Abstract:
A heating system comprises: a structure forming an elevated floor above a slab and supported by legs; and heating panels comprising an upper panel having downwardly formed outer walls and downwardly protruding structure-seating parts on parts inside the corners capable of taking the load so that the upper panel can be fixed above the structure, and a lower panel having an upwardly bent body to attach to the bottom of the upper panel, the heating means installed in the interior, and the penetration parts which the structure-seating parts penetrate, wherein when the upper panel and lower panel are attached, the empty space therebetween is filled with cement mortar or red clay and cured.

Description:
BACKGROUND 
       [0001]    The present invention relates to a heating system, and more particularly, to a heating system which has a structure that may form a floating floor and in which a heating means is applied to an inner space between upper and lower panels that define a two-layered floor on the structure. 
         [0002]    In general, an access floor is installed in an office room such as a computer room, an electrical room and an emergency room and is installed in a dual structure such that it is spaced apart from a bottom surface for the purpose of concealment of electric wires and the like, blocking of moisture and interior decoration of a floor. 
         [0003]    That is, because a number of servers and devices are installed in the electrical room or an equipment room of a company, power cables, LAN cables, private lines, telephone lines and the like are required. Thus, the access floor refers to a construction material that allows installation of a dual floor having a space below a floor such that all the wires may be used without obstructing passage. 
         [0004]    However, the access floor is used only for a floating floor structure. 
         [0005]    Meanwhile, in a current heating system for an apartment, a floor is finished by constructing a heat-insulating sound-absorbing member such as expanded polystyrene, foamed urethane and foamed polypropylene that are combustible sound absorbing materials or shock absorbing materials on a slab, forming a lightweight foamed concrete layer thereon, laying a hot water pipe that is a heating member thereon, and constructing a mortar layer thereon again. 
         [0006]    Such cement construction of the floor structure is totally performed by field technicians in a wet scheme. 
         [0007]    Such an existing technology has problems in that construction is difficult, maintenance and repairs when water leaks are generated are difficult because a large amount of pipe connecting members are arranged inside a concrete layer, a large amount of times are consumed for heating because hot water circulating pipes are connected in series to each other, and floor noise is transferred well because mortar for a heating pipe is integrated with the floor as well. 
         [0008]    To solve the problems of such a wet heating system, a hot water pipe is embedded in a panel formed of concrete, synthetic resin or yellow ocher or a dry heating panel having a groove or a fixing member into which the hot water pipe is inserted is developed and provided. 
         [0009]    Such a dry heating panel, which is a prefabricated heating system, is constructed in a scheme in which pre-manufactured dry panels are simply assembled on the spot, so that there are advantages in that a construction period thereof is shortened and maintenance thereof is easy as well. However, because the panel is manufactured such that the interior thereof is dry, there are problems in that solidity thereof deteriorates and there is no heat storage function. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention is conceived to solve the above problems, an aspect of the present invention is to provide a heating system in which a dry construction method in which a floating floor is formed by assembling and fixing a heating panel having a heat generating function and a heat storing function on a structure constituting a two-layered floor is used so that construction is simple and convenient, and noise reduction pad are attached to structure legs forming a two-layered structure so that floor noise may be remarkably reduced. 
         [0011]    Further, another aspect of the present invention is to provide a heating system in which to solve the conventional problem that a large amount of times are consumed for heating because pipes extending in series are thickly covered by cement mortar, panels in which heating pipe are installed are connected in parallel to each other so that heating is uniformly and rapidly performed, a high energy saving effect is achieved due to a high heat retaining property, cement mortar or yellow ocher is filled in the panels so that a heat storing property is high, and an upper portion of the heating panel, which constitutes a floor, is formed of aluminum so that a thermal conductivity thereof is high. 
         [0012]    To achieve the above aspects, a heating system according to an embodiment of the present invention includes: a structure supported by legs and constituting a floating floor on a slab; and heating panels, each of which comprises an upper panel having structure seaters protruding downward from portions inside edges of the upper panel, which support loads, such that the corresponding heating panel is fixed on the structure and having outer walls extending downward, and a lower panel having a body bent upward and coupled to a lower portion of the upper panel and having penetration parts which have a heating means installed in the penetration parts and through which the structure seating parts pass, wherein in a state in which the upper panel and the lower panel are coupled to each other, cement mortar or yellow ocher is filled in an empty space between the upper panel and the lower panel and is cured. 
