CN111287173A

CN111287173A - Assembled core-carrying pile and construction method

Info

Publication number: CN111287173A
Application number: CN202010109914.7A
Authority: CN
Inventors: 张越
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-02-23
Filing date: 2020-02-23
Publication date: 2020-06-16

Abstract

The invention discloses an assembled core-carrying pile and a construction method, wherein the core-carrying pile consists of solidified soil on the outer side and a precast pile of an inner core; the solidified soil is in a fluid state at the initial stage and is cemented on the outer surface of the precast pile to form a column shape after being solidified; the unconfined compressive strength of the solidified soil is more than or equal to 1 MPa; the slump of the solidified soil is less than 2 cm; when the precast pile is inserted into the fluid-state solidified soil, the fluid-state solidified soil flows upwards along the outer surface of the precast pile; the foundation soil is wrapped by the solidified soil and is cemented together. The method has the advantages of green, environment-friendly, safe and reliable social benefits, capability of reducing the manufacturing cost and shortening the construction period, and great economic value.

Description

Assembled core-carrying pile and construction method

Technical Field

The invention relates to the technical field of civil engineering, in particular to a constructional engineering pile structure and a pile sinking method thereof.

Background

In construction work, pile foundations are commonly used as the primary foundation form. The existing commonly used pile foundations mainly comprise cast-in-situ bored piles and precast piles. The cast-in-situ bored pile is formed by forming holes in the stratum and pouring concrete on site in the formed hole sites by using a slurry retaining wall or a pile casing retaining wall method, the quality of the pile foundation is influenced by the quality of the formed holes, the quality of retaining wall slurry, the quality of underwater poured concrete and other factors, and a large number of engineering quality accidents often occur due to the fact that management is not in place or a constructor lacks experience. In addition, the disposal of the retaining wall slurry also causes great damage to the environment. The pile casing wall protecting method for hole forming can achieve good hole forming quality, but the pouring quality of concrete is still difficult to overcome, and meanwhile, the problem that pile breakage is caused when sediment at the bottom of a pile is cleaned and the pile casing is pulled up is also difficult to solve. The engineering cost of the drilling and pouring pile foundation is high, the construction period is long, and the method is not friendly to the environment. The problems of the precast pile mainly occur in the pile sinking process, which can cause obvious soil squeezing effect on the periphery and damage to the peripheral pipelines, buildings and roads. When the pile sinking process encounters a hard stratum or a pile end needs to be embedded into a hard stratum, the pile sinking resistance is high, so that the pile cannot penetrate and be embedded into the hard stratum, or even if the pile penetrates through the hard stratum, the pile body is seriously damaged. It can be said that the existing pile foundation and the construction method thereof have more defects.

With the development intensity of underground space increasing and the massive construction of high-rise buildings, the pile tops of a plurality of engineering pile foundations are all positioned at the depth of 10 meters below the ground, and no matter the engineering pile foundations are cast-in-place piles or precast piles, the problem of long-distance pile feeding is solved. The cast-in-situ bored pile needs a large amount of over-grouting to ensure the quality of the pile body, and then the pile head is broken and excavated, which causes great damage to the connecting steel bars. When long-distance pile feeding is needed, pile feeding resistance is overlarge, and only axial pressurization is performed on a pile feeding rod and a precast pile without lateral limitation, so that the verticality of the precast pile is difficult to guarantee, the probability of pile feeding in place is very low, the precast pile higher than the part above the bottom surface of a base plate needs to be cut off after foundation pit excavation, and great waste is generated.

Therefore, at present, the strong composite pile and the static drilling root planting pile are popularized and applied to the engineering to replace a drilling cast-in-place pile and a precast pile, the stirring pile or the rotary spraying pile is adopted to guide holes and form reinforced soil, no matter stirring or rotary spraying is adopted, the formed cement soil pile body is poor in homogeneity, the strength of the cement soil pile body is completely dependent on the performance of foundation soil at the position, the strength is low (the unconfined compressive strength is less than 0.5MPa), the difference is large, the effect of real composite action cannot be achieved, and the accident that the outer layer stirring pile body is damaged by shearing is easy to generate. In addition, the cement soil formed by in-situ stirring has poor fluidity, and the soil squeezing effect generated when the precast pile is inserted is still serious.

