost is indirectly increased.

The prestressed concrete uplift pile is a post-tensioning unbonded uplift pile and a slow bonding uplift pile at present, the prestressed tendons used are steel strands, and the prestressed concrete uplift pile meets the primary and secondary crack control grades under the control of the prestress force and cannot generate cracks. The pile end concrete strength of the conventional prestressed concrete anti-pulling pile cannot meet the requirement due to sediment or groundwater seepage during pile end concrete pouring, at least the following two problems are caused, 1. The single pile anti-pulling bearing capacity is reduced; 2. the lower part of the slow-bonding steel strand is exposed in the underground water, and water flows out through the pore canal among the steel wires, so that the durability of the steel strand is reduced.

The post-tensioning method slow-bonding anti-floating pile is often unable to process the slow-bonding steel strand into a steel reinforcement cage by the self rigidity of the slow-bonding steel strand due to the small rigidity of the slow-bonding steel strand, and needs to be matched with common steel bars to make a steel reinforcement cage skeleton, and then the slow-bonding steel strand is bound on the steel reinforcement cage. Because the steel strand has very high tensile strength, the tensile bearing capacity of the pile body can be met by matching with relatively fewer steel strands, but the steel strand cannot form a cage by itself and a reinforcement cage framework needs to be added, so that the cost is increased and the reinforcement cage is complicated to process.

The post-tensioning unbonded anti-floating pile can cause prestress loss due to loosening of anchor heads and the like, and steel strands and concrete are not directly bonded with gaps, so that the anti-floating pile can possibly generate cracks under the buoyancy effect, corrosive gas and groundwater can be caused to directly contact with a longitudinal stressed main rib (steel strands) through the cracks, the steel strands are corroded, and the durability, the reliability and the safety of the foundation pile in the design service life are threatened.

Moreover, steel strands are generally 7 wires or 19 wires in the prestressed concrete anti-floating pile engineering, the diameter of each wire is smaller, and when the prestressed concrete anti-floating pile is damaged by water resistance and isolation layers, a plurality of wires are simultaneously corroded and are easy to damage.

Disclosure of Invention

The invention mainly aims to provide a pile pulling pile Zhang Kang after pulling and pressing combined slow bonding and a construction process thereof, and aims to solve at least one technical problem.

In order to achieve the above purpose, the invention provides a pull-press combined slow bonding post Zhang Kang pile pulling method, comprising the following steps: pile body; the pile body is internally provided with composite steel bars and anchoring steel bars which are arranged up and down, and the top ends of the composite steel bars penetrate out from the top of the pile body; a connector for connecting the composite rebar and the anchor rebar; the composite steel bar comprises a twisted steel bar for prestressed concrete, and a slow bonding layer and a protective pipe layer are sequentially laminated on the outer surface of the twisted steel bar.

In some embodiments of the present invention, the pile top is cast with a raft foundation, and a waterproof structure is arranged between the pile top and the raft foundation.

In some embodiments of the invention, the waterproof structure comprises: the cushion layer is paved on the ground around the pile body; the first waterproof layer is paved on the cushion layer; the second waterproof layer is continuously paved on the first waterproof layer and the upper surface of the pile body.

In some embodiments of the present invention, a third waterproof layer is further laid between the upper surface of the pile body and the second waterproof layer; the third waterproof layer extends to the inner ring part between the cushion layer and the first waterproof layer.

In some embodiments of the invention, the uplift pile further comprises: and the stirrups are in spring shapes, sleeved and connected with the outer rings of circumferences formed by the multiple groups of composite steel bars and the anchor steel bars together, and are unfolded along the length directions of the composite steel bars and the anchor steel bars.

In some embodiments of the invention, the uplift pile further comprises: the pile comprises a pile body and a plurality of erection ribs, wherein the erection ribs are arranged at the inner ring of the circumference formed by a plurality of groups of composite steel bars and anchoring steel bars at intervals along the height direction of the pile body, and each erection rib is respectively connected with the plurality of composite steel bars or the plurality of anchoring steel bars.

According to another aspect of the present invention, there is provided a construction process for pile pulling of Zhang Kang after pulling and pressing combined slow bonding, comprising the following steps:

Drilling a pile hole at the pile position;

Processing a composite reinforcement cage;

After the composite reinforcement cage is lowered into the pile hole, pouring concrete into the pile hole, and solidifying the concrete to form a pile body; or after pouring concrete into the pile hole, inserting a composite reinforcement cage into the concrete of the pile hole, and solidifying the concrete to form a pile body;

And tensioning each twisted steel of the composite reinforcement cage, and locking the twisted steel relative to the pile body after the twisted steel reaches the preset prestress, so as to finish the prestress application.

In some embodiments of the present invention, the screw reinforcement is penetrated from the top of the pile body, and after the work of stretching the screw reinforcement at the top of the pile body is completed, a raft foundation is cast at the top of the pile body.

