KR102396913B1 - The girder using hollow steel and its fabrication method - Google Patents

Abstract

A prestressed concrete girder is provided. According to an embodiment, a concrete girder has an I-shaped cross section including an upper flange, a web and a lower flange, in which a plurality of tension members for introducing prestress force are installed. The concrete girder comprises: a central portion extending in a longitudinal direction; a first multi-stage side cross-section portion extending from the central portion toward a first end portion and including at least one side cross-section section; and a second multi-stage side cross-section portion extending from the central portion toward a second end portion and including at least one side cross-section section. The girder includes a plurality of sheath pipes for imparting the prestress force step by step and an anchoring portion provided with a plurality of anchorages for anchoring the sheath pipes. The anchoring portion includes: a first anchoring portion for anchoring the plurality of sheath pipes at the first end portion; a second anchoring portion for anchoring the plurality of sheath pipes at the second end portion; third anchoring portions provided on the first multi-stage side cross-section portion and formed on both side surfaces of the web; and fourth anchoring portions provided on the second multi-stage side cross-section portion and formed on both side surfaces of the web. One end of the hollow steel is anchored to the third anchoring portion. The hollow steel is provided with an internal space into which a multi-purpose strand wire is inserted, wherein a yield strength is 400 MPa or more. The load capacity of the girder against brittle fracture of primary and secondary strand wires is additionally secured, and the strand wires are used, such that maintenance and additional prestress force can be introduced.

Description

The girder using hollow steel and its fabrication method

The present invention relates to a PSC girder and a construction method thereof.

After the improved PSC girder was developed in earnest in Korea from the late 1990s, numerous construction methods were developed and applied to many sites until now. If the improved PSC methods are broadly classified, pre-tension and post-tension method by tension method, single tension and multi-stage tension method by tension stage, tension after slab composition by tension period, tension method before slab composition, and end fixing and partial internal settlement by anchoring method. , may be I-shaped, Box-shaped, U-shaped, etc. for each shape. A common characteristic of these improved PSC methods is to increase the structural efficiency and lower the price in the traditional PSC method.

The standard PSC-I type girder recorded in the road bridge standard map has a height of 2.2m at 35m, but the improved PSC girder has only 1.5m~1.7m in height, which is the cause of the decrease in concrete strength. Examples include the increase in weight, the use of high-strength strands, effective strand arrangement, and the introduction of additional compression force through multi-level tensioning.

In addition to the above factors that can shorten the length of the girder, the most effective method is to reduce the self-weight of the girder. In particular, it is important to reduce the thickness of the abdomen.

As the limit state design method was introduced in Korea, the thickness of the abdomen should be secured up to 80mm above the diameter of the sheath pipe. It became a factor that reduced the efficiency.

In addition to the problem of enlargement of the abdominal plate, the problem of lateral curvature of the girder, which occurs during manufacturing as the girder becomes longer in span, is also frequently raised. A hole error may occur greatly, and a tensile force exceeding the allowable tensile force may occur at the end of the upper flange.

As such, it is necessary to prevent the enlarged abdomen of the improved PSC girders and prevent the occurrence of transverse curvature.

The problem to be solved by the present invention is to provide a girder capable of realizing long-span length, subdivide the diameter of the sheath pipe where the primary tension member is installed, but set the sheath pipe passing through the abdominal plate to Φ or less to maintain the abdominal plate within 180mm, 2 By lowering the passing height of the continuous part of the secondary tension member, the passage of the secondary tension member through the abdominal plate is excluded, thereby reducing the weight by 9% (40m) to 22% (60m) compared to the conventional PSC girder.

In addition, the present invention is to provide a girder that can effectively control transverse curvature, by symmetrically arranging the entire tension member to exclude transverse curvature to the maximum, and correcting before mounting the girder through the tension of the strand inserted into the hollow steel material. It is to provide a girder that can control the lateral curvature caused by manufacturing errors by allowing the girder to be mounted after it is finished.

In addition, the present invention is to provide a girder with increased rigidity and secured convenience in maintenance, and by partially replacing longitudinal reinforcing bars disposed on the lower flange of the conventional PSC girder with hollow steel, rigidity is additionally secured and maintained It is to provide a girder secured with a sheath pipe that is easy to manage.

In addition, the present invention is to provide a long-span girder of low profile height, and solves the conventional problem that it was not possible to introduce the required amount of tension in the secondary tension even though it is necessary to implement a low profile height at 50 m or more, It is to provide a girder with a low-profile and long-span length by performing tertiary tensioning with the inserted strand.

In order to solve the above problems, a plurality of tension members for introducing a prestress force are installed therein, and in a concrete girder having an I-shaped cross section including an upper flange, an abdomen and a lower flange, the girder is a central portion extending in the longitudinal direction between the first end and the second end; a plurality of sheath pipes extending in the longitudinal direction so that at least one end is fixed to the first end and the second end; and a hollow steel material installed in the longitudinal direction along the central portion with a length shorter than that of the plurality of sheath pipes, wherein the hollow steel material is provided with an internal space into which a multi-purpose strand is inserted, the priest Rest concrete girders are provided.

In addition, the present invention is a concrete girder having an I-shaped cross-section including an upper flange, an abdomen and a lower flange, in which a plurality of tension members for introducing a prestressing force are installed therein in order to solve the above problems, a central portion extending in the longitudinal direction; and a first multi-step side section extending from the central portion in the direction of the first end portion and including at least one side section section, and a second multi-step side section extending from the central section toward the second end section and including at least one side section section A plurality of sheath pipes for applying the pre-stressing force step by step, a fixing unit provided with a plurality of anchors for fixing the sheath pipe, and a length shorter than the plurality of sheath pipes, including; It provides a prestressed concrete girder, comprising a hollow steel material installed in the longitudinal direction along the central portion of the furnace, wherein the hollow steel material is provided with an internal space into which a multi-purpose strand is inserted.

In addition, the present invention, in order to solve the above problems, the fixing unit, the first fixing unit for fixing the plurality of sheath pipes at the first end; a second fixing part for fixing the plurality of sheath pipes at the second end; a third fixing part provided on the first multi-step side cross-section and formed on both sides of the abdomen; and a fourth fixing part provided on the second multi-stage side section, formed on both sides of the abdomen, wherein one end of the hollow steel material is fixed to the third fixing part, and the hollow steel material is inside An internal space in which a multi-purpose strand is inserted is provided, and the load-bearing capacity of the girder is additionally secured against brittle fracture of the primary and secondary stranded wires, including a yield strength of 400 MPa or more, and maintenance using the strands and a prestressed concrete girder capable of introducing additional prestressing force.

According to an embodiment of the present invention, it is possible to reduce the weight of the girder by minimizing the thickness of the abdomen through efficient arrangement of strands.

In addition, according to an embodiment of the present invention, by applying a hollow steel material, it is possible to further reduce the weight of the girder, it can be possible to control the lateral curvature before the mounting of the girder.

In addition, according to an embodiment of the present invention, the hollow steel can be used as a sheath pipe for installing a strand capable of securing the function of increasing the rigidity and maintenance of the girder.

In addition, according to one embodiment of the present invention, it is possible to manufacture a low-profile high-long-span girder by using a hollow steel material as a sheath pipe of a tertiary tension member in a long-span girder of 50 m or more.

