KR102358223B1 - Sacrificial steel pipe saving cast in placed pile and the construction method therefor - Google Patents

Abstract

The present invention relates to a sacrificial steel pipe saving type cast-in-place pile structure constructed on the ground comprising an underwater part, a sedimentary layer and a ground layer sequentially from an upper part. The sacrificial steel pipe includes: a geotextile tube pile constructed in the ground layer portion; and sacrificial steel pipe piles consecutively constructed on an upper side of the geotextile tube pile, and constructed in the underwater part and the sediment layer part. The geotextile tube pile includes: a geotextile tube provided on the outside; a rebar mesh provided inside the geotextile tube; and concrete placed and hardened inside the geotextile tube. The sacrificial steel pipe piles include: a sacrificial steel pipe provided on the outside; a rebar mesh provided inside the sacrificial steel pipe; and concrete placed and hardened inside the geotextile tube. In accordance with the present invention, as the geotextile tube pile and the sacrificial steel pipe piles are integrated in regard to the placement of a cast-in-place pile, economic feasibility can be increased due to a drop in the consumption of sacrificial steel pipe piles without causing a reduction in structural stability, and also, an expanded pile without a geotextile tube is formed in a front end part of the geotextile tube pile to increase a support force.

Description

Sacrificial steel pipe saving type cast-in-place pile structure and its construction method

The present invention relates to a sacrificial steel pipe saving-type cast-in-place pile structure and a construction method therefor, and more particularly, to a sacrificial steel pipe without a decrease in structural stability by merging geotextile tube piles and sacrificial steel pipe piles in constructing cast-in-place piles. It relates to a sacrificial steel pipe saving type cast-in-place pile structure and its construction method, which can greatly increase economic efficiency by significantly reducing the amount of

In general, in the construction of cast-in-place piles for installation of offshore structures, conventionally, after excavating with RCD equipment to the offshore ground layer, the steel pipe casing and sacrificial steel pipe (hereinafter referred to as 'sacrificial steel pipe') are transferred from the ground layer to the sedimentary layer and water. After installing it up to the middle part, inserting a rebar mesh inside, pouring concrete to construct an in-situ pile, and installing an offshore structure on the upper side.

In this conventional cast-in-place pile method (see Fig. 12), a sacrificial steel pipe is press-fitted while excavating from the upper surface of the water to the ground layer, and then a reinforcing bar mesh is inserted inside the sacrificial steel pipe, and concrete is poured for construction. , by installing a sacrificial steel pipe between the sedimentary layer and the ground layer, structural stability is secured, but there is a problem in that the construction cost increases due to excessive use of the expensive sacrificial steel pipe.

Republic of Korea Patent Publication No. 10-0618597

The present invention has been devised to solve the above problems, and an object of the present invention is to use geotextile tube piles for the ground layer and sacrificial steel pipe piles for the underwater part and the sedimentary layer, without compromising safety compared to existing piles. An object of the present invention is to provide a sacrificial steel pipe saving type cast-in-place pile structure and its construction method, which greatly reduces the amount of sacrificial steel pipe used and increases economic feasibility.

In addition, it is to provide a sacrificial steel pipe saving type cast-in-place pile structure and a construction method thereof that can secure a strong bearing capacity by forming an expanded pile from which the geotextile tube is removed at the tip of the geotextile tube pile.

In addition, it is to provide a sacrificial steel pipe saving type cast-in-place pile structure and a construction method thereof, in which loss of concrete is prevented by the geotextile tube, and the reinforcing bar coating thickness and adhesion to the ground layer can be reliably secured.

In addition, by pre-injecting mortar into the tip of the geotextile tube pile, injecting an initial fast curing mortar, injecting a fiber mixed mortar, or pressurizing the mortar after the geotextile tube pile or sacrificial steel pipe pile construction step, An object of the present invention is to provide a sacrificial steel pipe saving type cast-in-place pile structure that can reliably secure bearing capacity and a construction method thereof.