In some embodiments of the present invention, the raft foundation is cast on top of the pile body, the screw steel bars penetrate out from the top of the raft foundation, and the work of stretching the screw steel bars is completed on the top of the raft foundation.

In some embodiments of the invention, a waterproof structure is constructed on the top of the shaft before the raft foundation is cast on the top of the shaft.

Compared with the prior art, the invention achieves the following technical effects:

1. The composite steel bar has good anti-corrosion effect, and the waterproof structure at the top of the pile body is matched, so that the problems of corrosion and even structural failure of the reinforcement caused by the gap between the unbonded prestressed uplift pile reinforcement and the isolation pipe are greatly reduced.

2. The invention applies prestress to the pile body, can avoid the generation of pile body cracks, reduces the consumption of reinforcing steel bars, and greatly reduces the cost compared with the traditional anti-floating pile.

3. The composite steel bar adopts the slow-bonding material, and after the slow-bonding material is finally solidified, the composite steel bar can be solidified with the protective pipe layer and the concrete outside the pipe through the slow-bonding material, so that the elongation of the PSB steel bar is not reduced even if the anchor head is loosened, the prestress is almost not lost, and the composite steel bar has more excellent performance compared with unbonded prestress anti-pulling piles.

4. The invention adopts the screw-thread steel bar for prestressed concrete with high rigidity and high bending resistance, and the composite steel bar cage formed by the screw-thread steel bar, the vertical steel bar and the stirrup has high rigidity, is not easy to bend and twist when the concrete is poured in a lifting way or underwater way, and compared with a slow bonding steel strand method, the invention does not need to add a common steel bar cage bone to fix the slow bonding steel strand, thereby not only having simple structure, but also further reducing cost.

5. Compared with the structure adopting the steel strand which is generally 7 wires or 19 wires in the traditional pile foundation engineering, the diameter of each wire is smaller, and when the steel strand is corroded, the 7 wires or 19 wires are simultaneously corroded and easily damaged, so that the service life of the composite steel bar is longer.

6. The invention adopts the tension-compression combination type, the anchoring steel bar section is tension-type, so that even if the strength of the pile end concrete cannot meet the requirement due to sediment or groundwater seepage during pile end concrete pouring, the bottom of the anchoring steel bar is exposed in groundwater, and the durability of the pile body steel bar is not affected.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

FIG. 1 is a schematic diagram of the overall structure of a Zhang Kang pile pulled after pulling and pressing combined slow bonding;

Fig. 2 is a schematic structural view showing a composite reinforcing bar;

FIG. 3 is a schematic cross-sectional view taken at 1-1 of FIG. 1;

fig. 4 is a schematic view of a waterproof structure and a tensioned rebar according to an embodiment of the present invention;

fig. 5 is a schematic view of a waterproof structure and a tensioned rebar according to another embodiment of the present invention;

FIG. 6 is a construction process flow chart of the first anti-floating pile of the embodiment;

fig. 7 is a construction process flow chart of the second anti-floating pile according to the embodiment.

The reference numerals in the drawings are as follows: 1. pile body; 2. composite steel bars; 201. screw-thread steel bar; 202. a slow-release adhesive layer; 203. a protective tube layer; 3. anchoring the steel bars; 4. a connector; 5. stirrups; 6. erecting a rib; 7. a protective layer; 8. a raft foundation; 9. a waterproof structure; 901. a cushion layer; 902. a first waterproof layer; 903. a second waterproof layer; 904. a third waterproof layer; 905. a first seal ring; 906. a second seal ring; 907. a sealing strip; 908. a cavity; 909. a fourth waterproof layer; 910. a waterproof collar; 10. a pressure bearing plate; 11. a lock nut; 12. an anchor plate; 13. and (5) anchoring the nut.

Detailed Description

It should be understood that the described embodiments are merely some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the application as detailed in the accompanying claims.

In the description of the present application, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art. Furthermore, in the description of the present application, unless otherwise indicated, "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The pile pulling and pressing combined type slow bonding post Zhang Kang pile pulling and construction process provided by the embodiment of the application are described below with reference to the accompanying drawings.

The embodiment of the application discloses a pile pulling pile Zhang Kang after pulling and pressing combined slow bonding. As shown in fig. 1 and 2, the pile-pulling post Zhang Kang after the pulling-pressing combined slow bonding comprises a pile body 1 and a composite reinforcement cage, wherein the composite reinforcement cage is arranged in the pile body 1.

The composite reinforcement cage comprises a plurality of groups of composite reinforcement bars 2 and anchor reinforcement bars 3, wherein the composite reinforcement bars 2 and the anchor reinforcement bars 3 of each group are coaxially arranged, and one end, far away from the anchor reinforcement bars 3, of each group of composite reinforcement bars 2 penetrates out of the top of the pile body 1.

It will be appreciated that the composite steel bars 2 and the anchor steel bars 3 of each group are arranged along the height direction of the pile body 1, and the composite steel bars 2 are located above the anchor steel bars 3.