         [0013]    A heating system according to another embodiment of the present invention includes: a structure supported by legs and constituting a floating floor on a slab; and heating panels, each of which comprises an upper panel having structure seaters protruding downward from portions inside edges of the upper panel, which support loads, such that the corresponding heating panel is fixed on the structure and having outer walls extending downward, and a lower panel having a body bent upward and coupled to a lower portion of the upper panel, having penetration parts which have a heating means installed in the penetration parts and through which the structure seating parts pass, having a heating film attached to a lower bottom surface of the lower panel in a dry scheme, and having a ceramic plate or a fireproof insulation plate fixed to a lower side of the heating film through a steel plate, wherein in a state in which the upper panel and the lower panel are coupled to each other, cement mortar or yellow ocher is filled in an empty space between the upper panel and the lower panel and is cured. 
         [0014]    A heating system according to yet another embodiment of the present invention includes: a structure supported by legs and constituting a floating floor on a slab; and heating panels, each of which comprises an upper panel having structure seaters protruding downward from portions inside edges of the upper panel, which support loads, such that the corresponding heating panel is fixed on the structure, having protrusion fasteners for coupling between the upper panel and a lower panel and having outer walls extending downward, the lower panel having a body bent upward and coupled to a lower portion of the upper panel, having penetration parts through which the structure seating parts pass, and having fastening holes formed at locations corresponding to the protrusion fasteners for bolt coupling from below to above, and a pair of intermediate panels formed by vertically stacking ceramic plates, having through-holes through which the protrusion fasteners pass, and formed in a space defined by coupling the upper panel and the lower panel with a heating film interposed between the pair of ceramic plates. 
         [0015]    A heating system according yet another embodiment of the present invention includes: a structure supported by legs and constituting a floating floor on a slab; and heating panels, each of which comprises an upper steel plate not having structure seaters but having structure fasteners for fastening the corresponding heating panel on the structure such that the heating panel is fixed on the structure, and a lower box having a box shape, of which an upper portion is opened, having a flange extending outward, having a heating means installed in the lower box, and having fasteners allowing the lower box to be fastened to the structure, wherein in a state in which edges of the upper steel plate and the flange of the lower box are coupled to each other through welding, cement mortar or yellow ocher is filled in an empty space of the lower box and is cured. 
         [0016]    According to the technical solutions of the above problems, as a heating system is implemented using general panels having a two-layered structure, construction may be simply and conveniently performed in a dry scheme regardless of locations by positioning a heating panel on a structure constituting a dual floating floor, so that construction costs may be reduced, and weight lightening of a building may be helped due to the dual floor structure. 
         [0017]    Further, a heat storage property is high and cement or yellow ocher is filled in the panels, so that a load strength may be increased, footstep sounds are not generated and a noise absorbing effect of reducing floor noise is achieved as well. Further, when heat is supplied to the panels constituting the floor, heat may be uniformly and rapidly transferred. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view illustrating a process of coupling an upper panel and a lower panel to each other according to an embodiment of the present invention. 
           [0019]      FIGS. 2 and 3  are a perspective view illustrating the upper panel of  FIG. 1  and a perspective view illustrating a bottom surface (ceiling), respectively. 
           [0020]      FIG. 4  is a perspective view illustrating the lower panel of  FIG. 1 . 
           [0021]      FIG. 5  is a side sectional view illustrating a heating panel according to the embodiment of the present invention. 
           [0022]      FIG. 6  is a perspective view illustrating a rubber foam insulation on which the lower panel of  FIG. 1  is mounted. 
           [0023]      FIG. 7  is a system diagram illustrating a state in which heating water circulates in heating panels connected to a boiler according to the embodiment of the present invention. 
           [0024]      FIG. 8  is a view illustrating a state in which the heating panel of  FIG. 5  is installed on a structure. 
           [0025]      FIGS. 9 and 10  are exploded perspective views illustrating a heating panel according to other embodiments of the present invention. 
           [0026]      FIG. 11  is a perspective view illustrating a heating panel according to yet another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Hereinafter, configurations and effects of embodiments of the present invention will be described with reference to the accompanying drawings. 
         [0028]    It should be noted that the same elements in the drawings are designated by the same reference numerals as far as possible even though the elements are illustrated in different drawings. 
