CN115652917A - Construction method of screw-locking type prestress special-shaped precast concrete solid square pile - Google Patents

Abstract

The invention discloses a construction method of a screw-locking type prestressed special-shaped precast concrete solid square pile, and particularly relates to the technical field of construction of special-shaped precast concrete solid square piles, which comprises the following steps; step one, pile selection principle; 1. the designer should combine engineering geological condition, seismic fortification intensity, superstructure characteristics, load size, property, pile sinking equipment and other factors, and select corresponding pile type after comprehensive analysis, and if design needs, the pile body reinforcing bars can be increased according to specific conditions. The bearing capacity of the screw locking type joint is larger than that of a pile body, the initial rigidity is large when the screw locking type joint is stressed, the joint is free of a gap, rapid positioning and butt joint can be realized, the butt joint efficiency is higher, the accuracy is better, the stability of piling is better, deviation is not easy to occur, the stability of piling is better, the butt joint efficiency is higher, and the construction efficiency is improved.

Description

Construction method of screw-locking type prestressed special-shaped precast concrete solid square pile

Technical Field

The invention relates to the technical field of construction of special-shaped precast concrete solid square piles, in particular to a construction method of a screw-locking type prestressed special-shaped precast concrete solid square pile.

Background

The screw-lock type prestressed concrete pile adopts a pretensioning method production process and can be divided into three types, namely a special-shaped solid square pile, a special-shaped tubular pile and a common solid square pile, the pile body of the special-shaped solid square pile is square or longitudinally variable-section square, the pile and the pile are connected by screw-lock type joints, the concrete strength grade of the T-HFZ type pile is C80, and the screw-lock type prestressed concrete pile has the advantages of high single-pile bearing capacity, good driving resistance, high corrosion resistance, high pressure resistance, high pulling resistance and the like.

The invention patent of patent application publication No. CN 106245445A in the prior art discloses a prestressed concrete pipe pile foundation and a construction method thereof, and aims to provide a prestressed concrete pipe pile foundation and a construction method thereof, which not only have short construction period and low construction site requirement, but also can effectively solve the problems of easy corrosion and difficult maintenance of a steel pipe pile, have good installation stability and are beneficial to tower installation. The prestressed concrete tubular pile foundation comprises a solid concrete column pile and a concrete tubular pile located below the solid concrete column pile, wherein the concrete tubular pile is tubular, the upper end of the concrete tubular pile is connected with the lower end of the solid concrete column pile, and the lower end of the concrete tubular pile is open. The construction method of the prestressed concrete pipe pile foundation sequentially comprises the following steps: firstly, hoisting a prestressed concrete pipe pile foundation and placing the foundation at a specified position on the ground surface; and then, gradually knocking the prestressed concrete pipe pile foundation into the soil layer by using a pile driver.

However, in the construction method, the pile driver is adopted to gradually drive the prestressed concrete pipe pile foundation into the soil layer, the upper end of the concrete pipe pile is connected with the lower end of the solid concrete pile, the lower end of the concrete pipe pile is opened, gaps exist at the joint, and multi-point quick positioning and installation cannot be formed during butt joint, so that zero-gap self-locking cannot be realized by the connecting piece, the joints easily have the gaps, the strength is low after the upper pile and the lower pile are connected, the potential safety hazard is great, the efficiency is low easily caused, and the butt joint is slow.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a construction method of a screw-locking prestressed special-shaped precast concrete solid square pile, which comprises the following steps;

step one, pile selection principle;

1. the designer should combine factors such as engineering geological conditions, seismic fortification intensity, superstructure characteristics, load size, properties, pile sinking equipment and the like, select corresponding pile types after comprehensive analysis, and increase pile body reinforcing bars according to specific conditions if the design needs.

2. For large, important or complex geological projects, experimental construction, design inspection, construction parameters, treatment effect and applicability should be carried out before design.

3. When groundwater or foundation soil has medium or strong corrosion effect on concrete, AB type, B type or C type piles are selected, and pile body protection is in accordance with the regulations of the current industry standard.

4. For the pile foundation resisting uplift or bearing large horizontal load, various mechanical indexes of the selected pile type should meet the design requirements and relevant standard regulations, and for a single pile spliced by a plurality of sections of piles, the design of pile matching with the bearing capacity of the upper section of pile higher than that of the pile head can be adopted according to the vertical force and the horizontal force borne by the pile.

5. When crossing thick soft soil layers or liquefiable soil layers, the stability of the pile body and the influence thereof on the bearing capacity should be considered.

6. The influence of the rebound and uplift of the pit bottom soil on the stress of the pile body and the bearing capacity of the pile in the deep foundation pit excavation process is considered. Pile extension is reduced as much as possible in engineering, pile extension is preferably carried out after pile tips penetrate through a hard soil layer, single pile joints of compression-resistant piles should not exceed 2, bearing capacity of the joints of the piles should not be lower than that of pile bodies, and in order to reduce influence of lateral soil pressure of the piles on the joints when construction machinery travels, the length of the uppermost pile should not be smaller than 8m.

7. During pile extension, a pressure-bearing connection joint is adopted for the pressure-bearing pile, a pulling-resistant connection joint is adopted for the pulling-resistant pile, and the pulling-resistant connection joint is adopted when the pile body has the conditions of pressure resistance and pulling resistance.

8. When the tension screw lock type prestressed concrete square pile is connected with a bearing platform, the bearing platform connecting steel bars are directly connected with each prestressed steel bar through nuts;

step two, transporting and stacking;

1. the concrete strength of the screw lock type prestressed concrete excavating square pile can be delivered after the strength reaches 100 percent of the design strength.

