KR20160070865A

KR20160070865A - Backfiling method for heat pipe

Info

Publication number: KR20160070865A
Application number: KR1020140177181A
Authority: KR
Inventors: 윤길림; 김선빈; 오명학; 황중호
Original assignee: 한국해양과학기술원
Priority date: 2014-12-10
Filing date: 2014-12-10
Publication date: 2016-06-21

Abstract

The present invention relates to a method for backfilling a heat pipe and, concretely, to a method for backfilling a heat pipe which uses one or more among light mixed soil, soil cement and foamed concrete as a backfilling material for the heat pipe buried under the ground in place of sand having been used in a conventional art to bury the heat pipe under the ground and then to backfill the heat pipe. The present invention has advantages of recycling a large amount of excavated earth and waste generated during construction because of using the foamed mixed light soil and soil cement as the backfilling material by recycling the excavated earth generated in an excavation step to contribute to saving construction costs and minimizing environmental pollution; and installing an adjunct, playing a role of a support and a spacer, at a lower part of the heat pipe in a work environment that a construction period has to be reduced, and then placing the backfilling material to an upper part of the heat pipe at once by only one time placement process to be capable of being applied to an urban construction or a case that a construction period has to be reduced.

Description

Background Art [0002] BACKFILING METHOD FOR HEAT PIPE [0003]

The present invention relates to a method of constructing a heat pipe backing mate, and more particularly, to a method of constructing a heat pipe backing material by replacing at least one of lightweight mixed soil and soil cement or air- The present invention relates to a heat pipe backfill method and a backfilling method.

The existing submerged heat piping works after laying, 10 ~ 20cm under the piping, 20 ~ 30cm above the piping, and high quality sand is laid on top of it, . Refilling the periphery of the heat pipe with sand is intended to prevent frictional resistance between the pipe surface and the sand, thereby preventing damage to the heat pipe during expansion and contraction according to the temperature change inside the pipe.

However, due to the expansion of the construction market, the sand as construction material has gradually been exhausted and the price of sand has risen and the supply and demand of the material has been unsatisfactory. There has been a problem such as poor compaction after sand laying, Problems such as possibility and durability deteriorated. Particularly, in the L-shaped or Z-shaped bending portion of the heat piping line, a complete free end can not be formed and an expansion region is formed, and a displacement due to expansion or contraction is concentrated at the corresponding portion, , And most of the defects were caused by corrosion due to water leakage due to faulty condition during construction and common use. In addition, it is difficult to backfill and compaction in the narrow part such as the press-in section, and the damage of the soil discharge due to the excellence etc. has occurred after the construction.

On the other hand, there have been cases where soillite cement is applied as a filler material for underground buried pipelines outside of the country. This has resulted in reduction of construction cost, improvement of construction efficiency and shortening of construction period. Especially, when stabilized floating gravel such as soil cement is used, it is unnecessary to work with compaction equipment during backfilling, thus improving workability and low vibration construction. After the curing, the strength of the compaction sand is sufficiently developed, which contributes to improvement of the durability of the pipeline. However, the cost of the construction is increased, and the excavated soil generated after the terraces is inconveniently disposed.

In order to solve such problems and inconveniences, Korean Patent No. 1380326 has proposed a fire-retardant composition for a fluidized filler having low strength and ultra-high hardness, but it is necessary to use a separate fireproof material and a CaO content of a certain level The incineration residues included were separately prepared, so that there was still a problem that they could not be applied quickly in the field.

On the other hand, Korean Patent Registration No. 0324889 proposes a method of filling a protective layer of various kinds of buried pipes such as sewage, water, and gas pipes, but it is necessary to recycle excavated soil from the site or to have sufficient fluidity and self- But it still has the limitation that it does not help to improve stability and durability against swelling.

In order to overcome these problems and limitations, a trenching step is performed to excavate the heat pipe to a depth necessary for burying the heat pipe in the ground; Primary pouring and curing step for selecting and installing curing materials such as bubble mixed lightweight soil, soil cement or foamed concrete at the bottom of the piping to be installed; A heat piping installation step in which a heat piping is installed on the upper part of the first installed and cured section; A secondary casting and curing step in which one of the bubble mixed lightweight soil, the soil cement, or the foamed concrete is selected as the filler material and cured in the first placed portion and the upper portion of the heat pipe; And a road base layer and a package layer forming step of forming a road base layer and a packing layer on the upper portion of the secondary paved section. However, in the mixed lightweight soil, After the curing, additional pouring is made at the upper part. If the pouring of the primary pipe and the secondary pouring are performed, the air is considerably long, and the opening period of the road becomes longer and the construction cost is increased.

