Patent Publication Number: US-8539629-B2

Title: Fit-together type of precast concrete lining and bridging structural body

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is the U.S. National Phase of International PCT Application Serial No. PCT/KR2009/000780 for FIT-TOGETHER TYPE OF PRECAST CONCRETE LINING AND BRIDGING STRUCTURAL BODY, filed Feb. 18, 2009, which claims priority to Korean Patent Application No. 10-2008-0014354 for PRECAST CONCRETE DECK STRUCTURE, filed on Feb. 18, 2008, both of which are hereby incorporated by reference in their entirety for all purposes. 
     TECHNICAL FIELD 
     The present invention relates to a fit-together type of precast concrete lining and bridging structural body. More particularly, the present invention is directed to mounting pre-stressed members on concrete deck members interconnected in longitudinal and transverse directions so as to reinforce rigidity. 
     BACKGROUND ART 
     In general, deck structures are temporarily installed within or around a construction site for the purpose of maintaining a road, removing soil, and securing a work space for construction when underground structures or bridges are constructed. 
     When typical underground structures are constructed, vertical piles are installed before excavation construction, and then main girders and deck plates are installed while the ground is being partially excavated. When the deck plates are completely installed, the excavation and installation of struts depending on the excavation are repeated. In this way, the construction is carried out. 
     Further, in the case of temporary bridges, a plurality of pier beams are driven into the ground one by one at predetermined intervals, and stiffening members are interconnected and reinforced between the pier beams. Thereby, a lower support structure is installed. Main girders are installed on top of the installed lower support structure, and deck plates are installed on top of the main girders. 
     These deck structures are mostly formed of steel, and are configured to be able to construct a temporary road in such a manner that upper plate members are placed on a plurality of support members made of steel. 
     Further, these deck structures have sufficient strength so that each member can withstand the load of a vehicle, and have uneven surfaces to increase a frictional force. 
     However, most of the deck structures formed of steel are vulnerable to moisture, salt, calcium chloride, and acidic substances, and thus are easily corroded. 
     Further, the deck structures have short durability, and are difficult to use with snow-removal chemicals such as calcium chloride when snow accumulates in the winter. As such, safety management becomes an issue. 
     Particularly, the steel deck structures formed of steel not only require an excessive cost of production, but also suffer from much noise and vibration due to frequent traffic. Also, it is difficult to check levels of wear and corrosion of the bottoms of the steel deck structures, and thus to replace the steel deck structures. 
     To solve these problems, a complex deck plate in which concrete is poured between and integrated with section steels has been proposed in Korean Patent Laid Open publication No. 2004-0069886, titled “Concrete Reinforcement Section Steel Plate,” and Korean Utility Model Registration No. 0351464, titled “Bridge Deck.” 
     In Korean Patent Laid Open publication No. 2007-0070565, titled “Deck Plate Structure” and filed by the applicant of this application, an improved deck plate structure has been proposed, which is capable of being made of concrete, reducing dead weight, and enabling easy disassembly from and assembly to a main girder in a simple screwing mode. 
     DISCLOSURE 
     Technical Problem 
     However, conventional deck structures formed of a concrete material are designed to have a predetermined thickness so as to withstand the load applied from the top, and thus have heavy dead weight as well as difficulty in joining with main girders. 
     Further, due to the load applied from an upper portion to a lower portion, the deck plates are subjected to a compressive force at the upper portion, and a tensile force on the lower portion. In the case of the concrete material, rigidity against the compressive force is high, but rigidity against the tensile force is greatly lower than the rigidity against the compressive force. For this reason, the deck plates are easily damaged during construction. 
     Accordingly, the present invention has been made in an effort to provide a fit-together type of precast concrete lining and bridging structural body in which a deck structure, which integrates main girders with deck plates and is formed of a concrete material, is pre-stressed, thereby making it possible to increase rigidity against a tensile force and to reduce dead weight. 
     Technical Solution 
     This problem is solved by providing a fit-together type of precast concrete lining and bridging structural body which is assembled with a plurality of precast concrete deck members formed of a concrete material in an arbitrary shape to be connectable in longitudinal and transverse directions. 
     Further, such a problem is solved by providing a fit-together type of precast concrete lining and bridging structural body in which opposite ends of pre-stressed members generating pre-stress are fixed to the precast concrete deck members connected in numbers. 
     Advantageous Effects 
     According to the exemplary embodiments of the invention, precast concrete deck members connected in longitudinal and transverse directions are pre-stressed by pre-stressed members, thereby making it possible to increase load carrying capacity and rigidity against a tensile force to ensure stable use for a long time. 