1 is a view showing a girder according to an embodiment of the present invention, FIG. 2 is an enlarged view of a portion adjacent to the first end in FIG. 1, and FIG. 3 is an enlarged view of a portion adjacent to the second end in FIG. will be.
4 is a view showing the arrangement of the sheath pipe of the girder according to an embodiment of the present invention viewed from the side.
FIG. 5 (a) is a plan view of section S1 in FIG. 4, FIG. 5 (b) is a plan view of section S2 in FIG. 4, and FIG. 5 (c) is a plan view of section S3 in FIG. 4 Each of them showed what they were looking at.
6 to 9 are cross-sectional views of the girder cut along the respective perforated lines shown in FIG. 5 .
10 shows a form in which a hollow steel material according to an embodiment of the present invention is installed in the anchorage.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only this embodiment completes the disclosure of the present invention and provides those with ordinary knowledge to the content of the present invention. It is provided for more complete information.

When an element is referred to as being positioned 'above' or 'below' another element in this specification, it means that the element is positioned directly 'above' or 'below' another element, or an additional element is placed between those elements. It includes all the meanings that can be interposed. In this specification, the terms 'upper' or 'lower' are relative concepts set from the viewpoint of the observer. may mean

The same reference numerals in the plurality of drawings refer to elements that are substantially the same as each other. In addition, terms such as 'comprise' or 'have' are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, and includes one or more other features, number, or step. , it should be understood that it does not preclude the possibility of the existence or addition of an operation, a component, a part, or a combination thereof.

On the other hand, in the terms 'primary sheath pipe, primary tension member, primary stranded wire' referred to in the present invention, the primary means primarily applying prestressing force to the girder, and 'second sheath pipe, secondary tension member, 2 In 'Secondary Stranded Line', the 2nd order means applying the prestressing force secondarily after applying the 1st prestressing force, and the 3rd order or more means applying the prestressing force after the 2nd order. For example, the primary application of the prestressing force may be performed before the girder is applied, and the secondary application of the prestressing force may be performed before or after the girder is mounted, and tertiarily the prestressing force is applied. Applying force can be performed after mounting the girder and before or after synthesizing the sole plate on the upper part of the girder.

Meanwhile, as used herein, the term 'length direction' refers to a direction in which the girder extends, and may refer to a direction connecting the first end and the second end in FIG. 1 .

On the other hand, the term 'lengthwise center line of the girder' referred to in the present invention refers to a line connecting the width direction center of the girder abdomen in the longitudinal direction, and the center of the width direction of the girder abdomen from the first end to the second end in FIG. 1 can be referred to as a line connecting

Meanwhile, technical ideas not mentioned in the present invention may include the technical ideas described in Korean Patent Registration No. 10-1073390. That is, the present invention includes the technical configuration and effects described in Korean Patent Registration No. 10-1073390, but has improved effects compared to the prior art and effects that could not be expected in the prior art by adopting the technical configuration specifically described in this specification can be understood as being

The girder 10 according to an embodiment of the present invention, a plurality of tension members for introducing a prestressing force are installed therein, and I including an upper flange 11, an abdomen 12 and a lower flange 13 By having a type cross-section, the width of the abdomen 12 is minimized, the lateral curvature is controlled while increasing the rigidity of the girder 10, and the following drawings are used to explain the external It has the structure and internal structure, that is, the arrangement of the sheath tube.

1 is a view showing a girder according to an embodiment of the present invention, FIG. 2 is an enlarged view of a portion adjacent to the first end in FIG. 1, and FIG. 3 is an enlarged view of a portion adjacent to the second end in FIG. will be.

1 to 3 , the girder 10 includes an upper flange 11 , an abdomen 12 , and a lower flange 13 in the height direction, and a first end 110 and a second end in the longitudinal direction. The end portion 120, the first multi-step cross-section portion 130, the central portion 140, and the second multi-step cross-section portion 150 include at least one sheath tube and at least one hollow steel material according to the present invention. It includes a first fixing part 210 , a second fixing part 220 , a third fixing part 230 , and a fourth fixing part 240 for installing the 400 .

The first end 110 may include a first anchoring part 210 provided with a plurality of first anchoring holes 310 to which a plurality of primary sheath pipes 311a, 312a, 313a, and 314a can be fixed. The first end 110 may be formed in the first end block 111 .

The second end 120 constitutes the opposite end of the first end 110 around the center of the girder 10 in the girder 10, and a plurality of primary sheath pipes (311a, 312a, 313a, 314a) It may include a second fixing unit 220 provided with a plurality of second fixing holes 320 that can be fixed. The second end 120 may be formed in the second end block 121 .

The first multi-step side section 130 is a section extending from the first end block 111 toward the center of the girder 10 and includes at least one side section section. The first multi-side cross-section portion 130 includes a 1-1 side cross-section portion 131 , a 1-2 side cross-section portion 132 , a 1-1 side cross-section portion 131 , and a 1-2 side cross-section portion. It may include a 1-1 extension part 133 extending in the longitudinal direction between the 132 and a 1-2 extension part 134 extending from the 1-2 side cross-section part 132 to the central part 140 . can

For example, the 1-1 side end face portion 131 extends from the first end block 111 in the central direction of the girder 10 so that the width of the abdomen 12 is narrowed, and the 1-1 extension portion ( 133) extends in the central direction of the girder 10 while the width of the abdomen 12 is narrowed or maintained at a predetermined thickness from the 1-1 side section 131, and the 1-2 side section 132 may extend in the central direction of the girder 10 so that the width becomes narrower from the first extension portion 133 , and the first and second extension portions 134 may extend from the first extension portion 133 to the abdomen 12 from the second side end surface portion 132 . ) may extend in the central direction of the girder 10 while being narrowed or maintained at a predetermined thickness.

For example, the 1-1 side section 131 may extend in the central direction of the girder 10 so that the widths of the abdomen 12 and the lower flange 13 are narrowed. As an example, the width of the end point compared to the starting point of the 1-1 side section 131 may be reduced by 50% to 70% in the case of the abdomen 12, and by 5% to 15% in the case of the lower flange 13 can decrease. As such, the girder 10 of the present invention has a shape in which both the width of the abdomen 12 and the lower flange 13 are narrowed in the 1-1 side section 131, so that it is possible to effectively respond to the compressive stress at the end. And it can increase the effect of self-weight reduction. In addition, within the numerical range, the first anchoring hole 310 is stably embedded in the first end 110 and the first end block 111 and the 1-1 side section 131 are stably embedded in the process of applying the prestress force. ) can be prevented from being broken and a lightweight girder can be achieved at the same time.

For example, in the 1-1 extension portion 133 , the width of the lower flange 13 is constant, and the width of the abdomen 12 is narrowed at a smaller reduction rate than the 1-1 side cross-section portion 131 , or Alternatively, it may extend in the central direction of the girder 10 while being constantly maintained. For example, the end point of the 1-1 extension part 133 may be located on the same line as the start point of the third fixing part 230 .

For example, in the case of the abdomen 12, the width of the end point compared to the starting point of the first and second side cross-sections 132 may be reduced by 15% to 35%, and in the case of the lower flange 13, the width is kept constant. can be For example, the viewpoint of the 1-2 side cross-section part 132 may be on the same line as the viewpoint of the third fixing part 230 . Within the above numerical range, the 3-1 anchoring hole 331 and the 3-2 anchoring hole 332 are stably embedded in the third anchoring portion 230 and the third anchoring portion 230 in the process of applying a prestressing force. And it is possible to achieve a weight-reduced girder while preventing the first and second side section 132 from being damaged.

For example, in the first 1-2 extension portion 133 , the width of the lower flange 13 is constant, and the width of the abdomen 12 is narrowed at a rate of decrease smaller than that of the first and second side section 132 , or Alternatively, it may extend in the central direction of the girder 10 while being constantly maintained. For example, the end point of the first-second extension part 133 may be located on the same line as the end point of the third fixing part 230 .