         [0029]    In the following description of the present invention, when detailed descriptions of related well-known functions or configurations may unnecessarily make the subject matter of the present invention unclear, the detailed descriptions will be omitted. 
         [0030]    Further, when a specific part “includes” a specific element, this means that the specific part does not exclude other elements but may further include other elements as long as there is no specially contrary description. 
         [0031]      FIG. 1  is a perspective view illustrating a process of coupling an upper panel and a lower panel to each other according to an embodiment of the present invention,  FIGS. 2 and 3  are a perspective view illustrating the upper panel of  FIG. 1  and a perspective view illustrating a ceiling surface, respectively,  FIG. 4  is a perspective view illustrating the lower panel of  FIG. 1 , and  FIG. 5  is a side sectional view illustrating a heating panel according to the embodiment of the present invention. 
         [0032]    Although a heating pipe  27  connected to a boiler will be described below as an example of a heating means installed in a lower panel  20 , the present invention is not limited thereto, and it is apparent that a metal heating element used in an electric pad or the like, a carbon-coated heating element used in a stone bed or the like, an electric heating wire using a resistor, a carbon fiber or the like may be used as the heating means. 
         [0033]    As illustrated, a Korean floor heating system panel  60  includes an upper panel  10  and a lower panel  20 , and may further include a rubber foam insulation  40  herein. 
         [0034]    First, the upper panel  10  for conducting and storing heat, which is formed by molding aluminum to improve balance and preciseness, includes structure seaters  11 , outer walls  12 , protrusions  13 , protrusion fasteners  14 , ribs  15 , catching bosses  16 , catching steps  17 , fastening bosses  18 , through-holes  28  and caps  34 , and has a square shape or a rectangular shape. 
         [0035]    The outer walls  12  are formed on all sides of the upper panel  10  to protrude downward from a flat aluminum plate, and the fastening bosses  18  having fastening grooves  18   a  between the fastening bosses  18  and the outer walls  12  are formed by bending predetermined points of the outer walls  12  twice. 
         [0036]    That is, each fastening boss  18  and the corresponding outer wall  12  have an approximately “7” shape when viewed from below as illustrated in  FIG. 3 . 
         [0037]    Further, the corresponding catching step  17  and the corresponding catching boss  16  are formed on sides of the fastening boss  18  and the outer wall  12 , which are close to the corresponding fastening groove  18   a , at different heights. 
         [0038]    When viewed from insides of edges in which the outer walls  12  are formed, fastening holes are formed at centers of the structure seaters  11  formed in four locations that may support loads such that the upper panel  10  may be fixed to a structure  50  constituting a floating floor, the upper panel  10  is fastened to the structure  50  through the fastening holes of the structure seaters  11  using pieces  31  such as screws, and finishing caps  32  are inserted into upper portions of the upper panel  10 . 
         [0039]    Further, when there is no leg, the protruding structure seaters  11  do not protrude from a bottom surface of the lower panel, and thus the entire bottom surface of a heating panel  60  is seated on the structure  50 , so that only structure fasteners (not illustrated) may be used for the upper panel. 
         [0040]    Further, when the heating panel  60  is installed in the structure  50 , because loads of the heating panel  60  is focused on legs of the structure seaters  11 , threads are formed and fastening is performed using nuts N from below, so that the heating panel  60  may be supported. 
         [0041]    Here, when the size of the upper panel  10  is enlarged, a structure seater  11  may be additionally formed at a center of the upper panel to support a load at a central portion of the upper panel  10 . 
         [0042]    Further, the upper panel  10  includes the protrusions  13  for enhancing binding between the upper panel  10  and inner filling materials when cement mortar or yellow ocher is filled in the fastening grooves  18   a , the structure seaters  11  and the panel, the protrusion fasteners  14  for coupling with the lower panel  20 , and the ribs  15  for improving solidity between the catching protrusions  16  in the fastening grooves  18   a  and the upper panel  10 . 
         [0043]    Here, threads for bolt coupling are formed in the protrusion fasteners  14  so that the upper panel  10  is bolt-fastened to the lower panel  20 . 
         [0044]    Further, as illustrated in  FIG. 2 , fitting grooves  33   a  and fitting protrusions  33   b  may further formed on front, rear, left and right sides of the upper panel  10 . 