2. The hoisting of the screw-lock type prestressed concrete square pile needs to adopt a two-pivot method, the horizontal included angle between a steel cable and a pile body is not less than 45 degrees, the distance between two hoisting points and the pile end is not more than 0.21L, the steel cable is lightly lifted and lightly placed during loading and unloading, and throwing, collision and rolling are strictly forbidden.

3. The screw-lock type prestressed concrete square pile is required to meet the position requirements of a two-pivot method in the transportation process, wedge wood is filled to prevent sliding, and dislocation caused by unequal distances between the wedge wood and the pile end among layers is strictly prohibited.

4. The construction site stacked by the screw-lock type prestressed concrete square pile is compacted and leveled, a drainage measure is provided, the stacking is carried out according to a two-fulcrum method, the fulcrum of the lowest layer is preferably arranged on a skid or a gravel, and the fulcrums are arranged on the same horizontal plane. The stacking layer number is determined according to comprehensive analysis of pile body strength, ground bearing capacity, skid, stacking stability and the like, and is in accordance with the specification in a table;

step three, checking and acceptance;

1. the appearance quality and the size allowable deviation, the bending resistance test, the inspection rule and the like of the screw-lock type prestressed concrete square pile are executed according to the regulations of the national current standard

2. The incoming inspection and acceptance should have the following data: raw material quality test report: steel bar test report: concrete test block strength report: the product qualification certificate is attached when the product leaves the factory;

step four, pile sinking;

1. before construction, proper pile sinking process and machine are selected according to design files, surrounding environment of a construction site, geological conditions and the like.

2. Attention should be paid to the protection of the surrounding environment during the pile sinking process, effective protection measures should be taken for the underground facilities which are proved to be possibly damaged,

3. the hammer method can adopt a diesel hammer and a hydraulic hammer for pile sinking: static pressure pile sinking can adopt hydraulic machinery, and the construction method comprises a top pressing type and a holding pressing type; the construction by adopting a pilot hole auxiliary method or an implantation method can reduce the problem of the pile sinking and soil squeezing effect.

4. When the pile is hung, the pile body is strictly forbidden to collide with a pile machine, a rotating screw rod can be installed after the pile is hung in place, the verticality deviation when the first section of pile sinking is inserted into the ground does not exceed 0 and 3 percent, the pile body is vertical when the pile is sunk, the verticality deviation does not exceed 0.5 percent, two theodolites are arranged in a direction of 90 degrees away from the pile machine, the verticality of the pile body is calibrated, the pile pulling is not forced to correct when the deviation occurs, the pile body is prevented from cracking, and the verticality of the special-shaped pile body is strictly forbidden to be adjusted by adopting a method of forming an included angle between the upper special-shaped pile body and the axis of the butt threaded hole.

5. And (3) continuously driving a single pile to the end at one time, continuously performing pile splicing and pile feeding, stopping for no more than 30min, and when the pile top elevation is lower than the natural ground, performing construction until the last section of pile is exposed out of the natural ground by about 1000mm, and rechecking and recording the pile top positioning deviation.

6. When the abnormal conditions such as abnormal penetration, inclination of the pile body, displacement, damage of the pile body or the pile top and the like occur during pile sinking, the pile sinking is stopped, and the construction can be continued after the reason is found out and necessary treatment is carried out.

7. The pile cap and pile-feeding rod of pile machine are positioned by using internal triangular guide device, and matched with screw-locking prestressed concrete square pile, and have enough strength, rigidity and driving resistance, and when the pile is hammered or static-pressure driven, the gap between pile cap or pile-feeding device and pile periphery is 5-10 mm.

8. When the pile is required to be sent, the pile sender is adopted, the screw-lock type prestressed concrete square pile is strictly forbidden to be adopted to replace the pile sender, and the bending rigidity of the pile sender meets the corresponding requirements.

9. When the piles are spliced, the prying bar is strictly forbidden to pull the inserted bar to align the connecting hole, and if the inserted bar is found to be deformed or displaced, the inserted bar needs to be replaced.

10. The pile cap is provided with inner cavity exhaust, drainage and soil gushing holes, when the pile is hammered and statically pressed, the pile sinking speed and daily pile sinking amount are controlled, the rest time in 24 hours is not less than 8 hours, the displacement monitoring of the piles around the pile sinking is preferably carried out, the monitoring amount is not less than 3, the construction is immediately stopped when the piles float upwards, the reasons are found out, and the construction can be continued after measures are taken;

fifth, pile splicing;

1. when pile splicing is carried out, the pile head of the soil-entering part of the pile head is preferably 0.8-1.2 m higher than the ground, and a plug connector can be installed when the pile is lifted in place and is strictly installed before the pile is lifted in place.

2. When the piles are spliced, a crow bar is strictly forbidden to pull the rotating screw to align the connecting holes, and if the rotating screw is pulled, the rotating screw needs to be replaced.

3. After the plug connector is installed, a special handle is used for screwing, and the special clamping plate is used for checking the installation height of the rotating screw rod, so that the installation size is ensured to be within an allowable error.

4. Enough sealing material is arranged on the end face of the pile head, the operation time is within 2min, the initial setting time is not more than 6h, and the final setting time is not more than 12h.

5. Under the command of a specially-assigned person, the rotating screw rod and the axis of the positioning slot are moved to the same straight line, the rotating screw rod and the axis of the positioning slot are slowly inserted, collision is strictly avoided, after the rotating screw rod and the positioning slot are inserted, the sealing material is suitable to overflow the interface, and the interface is seamless.