     Further, it is possible to support the load applied from the top of a deck structure having a small thickness, and thus to make the deck structure light. Due to the knockdown type (fit-together type), installation and dismantlement are easy, and reuse is possible, and thus it is possible to provide convenient construction and low production costs. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIGS. 1 to 4  are exploded perspective views illustrating an exemplary embodiment of the present invention. 
         FIG. 5  is a cross-sectional view illustrating an exemplary embodiment of the present invention. 
         FIGS. 6 to 9  illustrate examples of fixing pre-stressed members according to an exemplary embodiment of the present invention. 
         FIGS. 10 to 15  are side views illustrating another exemplary embodiment of the present invention. 
         FIG. 16  is an exploded perspective view illustrating another exemplary embodiment of the present invention. 
         FIGS. 17 to 19  are front views illustrating examples of a transverse connection structure of the precast concrete deck member of  FIG. 16 . 
         FIGS. 20 and 21  are cross-sectional views illustrating yet another exemplary embodiment of the present invention. 
         FIG. 22  is a schematic plan view illustrating the state where the present invention is used. 
         FIG. 23  is an enlarged cross-sectional view of important parts which is taken along line A-A′ of  FIG. 22 . 
         FIGS. 24 to 28  are enlarged cross-sectional views of important parts which illustrate another exemplary embodiment of the present invention. 
     
    
    
     MODE FOR INVENTION 
     Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       FIGS. 1 to 4  are exploded perspective views illustrating an exemplary embodiment of the present invention, and illustrate various examples of a box-shaped precast concrete deck member. 
       FIG. 5  is a cross-sectional view illustrating an exemplary embodiment of the present invention, and illustrates various examples, each of which includes a concrete plate and at least one steel support beam fixed to a lower portion of the concrete plate such that precast concrete deck members are connected in longitudinal and transverse directions. 
       FIGS. 6 to 9  illustrate examples of fixing pre-stressed members according to an exemplary embodiment of the present invention, wherein  FIG. 6  illustrates an example in which the pre-stressed members are fixed to an upper plate at a predetermined length, and  FIGS. 7 to 9  are cross-sectional views illustrating an exemplary embodiment of the present invention, and illustrate examples of fixing pre-stressed members, which are fixed to a box-shaped precast concrete deck member, to a body via guide pipes. 
       FIGS. 10 to 15  are side views illustrating another exemplary embodiment of the present invention, wherein  FIG. 10  illustrates an example in which an eccentricity adjustor protrudes downwardly from precast concrete deck members between the other precast concrete deck members located at opposite ends in short span construction, and  FIGS. 11 to 15  illustrate examples of a deck serialization structure in which a plurality of precast concrete deck members are assembled between the other precast concrete deck members located at opposite ends of the deck serialization structure. 
       FIG. 16  is an exploded perspective view illustrating another exemplary embodiment of the present invention, and illustrates an example of a precast concrete deck member in which a flange is formed at one end of a web. 
       FIGS. 17 to 19  are front views illustrating examples of a transverse connection structure of the precast concrete deck member of  FIG. 16 , wherein  FIG. 17  illustrates an example in which shear keys integrally protrude from one of flanges for connection, and  FIGS. 18 and 19  illustrate examples in which first and second side plates having a male-and-female structure are mated with each other on opposite sides of a flange. 
       FIGS. 20 and 21  are cross-sectional views illustrating yet another exemplary embodiment of the present invention, and illustrate examples of forming an auxiliary anchor so as to be able to additionally install pre-stressed members on a precast concrete deck member. 
       FIG. 22  is a schematic plan view illustrating the state where the present invention is used.  FIG. 23  is an enlarged cross-sectional view of an important part which is taken along line A-A′ of  FIG. 22 , and illustrates an example of constructing precast concrete deck members so as to replace a first-stage one of multistage temporary frameworks supporting wall piles for walls of excavated ground. 
       FIGS. 24 to 28  are enlarged cross-sectional views of important parts which illustrate another exemplary embodiment of the present invention, and illustrate examples of installing a precast concrete deck member, an end of which is supported on a wall pile, wherein a movable anchor bracket member is configured to be installed under the end of the precast concrete deck member with no gap between the installed site and the precast concrete deck member. 
     As illustrated in  FIGS. 1 to 4 , a precast concrete deck member  1  of the present invention is basically manufactured in the shape of a box in which a space is defined by an upper plate  10  having a rectangular shape and sidewalls  20  protruding downwardly from the outer circumference of the upper plate  10 . 