The third fixing part 230 may be formed to be symmetrical to both sides of the abdomen 12 in the first multi-sided cross-sectional part 130 . For example, the third fixing part 230 may be provided on the side surface of the abdomen 12 in the section where the 1-2 side end face part 132 and the 1-2 extension part 134 are formed.

For example, the first inclined part 231 may be formed in the third fixing part 230 . In the first inclined portion 231 , the surface of the third fixing portion 230 has a predetermined angle upward from the lower flange 13 , extends in the central direction of the girder 10 , and then is bent back toward the lower flange 13 . It may have a shape extending downward. For example, the first inclined portion 231 has a predetermined angle upward from the lower flange 13 and extends in the central direction of the girder 10 , the 1-1 inclined portion 231a and the 1-1 inclined portion ( 231a), the second inclined portion 231b may be formed by being bent back to the lower flange 13 and extending in the central direction of the girder 10 . At this time, the 3-1 fixing hole 331 for installing the secondary sheath pipe 331a and the 3-2 fixing hole 332 for embedding the hollow steel 400 are the 1-1 inclined part 231a. It is installed in the lower flange 13 adjacent to the first end 110 at the first end 110 when the operator applies a secondary or more prestressing force, for example, it is possible to work on the first step part 232, so that the operator's It can ensure safety and improve the construction efficiency of secondary tension or tertiary tension or more.

That is, the girder 10 of the present invention has a structure in which the width of the first multi-step side section 130 is reduced to two or more steps in the longitudinal direction, but the third fixing section 230 is the first multi-step side section section 130 ) formed, for example, by matching the viewpoints of the third fixing part 230 and the 1-2 side cross-section 132, the secondary sheath pipe 331a and the hollow steel 400 are both abdominal ( 12) to have a structure that can not be arranged so as to dramatically reduce the width of the abdomen 12 while maximizing the structural efficiency of the secondary sheath pipe 331a and all sheath pipes 311a, 312a, 313a, 314a, 331a And the hollow steel 400 achieves an efficient arrangement structure in which each is symmetrical with respect to the longitudinal centerline of the girder 10, it is possible to manufacture a lightweight girder 10 between long legs.

As an example, the width of the abdomen 12 in the girder 10 of the present invention is changed to two steps from the first end block 111 to the middle of the girder, and may be changed from 640 mm to 180 mm.

For example, in the girder 10 of the present invention, the width of the lower flange 13 is the same or can be changed to one or more steps from the first end block 111 to the middle of the girder, and in one embodiment, 1100 It can be varied from mm to 900 mm.

The central portion 140 extends from the end of the first 1-2 extension portion 134, for example, the end of the third fixing portion 230 to form the longest section of the span of the girder 10, the girder of the present invention (10) adopts a structure in which the secondary sheath pipe 331a and the hollow steel 400 are not installed in the abdomen 12 in the entire first end 110 and the central portion 140 to increase the thickness of the abdomen 12 By reducing it as much as possible, a lightweight girder can be achieved.

The second multi-step side section 150 is a section extending from the central portion 140 toward the second end section 120 and includes at least one side section section. The second multi-sided cross-section portion 150 includes a 2-1 side cross-section portion 151, a 2-2 side cross-section portion 152, a 2-1 side cross-section portion 151, and a 2-2 side cross-section portion. A second extension 153 extending in the longitudinal direction between the 152 may be included.

For example, the second-first side cross-section portion 151 extends from the central portion 140 in the direction of the second end portion 120 so that the width of the abdomen 12 is widened, and the second extension portion 153 is the second -The width of the abdomen 12 is widened or maintained at a predetermined thickness from the -1 side cross-section 151, and extends in the direction of the second end 120, and the 2-2 side cross-section 152 is a second extension It may extend in the direction of the second end 120 so as to increase the width from 153 .

For example, the second-second side cross-section portion 151 may extend from the central portion 140 to the second end portion 120 so that the width of the abdomen 12 is widened. As an example, the width of the end point of the abdomen 12 of the second-first side section 151 may be increased by 100% to 250% compared to the starting point. While maintaining the rigidity of the girder 10 within the above numerical range, the secondary sheath pipe 331a and the hollow steel material 400 are not embedded in the abdomen 12 in the section where the 2-1 side cross-section part 151 is formed. It is possible to achieve a lightweight, long-span girder.

For example, a structure in which the viewpoint of the fourth fixing part 240 is formed at the viewpoint of the 2-1 side cross-section part 151 so that the secondary sheath pipe 331a rises through the fourth fixing part 240 is By being applied, an efficient sheath pipe arrangement structure that can keep the width of the girder 10 thin in the central portion 140 can be applied.

For example, in the second extension portion 153 , the width of the lower flange 13 is constant, and the width of the abdomen 12 is increased at a smaller increase rate than the second-first extension portion 151 or is constant. It may extend in the direction of the second end 120 of the girder 10 while maintaining the

For example, the 2-2 side cross-section portion 152 has the second end portion 120 from the second extension portion 153 such that the width of the abdomen 12 or the abdomen 12 and the lower flange 13 is widened. direction can be extended. For example, the width of the end point of the abdomen 12 of the second-second side cross-section 152 may be increased by 40-60% compared to the starting point. Within the numerical range, the second anchoring hole 320 is stably embedded in the second end 120 and the second end block 121 and the 2-2 side cross-section 152 are formed in the process of applying the pre-stressing force. It is possible to achieve a lightweight girder while preventing breakage.

For example, when the second end 120 constitutes a continuous portion of the girder 10 , the secondary sheath pipe 331a in the second extension 153 or the 2-2 side cross-section 152 is connected to the abdomen 12 . ) can be embedded in the form. At this time, since a separate anchorage for fixing the secondary sheath pipe 331a to the second end 120 is unnecessary, the abdomen 12 maintains a thin width while the symmetry of the secondary sheath pipe 331a is maintained. A structure disposed on the abdomen 10 in a state of being can be applied.

The fourth fixing part 240 may be formed such that a pair is symmetrical to each other on both sides of the abdomen 12 in the section where the second multi-side cross-sectional part 150 is formed. For example, the fourth fixing part 240 may be formed in the second-first side end face part 151 and the second extension part 153 .

For example, the second inclined part 154 and the second step part 155 may be formed in the fourth fixing part 240 . As an example, the second inclined portion 154 is formed in such a way that the surface of the fourth fixing portion 240 extends in the direction of the second end 120 with a predetermined angle upward from the lower flange 13, and then is bent. A second step portion 155 may be formed.

For example, a fourth anchoring hole 340 for installing a hollow steel material 400 to be described later may be formed in the second step portion 155 . Accordingly, the girder 10 of the present invention has a structure in which the hollow steel 400 is not installed in the abdomen 12 in the entire girder 10, so that the width of the abdomen 12 can be reduced, The operator can install the hollow steel material 400 in the fourth fixture 340 in the upper part of the lower flange 13 adjacent to the second end 120 and the upper part of the second step 155 in the upper part of the second step part 155. Efficiency can be improved.