Therefore, the engineering industry needs to find a construction method which can reduce the soil squeezing effect, improve the pile bearing capacity, eliminate the slurry and improve the quality and safety of pile foundation engineering, which can overcome the defects of the quality and construction of the traditional cast-in-situ bored pile and precast pile, reduce the manufacturing cost, accelerate the construction speed, protect the environment and realize the aim of civilized construction.

Disclosure of Invention

The invention aims to solve the technical problems that the existing pile foundation has long quality and construction period, high manufacturing cost, difficult construction, great influence on the surrounding environment and the like, and provides a novel pile foundation and a construction method thereof.

In order to achieve the purpose, the technical scheme adopted by the patent is as follows:

the fabricated core-carrying pile consists of solidified soil on the outer side and a precast pile with an inner core; the solidified soil is in a fluid state at the initial stage and is cemented on the outer surface of the precast pile to form a column shape after being solidified; the unconfined compressive strength of the solidified soil is more than or equal to 1 MPa; the slump of the solidified soil is more than 180 mm; when the precast pile is inserted into the fluid-state solidified soil, the fluid-state solidified soil flows upwards along the outer surface of the precast pile; the foundation soil is wrapped by the solidified soil and is cemented together.

The cross section of the precast pile is circular, and the outer surface of the precast pile is concave-convex; the joints of the assembled end piles are in screw lock type mechanical connection with the stressed main reinforcements in one-to-one butt joint, and the concrete contact surface is bonded by high-strength resin.

The cross section of the precast pile is square, and the outer surface of the precast pile is concave-convex; the joints of the assembled end piles are in screw lock type mechanical connection with the stressed main reinforcements in one-to-one butt joint, and the concrete contact surface is bonded by high-strength resin.

The fluid state solidified soil body is made of ground stirring equipment and is conveyed into the drill hole through a slurry pump.

The pile hole is formed by a long spiral drilling machine, the foundation rock soil in the drill hole is taken out by using the spiral blade, and meanwhile, the hollow drill rod of the long spiral drilling machine is used for conveying, so that fluid solidified soil is pressure-poured into the hole to fill the cavity in the drill hole.

The pile hole is a pile position guide hole of a rotary drilling rig and a mud protective wall; and (4) pouring fluidized solidified soil into the drill hole by using the material conveying pipe, and replacing slurry and muck in the drill hole.

The pile hole is made by leading hole at the pile position of the rotary drilling rig, protecting wall with slurry, adding curing agent after hole forming, and stirring and mixing with residue soil and slurry in the hole to prepare fluid state solidified soil.

The depth of the pile position lead hole is equal to or different from the length of the precast pile.

The filling length of the solidified soil in the pile position lead hole is partial or full.

The core-carrying pile construction steps are as follows:

the first step is as follows: pile center positioning;

the second step is that: positioning the pile in the same way as the center of the pile, and embedding an orifice protecting cylinder; when the soil layer at the opening is hard, the pile casing is not embedded;

the third step: leading holes at the pile position under the guide of the orifice pile casing, and taking out soil in the pile casing;

when the soil body is weaker, a long spiral drilling machine is adopted for forming holes, the foundation rock soil in the drill hole is taken out by utilizing the spiral blades, meanwhile, the hollow drill rod of the long spiral drilling machine is utilized for conveying, and the fluid state solidified soil is filled into the hole by pressure irrigation to fill the cavity in the drill hole.

When the soil body is hard or enters hard rock, leading the hole by the pile position of the rotary drilling rig, and protecting the wall by mud; and (4) pouring fluidized solidified soil into the drill hole by using the material conveying pipe, and replacing slurry and muck in the drill hole.