     Further, as illustrated in  FIG. 4 , the precast concrete deck member  1  of the present invention may be configured so that a plurality of through-holes  5  are bored through its body at predetermined intervals. 
     The plurality of through-holes  5  are formed either in the sidewalls  20  of the box-shaped precast concrete deck member  1  at predetermined intervals or in the web  30  of a T-shaped precast concrete deck member  1 , which will be described below, at predetermined intervals, thereby reducing the total weight of the precast concrete deck member  1  and improving the beauties of the precast concrete deck member  1 . 
     The precast concrete deck member  1  is constituted of a plurality of precast concrete deck members, which are connected in a longitudinal direction, i.e., in a lengthwise direction, and among which outermost precast concrete deck members  1   a  are located at opposite ends thereof and an intermediate precast concrete deck member  1   b  is located between the outermost precast concrete deck members  1   a.    
     The precast concrete deck members  1  may be connected in longitudinal and transverse directions, and provided with fastening holes  90  in the front and rear sidewalls and the opposite lateral sidewalls as illustrated in  FIG. 1 . Thus, the precast concrete deck members  1  may be assembled by fastening means such as bolts  90   a  and nuts  90   b.    
     As illustrated in  FIG. 2 , the precast concrete deck members  1  may be connected in longitudinal and transverse directions using fastening steel bars  91   a  passing through a plurality of coupling holes  91 , which are formed in the sidewalls  20  of each precast concrete deck member  1 , so as to hold the longitudinal and transverse connection. 
     As illustrated in  FIG. 3 , each precast concrete deck member  1  may include one pair of junction sidewalls facing each other so as to be connected in longitudinal and transverse directions. Shear keys  3  protrude from one of the paired junction sidewalls, and key insertion grooves  4  into which the shear keys  3  are inserted are formed in the other of the paired junction sidewalls. Thus, the precast concrete deck members  1  may be connected in the longitudinal and transverse directions by junction of the shear keys  3 . 
     In the present invention, it should be noted that, on the basic assumption that the longitudinal direction corresponds to the lengthwise direction of the precast concrete deck member  1  and that the transverse direction corresponds to the widthwise direction of the precast concrete deck member  1 , the longitudinal and transverse directions as described below refer to the lengthwise and widthwise directions of the precast concrete deck member  1 , respectively. 
     The shear keys  3  may protrude from one of the junction sidewalls in an arbitrary shape at predetermined intervals. Although not illustrated, the shear keys  3  may be continuously formed so as to extend on the junction sidewall in the lengthwise direction. 
     In detail, longitudinal shear keys  3   a  protrude from one of the longitudinal junction sidewalls of each precast concrete deck member  1 , and longitudinal key insertion grooves  4   a  are formed in the other longitudinal junction sidewall. The longitudinal shear keys  3   a  are inserted into the longitudinal key insertion grooves  4   a  in the junction sidewalls of the precast concrete deck members  1  facing each other, so that the precast concrete deck members  1  are connected in the longitudinal direction. 
     Further, transverse shear keys  3   b  protrude from one of the transverse junction sidewalls of each precast concrete deck member  1 , and transverse key insertion grooves  4   b  are formed in the other transverse junction sidewall. The transverse shear keys  3   b  are inserted into the transverse key insertion grooves  4   b  on the junction sidewalls of the precast concrete deck members  1  facing each other, so that the precast concrete deck members  1  are connected in the transverse direction. 
     The shear keys  3  are inserted into and joined in the insertion grooves  4  when the precast concrete deck members  1  are connected in the longitudinal and transverse directions. The precast concrete deck members  1  are connected in the longitudinal and transverse directions, thereby becoming a deck structure. In this state, the deck structure supports a shear force caused by the load applied from the top, thereby firmly holding the connection of the precast concrete deck members  1 . 
     Meanwhile, as illustrated in  FIG. 5 , the precast concrete deck members  1  includes a concrete plate  12  that can be connected in the longitudinal and transverse directions, and at least one steel beam  13  fixed to a lower portion of the concrete plate  12  and supporting the concrete plate  12  at an arbitrary height. 
     The steel beam  13  serves as a main girder when a deck or temporary bridge is constructed, and thus is easily used when a structure of the main girder is required. 