That is, the girder 10 of the present invention has a structure in which the width of the second multi-step side cross-section portion 150 increases to two or more steps in the direction from the central portion 140 to the second end portion 120, but the fourth fixing portion 240 ) is formed on the second multi-sided cross-section part 150, for example, by matching the viewpoints of the fourth fixing part 240 and the 2-1 side cross-section part 151, the secondary sheath pipe 331a is It is not installed in the abdomen 12 from the first end 110 to the 2-1 side section 151, and the hollow steel 400 is not installed in the girder abdomen 12 over the entire section of the girder 10. A structure that can be applied is applied to dramatically reduce the width of the abdomen 12 while maximizing the structural efficiency of the secondary sheath pipe 331a, and all sheath pipes 311a, 312a, 313a, 314a, 331a and hollow steel 400 ) achieves an efficient arrangement structure in which each is symmetrical with respect to the longitudinal center of the girder 10, thereby making it possible to manufacture a lightweight girder 10 between long legs.

For example, in the girder 10 of the present invention, the width of the abdomen 12 is changed to two stages from the 2-1 side cross-section 151 to the second end block 121, from 180 mm to 640 mm. can be changed to lead to

For example, in the girder 10 of the present invention, the width of the lower flange 13 is the same or can be changed to one or more steps from the 2-1 side cross-section 151 to the second end block 121, , in one embodiment, may be changed from 900 mm to 1100 mm.

As such, in the girder 10 of the present invention, the first multi-step cross-section portion 130 and the second multi-step cross-section portion 150 described above are formed, so that a plurality of sheath pipes 311a, 312a, 313a having different diameters are formed. , 314a, 331a) increase the arrangement efficiency, and at the same time, dramatically reduce the width of the abdomen 12 to achieve light weight of the girder, while securing the rigidity of the girder, correcting the lateral curvature, and reducing the tertiary or higher prestressing force. can be introduced

1 to 4, the girder 10 includes a plurality of sheath pipes 311a, 312a, 313a, 314a, 331a in which a plurality of tension members for imparting a pre-stressing force are installed, the girder 10 A plurality of sheath pipes (311a, 312a, 313a, 314a, 331a) for fixing the fixing unit (210, 220, 230, 240) and the fixing unit (311, 312, 313, 314, 320, 330, 340) is included. do. Hereinafter, the fixing units 210 , 220 , 230 , 240 and the fixing units 311 , 312 , 313 , 314 , 320 , 330 and 340 according to an embodiment of the present invention will be described.

A first anchoring hole 310 is provided in the first anchoring part 210 provided at the first end 110 , and the first anchoring hole 310 includes a 1-1 anchorage 311 and a 1-2 anchorage hole 312 . , the 1-3 anchorage hole 313, the 1-4 anchorage hole 314, (...), the 1-nth anchorage hole may be included. For example, the 1-1 anchoring hole 311 and the 1-2 anchoring hole 312 are spaced apart from each other by a predetermined distance in the height direction, and the 1-3 anchoring hole 313 and the 1-4 anchoring hole 314 are It may be arranged to be spaced apart from each other by a predetermined interval in the width direction. However, the above-described number of anchorages is merely an example of an embodiment, and the number of anchorages may increase or decrease depending on the extent of the extension of the girder 10 . On the other hand, the 1-1 anchorage hole 311 and the 1-2 anchorage hole 312 may be provided for the sheath pipes 311a and 312a passing through the abdomen 12 to be fixed, and the 1-3 anchorage holes 313 . ) and the 1-4 fixing holes 314 may be provided for the sheath pipes 313a and 314a that do not pass through the abdomen 12 to be fixed.

A second anchoring hole 320 is provided in the second anchoring part 220 provided at the second end 120 , and the second anchoring hole 320 includes a 2-1 anchorage 321 and a 2-2 anchorage hole 322 . , the second-3 anchorage 323, the 2-4 anchorage hole 324, (…), and the 2-nth anchorage hole may include, for example, the 2-1 anchorage hole 321 and the 2-2 anchorage area. The anchorage holes 322 are arranged to be spaced apart from each other by a predetermined distance in the height direction, and the second anchorage holes 323 and 2-4 anchorage holes 324 may be spaced apart from each other by a predetermined interval in the width direction. The number of anchors is merely a description of one embodiment, and the number of anchorages may increase or decrease depending on the degree of extension of the girder. The sheath tube (311a, 312a) passing through may be provided to be fixed, and the second-3 anchoring hole 323 and the 2-4 anchoring hole 324 are the sheath tube 313a that does not pass through the abdomen 12, 314a) may be provided for settling.

For example, the 1-1 anchorage 311, the 1-2 anchorage area 312, the 1-3 anchorage area 313, the 1-4 anchorage area 314, (...), the 1-nth anchorage area are 2-1 anchorage 321, 2-2 anchorage area 322, 2-3 anchorage area 323, 2-4 anchorage area 324, (...), 2-n anchorage area and girder 10, respectively ) can be arranged so as to be symmetrical with respect to the center.

The primary sheath pipes 311a, 312a, 313a, and 314a may be fixed to the first anchorage hole 310 and the second anchorage hole 320 . For example, the primary sheath pipe (311a, 312a, 313a, 314a) is a primary sheath pipe a (311a), a primary sheath pipe b (312a), a primary sheath pipe c (313a), and a primary sheath pipe. d(314a) may be included. Both ends of the primary sheath tube a (311a) may be fixed to the 1-1 anchoring hole 311 and the 2-1 anchoring hole 321. Both ends of the primary sheath tube b (312a) may be fixed to the first and second anchoring holes 312 and 2-2 anchoring holes 322 . Both ends of the primary sheath tube c (313a) may be fixed to the 1-3 anchoring hole 313 and the 2-3 anchoring hole 323. Both ends of the primary sheath tube d (314a) may be fixed to the 1-4 anchorage hole 314 and the 2-4 anchorage hole 324.

The primary sheath pipe a (311a) and the primary sheath pipe b (312a) are sheath pipes passing through the abdomen 12 of the girder 10, and are spaced apart by a predetermined interval in the vertical direction in the entire longitudinal direction of the girder 10. All sheath pipes including the primary sheath pipe a (311a) and the primary sheath pipe b (312a) by being arranged in a state of By being symmetrically arranged, the lateral curvature of the girder 10 can be reduced.

The primary sheath pipe c (313a) and the primary sheath pipe d (314a) are sheath pipes extending through the lower flange 13 without passing through the abdomen 12 of the girder 10, the length of the girder 10 The transverse curvature of the girder 10 is reduced by being arranged to be spaced apart by a predetermined interval in the width direction in the entire section in the direction and arranged to be symmetrical with respect to the longitudinal center line of the girder 10 in the entire section in the longitudinal direction of the girder 10 can be

The arrangement of the primary sheath tube (311a, 312a, 313a, 314a) will be described later with reference to FIG. 5 .

The third fixing part 230 may be provided to be spaced apart from the first end block 111 by a predetermined distance, and may be formed on both sides of the abdomen 12 to be symmetrical with each other. The third fixing part 230 may include a 1-1 inclined part 231a and a 1-2 inclined part 231b, and the specific form described above with reference to FIG. 2 may be applied.

The third anchoring hole 330 may include a 3-1 anchoring hole 331 in which the secondary sheath pipe 331a is fixed and a 3-2 anchoring hole 332 in which the hollow steel material 400 is fixed. For example, the 3-1 anchorage hole 331 and the 3-2 anchorage hole 332 are installed simultaneously on a single anchoring plate, or the 3-1 anchorage hole 331 and the 3-2 anchorage hole 332 are separate It can be installed separately on the fixing plate of the For example, the 3-2 anchoring hole 332 is installed on a separate anchoring plate separated from the anchoring plate in which the 3-1 anchoring hole 331 is installed, and is a fixing plate on which the secondary sheath pipe 331a is fixed. It can be applied to increase production efficiency while lowering production cost.

