Abstract:
Disclosed is a novel connection structure of an outrigger and a perimeter column. The connection structure has a function of automatically absorbing differential column shortening which is occurred between the core wall and the perimeter column during or after the construction of a building, thereby preventing excessive stress due to the differential column shortening. In addition, the invented apparatus also functions as damper by providing additional damping to the structure to resist dynamic loading such as wind and earthquake efficiently.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims all benefits of Korean Patent Application No. 2007-27568 filed on Mar. 21, 2007 and Korean Parent Application No. 2007-122864 filed on Nov. 29, 2007 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a novel joint detail and corresponding apparatus connecting outrigger and a perimeter column. This invention will automatically absorb differential column shortening between core walls and perimeter columns without any extra stresses occurred in the building and resist dynamic lateral loads such as wind or earthquake through additional damping provided with this apparatus. 
         [0004]    2. Background Description 
         [0005]    In general, the core wall is installed in high rise buildings to support lateral loads such as wind and/or earthquake, and extra vertical loads. Particularly outrigger structure system that the center core walls are connected with perimeter columns by outrigger is often adopted for the main lateral load resisting structure of a high rise building. 
         [0006]    With this structural system, perimeter columns share the lateral loads such as the wind and/or seismic load acting on the building, consequently preventing the structure from getting excessive bending moment and lateral displacement. In other words, the outriggers and the perimeter columns connected together can resist to the rotation of the core wall when a building subjects to dynamic horizontal loads, so that the story shear, lateral displacement and the bending moment of the core wall can be reduced significantly, as compared to the case where only the core structure resists to the horizontal load. 
         [0007]      FIG. 1  shows a schematic deformed shape of a building when lateral load is acting on a building with outriggers  1 .  FIG. 1   a  represents that a core wall  10  and perimeter columns  20  are connected by the outriggers  1 , and  FIG. 1   b  illustrates the deformed shape of the building due to the lateral load. Since one end of the outrigger  1  is installed to the core wall  10  and the other end  2  of the outrigger  1  is attached to the perimeter column  20 , when lateral load is applied from the left side, tension acts on the left perimeter column  20  and compressive force acts on the right perimeter column as shown in  FIG. 1   b . Therefore, the perimeter columns share and support the lateral load that would be otherwise supported by the core wall  10 . With this mechanics, the outrigger system prevents the building from getting the excessive bending moment and the lateral displacement. 
         [0008]    The core wall  10  is typically composed of concrete and the perimeter column  20  is composed of either iron frame, concrete or composite member made of the iron frame and concrete. Due to the difference in material characteristics and the amount of shared vertical load, different column shortenings through creep and shrinkage can occurs in the core wall  10  and the perimeter columns  20  during the construction of the building or after completion of the construction. Extra stress due to the differential column shortening is transferred from the perimeter columns  20  to the core wall  10  or from core wall  10  to the perimeter columns  20  through the outriggers  1 . 
         [0009]    In order to prevent the extra stress, which is caused by the differential column shortening between the core wall and the perimeter columns during and after construction, the adjustable connection links of the outriggers  1  shown in  FIG. 2  have been conventionally used.  FIG. 2   a  shows a state before the differential column shortening is caused,  FIG. 2   b  shows a state that the gap has closed due to different column shortening and  FIG. 2   c  shows a process of relocating shims to keep the gap between bearing surfaces in a specified range during the course of construction. 
         [0010]    As shown in  FIG. 2 , the end  2  of the outrigger  1  is located between the upper and lower brackets  21  and shim-plates  22  for the gap adjustment are stacked between the end  2  of the outrigger  1  and the bracket  21 . When greater column shortening is caused in the core wall than in the perimeter column  20  due to various factors such as shrinkage and creep, the tip of outrigger  1  moves in an arrow direction, so that the shim-plate  22  below the end  2  of the outrigger  1  is pressurized as shown in  FIG. 2   b . As a result, the extra stress in the form of compressive force is applied to the perimeter column  20  and the gap between the shim-plate  22  above the end  2  of the outrigger  1  and the bracket  21  becomes larger. In this case, as shown in  FIG. 2   c , a jack apparatus  23  is used temporarily to lift the end  2  of the outrigger  1  to relocate the shim-plate  22  from lower to upper space between tip of outrigger  1  and bracket  21 . Then, the jack apparatus  23  can be released. This process will be reiterated during the construction to prevent occurrence of extra stress due to the differential column shortening. To the contrary, when greater column shortening occurs in the perimeter column  20 , the reverse process should be performed. 