     As illustrated in  FIGS. 5(   a ) to  5 ( d ), two steel beams  13  may be mounted on opposite sides of the lower portion of the concrete plate  12  in a vertical direction. As in  FIGS. 5(   e ) and  5 ( f ), one steel beam  13  may be mounted in the middle of the lower portion of the concrete plate  12  in a vertical direction. 
     As illustrated in  FIGS. 5(   a ),  5 ( b ),  5 ( e ) and  5 ( f ), as the steel beam  13 , an H steel beam may be used to fix an upper flange thereof to the lower portion of the concrete plate  12 . 
     As illustrated in  FIGS. 5(   a ) and  5 ( e ), the H steel beam may be fixedly mounted on the lower portion of the concrete plate  12  by passing an anchor bolt  13   a , one end of which is bent and embedded in the concrete plate  12  and the other end of which is threaded and protrudes outwardly from the lower portion of the concrete plate  12 , through the upper flange thereof, and fastening a nut  13   b  to the threaded other end of the anchor bolt  13   a . As illustrated in  FIGS. 5(   b ) and  5 ( f ), the H steel beam may be integrally and fixedly mounted on the concrete plate  12  by embedding the upper flange thereof in the concrete plate  12 . 
     Further, as illustrated in  FIGS. 5(   c ) and  5 ( d ), a C or T steel beam may be used as the H steel beam, and integrally and fixedly mounted on the concrete plate  12  by embedding the upper flange thereof in the concrete plate  12 . 
     Meanwhile, as illustrated in  FIG. 3 , the pre-stressed members  2  are fixed to the precast concrete deck members  1 , which are connected in the longitudinal direction, at opposite ends thereof, and then are pre-stressed inside or outside the precast concrete deck members  1  to generate a compressive force. 
     It should be noted that any well-known members, such as strands, steel wires, and cables, which are pre-stressed to have a recovery force to be recovered to their original state, may be used as the pre-stressed members  2 . 
     The pre-stressed members  2  are fixed to upper anchors  11  provided on one side of the upper plate  10  of each precast concrete deck member  1 . 
     The upper anchors  11  may be provided on one side of the upper plate  10  at predetermined intervals, and distribute stress concentration caused by the fixation of the pre-stressed members  2 , so that the upper anchors  11  can prevent the precast concrete deck member  1  from being damaged by concentrating a compressive force, which reacts against a tensile force of the pre-stressed members  2 , in one place. 
     The upper anchors  11  are basically provided at ends of the upper plates  10  of the outermost precast concrete deck members  1  located on the opposite outermost ends at predetermined intervals when the precast concrete deck members  1  are connected in the longitudinal direction, wherein the upper anchors  11  are provided on the upper plates  10  of the opposite outermost precast concrete deck members  1  in symmetry. 
     Further, as illustrated in  FIG. 6 , the upper anchors  11  are provided on the ends of the upper plates  10  of the outermost precast concrete deck members  1  located on the opposite outermost ends at predetermined intervals when the precast concrete deck members  1  are connected in the longitudinal direction, wherein the pre-stressed members  2  are constant in length such that the fixed pre-stressed members  2  have the same length. Because of this standardization of the pre-stressed members  2 , it is possible to easily manufacture, install, and maintain the pre-stressed members  2 . 
     The upper anchors  11  of the outermost precast concrete deck members  1  located on the opposite outermost ends may be connected with guide pipes  2   a  such that the opposite ends of each pre-stressed member  2  are accurately fixed at opposite fixture places by guiding each pre-stressed member  2  in the corresponding guide pipe  2   a  so as to reach the fixture place of each pre-stressed member  2 . 
     Further, each pre-stressed member  2  passes through the lower portion of each intermediate precast concrete deck member  1 , and then is fixed to the upper anchors  11  of the outermost precast concrete deck members  1 . 
     In detail, the opposite ends of each pre-stressed member  2  pass through the intermediate precast concrete deck member  1 , and are fixed to the upper anchors  11  of the outermost precast concrete deck members  1 . Thereby, each pre-stressed member  2  is pre-stressed to provide a compressive force to the outermost and intermediate precast concrete deck members  1 , and thus increases resistance to a tensile force generated by the load applied from the top, thereby increasing rigidity. 
     As illustrated in  FIG. 7 , each pre-stressed member  2  may be fixed to transverse fixtures  22 , which are provided between the longitudinal sidewalls  21  formed in the lengthwise direction, i.e., in the longitudinal direction, among the sidewalls  20  of each precast concrete deck member  1 . 