One end of the secondary sheath pipe (331a) is fixed to the 3-1 anchoring hole 331 and may extend to the second end (120). For example, the second end 120 may constitute a continuous portion joined to the other girder 10, and at the second end 120 at the second end 120, a lower height than the primary sheath tube b (312a). can be extended to For example, the secondary sheath pipe (331a) is one disposed at the lowest position among the primary sheath pipes (311a, 312a) extending from the abdomen (12) of the girder (10) in the region where the fourth fixing part (240) is formed. It may extend to a lower height than the chassis tube b (312a). As described above, the secondary sheath pipe 331a is not disposed in the abdomen 12 from the first end 110 of the girder 10 to the 2-1 side cross-section 151 of the girder 10, so that the abdomen 12 ) by reducing the thickness of the girder 10 can be achieved in light weight. A specific arrangement form of the secondary sheath pipe 331a will be described later.

One end of the hollow steel material 400 may be fixed to the 3-2 anchorage hole 332 and extend to a fourth anchorage hole 340 to be described later. The hollow steel material 400 is not disposed on the abdomen 12 in the entire girder 10 , and the specific arrangement form of the hollow steel material 400 will be described later.

The fourth anchoring hole 340 may be provided in the second step portion 155 described above with reference to FIG. 3 . For example, the fourth anchoring hole 340 may be provided in the fourth fixing part 240 , and the fourth fixing hole 340 may be provided to face upward at a predetermined angle from the second step part 155 . The fourth anchoring holes 340 may be disposed to be spaced apart from each other by a predetermined distance in the direction of the central portion 140 from the second-second side end face portion 152 or may be disposed side by side in the width direction. For example, when the width of the second step portion 155 is increased as the width of the abdomen 12 is further reduced or the width of the lower flange 13 is increased, the fourth anchorage 340 is the second The step portion 155 may be arranged side by side in the width direction. Accordingly, when the operator applies a tertiary or more prestressing force or introduces a tension force for correcting lateral curvature, the support at the upper part of the lower flange 13 adjacent to the second end 120 or the upper part of the second step 155 is removed. It is possible to install and work, so that work efficiency can be improved.

Figure 5 shows the arrangement of the sheath pipe of the girder according to an embodiment of the present invention, Figure 5 (a) is a plan view of the section S1 in Figure 4, Figure 5 (b) is S2 in Figure 4 The section viewed in plan view, Fig. 5 (c) is a plan view of section S3 in Fig. 4, respectively, and Figs. 6 to 9 are cross-sections of the girder cut along the perforated lines shown in Fig. 5. it has been shown

It can be seen from FIG. 4 that the primary sheath tube b not shown in FIG. 5 is disposed under the primary sheath tube a (311a). On the other hand, Figure 5 may be understood as a conceptual diagram for showing the arrangement of the sheath pipe and the hollow steel material of the present invention.

The primary sheath pipe (311a, 312a, 313a, 314a) may extend in a straight line in the entire section of the girder 10 when viewed in a plan view.

The primary sheath pipe a (311a) and the primary sheath pipe b (312a) are arranged so that the longitudinal direction is symmetrical with respect to the center of the girder 10, respectively, so that lateral curvature can be reduced. The primary sheath pipe a (311a) and the primary sheath pipe b (312a) extend from the first end 110 to the central part 140, and in the area where the third fixing part 230 is formed, the third fixing part 230 It extends from a higher position, then passes through the abdomen 12 and leads to the lower flange 13, and passes through the abdomen 12 again in the region where the fourth anchorage part 240 is formed. It may extend to the second end 120 at a high position. The primary sheath pipe a (311a) and the primary sheath pipe b (312a) extend in a state spaced apart from each other in the height direction in the entire area in the longitudinal direction of the girder 10 as shown in FIG. can be maintained.

The primary sheath pipe a (311a) and the primary sheath pipe b (312a) pass through the abdomen 12 of the girder 10 and use a diameter of 60 mm or less to reduce the thickness of the abdomen 12 even under the limit state design method. It can be kept within 180 mm.

The primary sheath pipe c (313a) and the primary sheath pipe d (314a) extend from the lower flange 13 in a state spaced apart from each other in the width direction in the entire area in the longitudinal direction of the girder 10, the length of the girder 10 It is arranged so that the width direction is symmetrical with respect to the direction center line, so that lateral curvature can be reduced.

The primary sheath pipe c (313a) and the primary sheath pipe d (314a) do not pass through the abdomen 12 of the girder 10, and use a diameter of 80 mm or more so that a sufficient number of tension materials can be placed therein. By doing so, it is possible to solve the problem that the number of installed tension members that can occur according to the smaller diameter of the primary sheath pipe a (311a) and the primary sheath pipe b (312a) passing through the abdomen 12 is insufficient.

The secondary sheath pipe 331a is a lower flange ( 13), after passing through the central part 140, and extending upward along the fourth fixing part 240 disposed on the side of the abdomen 12 again, the lower primary sheath tube b (312a) and the fourth fixing port ( 340) at the height between the upper portions, it extends to the second end portion 120 through the second extension portion 153 , the second-second side cross-section portion 152 , and the second end block 121 . The secondary sheath pipe 331a may be joined to the secondary sheath pipe 331a of another girder segment at the second end 120 . Accordingly, the secondary sheath pipe (331a) is disposed so as not to pass through the abdomen (12), it is possible to keep the thickness of the abdomen (12) thin, thereby achieving weight reduction of the girder (10). For example, compared to the conventional PSC girder, 9% (40 m) to 22% (60 m) of light weight can be achieved to realize a span of 60 m or longer.

The hollow steel 400 is a lower flange 13 in the 3-2 anchorage port 332 through the third anchorage part 230 disposed on the side of the abdomen 12 so as not to pass through the minimum width section of the abdomen 12. ), and then extends to the fourth anchorage 340 again, and may extend in a straight line in the entire section of the girder 10 when viewed from a plan view.

That is, when the present invention is applied to the girder 10 for tensioning the tension member for each construction step, a plurality of primary sheath pipes (311a, 312a, 313a, 314a), a plurality of secondary sheath pipes (331a), and a hollow type The cause of lateral curvature can be fundamentally excluded by applying a completely geometrically symmetrical structure to all of the steel materials 400, and additionally due to manufacturing errors using a strand (410 in FIG. 10) installed in the hollow steel material 400 Possible lateral curvature can be controlled.

On the other hand, the girder 10 according to the above-described embodiment can be applied to a continuous bridge, and in the case of a girder for a simple bridge according to another embodiment of the present invention applied to a simple bridge, the first end 110 described above. The shape of the structure from to the center of the girder and the arrangement of strands are symmetrically applied from the center of the girder to the second end 120, so that a structure that is symmetrical with respect to the center of the girder may be applied. That is, the girder for the simple bridge may have a structure in which the shape of the first end block 111 in which the first multi-step side cross-section part 130 and the first end part 110 are formed is symmetrical with respect to the center of the girder can be applied. there is. In this case, the prestress force may be collectively introduced to the primary tension member and the secondary tension member installed in the plurality of sheath pipes in the first tension step before slab synthesis in the girder for the simple bridge.

At this time, the girder according to another embodiment of the present invention applied to a simple bridge is a primary tensioning step of the secondary tension member inserted into the above-described secondary sheath pipe and the primary tension member inserted into the above-mentioned primary sheath pipe. It can be mounted by tensioning it together. As such, in the embodiment of the present invention, not only multi-stage tension but also single tension may be applied.

10 shows a form in which a hollow steel material according to an embodiment of the present invention is installed in the anchorage.