         [0011]    Above described adjustable connection link is widely used for the construction of high-rise buildings with outriggers. However, this method has several issues to be solved. These issues are listed as shown below.
       If controlling the gap fails, additional stresses in the structural members may develop.   Keeping the joint gap in a specified range via shim plate replacements is highly difficult task to carry out.   Extra man power and devices are required during the construction for continuous measuring and monitoring process and shim plate replacements.   The response of the building with adjustable joints should be obviously different with that of the final staged building after construction with fixed joint condition.       
 
       SUMMARY OF THE INVENTION 
       [0016]    The present invention has been made to overcome the difficulty of keeping such a small gaps at the outrigger connections. This apparatus also should successfully resist dynamic loads generated from winds and earthquakes with additional damping. 
         [0017]    With this invented apparatus, the differential column shortening during construction will be automatically handled without any extra stresses to the structural members. 
         [0018]    Furthermore, the building with this apparatus is expected to show better performance than the same building with fixed outrigger joint condition since the apparatus will dissipate energy by providing additional damping to the structure. 
         [0019]    The other object of the invention is to provide a novel connection joint of an outrigger and perimeter columns preventing occurrence of extra stresses due to end rotation of the outrigger tips. 
         [0020]    The objects of this invention mentioned above can be accomplished by a connection structure of a perimeter column of a building and an outrigger connected to a core wall according to this invention. It comprises an apparatus provided between the perimeter column and the end of the outrigger to be extended or contracted in accordance with displacement of an end of the outrigger. Wherein the apparatus absorbs the vertical displacement of the end of the outrigger caused by a differential column shortening between the perimeter column and the core wall, thereby preventing extra stress from occurring and the apparatus also functions as damper by providing additional damping to the structure to resist dynamic loading such as wind and earthquake efficiently. 
         [0021]    In one embodiment of this invention, said apparatus may comprise hydraulic cylinders that are provided to upper and lower parts of the outrigger end, respectively. When one hydraulic cylinder is pressurized and then the increased pressure is gradually transferred to the other hydraulic cylinder. The hydraulic cylinder that receives the transferred pressure is to be extended. 
         [0022]    In another aspect of this invention, said hydraulic cylinders are connected to each other by an orifice apparatus that enables fluid to flow from the one hydraulic cylinder to the other hydraulic cylinder. 
         [0023]    In one embodiment of this invention, said apparatus comprise a hydraulic cylinder with an orifice integrated in the interior of the cylinder. 
         [0024]    In another aspect of this invention, said hydraulic cylinder integrated in the interior of the cylinder is provided to only one of the upper or lower parts of the outrigger end. 
         [0025]    In one embodiment of this invention, said end of the outrigger may be connected to the apparatus by hinges. 
         [0026]    In another embodiment of this invention, said connection structure further comprise a lock nut that prevents an end of the apparatus from being excessively pressurized. 
         [0027]    In one embodiment of this invention, said horizontal force transfer apparatus is provided at the gap between outer end face of the outrigger end and the perimeter column, thereby transferring horizontal force occurring between the perimeter column and the core wall. 