         [0045]    Accordingly, the fitting grooves  33   a  and the fitting protrusions  33   b  are fitted in each other between adjacent heating panels  60 , so that gaps are not generated during operations or after installation. 
         [0046]    Further, the upper panel  10  is opened/closed by covers  34  after upper portions of connectors  29  for connecting the heating pipe  27  and a hot water supply pipe  35  to each other and connecting the heating pipe  27  and a return water pipe  36  to each other is partially opened. 
         [0047]    Further, the through-holes  28  through which the hot water supply pipe  35  and the return water pipe  36  pass so that the pipes may be horizontally installed in the heating panel  60  are formed in the upper panel  10 . 
         [0048]    Next, the lower panel  20  includes a body  21 , bolt fastening holes  22 , fitting bosses  23 , filling holes  24 , through-holes  25 , wire meshes  26 , a heating pipe  27 , through-holes  28 , a hot water supply pipe  35 , a return water pipe  36  and connectors  29 , and has a square shape or rectangular shape to correspond to the upper panel  10 . 
         [0049]    Further, pipe through-holes  37  through which the hot water supply pipe  35  and the return water pipe  36  connected to the through-holes  28  may be connected and assembled are formed inside the lower panel  20 . 
         [0050]    In the lower panel  20 , the body  21  is formed by upward bending a steel plate in a quadrangular shape. The heating pipe  27  is arranged in the lower panel  20  in a zigzag shape, and has one end connected to the hot water supply pipe  35  installed while horizontally passing through one side of a bottom of the lower panel, through one connector  29 , and the other end connected to the return water pipe  36  installed while passing through the lower panel, through the other connector  29 . 
         [0051]    That is, the wire meshes  26  are horizontally or vertically installed inside the lower panel  20 , and the heating pipe  27  is bound to the wire meshes  26  and is connected to the hot water supply pipe  35  and the return water pipe  36  horizontally installed on one side and the other side of the bottom to be parallel to each other while passing through the lower panel  20 , through the T-shaped connectors  29 . 
         [0052]    Bent parts  21   a  that are bent inward and downward are formed at ends of upwardly bent portions of the body  21  to be fitted in and fastened to the fastening grooves  18   a  of the upper panel  10 , the fitting bosses  23  extending outward are formed at locations corresponding to the catching bosses  16 , and ends of the bent parts  21   a  are caught by and are not separated from the catching steps  17  of the fastening bosses  18  in a state in which the bent parts  21   a  are fitted in the fastening grooves  18   a.    
         [0053]    Further, the bolt fastening holes  22  are formed at locations corresponding to the protrusion fasteners  14  of the upper panel  10  for bolt fastening from below to above. 
         [0054]    The filling holes  24  are formed on side surfaces of the body  21 , which are upward bent, such that cement mortar or yellow ocher may be filled in an empty space inside the upper and lower panels  10  and  20 , and the through-holes  25  are formed at location corresponding to the structure seaters  11  of the upper panel  10  inside the lower panel  20  so that the heating panel  60  is fixed to the structure  50  through pieces  38 . 
         [0055]    Further, the through-holes  28  through which the hot water supply pipe  35  and the return water pipe  36  pass so that the pipes may be horizontally installed inside the heating panel  60  are formed in the lower panel  20 . 
         [0056]    Here, although a case where the through-holes  28  are formed in both the upper panel  10  and the lower panel  20  is described as an example, the through-holes  28  may be formed only in the lower panel  20 . 
         [0057]    Further, in  FIG. 4 , the pipe through-holes  37  are formed and partitioned in advance before cement mortar, yellow ocher or the like is filled in portions of the hot water supply pipe  35  and the return water pipe  36  except for portions of the connectors  29  and the covers  34 . 
         [0058]    Because of this, a space required when the hot water supply pipe  35  and the return water pipe  36  are assembled and installed or are replaced later may be ensured. 
         [0059]    Although such pipe through-holes  37  are not illustrated in the following other embodiments, it is apparent that pipe through-holes are formed in advance even in other embodiments so that a space may be ensured, and partitions or the like is formed so that the pipe through-holes may be partitioned. 
         [0060]    Next, the rubber foam insulation  40  illustrated in  FIG. 6  is injection-molded in accordance with an outer appearance of the lower panel  20  (a quadrangular box having an opened upper portion is illustrated in  FIG. 6 ), is attached to a lower side of the lower panel  20  and performs insulation such that heat is not transferred downward. 