Referring to FIG. 10 , the anchorage, for example, at least one of the 3-2 anchorage hole 332 and the fourth anchorage hole 340 is a hollow steel 400, a stranded wire 410, and a anchorage plate 420. , a fixing head 430 , a protective cap 440 , and a fastening means 450 .

On the other hand, the embodiment described with reference to FIG. 10 can be applied to a form of protecting the maintenance strand by inserting it into the hollow steel in advance, and when not inserting the maintenance strand into the hollow steel in advance, a small cap (not shown) ) can be used to close the entrance to the fixing plate. A method of introducing additional tension will be described later.

The hollow steel 400 is to be distinguished from a general sheath pipe, a strand 410 can be inserted therein, and a steel material having a yield strength of 400 MPa or more is applied to secure the rigidity of the girder 10 and bend the girder 10 To enable resistance to tension. For example, the hollow steel material 400 replaces the H16-6ea reinforcing bar that has been disposed at the bottom of a number of improved PSC girder including the conventional IPC, and when examining the brittle fracture according to the tension member loss rate of the stranded wire 410 (use limit III) Criteria) It can contribute to the increase of the additional load-bearing capacity of the girder (10). At the same time, as one or more strands 410 can be installed inside the n hollow steel materials 400 at the same time, a tension force is introduced to one side of the transversely curved direction before the girder 10 is mounted to the girder 10 ) can be utilized for correcting the lateral curvature, and after the girder 10 is mounted, it is possible to introduce a tertiary or more prestressing force to the girder 10, thereby increasing the convenience of maintenance.

For example, when a tension force is introduced into the 45m girder 10 with SWPC 7C 15.2mm 2 strands inside the hollow steel 400, a horizontal displacement of about 26mm is issued, so that it is possible to control the lateral curvature within a certain range. However, a rise of about 7mm occurs additionally during unilateral tension, but it is known that this rise is a controllable category, as it is usually possible to control the difference in elevation between girders in vertical curve bridges and cross-bridges during slab and pavement placement. there is. In this way, when the hollow steel 400 of the present invention is applied, it is possible to efficiently control the lateral curvature.

The appearance of the hollow steel 400 is not particularly limited, but for example, irregularities may be formed on the outside to improve the efficiency of integration with the concrete girder 10, and for example, spiral irregularities may be formed. .

For example, the hollow steel 400 contributing to the increase in the rigidity of the girder 10 is maintained by inserting a total of six strands 410, up to three on each side, when the need for maintenance emerges during common use. can increase the convenience of The maintenance tension through the non-attached strand to the secondary sheath pipe, which has been conventionally performed, has a disadvantage in that the length of the tension member is long, resulting in a large amount of loss in tension, and it is impossible to tension only a specific span, resulting in poor effectiveness. In contrast, in the tensioning method using the hollow steel 400 of the present invention, the tension loss is small, so the efficiency of tension is increased, and it is also possible to tension only the desired specific span. As an example, a non-attached strand may be applied to the strand 410 , or a method of inserting a general strand and filling an empty space with grease may be applied.

The strand 410 may be, for example, a coated non-attached strand, and for example, may be coated with a PE material.

The anchoring plate 420 may be formed on the concrete girder 10 so that the hollow steel 400 can be fixed after being drawn into the anchoring ports 332 and 340 .

The fixing head 430 is formed to protrude from the fixing plate 420 to the outside, and the hollow steel material 400 and the stranded wire 410 can be guided to be easily guided between the fixing plate 420 .

The protective cap 440 is fixed to the fixing plate 420 by a fastening means 450 such as a bolt or nut, and may extend by a predetermined length to surround the fixing head 430 . The protection cap 440 may protect the strand 410 exposed to the outside of the hollow steel 400 .

In the method of constructing a girder using a hollow steel material 10 according to an embodiment of the present invention, two non-attached steel strands are embedded in a secondary sheath pipe 331a together with a secondary tension material, and a hollow steel material 400 After mounting the girder 10 in an empty state, when additional tension is required, inserting an additional tension material into the hollow steel 400 to give tension; Mounting the girder 10 after embedding the non-attached stranded wire in the hollow steel 400 in advance without embedding the non-attached stranded wire in the secondary sheath pipe (331a); And after mounting the girder 10 in a state in which both the secondary sheath pipe (331a) and the hollow steel material 400 are emptied, at least one of a non-attached steel wire and a general steel wire is inserted into the hollow steel material 400 if necessary and to impart tension; may include at least one of

For example, when introducing a tertiary or higher tension force to the girder 10 of the present invention, it may be by a method of pre-buried non-attached steel wire in the secondary sheath pipe 331a. It is known that the tertiary tension is unnecessary in the 55m class, which is considered to be the limit extension of the conventional improved PSC girder. There are cases where it is necessary. For example, in the case of introducing conventional multi-stage tension, secondary tension is finally carried out after slab synthesis. In case of introducing excessive tension in the construction phase, the allowable compressive stress may be exceeded. Therefore, according to the construction method of the girder according to the present invention, after the secondary fixed load such as pavement is loaded after the secondary tension, the compressive force is partially relaxed, and then the tertiary tension force can be additionally introduced.

For example, when it is necessary to implement a low profile at 50 m or more, if the amount of tension required in the secondary tension cannot be introduced, the construction of the secondary fixed load on the girder 10 of the present invention is completed and the tension is partially relaxed. After the tertiary tension through the hollow steel 400, it is possible to implement a girder of solid height between the long legs.

The construction method of the girder 10 using the hollow steel material 400 according to an embodiment of the present invention in order to correct the lateral curvature before mounting of the concrete girder 10 is the above-described hollow steel material of the girder 10 ( 400) inserting one or more tension members; correcting lateral curvature by imparting tension to the tension member; Mounting the girder 10 is corrected for transverse curvature; and removing the tension member from the hollow steel 400 after relaxing the tension applied to correct the transverse curvature. At this time, between mounting the girder 10 and removing the tension member from the hollow steel 400 , it may further include synthesizing the slab on the girder 10 . The slab may be a cast-in-place deck, a precast deck, or a hybrid deck in which cast-in-place and precast types are mixed.

As described above, the girder frequently has a certain amount of transverse curvature during the construction stage due to problems such as formwork manufacturing error, asymmetry of introduction tension, and misplacement of the sheath pipe. However, this transverse curve does not pose any risk to structural safety and mounting stability, does not cause a problem when installing a river crossbeam, and in the case of an outer girder, if there is no aesthetic problem, the upper slab is poured or synthesized as it is. However, if there are problems such as structural safety and mounting stability due to more than a certain amount of lateral curvature, correction of lateral curvature is required. The present invention is a construction process in which a hollow steel material is installed in the shape of the girder 10 described above, a tension material is inserted into the hollow steel material 400 to correct lateral curvature, and the tension material is removed by releasing the tension after mounting the girder and slab synthesis. Through this, the lateral curvature caused by the construction error can be corrected very effectively.

A girder (10) using a hollow steel material (400) according to an embodiment of the present invention in order to introduce a tertiary or higher prestressing force to the concrete girder (10) to which the primary prestress force and the secondary prestress force are introduced The construction method includes inserting a plurality of tension members into the hollow steel 400 of the girder 10 described above; and imparting a tertiary or higher prestressing force to the tension member. In this case, applying the tertiary or higher prestressing force may include introducing an additional prestressing force after introducing the secondary prestressing force to the girder 10 in which the slab is synthesized.

Accordingly, according to an embodiment of the present invention, it is possible to provide a construction method of the concrete girder 10 that provides an effective compressive stress to the moment maximum portion in the low-profile and long-span girder 10.