         [0028]    In another embodiment of this invention, a roller or sliding plate may be used as the horizontal force transfer apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0030]      FIG. 1  shows a deformed shape of the building when lateral load is acting on a building with outriggers, wherein  FIG. 1   a  shows that a core wall and perimeter columns are connected by the outriggers and  FIG. 1   b  shows the deformed shape of the building due to the lateral load; 
           [0031]      FIG. 2  shows a schematic side view of typical outrigger and an perimeter column connection during construction using adjustable joint method, wherein  FIG. 2   a  shows a state before the differential column shortening is caused,  FIG. 2   b  shows a state that the gap has closed due to different column shortening and  FIG. 2   c  shows a process of relocating shims to keep the gap between bearing surfaces in a specified range during the course of construction; 
           [0032]      FIGS. 3 through 9  are schematic side views of outrigger connections with invented apparatus according to an embodiment as an orifice-integrated hydraulic cylinder or outer orifice-type hydraulic cylinder; 
           [0033]      FIGS. 10 and 11  are schematic side views showing states in which the apparatus is provided to only one side of an outrigger; 
           [0034]      FIGS. 12 to 15  are schematic side views according to an embodiment in which a sliding plate and a roller are used as a horizontal force transfer apparatus, respectively; and 
           [0035]      FIG. 16  is a schematic side view showing embodiments in which an orifice-integrated hydraulic cylinder with a bi-directional rod as a displacement reception apparatus is connected to an outrigger. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. 
         [0037]      FIGS. 3 to 9  are schematic side views showing connection structures of an outrigger  1  and a perimeter column  20 . In the invention, a displacement reception apparatus is provided to a connection of the outrigger  1  and the perimeter column  20 , i.e., between the end  2  of the outrigger  1  and upper and lower brackets  21  integrally attached to the perimeter column  20 . The displacement reception apparatus is contracted or extended in accordance with the displacement of the end  2  of the outrigger  1 , so that it automatically absorbs the displacement occurring between the end  2  of the outrigger  1  and the upper and lower brackets  21  of the perimeter column  20 , i.e., differential column shortening between the core wall and the perimeter column  20 . Therefore, the extra stress due to the differential column shortening occurring between the end  2  of the outrigger  1  and the perimeter column  20  is prevented from being applied to the perimeter column  20 . 
         [0038]    As the displacement reception apparatus, a variety of apparatuses can be used as long as they are contracted or extended in accordance with the displacement of the end  2  of the outrigger  1 .  FIGS. 3 and 4  show examples in which a hydraulic cylinder  30  having an orifice apparatus  31  therein is used as the displacement reception apparatus. To be more specific, in the embodiment shown in  FIG. 3 , the end  2  of the outrigger  1  is located between the upper and lower brackets  21  that are integrally attached to the perimeter column  20 , and cylinders (hereinafter, referred to as “hydraulic cylinder  30 ”), which are vertically operated by fluid pressure, are positioned between the brackets  21  and the end  2  of the outrigger  1 , respectively. When one of the hydraulic cylinders  30  is pressurized and the pressure is thus increased, the increased pressure is gradually decreased as time goes by, so that the pressure corresponding to the decreased pressure is applied to the other hydraulic cylinder  30  that is then extended. In case of the hydraulic cylinders  30  in the embodiment shown, the orifice apparatuses  31  are provided in the cylinders to perform the above operation. Specifically, when the one hydraulic cylinder  30  is pressurized and the pressure is thus increased, the orifice apparatuses  31  enable the fluid to slowly flow from the one hydraulic cylinder  30  to the other hydraulic cylinder  30 . Therefore, regarding the static relative displacement that is very slowly caused such as differential column shortening of a column, the inequality displacement is absorbed without causing the extra stress to the components of the outrigger connection. In addition, even when dynamic lateral load such as wind load or seismic load is applied, the rapid movement of fluid is prevented by the orifice apparatuses  31  enabling the fluid to slowly flow. As a result, the vertical force due to the pressure acting on the hydraulic cylinders  30  is transferred to the perimeter column  20  by the outrigger  1 , so that the bending moment and the lateral displacement acting on a building are decreased and the orifice apparatuses exhibit a damping action against the dynamic load. 