     Opposite ends of each transverse fixture  22  are integrally formed with the longitudinal sidewalls  21  of the precast concrete deck member  1 , and are supported between the longitudinal sidewalls  21  of the precast concrete deck member  1 , so that each transverse fixture  22  reinforces rigidity and is fixed by one of the opposite ends of each pre-stressed member  2 . 
     The transverse fixtures  22  are provided between the longitudinal sidewalls  21  of the outermost precast concrete deck members  1  located on the opposite outermost ends when the precast concrete deck members  1  are connected in the longitudinal direction, and each includes a plurality of anchors  2   b  to which the ends of the pre-stressed members  2  are fixed at predetermined intervals, thereby distributing stress concentration caused by the fixation of the pre-stressed members  2 . 
     Guide pipes  2   a  connecting the anchors  2   b  of the transverse fixtures  22  provided on each precast concrete deck member  1  are provided between the outermost precast concrete deck members  1  such that the opposite ends of each pre-stressed member  2  are accurately fixed to the opposite anchors  2   b  by guiding each pre-stressed member  2  in the corresponding guide pipe  2   a.    
     In detail, the opposite ends of each pre-stressed member  2  pass through the intermediate precast concrete deck member  1 , and are fixed to the anchors  2   b  of the transverse fixtures  22  of the outermost precast concrete deck members  1  in a tensioned state. Thereby, each pre-stressed member  2  provides a compressive force to the outermost precast concrete deck members  1  and the intermediate precast concrete deck members  1  which are connected with each other, and thus increases resistance to a tensile force generated by the load applied from the top, thereby increasing rigidity. 
     Further, as illustrated in  FIG. 8 , the pre-stressed members  2  may be inserted into the guide pipes  2   a  extending and fixed in the lengthwise direction of the opposite longitudinal sidewalls  21  of the precast concrete deck member  1 , and fixed to ends of the opposite longitudinal sidewalls  21 . 
     Each guide pipe  2   a  is provided with the anchors  2   b , to which the ends of each pre-stressed member  2  are fixed, at opposite ends thereof. 
     Each guide pipe  2   a  is basically inserted into and fixed to a wedge  21   a , which protrudes inwardly from each longitudinal sidewall  21  of the precast concrete deck member  1  by increasing the thickness of each longitudinal sidewall  21 . 
     The wedge  21   a  serves to increase the thickness of each longitudinal sidewall  21  in order to not only fix each pre-stressed member  2  but also prevent stress concentration caused by the fixation. 
     Further, as illustrated in  FIG. 9 , each guide pipe  2   a  may pass through the numerous precast concrete deck members  1  connected in the longitudinal direction, and opposite ends thereof may be fixed to outer ends of the outermost precast concrete deck members  1  located at the opposite ends. 
     The outer ends of the outermost precast concrete deck members  1  located at the opposite ends are provided with anchors  2   b , which are provided on the opposite ends of the guide pipe  2   a  and to which the ends of the pre-stressed member  2  are fixed, so as to be exposed. 
     Meanwhile, as illustrated in  FIG. 10 , the precast concrete deck member  1  is provided with an eccentric extension  23 , which protrudes downwardly between the positions where the opposite ends of the pre-stressed member  2  are fixed, thereby increasing the eccentric length of the pre-stressed member  2  to enhance the tensile force of the pre-stressed member  2 . 
     In a short span deck structure configured of two outermost precast concrete deck members  1 , which are located at opposite ends thereof in the longitudinal direction and to which the opposite ends of the pre-stressed member  2  are fixed, and an intermediate precast concrete deck member  1   b  located between the outermost precast concrete deck members  1 , the eccentric extension  23  basically protrudes downwardly from the intermediate precast concrete deck member  1   b  at an arbitrary length. 
     Although not illustrated, the eccentric extension  23  may be fixed to a hydraulic jack mounted on a lower surface of the upper plate  10  so as to enable the length protruding downwardly from the precast concrete deck member  1  to be adjusted. A slidable or movable bar may be coupled to a stationary bar fixed to the upper plate, and a lock part may be provided to move the movable bar. Thereby, the movable bar may slide to be fixed by the lock part, so that the eccentric extension  23  may adjust the length protruding downwardly from the precast concrete deck member  1 . In addition to this configuration, a well-known length adjustment structure may be used. 
     As described above, since the eccentric extension  23  can adjust the eccentric length, it is possible to adjust the tensile force of the pre-stressed members  2  according to the load applied to the deck structure to be constructed when the deck structure is designed. 