In addition, the girder 10 according to an embodiment of the present invention may be manufactured by precast in a factory. For example, if the manufacturing conditions in the field are unfavorable, the concrete strength may be increased and the cross section of the mold height rationalized may be pre-fabricated at the factory. For example, the concrete strength may be 60 MPa or more, and a shear protrusion may be formed on the junction section, that is, the second end.

In addition, in the construction method of the girder according to an embodiment of the present invention, the floor plate construction is applied by in-situ casting, Full Depth Precast, Half Depth Precast, precast flooring applicable to cantilever, or a combination thereof. can

The present invention also provides a sheath pipe arrangement method of the multi-stage tension prestressed concrete girder (10). Specifically, in the embodiment of the present invention, the primary sheath pipes 311a, 312a, 313a in the first fixing part 210 and the second fixing part 220 before the above-described concrete girder 10 is mounted on the bridge substructure. , 314a) and after some or all of the slab load is applied, using the third anchoring parts 230 installed on both sides near the ends of the concrete girder at both ends of the bridge to introduce additional tension force (10) including the sheath pipe arrangement method of

A plurality of primary sheath pipes (311a, 312a, 313a, 314a) are arranged along the longitudinal direction of the concrete girder 10 so as to be fixed to the first fixing part 210 and the second fixing part 220, but the concrete in the vertical direction The primary sheath pipe (311a, 312a, 313a, 314a) descends from one end of the concrete girder 10 to the central part 140 to be the lowest position in the central part of the girder 10 and rises from the central part 140 to the other end. ) to place; The secondary sheath pipe 331a is disposed along the longitudinal direction of the concrete girder 10 so that it is fixed to the third fixing part 230 and extends to the second fixing part 220, but the central part of the concrete girder 10 in the vertical direction. disposing the secondary sheath pipe 331a so that it descends from the third fixing part 230 to the central part 140 and rises from the central part 140 to the fourth fixing part 240 so as to be at the lowest position at 140; and inserting the primary tension material into the primary sheath tube (311a, 312a, 313a, 314a) and inserting the secondary tension material into the secondary sheath tube (331a).

For example, the primary sheath pipe (311a, 312a, 313a, 314a) and the secondary sheath pipe (331a) are each based on the longitudinal centerline of the girder 10 in the entire longitudinal direction of the concrete girder 10. It can be placed so that it is symmetrical left and right. Accordingly, the transverse curvature can be reduced by the sheath pipe arrangement method of the multi-step tension prestressed concrete girder 10 .

In addition, the hollow steel material 400 is disposed along the longitudinal direction of the concrete girder 10 so as to be fixed to the third fixing part 230 and the fourth fixing part 240, but the central part of the concrete girder 10 in the vertical direction ( It may further include disposing the hollow steel material 400 so as to descend from one end of the concrete girder 10 to the central portion 140 and rise from the central portion 140 to the other end so as to be the lowest position in 140). The effect according to the installation of the hollow steel 400 in the present invention is the same as described above.

For example, the primary sheath pipe (311a, 312a, 313a, 314a) is a primary sheath pipe (311a, 312a) passing through the abdomen 12 and the lower flange 13 without passing through the abdomen 12. Including the extending primary sheath pipe (313a, 314a), the secondary sheath pipe (331a) in the first multi-stage cross-section portion 130 and the second multi-stage cross-section portion 150 passes through the abdomen (12) The primary sheath pipe (311a, 312a) may be arranged to extend at a lower position than the. Accordingly, the secondary sheath pipe (331a) is arranged to be symmetrical with respect to the longitudinal center line of the girder (10) in the entire longitudinal direction of the girder (10) can be reduced lateral curvature.

As described above, the specific description of the present invention has been made by the embodiments with reference to the accompanying drawings, but since the above-described embodiments have only been described with preferred examples of the present invention, the present invention is limited only to the above embodiments. It should not be understood, and the scope of the present invention should be understood as the following claims and their equivalents.

For example, the drawings are schematically shown with each component as a main body to help understanding, and the thickness, length, number, etc. of each illustrated component may differ from the actual one in the course of drawing creation. In addition, the material, shape, dimension, etc. of each component shown in the above embodiment are merely examples, and are not particularly limited, and various changes are possible within a range that does not substantially depart from the effects of the present invention.

10: girder
11: Upper flange
12: abdomen
13: lower flange
110: first end
111: first end block
120: second end
121: second end block
130: first multi-step side section
131: 1-1 side section
132: first 1-2 side section
133: 1-1 extension
134: first 1-2 extension
140: central part
150: second multi-step side section
151: 2-1 side section
152: second 2-2 side section
153: second extension
154: second inclined unit
155: second step unit
210: first fixing unit
220: second fixing unit
230: third fixing unit
231: first inclined unit
231a: 1-1 slope part
231b: 1-2 inclined part
232: first step unit
240: fourth fixing unit
310: the first settlement
311: Settlement 1-1
311a: 1st sheath tube a
312: No. 1-2 anchorage
312a: primary sheath tube b
313: Settlement No. 1-3
313a: primary sheath tube c
314: Settlement No. 1-4
314a: 1st sheath tube d
320: the second anchorage
321: Settlement No. 2-1
322: 2-2 anchorage
323: Settlement 2-3
324: Settlement 2-4
330: Settlement 3
331: Settlement 3-1
331a: secondary sheath tube
332: No. 3-2 anchorage
340: the fourth settlement
400: hollow steel
410: strand
420: fixing plate
430: fixing head
440: protective cap
450: fastening means

Claims (21)