         [0039]    In the mean time, as shown in  FIGS. 5 to 9 , as the displacement reception apparatus, a hydraulic cylinder  30  having an outer orifice  31   a  can be used. In particular,  FIGS. 7 and 8  show an operating structure of the hydraulic cylinder  30  shown in  FIGS. 5 and 6 , in which a reference numeral  32  indicates a fluid pump  32  for supplying fluid each hydraulic cylinder  30 , a reference numeral  33  indicates a supply pipe and a reference numeral  34  indicates a supply branch pipe  34 . In addition, a reference numeral  35  indicates an opening/shutting valve and a reference numeral  36  indicates an over-pressure adjustment valve that is provided to an inlet of each hydraulic cylinder  30  and prevents the excessive pressure from being applied to the hydraulic cylinders  30 . 
         [0040]    In the invention, as shown in  FIGS. 3 to 6 , the displacement reception apparatus can be connected to the end  2  of the outrigger  1  by a hinge means  40 . Like this, when the displacement reception apparatus is connected to the end  2  of the outrigger  1  using the hinge means  40 , it is possible to prevent the extra stress caused due to the rotation force occurring at the end  2  of the outrigger, from being transferred to the perimeter column  20 . Therefore, it is preferably to use the hinge means  40  that is bi-directionally rotatable. 
         [0041]    In addition,  FIGS. 7 to 9  show lock nut-type hydraulic cylinders in which a lock nut  37  is provided to the hydraulic cylinder  30 . Like this, when the lock nut-type hydraulic cylinder is used, it is possible to limit a vertical movement range of the end  2  of the outrigger  1 . As a result, it is possible to prevent the excessive force from being applied to the hydraulic cylinder  30 . However, it is not to be understood that the hydraulic cylinder  30  is limited to the lock nut-type. For example, the hydraulic cylinder  30  having no lock nut  37  may be used. 
         [0042]    In the mean time, in order to connect the displacement reception apparatus and the brackets  21 , a variety of methods may be used, such as screw engagement, concrete casting to the connection. In addition, as shown in  FIGS. 4 and 6 , the brackets  21  and the displacement reception apparatus may be connected by the hinge means  40 . 
         [0043]    In the followings, an operating process of the hydraulic cylinder  30  at the connection of the outrigger  1  will be described with reference to  FIGS. 3 to 8 . 
         [0044]      FIG. 3  shows a case where much reduction is caused in the core wall than in the perimeter column  20 . Under such state, when the core wall is shrunken downward, as shown, the end  2  of the outrigger  1  pressurized the hydraulic cylinder  30  downward while causing displacement in a downward direction shown in an arrow. The pressurized hydraulic cylinder  30  is slowly shrunken, correspondingly to the downward displacement of the end  2  of the outrigger  1 , so that it accommodates the reduction of the core wall. At this time, the upper hydraulic cylinder  30  is extended correspondingly to the downward displacement of the end  2  of the outrigger  1 , i.e., the reduction of the core wall, so that the close state between the end  2  of the outrigger  1  and the hydraulic cylinder  30  is maintained. 
         [0045]    When the perimeter column  20  is much reduced than the core wall, i.e., when the end  2  of the outrigger  1  pressurizes the upper hydraulic cylinder  30  while causing the upward displacement, as shown in  FIG. 4 , the upper hydraulic cylinder  30  is pressurized and is shrunken correspondingly to the upward displacement of the end  2  of the outrigger  1 , so that it accommodates the reduction of the outrigger  1 . At this time, the lower hydraulic cylinder  30  is extended correspondingly to the upward displacement of the end  2  of the outrigger  1 , i.e., the reduction of the outrigger  1 , so that the close state between the end  2  of the outrigger  1  and the hydraulic cylinder  30  is maintained. 