Previous patent 1: Korean patent registration No. 1380526 (Registered on March 26, 2014) Previous Patent 2: Korean Patent Registration No. 0324889 (Registered on February 4, 2002) Previous Patent 3: Korean Patent Registration No. 0471195 (Registered on February 21, 2005)

The present invention was conceived to overcome the problems and limitations inherent in the conventional backfill piping backfill construction method as described above,

The object of the present invention is to provide a method of reducing the amount of sand in the urban area or the air which is required to shorten the period required for backfilling by using at least one of lightweight mixed soil and soil cement or air- Which is capable of shortening a construction period in order to prepare for a short case or the like.

A method for backfilling a hot piping according to the present invention comprises:

A step of excavating the ground to a required depth to bury the heat pipe in the ground; A heat pipe installation step of installing a heat pipe on the ground surface, wherein the heat pipe installed on the bottom surface is fixed by one or more accessories provided on the outer side; A pouring and curing step in which one of bubble mixed lightweight soil, soil cement or foamed concrete is selected as a filler and cured until the top of the heat pipe is covered from the bottom surface provided with the heat pipe; And a road base layer and a package layer forming step of forming a road base layer and a packaging layer on top of the poured sections.

At this time, in the heat pipe installation step, two or more heat pipes may be installed horizontally or vertically at regular intervals.

Another object of the present invention is to provide an accessory for use in the installation of the heat pipe, which is installed on the bottom of the heat pipe to support the heat pipe or prevent the float of the heat pipe from being installed on the wall.

It is preferable that the pedestal used in this case is made of a material that is elastic and absorbs impact and is resistant to heat, and the upper surface is preferably formed corresponding to the shape of the pipe so that various types of heat pipes can be fixed and fixed.

On the other hand, the air - mixed lightweight soils used as backfill are composed of excavated soil, cement and air bubbles mixed with water, and soillite cement is mixed with excavated soil and cement mixed with water. Also, the foamed concrete is formed by mixing cement, water and air bubbles.

The bubble mixed lightweight soil is composed of excavated soil, cement, water and air bubbles. The bubble-mixed lightweight soil is composed of 85 to 95 wt% of excavated soil mixed with water, 5 to 15 wt% of cement Preferably 0.3 to 0.4% by weight.

The bubble-mixed lightweight soils can be adjusted in the range of 7 ~ 13 kN / ㎥ according to the mixing ratio of the bubbles. The compressive strength of the lightweight soils can be adjusted up to 1,000kPa . Although the water permeability is somewhat different according to the mixing ratio of the components and constituent materials of the raw soil material, it is preferable to have a value of 2.0 ^-6 ~ 5.0 ^-5 cm / sec, which is similar to the permeability coefficient of the clay.

The soil cement is formed by mixing excavated soil, cement and water. The soil cement is formed by mixing 80 to 90% by weight of excavated soil mixed with water and 10 to 20% by weight of cement .

The unit weight of the soil cement is in the range of 18 to 21 kN / m 3, the compressive strength is preferably 1,200 to 6,000 kPa, and the water permeability is preferably 1.0 ^-7 cm / sec or less.

The foamed concrete is formed by mixing cement, water, and air bubbles. The foamed concrete is preferably prepared by mixing 90 to 95% by weight of water-mixed cement with 5 to 10% by weight of a foaming agent Do. At this time, water and cement are mixed in a weight ratio of 1: 1.

It is preferable that the unit weight of the foamed concrete is adjustable in the range of 7 to 9 kN / m 3 depending on the bubble mixing amount, and the compressive strength is in the range of 3,000 to 5,000 kPa.

Since the present invention uses the bubble mixed lightweight soil and soilless cement used as backfill materials by recycling the excavated soil that is formed at the stage of digging, it can recycle huge amounts of excavated soil and waste generated during the construction, And contributes to minimizing environmental pollution.

In addition, in the present invention, in the work environment in which the construction period is shortened, an appendix serving as a support and a spacing member is installed in the lower part of the heat pipe, and then the heat pipe is poured into the upper part of the heat pipe only once, Another advantage is that the construction can be applied in the case of shortening the construction period or the construction period of the downtown area.