A connector 4 is connected between each group of composite steel bars 2 and anchor steel bars 3, and the composite steel bars 2 and anchor steel bars 3 of the same group are stably connected through the connector 4 to form an integral structure.

Further, the composite steel bar 2 includes a deformed bar 201 for prestressed concrete, and a slow bonding layer 202 and a protective tube layer 203 are sequentially laminated on the outer surface of the deformed bar 201.

Through using the tie-in post Zhang Kang pile pulling of the tie-in post Zhang Kang of the combination type in this technical scheme, the tie-in layer 202 and the protective tube layer 203 of the composite reinforcement 2 that this pile pulled can effectively protect the twisted steel 201, and the twisted steel 201 compares in the 7 silk or 19 silk structures of steel strand wires, and it is a whole solid structure, and the diameter is great, has bigger rust allowance to the contrast steel strand wires, guarantees the durability and the anti effect of floating of pile pulled.

In addition, the twisted steel 201 has the characteristics of high rigidity and high bending resistance, the rigidity of the composite steel cage is improved, the composite steel cage is not easy to bend and deform in torsion when concrete is lifted and poured underwater, and compared with a slow bonding steel strand method, the method has the advantages that common steel cage bones are not required to be additionally added for fixing the slow bonding steel strands, and the cost is reduced.

Further, the slow-bonding layer 202 is made of slow-bonding material, the setting time of the slow-bonding material is controllable, the slow-bonding material is plastic material before solidification, has certain viscosity, and can not flow too fast under the action of gravity after being smeared on the surface of the twisted steel 201, and the slow-bonding material becomes solid after solidification and has high compressive strength, shear strength and bonding strength.

Before the slow bonding layer 202 is solidified, the threaded steel bar 201 is tensioned on the pile body 1, the elongation of the threaded steel bar 201 can move in the protective pipe layer 203, at the moment, the threaded steel bar 201 and the concrete have no bonding strength, then the slow bonding material is solidified, the composite steel bar 2 and the concrete have bonding strength and form a whole, the prestress applied by tensioning can be transferred to the through length range of the threaded steel bar 201 by the tensioning locking end, further, the pile body 1 is prestressed, the crack of the pile body 1 can be avoided, the consumption of the steel bar is reduced, the cost is further reduced, and even if the nut locking the threaded steel bar 201 is loose, the threaded steel bar 201 and the pile body 1 are connected by the slow bonding layer 202 and the protective pipe layer 203, the elongation of the steel bar is not reduced, and the prestress is not greatly lost.

In some embodiments of the invention, the protective tube layer 203 is externally threaded; after the pile body 1 material is solidified, the bonding strength of the composite steel bar and the concrete can be increased by increasing the mechanical biting force through the thread.

Further, the threads include, but are not limited to, trapezoidal threads, rectangular threads, or triangular threads, among other thread structures, without limitation.

Further, the material of the protective tube layer 203 may be PE (polyethylene), a polymer composite material, a metal material, or the like, which is not limited herein.

In some embodiments of the present invention, the connector 4 has a tubular structure, and the connector 4 has an adaptive screw structure with the screw reinforcement 201 and the anchor reinforcement 3, that is, one end of the connector 4 is screwed with the screw reinforcement 201, and the other end of the connector 4 is screwed with the anchor reinforcement 3, so that stable connection between the screw reinforcement 201 and the anchor reinforcement 3 is achieved, and connection stability between the screw reinforcement 201 and the anchor reinforcement 3 is improved.

Further, the anchor bars 3 are preferably the same type of bars as the screw bars 201.

In some embodiments of the invention, as shown in fig. 1 and 3, the composite reinforcement cage further comprises stirrups 5, studs 6 and a protective layer 7; the stirrups 5, the erection ribs 6 and the protection layers 7 are connected with the plurality of groups of composite steel bars 2 and the anchoring steel bars 3, so that the rigidity of the composite steel bar cage is further improved, and the composite steel bar cage is not easy to bend, twist, deform and the like during lifting and underwater concrete pouring.

In one embodiment, the stirrup 5 is spring-shaped, the stirrup 5 is sleeved and connected with the outer ring of the circumference formed by the multiple groups of composite steel bars 2 and the anchor steel bars 3 together, the stirrup 5 is unfolded along the length direction of the composite steel bars 2 and the anchor steel bars 3, and the stirrup 5 realizes stable and continuous reinforcement of the multiple groups of composite steel bars 2 and the anchor steel bars 3 along the length direction of the pile body 1.

In one embodiment, a plurality of stand bars 6 are arranged on the inner ring of the circumference formed by the plurality of groups of composite steel bars 2 and the anchor steel bars 3, the plurality of stand bars 6 are arranged at intervals along the height direction of the pile body 1, and each stand bar 6 is respectively connected with the plurality of composite steel bars 2 or the plurality of anchor steel bars 3.