     Meanwhile, as illustrated in  FIG. 11 , the precast concrete deck member  1  of the present invention is to be constructed into a deck serialization structure having a plurality of intermediate precast concrete deck members  1   b  between the outermost precast concrete deck members  1 . 
     Further, as illustrated in  FIGS. 12 to 15 , in the deck serialization structure having the plurality of intermediate precast concrete deck members  1   b  between the outermost precast concrete deck members  1 , the middle precast concrete deck member  1   b ′ supported by a middle post pile structure  80  among the intermediate precast concrete deck members  1   b  may be configured to have a wider cross-sectional area than the other intermediate precast concrete deck members  1   b  connected with the outermost precast concrete deck members  1 , thereby increasing rigidity against negative moment. 
     As illustrated in  FIGS. 12 and 14 , anchors  1   c  to which first ends of the pre-stressed members  2  in the deck serialization structure may be provided on the middle precast concrete deck member  1   b ′ supported by the middle post pile structure  80  among the intermediate precast concrete deck members  1   b.    
     As illustrated in  FIGS. 13 and 15 , the anchors  1   c  may be provided on the intermediate precast concrete deck members  1   b  located on the opposite sides of the middle precast concrete deck member  1   b ′ supported by the middle post pile structure  80  among the intermediate precast concrete deck members  1   b.    
     The anchors  1   c  are provided to correspond to the upper anchors  11  or the anchors  2   b  of the transverse fixtures  22  of the outermost precast concrete deck members  1  connected at the opposite ends of the deck serialization structure, and are fixed by the first ends of the pre-stressed members  2 , the second ends of which are fixed to the outermost precast concrete deck members  1  that are opposite to each other with respect to the middle precast concrete deck member  1   b ′ supported by the post pile structure  80 . 
     Further, when provided on the plurality of intermediate precast concrete deck member  1   b , the anchors  1   c  may be provided to arbitrarily adjust the lengths of the pre-stressed members  2  as illustrated in  FIGS. 12 and 13 , or to make lengths of the pre-stressed members  2  constant such that the fixed pre-stressed members  2  have the same length as illustrated in  FIGS. 14 and 15 . Because of this standardization of the pre-stressed members  2 , it is possible to easily manufacture, install, and maintain the pre-stressed members  2 . 
     The intermediate precast concrete deck member  1   b  having the anchors  1   c  is used in consideration of the lengths of the pre-stressed members  2  and convenient construction when the deck structure is designed. 
     Meanwhile, as illustrated in  FIG. 16 , the precast concrete deck member  1  may be manufactured to have a T-shaped body that a flange  40  is formed on top of a web  30 . 
     The web  30  has through-holes  5  formed at predetermined intervals, thereby reducing the total weight and improving the beauties. 
     The web  30  is provided with a lower support  50 , on which the pre-stressed members  2  are mounted, at a lower end thereof. Guide pipes  2   a  are inserted into the lower support  50  in a lengthwise direction. The pre-stressed members  2  are inserted into the guide pipes  2   a  communicating with each other when the precast concrete deck members  1  are interconnected in the longitudinal direction. 
     Each guide pipe  2   a  is provided with an anchor  2   b , to which one end of each pre-stressed member  2  is fixed, at one end thereof. The plurality of anchors  2   b  are provided on the lower support  50  at predetermined intervals, thereby distributing stress concentration caused by the fixation of the pre-stressed members  2 . 
     The flange  40  and the web  30  are provided with longitudinal shear keys  3   a  and longitudinal key insertion grooves  4   a  in opposite longitudinal end surfaces thereof, i.e., in longitudinal front and rear surfaces thereof, so that they are continuously connected in the longitudinal direction. 
     Further, as illustrated in  FIGS. 17 to 19 , the flange  40  has at least one transverse shear key  3   b  protruding from one side thereof and at least one transverse key insertion groove  4   b  engaged with the transverse shear keys  3   b  on the other side thereof, so that the flanges  40  are connected in the transverse direction. 
     As illustrated in  FIG. 17 , the flange  40  may be provided with a transverse shear key  3   b , which integrally protrudes from the flange  40 , and a transverse key insertion groove  4   b , which is integrally grooved in the flange  40 , on opposite sides thereof. 
     As illustrated in  FIG. 18 , the flange  40  may be provided with a first side plate  41 , which is formed of steel and from which the transverse shear key  3   b  protrudes, and a second side plate  42 , which is formed of steel and has the transverse key insertion groove  4   b  engaged with the transverse shear keys  3   b , on opposite sides thereof. 