Further, when the foundation is a sand layer, a rotary drilling rig is used for drilling holes, and then the curing agent is sprayed into the holes and is stirred and mixed with the residue soil in the holes to form fluid-state cured soil.

The filling depth of the fluid solidified soil is less than or equal to the length of the precast pile or greater than the length of the precast pile.

The fourth step: and moving the pile position drilling machine out of the abdication position to move the pile planting machine in place.

The fifth step: the core pile and the drill hole are concentrically implanted into the precast pile in the fluid state solidified soil in the drill hole;

and a sixth step: assembling a pile feeding rod on a pile planting machine, sleeving the end part of the pile feeding rod into the end part of a precast pile, and carrying out static pile feeding to overcome the flowing adhesive force of the fluidized solidified soil;

the seventh step: after the precast pile is delivered to the designed pile foundation depth, the pile delivery rod is pulled out;

eighth step: when the orifice pile casing is available, the fixture on the pile planting machine needs to be started, and the orifice pile casing is pulled out.

Compared with the existing stiff composite pile or static drilling root-planting pile, the method effectively ensures the quality uniformity, initial fluidity and final setting strength of the solidified soil body wrapped outside the precast pile, and the strength of the solidified soil is not influenced by the performance of the in-situ foundation soil; in addition, the precast pile of the core-carrying pile can not generate lateral extrusion to the lateral foundation soil in the process of inserting the fluid solidified soil, and the extrusion effect is eliminated.

Drawings

The invention is further described with reference to the following figures and detailed description.

Fig. 1 is a schematic view of a long core structure of a core-carrying pile.

Fig. 2 is a schematic view of a short core structure of the core-carrying pile.

Fig. 3 is a schematic view of an iso-core structure of the core-carrying pile.

Fig. 4 is a schematic diagram of a top expanding structure of the core-carrying pile.

FIG. 5 is a schematic view of a long auger drilling to extract soil and pressure-grouting solidified soil.

FIG. 6 is a schematic diagram of a rotary drilling rig for hole forming and pouring solidified soil to replace mud in the hole.

FIG. 7 is a schematic view of inserting square piles into fluidized solidified soil.

FIG. 8 is a schematic view of a rotary drilling guide hole and stirring of slurry and a slag soil reinforcing agent into fluidized solidified soil.

In the figure: the method comprises the following steps of 1-precast pile, 2-solidified soil, 21-fluidized solidified soil, 3-stratum, 4-expanded end solidified soil, 5-helical blade, 51-hollow drill rod, 6-rotary excavating cylindrical bucket, 61-rotary excavating machine drill rod, 62-stirring blade, 7-wall protection slurry, 71-orifice protection cylinder, 8-soil and 9-bamboo joint conveying pipe.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below by combining the specific drawings.

The fabricated core-carrying pile consists of a precast pile 1 and solidified soil 2 wrapped outside the precast pile. The solidified soil 2 adopted by the core-carrying pile is fluid solidified soil 21 which is obtained by collecting silt from the ground and mixing the silt through a powerful mixer, the influence of the in-situ soft soil performance and the underground water of the stratum 3 is avoided, the fluid solidified soil 21 pumped in can flow upwards along the wall of a drill hole in the process of inserting the precast pile 1, and the stratum 3 is not transversely extruded.

Fig. 1 shows a long core structure of a core-carrying pile, and shows that the solidified soil 2 only wraps the upper part of the precast pile 1, that is, the depth of the lead hole is equivalent to that of the solidified soil 2, and the lower part of the precast pile 1 is sunk into a deep stratum by a static pressure or hammering method. The core-carrying pile structure of the pile type can be selected when the upper stratum is weak, the fluid solidified soil 21 poured into the drill hole is used for reinforcing, the lower stratum is good, and the soil squeezing effect generated by pile sinking through static pressure or hammering has little influence on surrounding buildings and structures.