In one embodiment, a plurality of protection layers 7 are arranged on the outer ring of the circumference formed by the plurality of groups of composite steel bars 2 and the anchor steel bars 3, the plurality of protection layers 7 are arranged at intervals along the height direction of the pile body 1, and each protection layer 7 is respectively connected with the plurality of composite steel bars 2 or the plurality of anchor steel bars 3.

The erection ribs 6 and the protection layers 7 respectively support the inner periphery and the outer periphery of the plurality of groups of composite steel bars 2 and the anchoring steel bars 3, and the clamping effect is generated, so that the overall structure of the plurality of groups of composite steel bars 2 and the anchoring steel bars 3 is more stable.

In some embodiments of the present invention, as shown in fig. 1, a raft foundation 8 is cast on top of a pile body 1, and a waterproof structure 9 is provided between the top end of the pile body 1 and the raft foundation 8. Through waterproof construction 9, can reduce the possibility that external moisture even air gets into the region between compound reinforcing bar 2 and pile body 1, not only further promoted the protection to compound reinforcing bar 2, but also promoted the protection to pile body 1 structure, promoted the protection of even being located anchor reinforcing bar 3 and connector 4 of pile body 1 below.

In some embodiments of the present invention, as shown in fig. 1, the waterproof structure 9 includes a cushion layer 901, a first waterproof layer 902, and a second waterproof layer 903; wherein, the cushion layer 901 is paved on the ground around the pile body 1; a first waterproof layer 902 is laid on the cushion layer 901; second waterproof layer 903 is continuously laid on the upper surfaces of first waterproof layer 902 and pile body 1. Through the waterproof construction 9 of multilayer, realized the effective isolation to moisture and air to the overall structure of resistance to plucking stake has been protected.

Preferably, the bedding 901 is a concrete bedding and the second waterproof layer 903 is a polymer cement mortar waterproof layer.

In some embodiments of the present invention, as shown in fig. 4 and 5, waterproof structure 9 further includes a third waterproof layer 904, third waterproof layer 904 is laid between the upper surface of pile body 1 and second waterproof layer 903, and third waterproof layer 904 extends to the inner ring portion between mat 901 and first waterproof layer 902. The protective performance of the waterproof structure 9 is further improved by the third waterproof layer 904.

Preferably, the third waterproof layer 904 is a cement-based penetrating crystalline paint waterproof layer.

In one embodiment, as shown in fig. 4, a screw 201 is penetrated from the top of the pile body 1, the screw 201 is tensioned on the upper surface of the third waterproof layer 904, then the screw 201 is locked by the bearing plate 10 and the locking nut 11, then the second waterproof layer 903 is constructed, the top end of the screw 201 is fixed to the raft by the anchor plate 12 and the anchor nut 13, and the raft foundation 8 is continuously constructed.

Further, the screw reinforcement 201 is wrapped with a first ring 905 above the locking nut 11, and the first ring 905 is positioned in the second waterproof layer 903, so as to reduce the possibility of moisture and air entering the composite reinforcement 2 from the raft foundation 8.

Further, the second waterproof layer 903 and the third waterproof layer 904 are both hat-shaped, and the cap space of the third waterproof layer 904 is used for accommodating the top end of the pile body 1, and the cap peak of the third waterproof layer 904 is lower than the upper surface of the pile body 1, so that the path and difficulty for water entering between the pile body 1 and the raft foundation 8 from the outside are increased.

Further, a circle of second sealing ring 906 is further clamped between the second waterproof layer 903 and the third waterproof layer 904, and the second sealing ring 906 encloses the composite steel bar 2; preferably, the second sealing ring 906 is located at the junction of the cap and the visor, and the second sealing ring 906 is connected to the first waterproof layer 902.

Preferably, both the first seal 905 and the second seal 906 use a sealing paste.

In another embodiment, as shown in fig. 5, the screw 201 is penetrated from the top of the raft foundation 8, the screw 201 is tensioned at the upper surface of the raft foundation 8, and then the screw 201 is locked by the anchor plate 12 and the anchor nut 13.

Further, the composite steel bar 2 is provided with an annular sealing strip 907 wrapped by the anchor plate 12 and the second waterproof layer 903, and the sealing strip 907 is positioned on one side, close to the second waterproof layer 903, of the raft foundation 8.

Preferably, seal 907 is a water-swellable seal.

Further, the second waterproof layer 903 is located around the composite steel bar 2 to form an annular cavity 908, and the cavity 908 is filled with waterproof ointment. Preferably, the waterproof ointment is asphalt waterproof ointment.

Further, the first waterproof layer 902 extends from the cushion layer 901 to the top of the pile body 1 and is in a disc structure; a fourth waterproof layer 909 is further interposed between third waterproof layer 904 and first waterproof layer 902 at the top of pile body 1. Preferably, the fourth waterproof layer 909 employs a self-adhesive polymer modified asphalt waterproof roll.

