A static breaking construction method for the interior of bored pile head

Abstract

The invention discloses a static breaking construction method for the pile head of a bored pile, comprising the following steps: step S1, bored pile hole formation and steel cage production; step S2, pre-buried pipe fittings inside the pile head, installation of the top casing of the steel cage and lowering of the steel cage; step S3, concrete pouring of the solid pile; step S4, excavation and cleaning of the pile head; step S5, cutting of the pile head splitting line and injection of expansion agent for the pre-buried pipe fittings; step S6, static expansion and cracking inside the pile head. The construction method of the invention is simple to operate, green and environmentally friendly, greatly reduces the input of manpower, materials and machines for traditional pile head breaking construction, reduces the pile head breaking amount, noise and dust, ensures the construction quality of the pile head breaking, improves the construction efficiency of the pile head breaking, and reduces the construction cost.

Description

Technical Field

[0001] The present invention relates to the field of cast-in-place pile head breaking, and more specifically, to a construction method for statically breaking the interior of a bored cast-in-place pile head. Background Art

[0002] At present, in order to ensure the quality of pile heads, especially for underwater bored piles that are over-cast by 800-1000mm, the over-cast part of the pile head is broken manually using a pneumatic pick, or the pile head is broken from the outside using a blasting machine or a hydraulic pile cutter. This method causes high noise, high dust, large site requirements and low efficiency.

[0003] Therefore, it is urgent to develop a new static breaking method inside the bored pile head to make up for this deficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a static breaking construction method for the inside of a bored cast-in-place pile head, which reduces the amount of manual mechanical breaking of the pile head, noise and dust, is green and environmentally friendly, can effectively reduce construction costs and ensure the quality of pile head breaking construction, and improves the efficiency of pile head breaking construction.

[0005] In order to achieve these purposes and other advantages according to the present invention, a method for statically breaking the interior of a bored pile head is provided, comprising the following steps:

[0006] Step S1: Cast-in-place pile drilling and steel cage production

[0007] Cast-in-place pile drilling and preparation of steel cage;

[0008] Step S2: Pre-buried pipes inside the pile head, installation of the top casing of the steel cage and lowering of the steel cage

[0009] A pre-buried pipe fitting inside the pile head is coaxially arranged on the steel cage, the pre-buried pipe fitting inside the pile head comprises an annular hoop pipe and a plurality of risers one end of which is vertically connected to the hoop pipe, one end of the riser away from the hoop pipe is temporarily closed, and the riser is connected to the hoop pipe;

[0010] Step S3: Pile concrete pouring

[0011] Lowering the steel cage obtained by the improvement of step 2 into the grouting hole, and pouring concrete to place the top of the cast-in-place pile to exceed the grouting elevation, so as to obtain a cast-in-place pile, wherein the cast-in-place pile includes an upper pile head portion and a lower solid pile portion, the pre-buried pipe fittings inside the pile head are located in the pile head portion of the cast-in-place pile, and the bottom of the pre-buried pipe fittings inside the pile head is close to the bottom of the pile head portion of the cast-in-place pile;

[0012] Step S4: Pile head excavation and pile head cleaning

[0013] After the concrete reaches the designed strength, the soil layer around the pile is opened and excavated until the pile head is exposed; step S5, the pile head splitting line cutting and the pre-buried pipe expansion agent pouring

[0014] Cutting a circular pile head splitting cutting line at the dividing boundary between the pile head part and the solid pile part of the cast-in-place pile;

[0015] Release the temporary blockage of the end of the riser away from the hoop pipe, and inject expansion agent into the riser;

[0016] Step S6: Static cracking inside the pile head

[0017] After the expansion agent is allowed to fully expand, the pile head of the cast-in-place pile breaks along the pile head splitting cutting line and the hoop pipe, and is separated from the solid pile part of the cast-in-place pile, and the inside of the pile head of the cast-in-place pile ruptures along the riser.

[0018] According to a preferred embodiment of the present invention, the static breaking construction method inside the bored pile head also includes:

[0019] Step S7: Pile head removal and cleaning

[0020] Finally, continue to break and clean the broken pile head part of the cast-in-place pile.

[0021] According to a preferred embodiment of the present invention, in the construction method for static breaking inside the bored pile head, the hoop pipe and the riser are both made of PVC material.