In the sacrificial steel pipe saving type cast-in-place pile structure according to an example of the present invention, in the sacrificial steel pipe saving type cast-in-place pile structure constructed in the ground consisting of an underwater part, a sedimentary layer and a ground layer sequentially from the upper part, the civil works constructed in the ground layer part fiber tube piles; A sacrificial steel pipe pile that is continuously constructed on the upper side of the geotextile tube pile, and is constructed in the underwater part and the sedimentary layer part; and the geotextile tube pile is a geotextile tube provided on the outside, the geotextile Containing a reinforcing bar network provided inside the tube, and concrete poured and hardened inside the geotextile tube, wherein the sacrificial steel pipe pile includes a sacrificial steel pipe provided outside, a reinforcing bar network provided inside the sacrificial steel pipe, and It may include concrete that is poured into the sacrificial steel pipe and hardened.

It further includes an expansion pile provided at the front end of the geotextile tube pile, the expanded pile has a diameter expanded from the geotextile tube pile, the geotextile tube may be removed.

The sacrificial steel pipe of the sacrificial steel pipe pile may extend to an upper part of the geotextile tube pile and overlap the geotextile tube.

The geotextile tube pile may be constructed on the sedimentary layer and the ground layer portion, and the sacrificial steel pipe pile may be constructed on the underwater portion.

In addition, the present invention is a sacrificial steel pipe saving type cast-in-place pile construction method, sequentially from the top, after mounting the sacrificial steel pipe and the excavator on the ground consisting of the underwater part, the sedimentary layer and the ground layer, the sacrificial steel pipe is inserted while excavating to the ground layer step; Preparing a geotextile reinforcing bar network comprising a reinforcing bar network including an axial reinforcing bar and a band reinforcing bar or spiral reinforcing bar surrounding the axial reinforcing bar, and a geotextile tube surrounding a portion corresponding to the ground layer in the reinforcing bar network; inserting the geotextile reinforcement network and the tremie tube into the sacrificial steel pipe at the same time, or inserting the geotextile reinforcement network into the sacrificial steel pipe first and then inserting the tremie tube; forming geotextile tube piles by drawing the sacrificial steel pipe to the interface between the sedimentary layer and the ground layer while pouring concrete through the tremie pipe; forming a sacrificial steel pipe pile by pouring concrete while retaining the sacrificial steel pipe in the sedimentary layer and the submerged portion through the tremie pipe; It can be built in order.

An expansion pile provided at the distal end of the geotextile tube pile may be further formed, and the expanded pile may have an expanded diameter in the geotextile tube pile, and the geotextile tube may be removed.

In the step of forming the geotextile tube pile, the drawing of the sacrificial steel pipe is stopped before the interface between the sedimentary layer and the ground layer, so that the sacrificial steel pipe extends to an upper part of the geotextile tube pile and overlaps the geotextile tube. can be

The excavation of the ground layer may be extended in the lateral direction in parallel with the downward excavation.

In addition, it may further include a mortar injection pipe coupled to the reinforcing bar network, and prior to the step of forming the geotextile tube pile, mortar may be pre-injected into the lower surface of the front end using the mortar injection pipe.

In addition, further comprising a mortar injection pipe coupled to the reinforcing bar network, after the step of forming the geotextile tube pile or after the step of forming the sacrificial steel pipe pile using the mortar injection pipe to press the mortar on the lower surface of the tip After injecting or pre-injecting mortar into the lower surface of the tip by using the mortar injection pipe before the step of forming the geotextile tube pile, after the step of forming the geotextile tube pile or after the step of forming the sacrificial steel pipe pile Thereafter, the mortar can be injected under pressure using the mortar injection pipe.

According to the present invention, by using geotextile tube piles for the ground layer and sacrificial steel pipe piles for the underwater part and the sedimentary layer, the use of sacrificial steel pipe can be greatly reduced without compromising safety compared to existing piles, thereby increasing economic efficiency.

In addition, by forming an expansion pile from which the geotextile tube is removed at the distal end of the geotextile tube pile, it is possible to secure a strong supporting force.

In addition, it is to provide a sacrificial steel pipe saving type cast-in-place pile structure and a construction method thereof, in which loss of concrete is prevented by the geotextile tube, and the reinforcing bar coating thickness and adhesion to the ground layer can be reliably secured.

By pre-injecting mortar into the tip of the geotextile tube pile, injecting super-fast curing mortar, injecting fiber mixed mortar, or pressurizing mortar after the geotextile tube pile or sacrificial steel pipe pile construction step, the bearing capacity of the tip of the pile is increased. can be secured for sure.