     Further, as illustrated in  FIG. 19 , the first and second side plates  41  and  42  include bolted flange joints  43  extending downwardly therefrom. A joint bolt  46  passes through the flange joints  43 , and then a nut  47  is fastened to an end of the joint bolt  46 , so that the flanges  40  can be more firmly joined with each other. 
     The first and second side plates  41  and  42  may be welded to at least one reinforcement rod  6  embedded in the precast concrete deck member  1 . 
     Meanwhile, the precast concrete deck member  1  is formed in the box shape in which the sidewalls  20  protrude downwardly from the outer circumference of the upper plate  10  having an arbitrary shape, so that the sidewalls  20  serve as the main girder when the deck structure is installed. As a result, the deck structure can be installed without a separate main girder. 
     Further, the precast concrete deck member  1  has the T-shaped body in which the flange  40  is formed on top of the web  30 , so that the web  30  and the lower support  50  formed on the lower portion of the web  30  serve as the main girder when the deck structure is installed. As a result, the deck structure can be installed without a separate main girder. 
     As illustrated in  FIGS. 20 and 21 , the precast concrete deck member  1  may have at least one auxiliary anchor  60  on one side thereof such that the pre-stressed members  2  can be additionally installed. 
     As illustrated in  FIG. 20 , in the precast concrete deck member  1  formed in the box shape in which the sidewalls  20  protrude downwardly from the outer circumference of the upper plate  10  having an arbitrary shape, the auxiliary anchor  60  is formed to protrude from inner surfaces of the longitudinal sidewalls  21 . 
     Here,  FIG. 20(   a ) is a cross-sectional view of the precast concrete deck member  1  at an anchor to which the pre-stressed members  2  are fixed, and  FIG. 20(   b ) is a cross-sectional view of a joint where two precast concrete deck members  1  are connected to each other. It is shown that the pre-stressed members  2  pass through below the joint and then are fixed to the auxiliary anchor  60  installed on the lower portion of the upper plate  10 . 
     Further, as illustrated in  FIG. 21 , in the precast concrete deck member  1  having the T-shaped body in which the flange  40  is formed on top of the web  30 , the auxiliary anchors  60  are formed on both sides of the web  30  so as to protrude therefrom. 
     Here,  FIG. 21(   a ) is a cross-sectional view of the precast concrete deck member  1  at an anchor to which the pre-stressed members  2  are fixed, and  FIG. 21(   b ) is a cross-sectional view of a joint where the two precast concrete deck members  1  are connected to each other. It is shown that the pre-stressed members  2  pass through below the joint and then are fixed to the auxiliary anchors  60  installed on both sides of the web  30 . 
     The auxiliary anchors  60  are configured such that the pre-stressed members  2  can be additionally installed in consideration of the load generated from the upper portion of the deck structure when the deck structure is designed, and thus have an effect of increasing a degree of freedom when the deck structure is designed. 
     Meanwhile, as illustrated in  FIGS. 22 and 23 , the precast concrete deck members  1  of the present invention may be continuously connected on one side of a plane  100  of excavated ground in the longitudinal and transverse directions, and may be constructed so as to replace a first-stage one of multistage temporary frameworks  103  supporting wall piles  102  for excavated walls  101 . 
     The wall piles  102  are installed on the excavated walls  101  within the excavated plane  100 , and the temporary frameworks  103  supporting the wall piles  102  are installed between the wall piles  102  in multiple stages. In the present invention, as described above, the precast concrete deck members  1  are continuously connected in the longitudinal and transverse directions, and are constructed into the first-stage temporary framework  103 , so that the deck structure in which main girders serving to support the excavated walls  101  are integrated with deck plates is obtained. 
     Although not illustrated, the main girders and the deck plates continuously connected in the longitudinal and transverse directions may be integrated and constructed into the deck structure in an arbitrary temporary bridge. 
     As described above, the precast concrete deck member  1  constructed into the first-stage temporary framework  103  on one side of the excavated plane  100  is constructed on one side of the wall piles  101  so as to be in close contact with no gap, as illustrated in  FIGS. 24 to 27 . 
     As illustrated in  FIGS. 24 to 27 , a plurality of bolt insertion grooves  1   d  are formed in the lower surface of the precast concrete deck member  1  of the present invention in a connecting direction at predetermined intervals, i.e., in a longitudinal direction. A movable anchor bracket  70  is provided with installation holes  71 , into which installation bolts  72  fastened to the bolt insertion grooves  1   d  are fitted, in an upper portion thereof, and is installed on a lower portion of the end of the precast concrete deck member  1  so as to be movable in the longitudinal direction of the precast concrete deck member  1 . 