         [0061]    Here, as illustrated in  FIG. 6 , through-holes  41  are also formed at locations corresponding to the structure seaters  11  of the upper panel  10  in the rubber foam insulation (ethylene propylene diene monomer (EPDM))  40 , an expanded polystyrene insulation or the like, so that the heating panel  60  is fixed to the structure  50  through the pieces  31 . 
         [0062]    Here, an insulation (not illustrated) having no elasticity may be further interposed between the structure  50  and the heating panel  60  such that the heat is not leaked. 
         [0063]    In the above-described Korean floor heating system panel  60 , when the bent parts  21   a  of the lower panel  20  are properly pushed and inserted into the fastening grooves  18   a  formed at front, rear, left and right edges of the upper panel  10 , the fitting bosses  23  of the lower panel  20  are caught by and coupled to the catching protrusions  16  formed inside the fastening grooves  18   a , and at the same time, while the bent parts  21   a  of the lower panel  20  are inserted into the fastening grooves  18   a , ends of the bent parts  21   a  are caught by the inner catching steps  17 , so that the upper panel  10  and the lower panel  20  are dually coupled to each other. 
         [0064]    Next, the bolt fastening holes  22  of the lower panel  20  are bolt-fastened to the protrusion fasteners  14  of the upper panel  10 , which have threads on bottom surfaces thereof. 
         [0065]    In this way, cement mortar, yellow ocher or the like is filled in an empty space inside the panel in which the upper panel  10  and the lower panel  20  are coupled to each other, through the filling holes  24 , and is cured. Thereafter, the heating panel  60  is completed. 
         [0066]      FIG. 7  is a system diagram illustrating a state in which heating water circulates in heating panels connected to a boiler according to the embodiment of the present invention. 
         [0067]    As illustrated in  FIG. 7 , a hot water supply pipe  71  and a return water pipe  72  connected to a boiler B are connected to a branch port  73  and a reverse branch port  74 , respectively, and an outlet of the branch port  73  and an inlet of the reverse branch port  74  are connected to the hot water supply pipe  35  and the return water pipe  36 , respectively. 
         [0068]    The hot water supply pipe  35  and the return water pipe  36  pass through heating panels  60  that are arranged adjacent to each other, and are connected in parallel to the heating pipe  27  formed in each heating panel  60  through the T-shaped connectors  29 . 
         [0069]    Accordingly, hot water of the boiler B is supplied to the heating pipe  27  of the heating panel  60  through the hot water supply pipe  71 , the branch port  73 , the hot water supply pipe  35  and the connector  29 , is used for heating and is then supplied to the boiler B through the connector  29 , the return water pipe  36 , the reverse branch port  74  and the return water pipe  72  again. 
         [0070]      FIG. 8  is a view illustrating a state in which the heating panel of  FIG. 5  is installed on a structure. 
         [0071]    As illustrated in  FIG. 8 , heating panels  60  are installed in the structure  50  supported by legs  52  and floating in the air, in an assembling scheme, and the pieces  31  are coupled to the structure  50  through the structure seaters  11  of the upper panel  10  in a state in which the heating panels  60  are located on the structure  50 , so that the heating panels  60  are fixed to and installed in the structure  50 . 
         [0072]    Here, a lower portion of each heating panel  60  may be insulated through the rubber foam insulation  40 , or the structure  50  may be installed after the entire bottom surface is constructed using insulation. 
         [0073]    Further, height adjusting means are provided in the legs  52  in contact with the slab so that a height of the structure may be adjusted. 
         [0074]    Further, ends of the legs  52  are sharpened so that noise transferred to a lower floor through the structure is minimized, noise reduction pads  54  are attached to between upper and lower steel plates  53  as supports  51  of the legs  52  so that a noise absorbing effect of reducing floor noise is achieved, and pads are finished on upper surfaces of the heating panels  60  constituting a floating floor. Then, the construction is completed. 
         [0075]    Although the configuration in which the boiler B is connected to the heating pipe  27  of the heating panel  60  for the purpose of circulation of hot water has been described above as an example of the heating means, it is apparent that when the heating panel is manufactured to include an electric heating wire such as a carbon-coated heating element, a metal heating element and a sheet-type heating element, various kinds of heating panels may be manufactured by variously applying pipes and wires within the panel depending on the kinds of the electric heating wire. 