         [0046]    In the mean time, referring to the embodiment shown in  FIGS. 5 to 8  wherein a hydraulic cylinder  30  having an outer orifice apparatus  31   a  is used, under state that the hydraulic cylinders  30  are respectively provided to the upper and lower parts of the end  2  of the outrigger  1 , the hydraulic cylinders  30  are provided with the fluid and the upper and lower hydraulic cylinders  30  are connected by the outer orifice apparatus  31   a . Under such state, when the core wall is shrunken as the embodiment of  FIG. 3 , the end  2  of the outrigger  1  pressurizes the lower hydraulic cylinder  30 , as shown in  FIGS. 5 and 7 .  FIG. 7  illustrates an operating structure of the outer orifice apparatus  31   a . Before there occurs the differential column shortening between the core wall and the outrigger  1 , the opening/shutting valve  35  provided to the supply branch pipe  34  is closed with the hydraulic cylinders  30  being supplied with the fluid. At this time, while the fluid of the pressurized lower hydraulic cylinder  30  is supplied to the upper hydraulic cylinder  30  through the outer orifice apparatus  31   a , the lower hydraulic cylinder  30  is shrunken correspondingly to the downward displacement of the end  2  of the outrigger  1 , so that it accommodates the reduction of the core wall. At the same time, the upper hydraulic cylinder  30  to which the fluid is further supplied through the outer orifice apparatus  31   a  is extended correspondingly to the downward displacement of the end  2  of the outrigger  1 , i.e., the reduction of the core wall, so that the close state between the end  2  of the outrigger  1  and the hydraulic cylinder  30  is maintained. 
         [0047]      FIGS. 6 and 8  correspond to  FIGS. 5 and 7 , which show a state that the perimeter column  20  is much reduced than the core wall. In this case, as the embodiment of  FIGS. 5 and 7 , the fluid moves through the outer orifice apparatus  31   a , thereby contracting/extending the hydraulic cylinders  30 . 
         [0048]    Like this, even when there occurs the upper/lower displacement at the end  2  of the outrigger  1  due to the differential column shortening between the core wall and the perimeter column  20 , which occurs during the construction of the building, the displacement of the end  2  of the outrigger  1  is automatically accommodated by the automatic extension and contraction of the upper and lower hydraulic cylinders  30 , so that the differential column shortening between the core wall and the perimeter column  20  is corrected. Therefore, the extra stress due to the differential column shortening is prevented from being transferred to the perimeter column  20  through the outrigger  1 . 
         [0049]    In particular, the extension and contraction operation of the hydraulic cylinders  30  is automatically performed correspondingly to the differential column shortening between the core wall and the perimeter column  20 , so that it is not necessary to measure the differential column shortening between the core wall and the perimeter column  20  one by one. Meanwhile, when the lateral load due to the dynamic load such as seismic or wind load acts, an overturning moment is caused in the core wall, which is transferred to axial force of the perimeter column  20  by the outrigger  1 . In this invention, regarding the instantaneous dynamic load, the rapid extension and contraction of the hydraulic cylinders  30  are limited by the orifice apparatuses  31 ,  31   a . As a result, the overturning moment of the core wall, which is transferred by the outrigger  1 , is transferred to the axial force of the perimeter column  20  through the outrigger  1  and the hydraulic cylinders  30 , so that it effectively resists to the lateral load of the overall structure. 
         [0050]      FIG. 9  shows a double acting type embodiment in which the hydraulic cylinder has two outer orifice apparatuses  31   a . In the embodiment shown in  FIG. 9 , the operating process is same as the embodiment shown in  FIGS. 7 and 8 , except that a supply pipe  33 , a supply branch pipe  34 , an opening/shutting valve  35  and an overpressure adjustment valve  36  are further provided. Therefore, the repetitive description is omitted. 
         [0051]      FIGS. 10 and 11  are schematic side views showing a state in which a hydraulic cylinder  30  having an orifice apparatus  31  integrated thereto is provided to only one side of an outrigger  1 . The hydraulic cylinder  30  can be provided to only one of the upper and lower parts of the outrigger  1 . Even when the hydraulic cylinder  30  is provided to only one of the outrigger  1 , the differential column shortening is corrected by the contraction and extension of the hydraulic cylinder  30 . 