[0022] According to a preferred embodiment of the present invention, in the construction method for static breaking inside the bored pile head, the hoop pipe and the riser are connected by a three-way joint.

[0023] According to a preferred embodiment of the present invention, in the static breaking construction method for the interior of the bored pile head, the end of the riser away from the hoop pipe is temporarily detachably closed by a riser cap.

[0024] According to a preferred embodiment of the present invention, in the static breaking construction method for the internal part of the bored pile head, a pile head positioning stiffening hoop is circumferentially installed on the steel cage, and is located at the boundary between the pile head part and the solid pile part of the bored pile;

[0025] The outside of the steel cage is spirally provided with pile body spiral stirrups along its height direction.

[0026] The hoop pipe is tied and fixed on the pile head positioning reinforcing hoop, so as to fix the pre-buried pipe fittings inside the pile head in the pile head part of the cast-in-place pile.

[0027] According to a preferred embodiment of the present invention, in the static breaking construction method for the interior of the bored pile head, the pile head splitting cutting line, the pile top elevation of the bored pile, the pile head positioning stiffening hoop and the hoop pipe are all at the same height.

[0028] According to a preferred embodiment of the present invention, in the construction method for statically breaking the interior of a bored pile head, in step S5, the cutting depth of the pile head splitting cutting line is 0.6 times the thickness of the steel bar protective layer of the steel cage.

[0029] According to a preferred embodiment of the present invention, in the static breaking construction method inside the bored pile head, an overflow port is provided on the vertical pipe, and when the expansion agent flows out of the overflow port, the embedded pipe fittings inside the pile head are now filled with the expansion agent.

[0030] According to a preferred embodiment of the present invention, the static breaking construction method for the interior of the bored pile head further comprises in step S2, sleeved with a steel cage top sleeve on each steel bar of the pile head portion of the steel cage, and the top of the steel cage top sleeve is temporarily closed.

[0031] The present invention includes at least the following beneficial effects: the construction method of the present invention utilizes the pre-buried pipe fittings in the pile head with a simple structure to break the pile head, which is simple to operate, green and environmentally friendly, greatly reduces the input of manpower, materials and machinery for traditional pile head breaking construction, reduces the pile head breaking amount, noise and dust, ensures the quality of pile head breaking construction, improves the efficiency of pile head breaking construction, and reduces construction costs.

[0032] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural diagram of a static breaking construction method inside a bored pile head in a preferred embodiment of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of the pre-buried pipe fittings inside the pile head in the above embodiment. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0036] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0037] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0038] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0039] like Figure 1-2 As shown, a static breaking construction method inside a bored pile head of the present invention comprises the following steps:

[0040] Step S1: Cast-in-place pile drilling and steel cage production

[0041] According to the bored pile design documents and construction plan, bored pile holes and steel cages are made to obtain bored holes and steel cages; Step S2: pre-buried pipes inside the pile head, installation of the top casing of the steel cage and lowering of the steel cage

[0042] A pre-buried pipe fitting 1 is coaxially arranged on the steel cage 2, and the bottom of the pre-buried pipe fitting 1 is located at the pile head breaking interface (the boundary between the pile head part and the solid pile part of the cast-in-place pile). Figure 2As shown, the pile head internal embedded pipe fitting 1 includes an annular hoop pipe 110 and a plurality of vertical pipes 120 connected to the hoop pipe 110 at one end, and the end of the vertical pipe 120 away from the hoop pipe 110 is temporarily closed by a vertical pipe cap 130; the hoop pipe 110 and the vertical pipe 120 are connected by a three-way joint 140. The hoop pipe 110 is the main component for vertical static breaking inside the pile head. It can use the market standard PVC round pipe, or it can be customized to use PVC square pipe to increase the acceptance area of ​​the pile head. If the round pipe is used, the outer diameter of the hoop pipe 110 is the same as the inner diameter of the pile head positioning hoop. The three-way joint 140 is the key component for connecting the hoop pipe 110 and the vertical pipe 120. The size of the joint matches the size of the hoop pipe 110 and the vertical pipe 120. When connecting, the interface is coated with connecting glue to ensure a stable and sealed connection. The three-way joint 140 is a pipe fitting for pouring a strong expansion agent into the channel and for radially expanding and breaking the pile head when the pile head is broken. The vertical pipe 120 is 100 mm higher than the over-cast concrete surface of the pile head. The vertical pipe cap 130 is a sealing measure for the upper port of the vertical pipe 120 to prevent concrete from entering the internal embedded pipe fitting 1 of the pile head inside the bored pile head, which affects the effect of the later strong expansion agent pouring and internal static breaking.