delete In the concrete girder having a plurality of tension members for introducing the prestressing force installed therein, and having an I-shaped cross section including an upper flange, an abdomen and a lower flange,
a central portion extending in the longitudinal direction; and
A first multi-step side section extending from the central portion in the direction of the first end portion and including at least one side section section, and a second multi-step side section section extending from the central section in the direction of the second end section and including at least one side section section at least one of the parts;
including,
A plurality of sheath pipes for applying the prestressing force step by step, a fixing unit provided with a plurality of anchors for fixing the sheath pipe, and a hollow installed along the central portion with a length shorter than the plurality of sheath pipes in the longitudinal direction It includes a molded steel,
The hollow steel material is provided with an internal space into which a multi-purpose strand is inserted,
The fixing part includes a first fixing part for fixing the plurality of sheath pipes at the first end, a second fixing part for fixing the plurality of sheath pipes at the second end, and the first multi-step side end surface part. A third fixing part formed on both sides of the abdomen and a fourth fixing part formed on both sides of the abdomen provided on the second multi-stage cross-section part are provided, and the third fixing part has one end of a hollow steel material is settled,
In the third fixing part, a 3-1 fixing hole for fixing a secondary sheath pipe in which a secondary tension member for introducing the pre-stress force to the girder is installed and a third fixing hole for fixing the hollow steel material -2 An anchorage is provided,
The hollow steel is fixed to the fourth anchorage provided in the 3-2 anchorage and the fourth anchorage, and descends to the lower flange from the side of the abdomen along the third anchorage, and the lower flange in the central portion. The width of the abdomen decreases as it extends along the lower flange and has an arrangement structure that rises from the side of the abdomen along the fourth fixing part,
The first multi-stage cross-section portion includes a 1-1 side cross-section extending in the central direction of the girder to narrow the width of the abdomen in the first end block, and a central direction of the girder in the 1-1 side cross-sectional portion In the first 1-1 extension portion extending to Including a 1-2 extension portion extending in the central direction of the girder,
The third fixing part is provided in the section of the 1-2 side section and the 1-2 extension part, and the secondary sheath pipe descends from the side of the abdomen to the lower flange along the third fixing part to the central part As it has an arrangement structure that extends along the lower flange and rises along the abdomen in the section in which the second multi-stage side section is formed, the width of the abdomen is reduced and the secondary sheath pipe is installed in the entire section of the girder Prestressed concrete girder, which is arranged to be symmetrical with respect to the longitudinal centerline of the girder.
3. The method according to claim 2,
The hollow steel material, including a yield strength of 400 MPa or more, ensures the rigidity of the girder and enables resistance to bending tension of the girder, and has irregularities on the surface to improve the efficiency of integration with the concrete girder , prestressed concrete girders.
4. The method according to claim 3,
The unevenness is a spiral unevenness, the prestressed concrete girder.
delete 3. The method according to claim 2,
The third fixing part has a predetermined angle upward from the lower flange and is bent in the direction of the lower flange from the 1-1 inclined part and the 1-1 inclined part extending in the central direction of the girder to the center of the girder. Including a 1-2 inclination portion extending toward,
When the 3-1 anchorage and the 3-2 anchorage are installed in the 1-1 inclination part and the operator applies the prestress force secondarily or more, in the first step part adjacent to the first end part Workable, prestressed concrete girder.
3. The method according to claim 2,
The second multi-stage cross-section portion,
a 2-1 side cross-section extending in the direction of the second end to widen the width of the abdomen from the central portion;
a second extension portion extending in the direction of the second end portion from the second-first side end surface portion; and
a 2-2 second side cross-section portion extending in the direction of the second end portion to widen the width of the abdomen in the second extension portion;
including,
The fourth fixing part is provided in the section 2-1 side section and the second extension part, and the hollow steel material descends from the side of the abdomen to the lower flange along the third fixing part, and from the central part to the lower part. The width of the abdomen is reduced as it extends along the flange and has an arrangement structure that rises from the side of the abdomen along the fourth fixing part in the lower flange, the prestressed concrete girder.
8. The method of claim 7,
The fourth fixing part includes a second inclined part extending in the direction of the second end at a predetermined angle upward from the lower flange, and a second step part bent at the second inclined part and extending in the direction of the second end. do,
A prestressed concrete girder, wherein the fourth anchorage is installed in the second step portion and is upwardly installed at a predetermined angle in the direction of the second end.
3. The method according to claim 2,
The plurality of sheath pipes are a primary sheath pipe in which a primary tension material for primarily introducing a prestressing force to the girder is installed, and a secondary tensioning material for secondaryly introducing a prestressing force to the girder. including the chassis tube;
Prestressed concrete girder, wherein the primary sheath pipe is arranged to be symmetrical with each other on the basis of the longitudinal centerline of the girder in the entire longitudinal direction of the girder to reduce lateral curvature.
10. The method of claim 9,
The primary sheath pipe includes a primary sheath pipe passing through the abdomen and a primary sheath pipe extending along the lower flange without passing through the abdomen,
In the first multi-stage cross-section portion and the second multi-stage cross-section portion, the secondary sheath pipe extends at a position lower than the primary sheath pipe passing through the abdomen, so that the secondary sheath pipe moves in the longitudinal direction of the girder. Prestressed concrete girder that is arranged to be symmetrical with each other based on the longitudinal centerline of the girder in the section to reduce lateral curvature.
3. The method according to claim 2,
One or two or more of the hollow steel materials are installed on the girder, and each of the hollow steel materials has one or two or more tension members installed therein. A prestressed concrete girder capable of correcting lateral curvature, and capable of introducing the prestressing force to the girder in a third or more order after the girder is mounted.
3. The method according to claim 2,
The girder is a prestressed concrete girder having a structure in which the shape of the first multi-stage cross-section and the first end block in which the first end is formed is symmetrical about the center of the girder in order to be applied to a simple bridge.
13. The method of claim 12,
The girder is a prestressed concrete girder that can collectively introduce prestressing force to the primary and secondary tension members installed in the plurality of sheath pipes in the first tension step before slab synthesis.
In the construction method of the girder to correct the lateral curvature before the mounting of the concrete girder,
Inserting at least one tension member into the hollow steel material embedded in the concrete girder according to any one of claims 2 to 4 and 6 to 13;
Correcting the lateral curvature by applying a tension force to the tension member;
Mounting the girder the lateral curvature is corrected; and
removing the tension member from the hollow steel material after relaxing the tension force applied to correct the transverse curvature;
Containing, the construction method of the prestressed concrete girder.
15. The method of claim 14,
Between mounting the girder and removing the tension member from the hollow steel,
The method of constructing a prestressed concrete girder further comprising synthesizing a slab on the girder.
In the construction method of a girder introducing a tertiary or more prestressing force to a concrete girder to which the primary prestressing force and the secondary prestressing force are introduced,
Inserting a tension member into each of the plurality of hollow steel materials embedded in the concrete girder according to any one of claims 2 to 4 and 6 to 13; and
applying the tertiary or more prestressing force to the tension member;
Containing, the construction method of the prestressed concrete girder.
14. The method according to any one of claims 2 to 4 and 6 to 13,
The girder is a pre-stressed concrete girder that is manufactured in a factory.
delete Before the concrete girder according to claim 2 is mounted on the bridge substructure, the primary sheath pipe is tensioned in the first and second fixing parts and the concrete girders at both ends of the bridge after some or all of the slab load is applied In the sheath pipe arrangement method of a multi-step tension girder introducing an additional tension force using the third fixing part installed on both sides near the end,
A plurality of the primary sheath pipes are arranged along the longitudinal direction of the concrete girder so as to be fixed to the first fixing part and the second fixing part, but in the vertical direction to be the lowest position in the center of the concrete girder. Disposing the primary sheath pipe to descend from one end to the central part and to rise from the central part to the other end;
The secondary sheath pipe is disposed along the longitudinal direction of the concrete girder so that it is fixed to the third fixing unit and extends to the second fixing unit, but the third fixing unit is positioned at the lowest position in the center of the concrete girder in the vertical direction. disposing the secondary sheath pipe so as to descend from the central part and rise from the central part to the fourth fixing part; and
inserting a primary tension material into the primary sheath tube, and inserting a secondary tension material into the secondary sheath tube;
including,
The primary sheath pipe and the secondary sheath pipe are arranged so that each is symmetrical with respect to the longitudinal center line of the girder in the entire longitudinal direction of the concrete girder, the multi-step tension prestressed concrete girder sheath pipe arrangement method.
20. The method of claim 19,
The hollow steel material is disposed along the longitudinal direction of the concrete girder so as to be fixed to the third and fourth fixing units, but at one end of the concrete girder so as to be at the lowest position in the center of the concrete girder in the vertical direction. Descending to the central portion and arranging the hollow steel material so as to rise from the central portion to the other end, the multi-step tension prestressed concrete girder sheath pipe arrangement method.
20. The method of claim 19,
The primary sheath pipe includes a primary sheath pipe passing through the abdomen and a primary sheath pipe extending along a lower flange without passing through the abdomen, wherein the first multi-stage cross-section portion and the second multi-stage cross-section In part, the secondary sheath pipe is arranged to extend at a lower position than the primary sheath pipe passing through the abdomen, so that the secondary sheath pipe is mutually based on the longitudinal center line of the girder in the entire longitudinal direction of the girder. A sheath pipe arrangement method for multi-level tension prestressed concrete girder, which is arranged so as to be symmetrical to reduce lateral curvature.

Images