Fig. 2 shows a short core structure of a core-carrying pile, in which the solidified soil 2 is fully wrapped around a precast pile 1, and the depth of the solidified soil 2 poured into a lead hole is greater than the length of the precast pile 1, which is a weak foundation condition for the stratum above a needle cushion layer. The lower part of the precast pile 1 uses the solidified soil 2 to replace the precast pile 1 with higher cost, because the strength of the solidified soil 2 is higher, the bearing and settlement control requirements of the foundation can be met.

In the iso-core structure of the core-carrying pile shown in fig. 3, the solidified soil 2 is shown to wrap the whole precast pile 1, the depth of the solidified soil 2 poured into the lead hole is equal to the length of the precast pile 1, and the soil squeezing effect generated in the pile sinking process of the precast pile 1 can be eliminated. For the foundation with poor upper soil layer, when the pile foundation needs to enter a harder bearing stratum and the pile sinking can not be realized by direct static pressure or hammering, a method of leading holes to penetrate through the hard stratum or enter the harder bearing stratum and then pouring solidified soil into the holes is the most effective pile sinking construction technology.

The diameter-expanding structure of the top of the core-carrying pile is shown in fig. 4, the solidified soil 2 is shown to wrap the whole precast pile 1, the diameter of the solidified soil 2 is distributed to be large at the top and small at the bottom, and the solidified soil is a reinforcing and protecting measure for protecting the precast pile 1 when needles are in a silt and muddy stratum at the pile top. The upper part of the pile body is provided with the solidified soil 2 with the enlarged diameter to surround the precast pile 1 to form a combined pile body with higher horizontal rigidity, so that the pile body can resist higher lateral pressure and cannot cause core-carrying pile inclination and pile breakage accidents.

EXAMPLE I core-carrying pile formed by inserting precast pile into long spiral drilling pressure-grouting solidified soil

The construction technology of the core-carrying pile formed by inserting the precast pile into the long spiral drilling pressure-grouting solidified soil is shown in fig. 5, and the specific manufacturing steps are as follows:

the first step is as follows: pile center positioning;

the second step is that: pre-burying a guide hole opening protecting cylinder 71 in the same positioning as the center of the pile;

the third step: under the guidance of the orifice pile casing 71, a long spiral drilling machine is adopted to guide holes at the pile position, and soil 8 in the pile casing 71 is taken out; when the soil reaches the bottom of the pile position hole, the soil body 8 in the hole position is taken out by adopting the spiral blades 5, meanwhile, the fluid state solidified soil 21 is pressure-filled by utilizing the hollow drill rod, and the pressure filling is stopped when the position reaches the pile top position

The fourth step: and moving the auger drilling machine out of the way and moving the pile planting machine in place.

The fifth step: concentrically positioning the steel pile casing 71, and implanting the precast pile 1 into the fluid solidified soil 21;

and a sixth step: assembling the pile feeding rod on the pile machine, sleeving the end part of the pile feeding rod into the end part of the precast pile 1, and carrying out static pile feeding, as shown in fig. 7;

the seventh step: and (4) after the precast pile 1 is delivered to the designed pile delivery depth, pulling out the pile delivery rod.

Eighth step: and starting the clamp on the pile machine, and pulling out the orifice pile casing 71.

Example two, dig core-carrying stake of inserting precast pile formation in drilling pressure irrigation solidification soil soon

When the core-carrying pile needs to penetrate through a hard stratum or be embedded into a rock stratum, the core-carrying pile formed by inserting the precast pile 1 into the solidified soil 21 through rotary drilling and pressure filling can only be adopted, as shown in fig. 6, the specific manufacturing steps are as follows:

the first step is as follows: pile center positioning;

the second step is that: positioning the pile in the same way as the center of the pile, and embedding an orifice pile casing 71;

the third step: under the guidance of the orifice pile casing 71, a rotary drilling machine drill rod 61 is adopted to drive a barrel type drill bit 6 to drill a hole, and soil 8 in the pile casing 71 is taken out; and (3) adopting the slurry 7 to protect the wall, when the wall reaches the bottom of the hole of the pile position, utilizing the bamboo joint pipe 9 to descend to the bottom of the drilled hole to press and pour the fluid state solidified soil 21, and stopping when the pile top position of the precast pile 1 is reached.