1 is a manufacturing state diagram of a geotextile reinforcing bar network of a sacrificial steel pipe saving type cast-in-place pile structure according to an example of the present invention;
2 to 11 is a construction process diagram of a sacrificial steel pipe saving type cast-in-place pile according to an example of the present invention
12 is a view showing an existing (conventional) cast-in-place pile

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but another component is between each component. may be “connected”, “coupled” or “connected”.

1 is a state diagram of a geotextile reinforcing bar network of a sacrificial steel pipe saving type cast-in-place pile structure according to an example of the present invention.

10 to 11, the sacrificial steel pipe saving-type cast-in-place pile structure according to an example of the present invention is a cast-in-place pile 100 that is sequentially constructed from the top to the ground consisting of a submerged part, a sedimentary layer, and a ground layer. As a civil engineering work It may include a fiber tube pile 110 and a sacrificial steel pipe pile 120 .

Geotextile tube pile 110 may be constructed in the ground layer portion. Geotextile tube pile 110 is a geotextile tube 114 provided on the outside, a reinforcing bar network 112 provided inside the geotextile tube 114, and a geotextile tube 114 that is poured into and hardened. It may contain concrete.

In addition, it may further include an expansion pile 140 provided at the front end of the geotextile tube pile (110). The expansion pile 140 is expanded in diameter in the geotextile tube pile 110 , and the geotextile tube 114 may be removed. The expansion pile 140 may increase the bearing capacity and prevent subsidence.

The sacrificial steel pipe pile 120 is continuously constructed on the upper side of the geotextile tube pile 110 , and may be constructed in the underwater part and the sedimentary layer part. The sacrificial steel pipe pile 120 includes a sacrificial steel pipe 124 provided on the outside, a reinforcing bar network 112 provided inside the sacrificial steel pipe 124, and concrete poured and hardened in the sacrificial steel pipe 124. can

It is preferable that the sacrificial steel pipe 124 and the geotextile partially overlap at the connection part of the geotextile tube pile 110 and the sacrificial steel pipe pile 120 .

The sacrificial steel pipe 124 of the sacrificial steel pipe pile 120 may extend to an upper part of the geotextile tube pile 110 and overlap the geotextile tube 114 . That is, the geotextile and the sacrificial steel pipe 124 are not connected to each other at the connection part, but the sacrificial steel pipe 124 extends downward to sufficiently overlap the geotextile. This may increase the structural safety of the pile by partially inserting the lower portion of the sacrificial steel pipe 124 into the ground layer.

The geotextile tube pile 110 may be installed in the sedimentary layer and the ground layer, and the sacrificial steel pipe pile 120 may be constructed in the underwater part. That is, by extending the geotextile tube pile 110 upward in consideration of the state of the sedimentary layer, it is possible to reduce the amount of use of the sacrificial steel pipe 124 and increase economic efficiency.

In addition, a mortar injection pipe 136 may be further included in the reinforcing bar network 112 . Before construction of the geotextile tube pile 110 through the mortar injection pipe 136, the mortar may be pre-injected to increase the adhesion of the tip. The mortar can prevent concrete from leaking by filling unexpected cracks that may exist at the tip by using the super-fast hardening mortar. The mortar can increase the filling effect such as cracks by using a fiber-mixed mortar. Alternatively, by pressurizing mortar after the construction of the geotextile tube pile 110 or the sacrificial steel pipe pile 120, it is possible to reliably secure the bearing capacity of the tip end of the pile.

The following describes the construction method of the present invention sacrificial steel pipe saving type cast-in-place pile 100 configured as described above.

First, referring to FIGS. 2 to 3 , the sacrificial steel pipe 124 and the excavator are mounted on the ground consisting of the underwater part, the sedimentary layer and the ground layer sequentially from the top according to the design drawing, and the underwater part, the sedimentary layer and the ground layer The sacrificial steel pipe 124 may be inserted into the underwater part, the sedimentary layer, and the ground layer while excavating. The sacrificial steel pipe 124 may be vertically stacked and connected in plurality according to the depth of excavation.

Referring to FIG. 5 , a plurality of axial reinforcing bars and a reinforcing bar network 112 surrounding the axial reinforcing bars with band reinforcing bars and/or spiral reinforcing bars are formed, and a portion corresponding to the ground layer in the reinforcing bar network 112 is formed with a geotextile tube. It can be wrapped with (114) to form a geotextile reinforcing bar network (130).