         [0052]      FIGS. 12 to 15  are schematic side views showing that a horizontal force transfer apparatus  50  is provided. When horizontal force occurs at the outrigger  1  and the end face of outrigger  1  is thus contacted to the outrigger  20 , the end  2  of the outrigger  1  is vertically moved by the horizontal force transfer apparatus  50 . Although a slide plate or roller is used as the horizontal force transfer apparatus  50 , as shown in  FIGS. 12 to 15 , the invention is not limited thereto. For example, an apparatus that can vertically move the end  2  of the outrigger  1  while reducing the friction force can be used. 
         [0053]      FIG. 16  is a schematic side view showing an embodiment in which an orifice-integrated hydraulic cylinder  60  as a displacement reception apparatus in which a bi-directional rod is used is connected to the outrigger  1 . When a bi-directional rod is used, a reciprocating movement is smoothly made and the somewhat horizontal load to be applied to the rod can be supported because bearings catching the piston rod are provided at both sides. In addition, since the two hydraulic cylinders provided at the upper and lower parts of the outrigger  1  can be replaced with the hydraulic cylinder  60  having the single bi-directional rod, a structure of the apparatus is simplified. In addition, as a method for fixing the hydraulic cylinder  60  having the bi-directional rod, a variety of methods such as screw engagement or using a pin can be used. 
         [0054]    In the mean time, in the invention, the upper and lower hydraulic cylinders  30  are applied to pressure and extended/contracted by the mechanical structure using the orifice apparatuses  31 ,  31   a . However, the upper and lower hydraulic cylinders  30  may be applied to pressure and extended/contracted by an electronic manner. In other words, the invention is not limited to the above embodiments. Meanwhile, the invention is not limited to the case where the hydraulic cylinder  30  is operated by the hydraulic pressure. For example, the air pressure may be used. In addition, although the hydraulic cylinder  30  has been described as an example of the displacement reception apparatus, a variety of known dampers such as fluid damper and gas damper may be used. 
         [0055]    In addition, in the above embodiments, it has been described that the end  2  of the outrigger  1  is positioned between the upper and lower brackets  21  integrally attached to the perimeter column  20 . However, the invention is not limited thereto. For example, it may be possible that the perimeter column  20  itself is divided into upper and lower parts and the outrigger end  2  is located between the divided perimeter columns  20 . 
         [0056]    According to the invention, the displacement reception apparatus, which is contracted or extended in accordance with the displacement of the outrigger end, is provided to the connection of the outrigger and the perimeter column, so that it automatically absorbs the differential column shortening between the core wall and the perimeter column, thereby preventing the extra stress due to the differential column shortening from occurring, and decreasing the bending moment and the lateral displacement caused in the building due to the lateral load such as wind load or seismic load. 
         [0057]    Therefore, contrary to the prior art, it is not necessary to measure the differential column shortening in the outrigger connection one by one. In addition, it is not necessary for an operator to operate a jack apparatus to change a shim-plate (to additionally insert the shim-plate or to remove it). As a result, the procedures are simplified and the construction efficiency is increased, so that the cost of construction can be reduced. 
         [0058]    In particular, according to the invention, the absorption and correction of the differential column shortening are continuously performed during or even after the construction. Accordingly, it is possible to effectively cope with the periodic differential column shortening after the completion of construction. 
         [0059]    In addition, according to the invention, since the displacement reception apparatus provided to the outrigger end serves as a damper member, it is possible to reduce and control the vibration that is caused during and after the construction. 
         [0060]    Furthermore, according to the invention, even when the lateral load is applied during the construction of a building, the lateral load is dispersed by the outrigger. In other words, the perimeter column as well as the core wall shares the lateral load, so that it is possible to prevent the excessive lateral load from being applied to the core wall. 
         [0061]    Particularly, according to the invention, the outrigger and the displacement reception apparatus are connected by the hinge, so that it is possible to prevent the extra stress due to the rotation force occurring in the outrigger from being transferred to the perimeter column. 
         [0062]    While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the invention as defined by the appended claims.