Further, the composite steel bar 2 is sleeved with a waterproof collar 910, and the waterproof collar 910 is clamped between the first waterproof layer 902 and the fourth waterproof layer 909; in other embodiments, the inner ring of waterproof collar 910 may also extend up to annular cavity 908, against the side wall of annular cavity 908. Preferably, the waterproof collar 910 is a rubber waterproof collar.

The invention also provides a construction process for pile pulling by Zhang Kang after pulling and pressing combined slow bonding, which comprises the following steps:

S0, selecting a construction process according to pile type, drilling depth, soil layer condition and the like.

S1, drilling a pile hole at a pile position.

Specifically, in this embodiment, the pile hole forming mode may be selected from rotary drilling rig hole forming, long spiral drilling rig hole forming, percussion drilling rig hole forming, manual hole digging, etc.

S2, machining the composite reinforcement cage.

S3, after the composite reinforcement cage is lowered to the pile hole, pouring concrete into the pile hole to form a pile body 1; or after pouring concrete into the pile hole, inserting the composite reinforcement cage into the concrete of the pile hole.

And S4, tensioning each twisted steel 201 of the composite reinforcement cage, and locking the twisted steel 201 relative to the pile body 1 after the twisted steel 201 reaches the preset prestress, so as to finish the pile body prestress application.

In one embodiment, as shown in fig. 4, screw steel 201 is penetrated from the top of pile body 1, and raft foundation 8 is cast on the top of pile body 1 after tensioning screw steel 201 is completed on the top of pile body 1.

The pile body top tensioning twisted steel specifically comprises the following steps:

A. Pile cutting head: after the pile body 1 reaches the initial setting, the pile top is cut to the designed elevation, and the pile head is cleaned; and then curing.

B. And (3) constructing a concrete cushion layer: construction is performed according to the designed cushion 901.

C. Cement-based penetrating crystallization type coating: the nylon brush is used for forcefully smearing the pile head and the cushion layer 901 around the pile within the range of not less than 150mm for a plurality of times, so that the concave-convex parts can be smeared in place.

D. Stretching: firstly, penetrating the bearing plate 10 into a threaded steel bar 201 through a middle hole, and filling the bearing plate on the pile top; and then the locking nut 11 is screwed to the bearing plate 10, the special tensioner is used for tensioning the threaded steel bar 201, the tensioning control force is reached, the load is held for a period of time, and the locking nut 11 is locked after the tensioning control force is stable and does not drop.

Further, the stretching may be performed simultaneously by using a plurality of stretchers, but it is preferable to uniformly stretch the material to prevent the generation of excessive eccentric force.

E. sealing with sealing paste: and sealing paste is smeared on the position of the screw thread steel bar 201 at the top of the locking nut 11 to form a first sealing ring 905, and sealing paste is smeared on the interface of the pile head and the cushion layer 901 to form a second sealing ring 906, so that the waterproof overall tightness is ensured.

F. The first waterproof layer 902 is constructed.

G. And (3) constructing a polymer cement mortar waterproof layer: and finally, constructing a polymer cement mortar waterproof layer, wherein the pile top part is covered with the sealant.

H. The anchor plate 12 and the anchor nut 13 are arranged, and in order to prevent the anchor plate 12 from sliding, the anchor plate 12 can be welded with the raft main rib; finally, the raft foundation 8 is poured.

In one embodiment, as shown in fig. 5, the raft foundation 8 is cast on top of the pile body 1, the screw steel bars 201 are penetrated out from the top of the raft foundation 8, and tensioning of the screw steel bars 201 is completed on the top of the raft foundation 8.

The raft foundation top tensioning twisted steel specifically comprises the following steps:

A. Pile cutting head: after the pile body 1 reaches the initial setting, the pile top is cut to the designed elevation, and the pile head is cleaned; and then curing.

B. and (3) constructing a concrete cushion layer 901: construction is performed according to the designed cushion 901.

C. Cement-based penetrating crystallization type coating: the nylon brush is used for forcefully smearing the pile head and the cushion layer 901 around the pile within the range of not less than 150mm for a plurality of times, so that the concave-convex parts can be smeared in place.

D. The pile top is stuck with the self-adhesive polymer modified asphalt waterproof coiled material.

E. And (3) installing a rubber waterproof sleeve ring and fully sealing by using asphalt waterproof ointment, and attaching a water-swelling sealing strip to the peripheral surface of the composite steel bar 2.

F. The first waterproof layer 902 is constructed.

G. and (3) constructing a polymer cement mortar waterproof layer: and constructing a polymer cement mortar waterproof layer, wherein the pile top part is required to be wrapped with the sealant.

H. and pouring a raft foundation 8.

I. Stretching: firstly, penetrating the anchor plate 12 into a threaded steel bar 201 through a middle hole, and laying the anchor plate on a raft foundation 8; the anchor nut 13 is then screwed onto the anchor plate 12. And tensioning the threaded steel bar 201 by using a special tensioner, holding the load for a period of time after reaching the tensioning control force, and locking the anchor nut 13 after the tensioning control force is stable and does not drop.