6. The spliced splicing pile base is pressed into the ground 3 meters behind and the hoisting steel wire rope can be disassembled.

7. When the temperature is lower than 10 ℃, the epoxy resin and the curing agent can be heated when the epoxy resin and the curing agent cannot be mixed, but the heating temperature is controlled and is preferably 20-30 ℃.

8. The pile is not cut generally, and effective measures are taken to ensure the quality of the screw-locking type prestressed concrete square pile after pile cutting.

Preferably, the screw-locking prestressed concrete square pile in the second step comprises a special-shaped pile body, and a butt joint assembly is installed at the lower position of the special-shaped pile body;

the butt joint component comprises a plurality of butt joint threaded holes formed in an embedded mode and arranged below the special-shaped pile body, a rotary screw rod is connected to the inner portion of each butt joint threaded hole in a threaded connection mode, the bottom end portion of the rotary screw rod is connected with a rotary head in a welding mode, a connecting plug with the outer wall polished, is fixed at the bottom end position of the rotary head, a pile head is arranged below the connecting plug, a plurality of positioning slots are formed in the top end of the pile head, two symmetrically arranged extrusion elastic ring clamping blocks are installed inside the positioning slots, an upper pressing support plate and a lower pressing support plate are fixed at the bottom end of each extrusion elastic ring clamping block, and linkage springs used for enabling the extrusion elastic ring clamping blocks to float up and down are welded at the bottom end portions of the lower pressing support plates.

Preferably, the plurality of inserting joints are in one-to-one correspondence with the plurality of positioning slots, the positioning slots and the inserting joints are located at positions same as a horizontal line, the inner wall of the inserting joint is subjected to fillet treatment and polishing treatment, and the two extrusion elastic ring clamping blocks are distributed in a circular ring shape at equal intervals.

Preferably, the outer wall of pile head is pour and is fixed go up guide pile frame, handles through the radius angle in the inner wall turning line position department of guide pile frame, the bottom of guide pile frame just is close to its rectangle edge line position punishment and has distributed a plurality of connecting support rods, guide pile frame inner wall is equipped with the arc spigot surface, and it has fixed the frame of pouring to pour in the bottom position department of connecting support rod, the linkage pile body has been pour on the top of dysmorphism pile body, has pour the connecting pile top on the top of linkage pile body fixedly, linkage pile body cross sectional area is less than connecting pile top cross sectional area.

Preferably, the bottom of pile head is pour and is fixed with grafting pile driver seat, fixed direction socket is poured to the bottom of grafting pile driver seat, and the embedding is pour and is fixed with four grafting branch in the bottom of direction socket, and the top plug is all welded to the bottom of every grafting branch, the outer wall of point plug is the ring equidistance and distributes and have a plurality of grafting blades, the bottom cross sectional area of direction socket is greater than its top cross sectional area, direction socket outer wall is through polishing processing, and is a plurality of the grafting blade all with sharp plug welded fastening, and the two corner line position departments of one side of grafting blade all handle through the radius angle.

The invention has the technical effects and advantages that:

1. the invention adopts the screw-lock type prefabricated square pile to install the pile head inserted link by adopting an electric tool, special anticorrosive materials are smeared at the joint, the inserted link is inserted into the middle nut by the self weight of the pile, the connecting piece realizes zero-gap self-locking, the joint is seamless, and equal-strength connection of an upper pile and a lower pile is realized, thereby solving the damage to the strength of a prestressed steel bar pier head and concrete at the end part of the pile when the pile is spliced by electric welding, reducing the potential safety hazard caused by unreliable end plate welding, realizing the pile splicing resistance, safety, rapidness, reliability and corrosion resistance, the bearing capacity of the screw-lock type joint is greater than that of a pile body, the initial rigidity is large when the pile is stressed, and the joint is gapless, so the performance of the screw-lock type prefabricated square pile is superior to other joint forms with initial gaps after iron parts are exposed or stressed;

2. according to the invention, the butt joint component is adopted to enable the plug connector to drive the connecting swivel head to enable the rotating screw rod to rotate, the rotating screw rod is in threaded connection with the butt joint threaded hole, the epoxy resin curing agent is coated on the upper surface position of the pile head, the connecting pile top can be downwards placed by using a crane, the special-shaped pile body drives the rotating screw rod to enable the connecting swivel head to downwards move, the plug connector can be inserted into the positioning slot, the two extrusion elastic ring clamping blocks are expanded and expanded outwards, the plug connector is clamped with the two extrusion elastic ring clamping blocks, the plug connector is locked, the butt joint is completed by the special-shaped pile body and the pile head, when the butt joint installation of the piles is realized, the quick positioning butt joint can be realized, the butt joint efficiency is higher, and the accuracy is better;

3. according to the invention, the guide pile frame is adopted to drive the connecting support rods to enable the fixed pouring frame to move downwards, the fixed pouring frame drives the pile head to enable the inserting pile base to move downwards, the guide socket drives the inserting support rods to be inserted into soil, and the inserting support rods drive the pointed plugs to be inserted downwards;

to sum up, through the interact of above-mentioned a plurality of effects, the bearing capacity is greater than the pile body to the screw lock formula joint, and initial rigidity is big during the atress, connects the zero clearance, can realize quick location butt joint, and butt joint efficiency is faster, and the accuracy is better, and the stability is better in piling, is difficult for taking place the skew, and to sum up the stability is better in piling, and butt joint efficiency is higher, improves the efficiency of construction.

Drawings

Fig. 1 is a schematic view of the external structure of a screw-lock type prestressed concrete square pile according to the present invention.