The fourth step: and moving the rotary drilling rig out to give way, and moving the pile planting machine in place.

The fifth step: in the steel pile casing 71, the precast pile 1 is concentrically implanted into the fluid solidified soil 21;

EXAMPLE III core-carrying pile formed by inserting precast pile into rotary drilling hole-leading stirring solidified soil

The construction method of the core-carrying pile is basically the same as that of the second embodiment, except that the fluid-state solidified soil 2 is not pre-mixed from the ground and then pressure-poured into the hole, but the wall protection slurry and the muck in the hole are stirred and mixed with the solidifying agent by a stirring blade 62 driven by a drill rod of the rotary excavator to form the fluid-state solidified soil by a mode of adding the solidifying agent into the hole, as shown in fig. 8. The pre-pile 1 is then inserted as shown in fig. 7.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An assembled core-carrying pile and a construction method are characterized in that the core-carrying pile consists of solidified soil on the outer side and a precast pile with an inner core; the solidified soil is in a fluid state at the initial stage and is cemented on the outer surface of the precast pile to form a column shape after being solidified; the unconfined compressive strength of the solidified soil is more than or equal to 1 MPa; the slump of the solidified soil is more than 180 mm; when the precast pile is inserted into the fluid-state solidified soil, the fluid-state solidified soil flows upwards along the outer surface of the precast pile; the foundation soil is wrapped by the solidified soil and is cemented together.

2. The fabricated core-carrying pile and the construction method thereof as claimed in claim 1, wherein the prefabricated pile has a circular cross section and a concavo-convex outer surface; the joints of the assembled end piles are in screw lock type mechanical connection with the stressed main reinforcements in one-to-one butt joint, and the concrete contact surface is bonded by high-strength resin.

3. The fabricated core-carrying pile and the construction method thereof as claimed in claim 1, wherein the prefabricated pile has a square cross section and a concavo-convex outer surface; the joints of the assembled end piles are in screw lock type mechanical connection with the stressed main reinforcements in one-to-one butt joint, and the concrete contact surface is bonded by high-strength resin.

4. The fabricated core-bearing pile and method of construction as claimed in claim 1, wherein the fluidized solidified soil mass is formed by surface agitation equipment and is fed into the borehole by a slurry pump.

5. The fabricated core-carrying pile and the construction method as claimed in claim 1, wherein the pile hole is formed by a long auger drilling machine, the ground rock soil in the drill hole is taken out by the helical blade, and simultaneously, the hollow drill rod of the long auger drilling machine is used for conveying, so that the fluid-state solidified soil is pressure-poured into the hole to fill the cavity in the drill hole.

6. The fabricated core-carrying pile and the construction method thereof according to claim 1, wherein the pile hole is a pile position guide hole of a rotary drilling rig, and a mud protective wall; and (4) pouring fluidized solidified soil into the drill hole by using the material conveying pipe, and replacing slurry and muck in the drill hole.

7. The fabricated core-carrying pile and the construction method thereof as claimed in claim 1, wherein the pile hole is a hole leading hole of a rotary drilling rig, a mud wall is protected, and after the hole is formed, a curing agent is added to be mixed with the residue soil and the mud in the hole to form fluid-state cured soil.

8. The fabricated core-carrying pile and the construction method thereof according to claim 1, wherein the depth of the pile position guide hole is equal to or different from the length of the precast pile.

9. The fabricated core-carrying pile and the construction method thereof according to claim 1, wherein the filling length of the solidified soil in the pile position lead hole is partial or full.

10. The fabricated core-carrying pile and the construction method thereof according to claim 1, wherein the steps are as follows:

the first step is as follows: pile center positioning;

eighth step: when the orifice casing exists, the fixture on the pile planting machine is started, and the orifice casing is pulled out.