Further, the stretching may be performed simultaneously by using a plurality of stretchers, but it is preferable to uniformly stretch the material to prevent the generation of excessive eccentric force.

The construction process of pile pulling Zhang Kang after pulling and pressing combined slow bonding in the application will be further described below with reference to specific examples.

Example 1

The process of drilling holes by a rotary drilling rig and underwater concrete pouring is shown in fig. 6.

1) And (3) preparation of construction: and preparing a construction drawing.

During or before the process, the composite steel bar processing production line is used for manufacturing the required composite steel bars, and comprises a steel bar feeding device, a locating plate, a gel coating device, a protective tube blow molding device, an embossing device and a water cooling device from front to back.

The manufacturing of the composite steel bar comprises the following steps:

101 Starting the bar feeding device, and feeding the prestressed concrete screw-thread steel bars into the positioning plate by using the motor.

102 Centering the twisted steel at the positioning plate to ensure that the twisted steel is concentric on the production line and does not bend.

103 The screw thread reinforcing steel bar enters the gelatinizing coating device from the positioning plate, the screw thread reinforcing steel bar passes through the slow bonding agent glue cavity, and the surface can be uniformly coated with the slow bonding material.

Further, the temperature controller is arranged in the gel coating device, and the temperature of the slow bonding layer is controlled to be 20-25 ℃, so that the slow bonding material is prevented from being cured too fast due to too high temperature, or the viscosity is prevented from being high due to too low temperature of the slow bonding material, and uneven coating is avoided.

104 The screw-thread reinforcing steel bar and the slow bonding material continuously enter a protective tube blow molding device from the gel coating device, and the blow molding device is used for spraying the material of the protective tube layer on the surface of the slow bonding layer to initially form the protective tube layer.

105 The screw thread reinforcing steel bar, the slow bonding material and the protective tube layer continuously enter the embossing device from the protective tube blow molding device, the embossing device is two steel turntables with required external threads, the pressure of the steel turntables can be adjusted, and the screw thread structure is extruded on the outer surface of the protective tube layer through the embossing device, so that the formed composite reinforcing steel bar is obtained.

106 The composite steel bar continuously enters a cooling device from the embossing device, and is cooled by adopting a cooling water tank mode, so that the protective pipe layer is rapidly shaped; the cooling device comprises a cooling water tank, a water tank and a water pump, wherein water is circulated in the water tank and the cooling water tank by the water pump, and the water temperature is controlled by controlling the water pumping speed of the water pump.

2) Pile position measurement and placement: after the site is leveled in a three-way, pile position measurement and placement are carried out by using a calibrated measuring instrument, a drill bit is driven into the pile position, lime is poured for marking, and protection is carried out, so that the pile hole is constructed and positioned.

After the pile position is set, the relevant units are required to carry out retest and acceptance, and the pile can be piled after the pile position is confirmed to be correct.

3) And (3) manufacturing and burying a protective barrel: the embedding depth of the steel pile casing is not less than 1.5m, the steel pile casing is made of steel plates with the thickness of 6-8 mm, and 1-2 grout overflow holes are formed in the upper part of the steel pile casing.

When the steel pile casing is deeply embedded, a plurality of sections of steel pile casings are connected for use. The inner diameter of the steel casing should be greater than the outer diameter of the drill bit, and the diameter of the casing is 200mm greater than the diameter of the hole.

The gap between the outside of the pile casing and the hole wall is filled with surrounding slag soil to fix the pile casing, so that the pile casing is not shifted or inclined, and the steel pile casing is prevented from deflecting during the tamping.

4) And (3) positioning a drilling machine: after the drilling machine is installed, the drilling machine is moved to a pile position, the machine body of the drilling machine is stable and does not incline, the drilling machine is adjusted to ensure that the drill point is aligned with the pile position mark, the drill rod verticality is adjusted through the leveling device after the drill point is aligned with the pile position, and the drill rod verticality and the drill bit are repeatedly adjusted to ensure that the drill rod verticality and the drill bit are aligned with the pile position.

5) Pore-forming: and (3) forming holes by using a rotary drilling rig according to engineering geological conditions such as ground water, soil layers and the like.

Hole forming by a rotary drilling rig: the pore-forming is to control the drilling pressure and drilling speed according to the soil layer condition, and the pressure is reduced when the pore-forming meets the hard soil layer, and the pore-forming is repeatedly drilled up and down to ensure that the verticality of the pore-forming meets the requirement and does not collapse; when the clay layer is drilled into the viscous soil layer, the clay layer is easy to neck, the drill bit is hung at the shrinkage cavity part to repeatedly sweep the hole, the drilling speed is reduced, the drill lifting speed is low, and the hole is repeatedly swept for a plurality of times to ensure the smoothness of the drilling tool.

6) Hole cleaning: and taking out the sediment at the bottom of the hole by adopting a hole-cleaning drill bit.