Fig. 2 is a schematic view of a partial structure of a butt joint of a plug and a pile head in the screw-lock type prestressed concrete square pile.

Fig. 3 is a schematic view of the vertical section structure of the screw-lock prestressed concrete square pile of the present invention.

Fig. 4 is an enlarged schematic view of a portion a in fig. 3 according to the present invention.

Fig. 5 is a schematic view of a cut-off structure of an insertion pile base in the screw-lock type prestressed concrete square pile.

Fig. 6 is a schematic diagram showing the number of stacked layers of the screw-lock type prestressed concrete square pile according to the present invention.

The reference signs are: 1. a special-shaped pile body; 2. butting the threaded holes; 3. rotating the screw rod; 4. connecting a rotary head; 5. a plug-in connector; 6. pile head; 7. extruding the elastic ring fixture block; 8. pressing the support plate; 9. a linkage spring; 10. a guide pile frame; 11. an arc-shaped guide surface; 12. connecting a support rod; 13. fixing the pouring frame; 14. linking the pile body; 15. connecting pile tops; 16. inserting a pile base; 17. a guide socket; 18. positioning the slot; 19. inserting a supporting rod; 20. a sharp plug; 21. and inserting the blades.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The examples are as follows:

as shown in the attached drawings 1-6, the screw-locking type prestressed concrete square pile in the second step comprises a special-shaped pile body 1, and a butt joint assembly is arranged at the lower position of the special-shaped pile body 1;

the butt joint subassembly is including setting up the butt joint screw hole 2 that a plurality of embeddings of dysmorphism pile body 1 below were seted up, and the equal threaded connection in inside of every butt joint screw hole 2 rotates screw rod 3, the bottom position welding of rotating screw rod 3 is gone up and is connected swivel 4, and the bottom position department of connecting swivel 4 is fixed with the bayonet joint 5 that the outer wall was through polishing treatment, the below of bayonet joint 5 is equipped with pile head 6, a plurality of positioning slot 18 have been seted up on the top of pile head 6, there are two extrusion elastic ring fixture blocks 7 that the symmetry set up at positioning slot 18's internally mounted, and the bottom mounting of extrusion elastic ring fixture block 7 pushes down extension board 8, the bottom position welding of pushing down extension board 8 has the linkage spring 9 that is used for playing the effect of floating from top to bottom to extrusion elastic ring fixture block 7, a plurality of bayonet joints 5 all correspond one-to-one with a plurality of positioning slot 18, and be in same position department between positioning slot 18 and the bayonet joint 5, the inner wall of bayonet joint 5 is through polishing treatment by water flat line radius angle, two extrusion ring fixture blocks 7 are the equidistance distribution setting up and are the equidistance.

In some embodiments, as shown in fig. 1, an outer wall of a pile head 6 is cast and fixed with a guide pile frame 10, corner lines of an inner wall of the guide pile frame 10 are rounded, a plurality of connecting struts 12 are distributed at the bottom end of the guide pile frame 10 and near rectangular edge lines of the guide pile frame, the inner wall of the guide pile frame 10 is provided with an arc-shaped guide surface 11, a fixed casting frame 13 is cast and fixed at the bottom end of the connecting struts 12, so that the guide pile frame 10 can be slightly knocked by a pile driver, the guide pile frame 10 drives the connecting struts 12 to move the fixed casting frame 13 downwards, so as to improve the knocking resistance of the guide pile frame 10, a linkage pile body 14 is cast at the top end of a special-shaped pile body 1, a connecting pile top 15 is cast at the top end of the linkage pile body 14, the cross-sectional area of the linkage pile body 14 is smaller than the cross-sectional area of the connecting pile top 15, so that the connecting pile top 15 can be hoisted by a crane, and the linkage pile top 15 drives the linkage pile body 14 to move.

In some embodiments, as shown in fig. 1 to 5, a socket pile base 16 is cast and fixed at the bottom end of the pile head 6, an upper guide socket 17 is cast and fixed at the bottom end of the socket pile base 16, four socket struts 19 are embedded and cast at the bottom end of the guide socket 17, an upper tip plug 20 is welded at the bottom end of each socket strut 19, a plurality of socket blades 21 are equidistantly distributed on the outer wall of the tip plug 20 in a circular ring shape, the cross sectional area of the bottom end of the guide socket 17 is larger than that of the top end thereof, the outer wall of the guide socket 17 is polished, the plurality of socket blades 21 are welded and fixed with the tip plug 20, and the two corner line positions on one side of each socket blade 21 are all chamfered.

A construction method of a screw-locking type prestressed special-shaped precast concrete solid square pile comprises the following steps;

step one, pile selection principle;

1. the designer should combine engineering geological condition, seismic fortification intensity, superstructure characteristics, load size, load property, pile sinking equipment static pressure, hammering or implanting and other factors, and select corresponding pile type after comprehensive analysis, and if design needs, pile body reinforcing bars can be increased according to specific conditions.

2. For large, important or complex geological projects, experimental construction, design inspection, construction parameters, treatment effect and applicability should be carried out before design.

3. When groundwater or foundation soil has medium or strong corrosion effect on concrete, AB type, B type or C type piles should be selected, and pile body protection should meet the regulations of the existing industry standard 'technical specification of prestressed concrete special-shaped precast piles' JGJ/T405.

4. For the pile foundation which resists pulling or bears larger horizontal load, various mechanical indexes of the selected pile type can meet the design requirements and the regulations of relevant specifications. For a single pile spliced by a plurality of sections of piles, the number of the reinforcing steel bars of the pile head on the design that the bearing capacity of the pile section is higher than that of the pile head is the same according to the vertical force and the horizontal force born by the pile.