1 is a view showing an entire process of a heat pipe backfill construction method according to the present invention.
FIG. 2 is a bottom section of a state in which two heat pipes are supported on the floor surface from the floor surface by using a supporting structure and laterally installed on the floor surface after the terrace.
FIG. 3 is a view showing an underground section in a state in which two heat pipes are vertically installed from the bottom surface using a two-sided structure.
4 is a photograph showing the state of the pouring and curing step after the heat pipe is installed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing an entire process of the heat pipe backfilling method according to the present invention, and FIG. 4 is a photograph showing a state of a pouring and curing step after the heat pipe is installed.

In step S100, the ground is excavated to a required depth to bury the heat pipe in the ground. Heat pipes vary in diameter from 50 mm or less to 650 mm or more, and double heat insulation pipes composed of steel pipes for heat transfer - polyurethane insulation and polyethylene pipes are used. The depth of excavation depends on the diameter of the heat pipe. The excavation depth is usually 600 to 1,500 cm.

In the heat pipe installation step (S200), at least one heat pipe is installed horizontally or vertically on the floor surface generated in the tearing step. In the heat pipe installation step (S100), in order to fix the heat pipe immediately after the installation of the floor surface and the curing step, the heat pipe is fixed to the floor structure so as to be supported from the floor surface. So that it can be fixed in the ground via a float prevention structure or the like to serve as a support.

The support structures and the anti-flood structures can be used independently or together. The anti-flood structures can be used when underground water works or pipelines are floated. Is preferably used. Also, in some cases, it is also possible to suspend the heat pipe by hanging it on a supporting stand or the like so as to fix the heat pipe at a predetermined distance from the floor surface.

In the pouring and curing step (S300), all the heat pipes are covered from the bottom of the depth to be installed of the heat pipe, and one of the bubble mixed lightweight soil, the soil cement or the foam concrete is selected as the filler, to be.

It is preferable to select a material having high strength and rigidity and high water hardness in order to minimize settlement and erosion of the heat pipe used in the backfill material used. It is preferable to apply the present invention to a work environment in which the construction period must be shortened because the backfilling construction is completed through one pouring and curing.

In the step S400 of forming the road base layer and the pavement layer, the road base layer and the pavement layer are sequentially or simultaneously formed on the pultruded and cured sections.

After the heat pipes are installed in the ground through the above steps, they are filled back to form an underground section as shown in FIG. 2 or FIG.

FIG. 2 is a bottom view of a state in which two heat pipes are supported on the floor surface from the floor surface by using a supporting structure and laterally installed on the floor surface after the terrace, FIG. And the heat pipe is installed using two support structures.

After the bottom surface 100 is formed through the trenching step S100, the upper surface of the bottom surface of the heat pipe 300, which is floated from the bottom surface through the supporting structure 500, At least one side or two or more side by side along the bottom surface.

The support structure 500 is attached to the bottom surface of the conduit and serves as a support and a spacer. When the support structure 500 is used to install the heat pipe 10, It is possible to complete the rebar construction. At this time, when the installation width is narrow, as shown in FIG. 3, the supporting structure 500 is applied to the two piping pipes 10 in the vertical direction.

Then, one of bubble mixed lightweight soil, soil cement, or foamed concrete is selectively installed as a backfill material on the floor surface through the pouring and curing step (S300) and then cured to form the poured layer 200.

After the pouring layer 200 is formed, the road base layer 300 and the packaging layer 400 are sequentially formed on the pouring layer 200 through the road base layer and the pavement layer forming step S400, It is finished.

Claims

A step of excavating the ground to a required depth to bury the heat pipe in the ground;
A heat pipe installation step of installing a heat pipe on the ground surface, wherein the heat pipe installed on the bottom surface is fixed by one or more accessories provided on the outer side;
A pouring and curing step in which one of bubble mixed lightweight soil, soil cement or foamed concrete is selected as a filler and cured until the top of the heat pipe is covered from the bottom surface provided with the heat pipe; And
And forming a road base layer and a packaging layer on the upper portion of the paved section.

The method according to claim 1,
Wherein two or more heat pipes are installed horizontally or vertically at regular intervals in the heat pipe installation step.

The method according to claim 1,
Wherein the accessory used in the heat pipe installation step is a float prevention structure that is installed on the bottom of the heat pipe and supports the float or the floating wall to prevent floatation of the heat pipe.

The method according to any one of claims 1 to 3,
Wherein the bubble-mixed lightweight soil is formed by mixing excavated soil, cement, and air bubbles mixed with water.

4. The method according to any one of claims 1 to 3,
Wherein the soil cement is formed by mixing excavated soil and cement mixed with water.

4. The method according to any one of claims 1 to 3,
Wherein the foamed concrete is formed by mixing cement, water and air bubbles.