7) Processing a composite reinforcement cage: and (3) processing the standing bars, connecting the composite steel bars with the anchoring steel bars through connectors, penetrating the anchor hoops into the composite steel bars, welding the anchor hoops on the standing bars, and finally binding the stirrups.

Further, the anchoring steel bars adopt PSB steel bars, and the PSB steel bars are directly welded with the erection steel bars.

8) And (3) lowering a composite reinforcement cage: the composite steel reinforcement cage is installed by adopting an automobile crane, and the steel reinforcement cage is hung vertically, accurately and slowly during installation, so that friction between the steel reinforcement cage and the hole wall is avoided or reduced as much as possible, excessive dregs are prevented from being rubbed off, excessive thick dregs at the bottom of the hole are caused, secondary bottom cleaning or repeated bottom cleaning is caused, and waste is caused.

9) And (3) catheter installation: the guide pipe is installed by using an automobile crane, the connecting joints of the guide pipe are uniformly connected by using screw threads, and the sealing is enhanced by using a rubber gasket.

The bottom of the guide pipe is 30 cm-50 cm away from the bottom of the pile hole, and the hopper is arranged at the top of the guide pipe and connected by screw threads.

10 Pressure tank concrete: the guide pipe extends to the bottom of the hole, concrete is poured into the hopper, accumulated water and sediments are extruded onto the concrete surface during pouring, and finally the outside of the hole is removed.

Therefore, in the pouring process, the lifting of the guide pipe cannot be too strong, so that the concrete surface is pulled out in a hands-free manner, and the pile body quality is affected.

After the central pressure concrete pouring is completed, the drill bit is not moved away from the hole, and the accumulated soil in the hole is timely cleaned by a small excavator or manually, so that the accumulated soil is prevented from falling into the hole.

11 Chiseling pile heads): and removing the part above the pile top design elevation by a manual and mechanical combination method.

Further, the pile top removing process should avoid damaging the deformed bars and the protective tubes on the outermost layers.

12 Tensioning and locking: stretching is performed by using an oil pump and a stretcher.

Firstly, the stretcher is placed on the bearing plate, and the top of the stretcher is connected with the top end of the twisted steel of the composite steel by using the limit nut, so that the twisted steel can be stretched along with the increase of the extending stroke of the stretcher, thereby exerting prestress. And secondly, an oil pump is started to pressurize the stretcher, the threaded reinforcing steel bars are stretched along with the extending stroke of the stretcher, the prestress is gradually increased, and the locking nut is locked when the pressure indication value of the oil gauge reaches the designed prestress. Finally, releasing the pressure to finish the prestress application.

Example 2

The process of forming holes by a long spiral drilling machine and pressing concrete and then inserting a reinforcement cage is shown in fig. 7.

1) Preparation for construction is the same as in step 1) of example 1.

2) Paying-off positioning: and testing the pile position axis and the positioning point according to the pile position design drawing requirements, and marking.

3) And (3) positioning a drilling machine: after the drilling machine is in place, the drilling machine is kept stable, the drilling tower is adjusted to be vertical, the connection of the drill rod is firm, and the drill point is centered with the pile position point.

Further, the drill rod, the soil blocks in the drill tip, residual concrete and the like should be cleaned before the drilling machine is started.

4) Drilling by a drilling machine: the drilling speed is controlled according to the stratum condition and the parameters determined by the pile forming process test.

Furthermore, in the drilling process of the drilling machine, the drill rod is not required to be reversed or lifted, and a skip method is required to be adopted for preventing channeling.

5) And (5) performing concrete pressing and pouring operation after the final hole inspection and acceptance of the elevation of the designed pile bottom is achieved.

Furthermore, the pumping of concrete is preferably continuously carried out, the concrete is pumped while the drilling is carried out, the drilling rate is controlled according to the technological parameters of the test pile, the drilling rate is controlled to be matched with the concrete pumping quantity, the height of the concrete in the hopper is kept to be not less than 400mm, and the drill bit is ensured to be buried below the concrete surface all the time to be not less than 1000mm.

6) Processing a composite reinforcement cage:

The process is different from the process of forming holes by a rotary drilling machine and pouring concrete underwater in that the bottom of the composite reinforcement cage is required to be made into a conical tip shape and welded firmly.

Firstly, processing a standing rib, connecting a composite steel bar with an anchor steel bar through a connector, penetrating a hoop into the composite steel bar, and then welding the hoop on the standing rib; then, anchoring the reinforcing steel bars by pit bending, making the bottom of the cage into a cone-tip shape, and winding the reinforcing steel bars around the cone-tip edge for welding to ensure that the cone-tip is firm; then, welding U-shaped steel bars in the conical tip, and providing a fulcrum for the vibration guide rod to prevent the vibration from penetrating through the steel bar cage; and finally binding stirrups.

Further, the anchoring steel bars adopt PSB steel bars, and the PSB steel bars are directly welded with the erection steel bars.

7) Inserting a reinforcement cage: the vibration guide rod is arranged in the horizontal ground penetrating steel bar cage and is reliably connected with the vibration device, and the top of the steel bar cage is connected with the vibration device.