6 to 7 , the geotextile reinforcing bar network 130 formed as described above may be inserted into the sacrificial steel pipe 124 using a crane. The lower end of the geotextile tube 114 may be fixed to the lower portion of the reinforcing bar network 112 with a separate fixing member. A plurality of gap maintaining members may be further installed in the reinforcing bar network 112 of the geotextile reinforcing bar network 130 so that the reinforcing bar network 112 and the geotextile tube 114 are spaced apart.

Inserting the tremie tube 200 into the sacrificial steel pipe 124 into which the geotextile reinforcement network 130 is inserted, or inserting the geotextile reinforcement network 130 and the tremie tube 200 into the sacrificial steel pipe 124 at the same time can do.

8 to 11 , concrete may be injected using a pump car through the Tremi tube 200 . In the concrete, since the geotextile tube 114 serves as a formwork, it prevents the loss of concrete and protects the outside of the concrete, so that quality assurance and constructability are improved, and the construction cost can be reduced, thereby increasing economic efficiency.

As the concrete is poured, the sacrificial steel pipe 124 may be drawn up to the interface between the sedimentary layer and the ground layer to form the geotextile tube pile 110 . In this case, it is preferable to partially overlap the connection part of the sacrificial steel pipe 124 and the geotextile. Concrete pouring may be performed while drawing the Tremi tube 200 . The drawing of the sacrificial steel pipe 124 can be performed slightly after pouring concrete.

By stopping the drawing of the sacrificial steel pipe 124 before the interface between the sedimentary layer and the ground layer, the sacrificial steel pipe 124 may extend to an upper portion of the geotextile tube pile 110 and overlap the geotextile tube 114 . That is, by stopping the drawing at the upper 1/2, 1/3, or 1/4 position of the geotextile tube pile 110, the overlap of the sacrificial steel pipe 124 and the geotextile tube 114 is reliably secured and the pile structural stability can be ensured. The sacrificial steel pipe 124 drawn to the upper part of the underwater part may be separated and stored separately.

When the geotextile tube pile 110 is formed, the sacrificial steel pipe pile 120 is formed by further pouring concrete through the Tremi pipe 200 while retaining the sacrificial steel pipe 124 in the sedimentary layer and the underwater part. Cast-in-place piles 100 can be constructed. The sacrificial steel pipe 124 of the sacrificial steel pipe pile 120 is located in the sedimentary layer and the underwater part, and can prevent corrosion by seawater or the like.

Referring to FIG. 4 , an expansion pile 140 may be formed at the tip. For this purpose, an expansion hole may be formed in advance during excavation. The geotextile tube 114 is removed from the portion where the expansion pile 140 is formed, so that the expansion pile 140 having a large diameter may be formed. The diameter of the expansion pile 140 may be up to 2 to 5 times that of the geotextile tube pile 110 .

In addition, when excavating the ground layer, the excavation can be extended in the lateral direction in parallel with the downward excavation. This may facilitate the insertion of the sacrificial steel pipe 124 .

Before the geotextile tube pile 110 or the expansion pile 140 is formed, mortar may be pre-injected into the lower surface of the front end through the mortar injection pipe 136 coupled to the reinforcing bar network 112 . This can increase the adhesive force of the tip and at the same time increase the structural stability.

The mortar may be a super fast curing mortar or a fiber mixed mortar. The super-fast hardening mortar or fiber-mixed mortar can increase the structural stability of the tip by preventing concrete leakage by filling in unexpected cracks at the tip.

In addition, after the step of forming the geotextile tube pile 110 or after the step of forming the sacrificial steel pipe pile 120, the mortar injection pipe 136 is used to pressurize the mortar into the lower surface of the front end, or the civil engineering Before the step of forming the fiber tube pile 110, the mortar injection pipe 136 is used to pre-inject mortar into the lower surface of the tip, and then after the step of forming the geotextile tube pile 110 or the sacrificial steel pipe pile ( After the step of forming 120), the mortar can be injected under pressure using the mortar injection pipe 136 on the lower surface of the tip. Such pressure injection can dramatically increase the structural stability of the tip.