5. When crossing thick soft soil layers or liquefiable soil layers, the stability of the pile body and the influence thereof on the bearing capacity should be considered.

6. The influence of the rebound and uplift of the pit bottom soil on the stress of the pile body and the bearing capacity of the pile in the deep foundation pit excavation process is considered. Pile extension is reduced as much as possible in engineering, pile extension is preferably carried out after pile tips penetrate through a hard soil layer, single pile joints of compression-resistant piles should not exceed 2, bearing capacity of the joints of the piles should not be lower than that of pile bodies, and in order to reduce influence of lateral soil pressure of the piles on the joints when construction machinery travels, the length of the uppermost pile should not be smaller than 8m.

7. When pile splicing is carried out, a pressure-bearing pile is required to adopt a pressure-bearing connecting joint, an uplift pile is required to adopt an uplift connecting joint, and when the pile body has the conditions of pressure resistance and uplift, the uplift connecting joint is required to be adopted.

8. When the tensioned < uplift-resistant screw lock type prestressed concrete square pile is connected with a bearing platform, the bearing platform connecting steel bars are directly connected with each prestressed steel bar through nuts;

step two, transporting and stacking;

1. the concrete strength of the screw lock type prestressed concrete excavating square pile can be delivered after the strength reaches 100 percent of the design strength.

2. The hoisting of the screw-lock type prestressed concrete square pile needs to adopt a two-pivot method, the horizontal included angle between a steel cable and a pile body is not less than 45 degrees, and the distance between two hoisting points and a pile end is not more than 0.21L (L is the length of a pile section, and the pile is lightly lifted and lightly placed during loading and unloading, and throwing, collision and rolling are strictly forbidden.

3. The screw-lock type prestressed concrete square pile should meet the position requirement of a two-pivot method in the transportation process that the distance between the pivot and the pile end is not more than 0.21L), and wedge wood is used for preventing sliding, so that dislocation caused by unequal distances between the wedge wood and the pile end among layers is strictly prohibited.

4. The construction site stacked by the screw-lock type prestressed concrete square pile is compacted and leveled, a drainage measure is provided, the stacking is carried out according to a two-fulcrum method, the fulcrum of the lowest layer is preferably arranged on a skid or a gravel, and the fulcrums are arranged on the same horizontal plane. The stacking layer number is determined according to comprehensive analysis of pile body strength, ground bearing capacity, skid and stacking stability, and the like, and the stacking layer number is in accordance with the regulations in a table;

step three, checking and acceptance;

1. the appearance quality and size allowable deviation, the bending resistance test and the inspection rule of the screw-lock type prestressed concrete square pile are executed according to the regulations of the national current standard 'pretensioning prestressed centrifugal concrete special-shaped pile' GB31039 'technical specification of prestressed concrete special-shaped precast pile' JGJ/T405

2. The incoming acceptance should have the following data: raw material quality test report: steel bar test report: concrete test block strength report: when leaving the factory, the product is attached with a qualification certificate;

step four, pile sinking;

1. before construction, a proper pile sinking process and proper pile sinking machinery are selected according to design files, the surrounding environment of a construction site, geological conditions and the like.

2. Attention should be paid to the protection of the surrounding environment during the pile sinking process, effective protection measures should be taken for the underground facilities which are proved to be possibly damaged,

3. the hammer method can adopt a diesel hammer and a hydraulic hammer for pile sinking: static pressure pile sinking can adopt hydraulic machinery, and the construction method comprises a top pressing type and a holding pressing type; the construction by adopting a pilot hole auxiliary method or an implantation method can reduce the problem of the pile sinking and soil squeezing effect.

4. When a pile is hung, a pile body is strictly forbidden to collide with a pile machine, a rotating screw rod can be installed at the rear part where the pile is hung in place, the verticality deviation when a first section of sunk pile is inserted into the ground is not more than 0 and 3 percent, the pile body is vertical when the pile is sunk, the verticality deviation is not more than 0.5 percent, two theodolites are arranged in a direction of 90 degrees from the unaffected range of the pile machine to calibrate the verticality of the pile body, the pile is not forcibly pulled to correct the verticality when the deviation occurs, so that the pile body is prevented from cracking, and the verticality of the special-shaped pile body is strictly forbidden to be adjusted by adopting a method of forming an included angle between the upper special-shaped pile body and a butt-joint threaded hole axis.

5. After the pile placing position of the guide socket 17 is determined, a pile driver can be used for slightly knocking the guide pile frame 10, the guide pile frame 10 drives the connecting support rods 12 to enable the fixed pouring frame 13 to move downwards, the fixed pouring frame 13 drives the pile head 6 to enable the inserting pile seat 16 to move downwards, the inserting pile seat 16 drives the guide socket 17 to insert downwards, the guide socket 17 drives the inserting support rods 19 to insert into soil, the inserting support rods 19 drive the pointed plugs 20 to insert downwards, the pointed plugs 20 drive the inserting blades 21 to insert downwards into the soil, therefore, the whole guide socket 17 can rapidly sink according to the specified position, when the upper surface of the pile head 6 is 0.8m higher than the ground, and a single pile is continuously driven to the bottom once, pile receiving and pile sending are continuously carried out, the middle stopping time is not more than 30min, when the pile top elevation is lower than the natural ground, the pile top positioning deviation is rechecked and recorded when the last section of pile is exposed to the natural ground by about 1000 mm.

6. When the abnormal conditions such as abnormal penetration, inclination of the pile body, displacement, damage of the pile body or the pile top and the like occur during pile sinking, the pile sinking is stopped, and after reasons are found and necessary treatment is carried out, construction can be continued.