     In the box-shaped precast concrete deck member  1 , the plurality of bolt insertion grooves  1   d  are formed in a lower edge of the longitudinal sidewall  21  at predetermined intervals. In the T-shaped precast concrete deck member  1 , the plurality of bolt insertion grooves  1   d  are formed in a bottom surface of the lower support  50  at predetermined intervals. 
     The movable anchor bracket  70  is supported and fixed to the wall pile  102  supporting the wall  101  of the excavated ground or an abutment (not shown) of the temporary bridge, and approaches an installed place, i.e., the wall pile  102  or the temporary abutment, until the installation holes  71  are aligned with the bolt insertion grooves  1   d . Then, the installation bolts  72  are fitted into the installation holes  71 , and fastened to the bolt insertion grooves  1   d . Thereby, it is possible to prevent a gap between the installed place and the precast concrete deck member  1  as well as longitudinal movement of the precast concrete deck members  1  connected in the longitudinal and transverse directions. 
     As illustrated in  FIG. 24 , the movable anchor bracket  70  is placed on a support  102   a  installed on an upper end of the wall pile  102 . In detail, the movable anchor bracket  70  is closely placed on and fixed to either a spacer such as an H section beam or a wale  104  installed on the support  102   a  to support the wall pile  102 , and then can be fastened to a lower portion of the end of the precast concrete deck member  1  using the installation bolts  72 . 
     Further, as illustrated in  FIG. 25 , a plurality of pin insertion grooves  73   a  are formed in a lower edge of the longitudinal sidewall  21  of the precast concrete deck member  1  at predetermined intervals. A plurality of pins  73  inserted into the pin insertion grooves are formed on the top surface of the movable anchor bracket. The movable anchor bracket  70  approaches the installed place, i.e., the wall pile  102  or the temporary abutment (not shown) such that the pins  73  are inserted into the pin insertion grooves  73   a . Thereby, it is possible to prevent a gap between the installed place and the precast concrete deck member  1  as well as longitudinal movement of the precast concrete deck members  1  connected in the longitudinal and transverse directions. 
     As illustrated in  FIG. 26 , the movable anchor bracket  70  is placed on a support  102   a  installed on an upper end of the wall pile  102 , connected to either a spacer such as an H section beam or a wale  104  supporting the wall pile  102  using a length adjusting jack  105 , and displaced by the length adjusting jack  105  such that the installation holes  71  are aligned to the bolt insertion grooves  1   d . Then, the installation bolts  72  are fitted into the installation holes  71  and fastened to the bolt insertion grooves  1   d . Thereby, the movable anchor bracket  70  may be installed. 
     The length adjusting jack  105  is operated similar to a well-known jack that has a hydraulic cylinder and can adjust the length, and adjusts a gap between the movable anchor bracket  70  and the spacer such as the H section beam or the wale  104 . This configuration or operation is well known, and thus detailed descriptions thereof will not be repeated. 
     Further, as illustrated in  FIG. 27 , the movable anchor bracket  70  may be installed by fixing one end thereof to the spacer such as the H section beam or the wale  104  fixed to the wall pile  102 , being displaced such that the installation holes  71  are aligned to the bolt insertion grooves  1   d , fitting the installation bolts  72  into the installation holes  71 , and fastening the installation bolts  72  to the bolt insertion grooves  1   d.    
     As illustrated in  FIG. 28 , a spacing insertion recess  1   e , into which the spacer such as the H section beam or the wale  104  fixed to the wall pile  102  is inserted, is formed in the lower portion of the end of the precast concrete deck member  1 . The wale  104  is inserted into the spacing insertion recess  1   e  formed in the lower portion of the end of the precast concrete deck member  1  such that the precast concrete deck member  1  comes into close contact with the wall pile  102 . Thereby, it is possible to prevent a gap between the installed place and the precast concrete deck member  1  as well as longitudinal movement of the precast concrete deck members  1  connected in the longitudinal and transverse directions. 
     Meanwhile, the precast concrete deck member  1  may further increase the rigidity against the tensile force by embedding reinforcement rods  6  in the body thereof. This corresponds to configuration of conventional reinforced concrete, and so detailed description thereof will be omitted. 
     The present invention is not limited to the disclosed embodiments. Thus, the present invention may be embodied in many different forms without departing from the gist of the present invention. Thus, it should be understood that these modifications are included in the present invention.