[0043] In the above embodiment, the steel cage 2 may be provided with a pile head positioning reinforcing hoop 5 in an annular direction, and the hoop 5 is located at the boundary between the pile head part and the solid pile part of the cast-in-place pile; the pile body spiral hoop 7 is spirally provided on the outside of the steel cage along its height direction. The hoop pipe 110 is tied and fixed on the pile head positioning reinforcing hoop 5, so as to fix the embedded pipe 1 inside the pile head to the bottom of the pile head part of the cast-in-place pile. In the step S1, it is important to ensure that the pile head positioning reinforcing hoop 5 and the pile body spiral hoop 7 are installed accurately, so as to provide guarantee for the subsequent static breaking inside the pile head.

[0044] A top sleeve 3 of the steel cage is sleeved on each steel bar of the pile head of the steel cage, and the top sleeve of the steel cage is temporarily closed by a main bar sleeve cap 320. The lower part of the top sleeve 3 of the steel cage is sealed and fixed to the steel bars of the pile head of the steel cage by a rubber ring. After the pre-embedded pipe fittings 1 inside the pile head and the top sleeve 3 of the steel cage are installed, the steel cage is lowered to the designated position in the pile hole for positioning and fixing.

[0045] Step S3: Pile concrete pouring

[0046] The steel cage obtained by the improvement of step 2 is lowered into the grouting hole and fixed, and then the concrete pouring conduit is lowered and the bottom is cleaned, and concrete is poured to place the cast-in-place pile top to exceed the pouring elevation to obtain a cast-in-place pile. During the lowering of the concrete pouring conduit and the concrete pouring process, the insertion, placement and swing of the concrete pouring conduit are strictly controlled to prevent collision and damage to the embedded pipe structure 1 inside the pile head, which will cause the subsequent expansion agent pouring failure and affect the internal static breaking effect.

[0047] The cast-in-place pile includes an upper pile head portion and a lower solid pile portion, the pile head internal embedded pipe fitting 1 is located in the pile head portion of the cast-in-place pile, and the bottom of the pile head internal embedded pipe fitting 1 is close to the bottom of the pile head portion of the cast-in-place pile; Figure 1 As shown, the part above the pile head positioning reinforcing hoop 5 is the pile head part, and the part below the pile head positioning reinforcing hoop 5 is the solid pile part.

[0048] Step S4: Pile head excavation and pile head cleaning

[0049] After the concrete reaches the designed strength, the soil layer around the bored pile is opened and excavated until the pile head of the bored pile is exposed, and the pile top line is marked at the designed pile top elevation of the bored pile. In this process, the soil layer near the pile head should be cleaned manually to prevent the exposed riser 120 from being damaged and soil from being poured in, which would cause the subsequent expansion agent pouring to fail and affect the internal static breaking effect.

[0050] Step S5: Pile head splitting line cutting and pre-buried pipe expansion agent pouring

[0051] At the dividing boundary between the pile head part and the solid pile part of the cast-in-place pile, that is, at the pile top elevation, a circular pile head splitting cutting line is cut;

[0052] Release the temporary closure of the end of the riser 120 away from the hoop tube 110, that is, remove the riser cap 130, and inject the expansion agent into the riser 120; a hand-held syringe can be used to inject it to ensure that the interior of the pre-buried pipe fitting 1 inside the pile head is fully filled. The riser 120 is provided with an overflow port. When the expansion agent flows out of the overflow port, it means that the pre-buried pipe fitting 1 inside the pile head is now filled with the expansion agent. In order to ensure that there is no foreign matter inside the pre-buried pipe fitting 1 inside the pile head during injection, a high-pressure air gun can be used to blow the interior before injection.

[0053] Step S6: Static cracking inside the pile head

[0054] After the expansion agent is fully expanded, the pile head of the cast-in-place pile is broken along the pile head splitting cutting line and the hoop pipe 110 , and is separated from the solid pile part of the cast-in-place pile. In addition, the inside of the pile head of the cast-in-place pile is ruptured along the riser 120 .

[0055] According to a preferred embodiment of the present invention, the static breaking construction method inside the bored pile head also includes:

[0056] Step S7: Pile head removal and cleaning

[0057] Finally, continue to break and clean the broken pile head part of the cast-in-place pile.