7. The pile cap and the pile feeding rod of the pile machine are strictly positioned by adopting an inner triangular guide device, the pile cap and the pile feeding rod are matched with a screw-locking prestressed concrete square pile and have enough strength, rigidity and driving resistance, and when the pile is hammered or statically sunk, the clearance between the pile cap or the pile feeder and the periphery of the pile is 5mm.

8. When the pile is required to be sent, the pile sender is adopted, the screw-lock type prestressed concrete square pile is strictly forbidden to be adopted to replace the pile sender, and the bending rigidity of the pile sender meets the corresponding requirements.

9. When the piles are spliced, the prying bar is strictly forbidden to pull the inserted bar to align the connecting hole, and if the inserted bar is found to be deformed or displaced, the inserted bar needs to be replaced.

10. The pile cap is provided with inner cavity exhaust, drainage and soil gushing holes, when the pile is hammered and statically pressed, the pile sinking speed and daily pile sinking amount are controlled, the rest time in 24 hours is not less than 8 hours, the displacement monitoring of the piles around the pile sinking is preferably carried out, the monitoring amount is not less than 3, the construction is immediately stopped when the piles float upwards, the reasons are found out, and the construction can be continued after measures are taken;

fifthly, pile splicing;

1. when pile splicing is carried out, the pile head of the part of the pile head entering the soil is higher than the ground by 0.8m, a plug connector can be installed when the pile is hung in place, and installation before the pile is strictly forbidden.

2. When the piles are spliced, a crow bar is strictly forbidden to pull the rotating screw to align the connecting holes, and if the rotating screw is pulled, the rotating screw needs to be replaced.

3. After the plug connector is installed, a special handle is used for screwing, the installation height of the rotating screw rod is checked by using a special clamping plate, and the installation size is guaranteed to be within an allowable error.

4. Enough sealing materials are arranged on the end face of the pile head and are composed of epoxy resin and an epoxy resin curing agent according to a proportion, the operation time is within 2min, the initial setting time is not more than 6h, and the final setting time is not more than 12h.

5. Under the command of a specially-assigned person, the rotating screw rods and the axes of the positioning slots are moved to the same straight line, the rotating screw rods and the axes of the positioning slots are slowly inserted, collision is strictly prohibited, after the inserting is carried out, the sealing material is suitable to overflow the interface, the interface has no gap, the connecting pile top 15 can be hoisted by using a crane, the connecting pile top 15 drives the linkage pile body 14 to move upwards, the linkage pile body 14 drives the special-shaped pile body 1 to move upwards, after the special-shaped pile body 1 is lifted to a designated height, the inserting heads 5 can be driven by using an electric hand drill one by one to rotate, the inserting heads 5 drive the connecting rotating heads 4 to rotate the rotating screw rods 3, the rotating screw rods 3 are in threaded connection with the butt joint threaded holes 2, so that the rotating screw rods 3 can be installed at the inner positions of the special-shaped pile body 1, after the rotating screw rods 3 are installed, the epoxy resin curing agent is used for coating at the upper surface positions of the pile heads 6, the connecting pile top 15 can be lowered by a crane, and the guiding of the special-shaped pile body 1 is ensured to enter the guiding pile frame 10 along the guiding direction of the arc-shaped guiding surface 11, so that the special-shaped pile body 1 drives the rotating screw rod 3 to enable the connecting swivel 4 to move downwards, the plug-in connector 5 can be inserted into the positioning slot 18 and enter the inner wall positions of the two extrusion elastic ring clamping blocks 7 along the positioning slot 18, so that under the action of the extrusion force of the plug-in connector 5, the two extrusion elastic ring clamping blocks 7 expand outwards, the plug-in connector 5 is clamped with the two extrusion elastic ring clamping blocks 7, the extrusion elastic ring clamping blocks 7 drive the lower pressing plate 8 to move downwards, the lower pressing plate 8 extrudes the linkage spring 9 to realize compression at the bottom end position of the inner wall of the positioning slot 18, the locking operation of the plug-in connector 5 is realized, and the butt joint of the special-shaped pile body 1 and the pile head 6 is completed.

6. The spliced splicing pile base is pressed into the ground 3 m behind and the hoisting steel wire rope can be disassembled.

7. When the temperature is lower than 10 ℃, the epoxy resin and the curing agent can be heated when the epoxy resin and the curing agent cannot be mixed, but the heating temperature is controlled and is preferably 20-30 ℃.

8. The pile is not cut generally, and effective measures are taken to ensure the quality of the screw-locking prestressed concrete square pile after pile cutting.

The points to be finally explained are: first, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may be a mechanical connection or an electrical connection, or a communication between two elements, and may be a direct connection, and "upper," "lower," "left," and "right" are only used to indicate a relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may be changed;

secondly, the method comprises the following steps: in the drawings of the disclosed embodiments of the invention, only the structures related to the disclosed embodiments are referred to, other structures can refer to common designs, and the same embodiment and different embodiments of the invention can be combined with each other without conflict;

and finally: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.