         [0076]    Further, it is preferred that a bimetal temperature sensor (not illustrated) operated at a temperature of approximately 60-65° C. is provided in the heating means to prevent overheating, so that burns and fires caused by the overheating may be prevented. 
         [0077]      FIGS. 9 and 10  are exploded perspective views illustrating the heating panel according to other embodiments of the present invention. 
         [0078]    As illustrated in  FIG. 9 , an upper panel and a lower panel constituting the heating panel have the same structures and shapes as those of the upper panel  10  and the lower panel  20  illustrated in  FIGS. 3 and 4 . However, the upper panel  10  does not have the protrusions  13  and the through-holes  29  and the lower panel  20  does not have the heating pipe  27 , the hot water supply pipe  35 , the return water pipe  36  and the connectors  29  that are heating means. 
         [0079]    Instead, a heating film  27   a  or a thin sheet-type heating element is installed on a lower bottom surface of the lower panel  20  as the heating means. 
         [0080]    Here, a fireproof insulation plate or a ceramic plate (not illustrated) is further provided below the heating film  27   a  and is finished and fixed through a box-shaped steel plate  37  and pieces  38 . 
         [0081]    Here, when the structure seaters  11  of the upper panel  10  do not protrude from a bottom surface of the heating panel  60  and are used only for fastening the structure, the entire bottom surface of the heating panel is seated on the structure  50 . 
         [0082]    Next, as illustrated in  FIG. 10 , an upper panel and a lower panel constituting a heating panel have the same shapes as those of the upper panel  10  and the lower panel of  FIGS. 2B and 3 . However, the upper panel  10  does not include the protrusions  13  and the through-holes  29 , and the lower panel  20  does not include the heating pipe  27 , the hot water supply pipe  35 , the return water pipe  36 , the connectors  29  and the wire meshes  26  and the filling holes  24  for filling cement mortar or yellow ocher. 
         [0083]    Instead, for heating means and for storing heat, intermediate panels  90   a  and  90   b  and a heating film  27   a  are provided in an inner space defined by coupling the upper panel  10  and the lower panel  20  to each other. The pair of intermediate panels  90   a  and  90   b  are ceramic plates or fireproof insulation plates and are vertically spaced apart from each other, and the heating film  27   a  is interposed therebetween. 
         [0084]    Further, through-holes  93  through which the protrusion fasteners  14  of the upper panel  10  may pass are formed in the intermediate panels  90   a  and  90   b.    
         [0085]    Here, the structure seaters  11  of the upper panel  10  are not formed and only structure fasteners may be used. 
         [0086]      FIG. 11  is a perspective view illustrating a heating panel according to yet another embodiment of the present invention. 
         [0087]    As illustrated in  FIG. 11 , the heating panel  60  according to yet another embodiment of the present invention includes a quadrangular upper steel plate  70  and a quadrangular lower box  80 , of which a body made of steel is upward bent so that an upper side of the lower box  80  is opened. Further, a flange  82  extending outward is formed at an upper portion of the lower box  80  and edges of the flange  82  and the upper steel plate  70  are spot-welded so that the heating panel  60  is configured. 
         [0088]    Here, a heating panel  87  or the like, which is a heating means, is installed in an inner space of the lower box, which is like  FIG. 4 , is bound through wire meshes  86  or the like, and is connected to a hot water supply pipe  85  and a return water pipe  89  through connectors  83 . 
         [0089]    Further, through-holes  88  through which the hot water supply pipe  85  and the return water pipe  89  pass and a pipe connecting space between panels are partitioned and formed in the lower box  80 , and portions of the upper steel plate  70 , which are located above the connectors  83 , are partially opened, so that pipes between panels, that is, the hot water supply pipe  85  and the return water pipe  89  are connected through covers  74 . 
         [0090]    In a state in which the upper steel plate  70  and the lower box are coupled to each other, cement mortar or yellow ocher is filled through filling holes  84  formed on side surfaces of the lower box  80  and is then cured. 
         [0091]    Although the technical spirit of the present invention has been described above together with the accompanying drawings, this description is merely examples of exemplary embodiments of the present invention but does not delimit the present invention. Further, it is apparent that those skilled in the art may derive various modifications and imitations without departing from the scope of the technical spirit.