[0058] According to a preferred embodiment of the present invention, in the static breaking construction method for the internal part of the bored pile head, the hoop pipe 110 and the riser 120 are both made of PVC material, which has a certain strength and can also crack under the expansion force of the expansion agent.

[0059] According to a preferred embodiment of the present invention, in the static breaking construction method for the interior of the bored pile head, the pile head splitting cutting line, the pile top elevation of the bored pile, the pile head positioning stiffening hoop 5 and the hoop pipe 110 are all at the same height.

[0060] According to a preferred embodiment of the present invention, in the construction method for statically breaking the interior of a bored pile head, in step S5, the cutting depth of the pile head splitting cutting line is 0.6 times the thickness of the steel bar protective layer of the steel cage.

[0061] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A construction method for statically breaking the interior of a bored pile head, characterized in that: The following steps are involved: Step S1: Cast-in-place pile drilling and steel cage production Cast-in-place pile drilling and preparation of steel cage; Step S2: Pre-buried pipes inside the pile head, installation of the top casing of the steel cage and lowering of the steel cage A pre-buried pipe fitting inside the pile head is coaxially arranged on the steel cage, wherein the pre-buried pipe fitting inside the pile head comprises an annular hoop pipe and a plurality of risers one end of which is vertically connected to the hoop pipe, one end of the riser away from the hoop pipe is temporarily closed, and the riser is connected to the hoop pipe; Step S3: Pile concrete pouring Lowering the improved steel cage obtained in step S2 into the grouting hole, and pouring concrete to place the top of the cast-in-place pile to exceed the grouting elevation, so as to obtain a cast-in-place pile, wherein the cast-in-place pile includes an upper pile head portion and a lower solid pile portion, the pre-buried pipe fittings inside the pile head are located in the pile head portion of the cast-in-place pile, and the bottom of the pre-buried pipe fittings inside the pile head is close to the bottom of the pile head portion of the cast-in-place pile; Step S4: Pile head excavation and pile head cleaning After the concrete reaches the designed strength, the soil layer around the bored pile is opened and excavated until the pile head of the bored pile is exposed; Step S5: Pile head splitting line cutting and pre-buried pipe expansion agent pouring Cutting a circular pile head splitting cutting line at the dividing boundary between the pile head part and the solid pile part of the cast-in-place pile; Release the temporary blockage of the end of the riser away from the hoop pipe, and inject expansion agent into the riser; Step S6: Static cracking inside the pile head Standing still, after the expansion agent is fully expanded, the pile head of the cast-in-place pile is broken along the pile head splitting cutting line and the hoop pipe, and is separated from the solid pile part of the cast-in-place pile, and the inside of the pile head of the cast-in-place pile is ruptured along the riser; The hoop pipe and the riser are connected by a three-way joint; The end of the riser away from the hoop pipe is temporarily detachably closed by a riser cap; A pile head positioning reinforcing hoop is installed circumferentially on the steel cage and is located at the boundary between the pile head part and the solid pile part of the cast-in-place pile; The outside of the steel cage is spirally provided with pile spiral stirrups along its height direction; The hoop pipe is tied and fixed on the pile head positioning reinforcing hoop, so as to fix the pre-buried pipe fittings inside the pile head in the pile head part of the cast-in-place pile; The pile head splitting cutting line, the pile top elevation of the cast-in-place pile, the pile head positioning stiffening hoop and the hoop pipe are all at the same height; In the step S5, the cutting depth of the pile head splitting cutting line is 0.6 times the thickness of the steel bar protective layer of the steel cage; The step S2 also includes sleeves being provided on each steel bar of the pile head portion of the steel cage, and the top of the steel cage top sleeves being temporarily closed.

2. The static breaking construction method inside the bored pile head according to claim 1 is characterized in that: Also includes: Step S7: Pile head removal and cleaning Finally, continue to break and clean the broken pile head part of the cast-in-place pile.

3. The static breaking construction method inside the bored pile head according to claim 1 is characterized in that: The hoop pipe and the stand pipe are both made of PVC material.

4. The static breaking construction method inside the bored pile head according to claim 1 is characterized in that: The vertical pipe is provided with an overflow port. When the expansion agent flows out of the overflow port, the pre-buried pipe fittings inside the pile head are fully filled with the expansion agent.

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