In the above, even though it has been described that all the components constituting the embodiment of the present invention operate by being combined or combined into one, the present invention is not necessarily limited to this embodiment. That is, within the scope of the present invention, all the components may be configured or operated by selectively combining one or more components. In addition, terms such as "comprises", "comprises" or "have" described above mean that the corresponding component may be inherent, unless otherwise specified, excluding other components. Rather, it should be construed as being able to further include other components. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, unless otherwise defined. Terms commonly used, such as those defined in the dictionary, should be interpreted as being consistent with the contextual meaning of the related art, and are not interpreted in an ideal or excessively formal meaning unless explicitly defined in the present invention.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: cast-in-place pile
110: geotextile tube pile
112: rebar mesh
114: geotextile tube
120: sacrificial steel pipe pile
112: rebar mesh
124: sacrificial steel pipe
130: geotextile reinforcing bar network
136: mortar injection pipe
140: expansion pile
200: Tremi Hall

Claims (10)

In the sacrificial steel pipe saving type cast-in-place pile structure constructed on the ground consisting of the underwater part, the sedimentary layer and the ground layer sequentially from the top,
Geotextile tube piles constructed on the ground layer;
Containing; as a sacrificial steel pipe pile that is continuously constructed on the upper side of the geotextile tube pile, and is constructed on the underwater part and the sedimentary layer part;
The geotextile tube pile includes a geotextile tube provided outside, a reinforcing bar network provided inside the geotextile tube, and concrete poured and hardened inside the geotextile tube,
The sacrificial steel pipe pile includes a sacrificial steel pipe provided outside, a reinforcing bar network provided inside the sacrificial steel pipe, and concrete poured and hardened inside the sacrificial steel pipe,
Further comprising an expansion pile provided at the tip of the geotextile tube pile,
The expansion pile is expanded in diameter from the geotextile tube pile, and the geotextile tube is removed,
The sacrificial steel pipe of the sacrificial steel pipe pile extends to an upper part of the geotextile tube pile and overlaps the geotextile tube,
Further comprising a mortar injection pipe coupled to the reinforcing bar network,
After constructing the geotextile tube pile or after constructing the sacrificial steel pipe pile, pressurizing mortar into the lower surface of the distal end using the mortar injection pipe, or before constructing the geotextile tube pile, the mortar injection pipe After pre-injecting mortar into the lower surface of the tip using Sacrificial steel pipe saving type cast-in-place pile structure. delete delete delete inserting the sacrificial steel pipe while excavating to the ground layer after mounting a sacrificial steel pipe and an excavator on the ground consisting of an underwater part, a sedimentary layer, and a ground layer sequentially from the top;
Preparing a geotextile reinforcing bar network comprising a reinforcing bar network including an axial reinforcing bar and a band reinforcing bar or spiral reinforcing bar surrounding the axial reinforcing bar, and a geosynthetic fiber tube surrounding a portion corresponding to the ground layer in the reinforcing bar network;
inserting the geotextile reinforcement network and the tremie tube into the sacrificial steel pipe at the same time, or inserting the geotextile reinforcement network into the sacrificial steel tube first and then inserting the tremie tube;
forming geotextile tube piles by drawing the sacrificial steel pipe to the interface between the sedimentary layer and the ground layer while pouring concrete through the tremie pipe;
forming a sacrificial steel pipe pile by pouring concrete while retaining the sacrificial steel pipe in the sedimentary layer and the underwater part through the tremie pipe; build in order,
Further forming an expansion pile provided at the tip of the geotextile tube pile,
The expansion pile is expanded in diameter from the geotextile tube pile, the geotextile tube is removed,
In the step of forming the geotextile tube pile, the drawing of the sacrificial steel pipe is stopped before the interface between the sedimentary layer and the ground layer, so that the sacrificial steel pipe extends to an upper part of the geotextile tube pile and overlaps the geotextile tube. become,
Further comprising a mortar injection pipe coupled to the reinforcing bar network,
After the step of forming the geotextile tube pile or after the step of forming the sacrificial steel pipe pile, pressurizing mortar into the lower surface of the front end using the mortar injection pipe, or before the step of forming the geotextile tube pile After pre-injecting mortar into the lower surface of the tip using a mortar injection pipe, after the step of forming the geotextile tube pile or after the step of forming the sacrificial steel pipe pile, the mortar is injected under pressure using the mortar injection pipe A method of constructing a sacrificial steel pipe saving type cast-in-place pile, characterized in that delete delete delete delete delete

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