Claims (10)

1. A construction method of a screw-locking type prestressed special-shaped precast concrete solid square pile is characterized by comprising the following steps: comprises the following steps;

step one, pile selection principle;

1. the designer should combine the factors of engineering geological condition, seismic fortification intensity, upper structure characteristics, load size, property, pile sinking equipment and the like, and select the corresponding pile type after comprehensive analysis, and if the design needs, the pile body reinforcing bars can be increased according to specific conditions;

2. for large, important or complicated geological engineering, experimental construction is carried out before design, and design, construction parameters, treatment effect and applicability are checked;

3. when groundwater or foundation soil has medium or strong corrosion effect on concrete, AB type, B type or C type piles are selected, and pile body protection meets the regulations of the current industry standard;

4. for a pile foundation which resists pulling or bears a large horizontal load, various mechanical indexes of a selected pile type meet design requirements and relevant standard regulations, and for a single pile spliced by a plurality of sections of piles, the design of pile configuration that the bearing capacity of the pile section above is higher than that of a pile head can be adopted according to the vertical force and the horizontal force borne by the pile;

5. when the pile penetrates through a thick soft soil layer or a liquefiable soil layer, the stability of the pile body and the influence of the pile body on the bearing capacity are considered;

6. in the deep foundation pit excavation, the influence of pit bottom soil resilience and uplift on pile body stress and pile bearing capacity in engineering is considered to reduce pile splicing as much as possible, pile splicing is preferably carried out after a pile tip passes through a hard soil layer, the number of single pile joints of the compression-resistant pile is not more than 2, the bearing capacity of the joint of the pile is not lower than that of the pile body, and in order to reduce the influence of lateral soil pressure of the pile on the joint when construction mechanical equipment travels, the length of the uppermost pile is not less than 8m;

7. during pile splicing, a pressure-bearing pile is connected with a pressure-bearing connector, an uplift pile is connected with an uplift connector, and the uplift connector is adopted when the pile body has the conditions of pressure resistance and uplift;

8. when the tension screw lock type prestressed concrete square pile is connected with a bearing platform, the bearing platform connecting steel bars are directly connected with each prestressed steel bar through nuts;

step two, transporting and stacking;

1. the concrete of the screw-lock type prestressed concrete excavating square pile can leave a factory after the strength reaches 100% of the designed strength;

2. the hoisting of the screw-lock type prestressed concrete square pile needs to adopt a two-pivot method, the horizontal included angle between a steel cable and a pile body is not less than 45 degrees, the distance between two hoisting points and the pile end is not more than 0.21L, the steel cable is lightly lifted and lightly placed during loading and unloading, and throwing, collision and rolling are strictly forbidden;

3. the screw-lock type prestressed concrete square pile is required to meet the position requirements of a two-pivot method in the transportation process, wedge wood is filled to prevent sliding, and dislocation caused by unequal distances between the wedge wood and the pile end among layers is strictly prohibited;

4. the construction site stacked by the screw-lock type prestressed concrete square pile is compacted and leveled, a drainage measure is provided, the stacking is carried out according to a two-fulcrum method, the lowest layer fulcrum is preferably arranged on a skid or a sandstone, the fulcrums are arranged on the same horizontal plane, the number of stacked layers is determined according to the comprehensive analysis of pile body strength, ground bearing capacity, skid and stacking stability and the like, and the stacked construction site is required to meet the regulations in a table;

step three, checking and acceptance;

1. the appearance quality and size allowable deviation, the bending resistance test, the inspection rule and the like of the screw-lock type prestressed concrete square pile are executed according to the regulations of the national current standard;

2. the incoming acceptance should have the following data: raw material quality test report: steel bar test report: concrete test block strength report: when leaving the factory, the product is attached with a qualification certificate;

step four, pile sinking;

1. before construction, proper pile sinking process and machine are selected according to design files, surrounding environment of a construction site, geological conditions and the like;

2. attention should be paid to the protection of the surrounding environment during the pile sinking process, effective protection measures should be taken for the underground facilities which are proved to be possibly damaged,

3. the hammer method can adopt a diesel hammer and a hydraulic hammer for pile sinking: static pressure pile sinking can adopt hydraulic machinery, and the construction method comprises a top pressing type and a holding pressing type; the problem of pile sinking and soil squeezing effect can be reduced by adopting a pilot hole auxiliary method or an implantation method for construction;

4. when the pile is hung, the pile body is strictly forbidden to collide with a pile machine, a rotating screw rod can be installed after the pile is hung in place, the verticality deviation when the first section of pile sinking is inserted into the ground is not more than 0 and 3 percent, the pile body is vertical when the pile is sunk, the verticality deviation is not more than 0.5 percent, two theodolites are arranged in a direction of 90 degrees away from the pile machine without influence, the verticality of the pile body is calibrated, the pile pulling is not forced to correct when the deviation occurs, so that the pile body is prevented from cracking, and the verticality of the special-shaped pile body is strictly forbidden to be adjusted by adopting a method of forming an included angle between the upper special-shaped pile body and the axis of a butt threaded hole;

5. continuously driving a single pile to the bottom once, continuously performing pile extension and pile feeding, keeping the middle idle time not more than 30min, and rechecking and recording the pile top positioning deviation when the pile top elevation is lower than the natural ground and the last section of pile is exposed out of the natural ground by about 1000 mm;

6. when the pile is sunk, if abnormal conditions such as abnormal penetration, inclination of a pile body, displacement, damage of the pile body or a pile top and the like occur, pile sinking is stopped, and construction can be continued after reasons are found out and necessary treatment is carried out;

7. the pile cap and the pile feeding rod of the pile machine are strictly positioned by adopting an inner triangular guide device, the pile cap and the pile feeding rod are matched with a screw-locking prestressed concrete square pile and have enough strength, rigidity and driving resistance, and when the pile is hammered or statically sunk, the clearance between the pile cap or the pile feeder and the periphery of the pile is 5-10 mm;

8. when the pile is required to be sent, the pile feeder is adopted, the screw-lock type prestressed concrete square pile is strictly forbidden to replace the pile feeder, and the bending rigidity of the pile feeder can meet the corresponding requirements;