Further, when the reinforcement cage is hoisted, measures are taken to prevent deformation, and the reinforcement cage is aligned with a hole site during placement and ensures vertical centering.

Specifically, when inserting the steel reinforcement cage, rely on the dead weight of steel reinforcement cage and pipe to insert slowly earlier, when can not continue the interpolation by relying on the dead weight, open vibrating device, make the steel reinforcement cage sink to the design degree of depth, disconnect vibrating device and steel reinforcement cage's connection, slowly vibrate in succession and pull out the steel pipe.

Furthermore, the reinforcement cage should be continuously lowered, and should not be stopped, and the method of direct unhooking is forbidden during lowering.

8) After the pile body reaches a certain strength (3-7 days after pouring), the soil can be cleaned by grooving, soil excavation among piles and the like.

9) Chisel pile head

And removing the part above the pile top design elevation by a manual and mechanical combination method.

Further, the process of removing should avoid damaging the composite steel bar and its outermost protective tube.

10 Tension and lock

Stretching is performed by using an oil pump and a stretcher.

Firstly, placing a stretcher on a bearing plate, and connecting the top of the stretcher with a rib body by using a limit nut, so that a threaded reinforcing steel bar can be stretched along with the increase of the extending stroke of the stretcher, thereby applying prestress; secondly, an oil pump is started to pressurize the stretcher, the threaded reinforcing steel bars are stretched along with the extending stroke of the stretcher, the prestress is gradually increased, and when the pressure indication value of the oil gauge reaches the designed prestress, the locking nut is locked; finally, releasing the pressure to finish the prestress application.

The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims (10)

1. Pulling and pressing combined type post-slow bonding Zhang Kang pile pulling is characterized by comprising the following steps of:

Pile body;

the pile body is internally provided with composite steel bars and anchoring steel bars which are arranged up and down, and the top ends of the composite steel bars penetrate out from the top of the pile body;

a connector for connecting the composite rebar and the anchor rebar;

The composite steel bar comprises a twisted steel bar for prestressed concrete, and a slow bonding layer and a protective pipe layer are sequentially laminated on the outer surface of the twisted steel bar.

2. The pile pulling and pressing combined type post-construction Zhang Kang pile pulling according to claim 1, wherein a raft foundation is cast on the top of the pile body, and a waterproof structure is arranged between the top of the pile body and the raft foundation.

3. The post-construction Zhang Kang pile extractor of claim 2, wherein the waterproof structure comprises:

the cushion layer is paved on the ground around the pile body;

the first waterproof layer is paved on the cushion layer;

The second waterproof layer is continuously paved on the first waterproof layer and the upper surface of the pile body.

4. The pile pulling and pressing combined type slow bonding post Zhang Kang according to claim 3, wherein a third waterproof layer is further paved between the upper surface of the pile body and the second waterproof layer; the third waterproof layer extends to the inner ring part between the cushion layer and the first waterproof layer.

5. The post-construction Zhang Kang post-construction pile pulling method of claim 1, further comprising:

And the stirrups are in spring shapes, sleeved and connected with the outer rings of circumferences formed by the multiple groups of composite steel bars and the anchor steel bars together, and are unfolded along the length directions of the composite steel bars and the anchor steel bars.

6. The post-construction Zhang Kang post-construction pile extractor of claim 5, further comprising:

the pile comprises a pile body and a plurality of erection ribs, wherein the erection ribs are arranged at the inner ring of the circumference formed by a plurality of groups of composite steel bars and anchoring steel bars at intervals along the height direction of the pile body, and each erection rib is respectively connected with the plurality of composite steel bars or the plurality of anchoring steel bars.

7. A construction process for pile pulling of Zhang Kang after pulling-pressing combined slow bonding according to any one of claims 1-6, which is characterized by comprising the following steps:

Drilling a pile hole at the pile position;

Processing a composite reinforcement cage;

After the composite reinforcement cage is lowered into the pile hole, pouring concrete into the pile hole, and solidifying the concrete to form a pile body; or after pouring concrete into the pile hole, inserting a composite reinforcement cage into the concrete of the pile hole, and solidifying the concrete to form a pile body;

And tensioning each twisted steel of the composite reinforcement cage, and locking the twisted steel relative to the pile body after the twisted steel reaches the preset prestress, so as to finish the prestress application.

8. The construction process according to claim 7, wherein the screw reinforcement is penetrated from the top of the pile body, and the raft foundation is cast on the top of the pile body after the work of stretching the screw reinforcement at the top of the pile body is completed.

9. The construction process according to claim 7, wherein the raft foundation is cast on top of the pile body, the screw reinforcement is penetrated out from the top of the raft foundation, and the work of tensioning the screw reinforcement is completed on the top of the raft foundation.

10. The construction process according to claim 8 or 9, wherein a waterproof structure is constructed on the top of the pile body before the raft foundation is cast on the top of the pile body.