9. when the piles are spliced, a prying rod is strictly forbidden to pull the inserted bar to align the connecting hole, and if the inserted bar is found to be deformed or displaced, the inserted bar needs to be replaced;

10. the pile cap is provided with inner cavity air exhaust, water drainage and soil gushing holes, when the pile is hammered and statically sunk, the pile sinking speed and daily pile sinking amount are controlled, the rest time in 24 hours is not less than 8 hours, the displacement monitoring of the piles around the sunk pile is preferably carried out, the monitoring amount is not less than 3, the construction is immediately stopped when the pile floats upwards, the reason is found out, and the construction can be continued after measures are taken;

fifthly, pile splicing;

1. when pile splicing is carried out, the pile head of the part of the pile head, which enters the ground, is higher than the ground by 0.8-1.2 m, a plug connector can be installed when the pile is hung in place, and installation before the pile is strictly forbidden;

2. when the piles are spliced, a crow bar is strictly forbidden to pull the rotating screw to align the connecting holes, and if the rotating screw is pulled, the rotating screw needs to be replaced;

3. after the plug connector is installed, a special handle is used for screwing, and a special clamping plate is used for checking the installation height of the rotating screw rod, so that the installation size is ensured to be within an allowable error;

4. placing enough sealing materials on the end face of the pile head, wherein the operation time is within 2min, the initial setting time is not more than 6h, and the final setting time is not more than 12h;

5. under the command of a specially-assigned person, the rotating screw and the axis of the positioning slot are moved to the same straight line, the rotating screw and the axis of the positioning slot are slowly inserted, collision is strictly prohibited, after the inserting connection, the sealing material is suitable to overflow the interface, and the interface is seamless;

6. the spliced splicing pile base is pressed into the ground 3 meters later and a hoisting steel wire rope can be disassembled;

7. when the temperature is lower than 10 ℃, the epoxy resin and the curing agent can be heated when the epoxy resin and the curing agent cannot be mixed, but the heating temperature is controlled and is preferably 20-30 ℃;

8. the pile is not cut generally, and effective measures are taken to ensure the quality of the screw-locking prestressed concrete square pile after pile cutting.

2. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 1, characterized in that: the screw locking type prestressed concrete square pile in the second step comprises a special-shaped pile body (1), and a butt joint assembly is installed at the lower position of the special-shaped pile body (1);

the butt joint component comprises butt joint threaded holes (2) formed in a plurality of embedded parts below the special-shaped pile body (1), a rotating screw rod (3) is connected to the inner uniform threaded part of each butt joint threaded hole (2) in a connecting mode, a rotary head (4) is connected to the bottom end of the rotating screw rod (3) in a welding mode, a connecting head (5) with the outer wall polished is fixed to the bottom end of the connecting head (4), a pile head (6) is arranged below the connecting head (5), a plurality of positioning slots (18) are formed in the top end of the pile head (6), two extrusion elastic ring clamping blocks (7) symmetrically arranged are installed inside the positioning slots (18), an upper pressing support plate (8) and a lower pressing support plate (8) are fixed to the bottom end of each extrusion elastic ring clamping block (7), and linkage springs (9) used for enabling the extrusion elastic ring clamping blocks (7) to float up and down are welded to the bottom end of the lower pressing support plate (8).

3. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 2, characterized in that: the plug connectors (5) are in one-to-one correspondence with the positioning slots (18), and the positioning slots (18) and the plug connectors (5) are located at the same horizontal line.

4. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 2, characterized in that: the inner wall of the plug-in connector (5) is subjected to fillet treatment and polishing treatment, and the two extrusion elastic ring clamping blocks (7) are distributed in a circular ring shape at equal intervals.

5. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 2, characterized in that: the outer wall of the pile head (6) is poured and fixed with an upper guide pile frame (10), and the corner line position of the inner wall of the guide pile frame (10) is subjected to fillet treatment.

6. The construction method of the screw-locking prestressed special-shaped precast concrete solid square pile according to claim 5, characterized in that: the bottom of guide pile frame (10) just is close to its rectangle edge line position punishment and has a plurality of connecting support poles (12) to distribute, guide pile frame (10) inner wall is equipped with arc spigot surface (11), pours at the bottom position department of connecting support pole (12) and is fixed with fixed frame (13) of pouring.

7. The construction method of the screw-locking prestressed special-shaped precast concrete solid square pile according to claim 2, characterized in that: the special-shaped pile comprises a special-shaped pile body (1), a linkage pile body (14) is poured at the top end of the special-shaped pile body (1), a connecting pile top (15) is fixedly poured at the top end of the linkage pile body (14), and the cross section area of the linkage pile body (14) is smaller than that of the connecting pile top (15).

8. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 2, characterized in that: the bottom of pile head (6) is pour and is fixed with grafting pile seat (16), the bottom of grafting pile seat (16) is pour and is fixed with direction socket (17), pours in the bottom embedding of direction socket (17) and is fixed with four grafting branches (19), and sharp plug (20) are all welded to the bottom of every grafting branch (19), the outer wall of sharp plug (20) is that the ring equidistance distributes and has a plurality of grafting blades (21).

9. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 8, characterized in that: the cross section area of the bottom end of the guide socket (17) is larger than that of the top end of the guide socket, and the outer wall of the guide socket (17) is polished.

10. The screw-locking type prestressed special-shaped precast concrete solid square pile construction method according to claim 8, characterized in that: the plurality of inserting blades (21) are all welded and fixed with the tip plugs (20), and the positions of two corner lines on one side of each inserting blade (21) are all subjected to fillet treatment.

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