JP2019157508A - Under-ground piled column and seismic base-isolated buildings - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structural Shinbashira equipped with a seismic isolation device, which eliminates the need for replacement with a main pillar material after burying the structural true pillar, and can facilitate burying by reducing the weight. Provide pillars. SOLUTION: The structural pillar 10 for solving the above problem is a structural pillar 10 used in a reverse striking method, and has an upper half portion 12 having a closed cross section constituting a main pillar of a basement floor. It is provided with a lower half portion 16 having an open cross section buried deeper than the foundation, and is characterized in that a seismic isolation device 14 is interposed between the upper half portion 12 and the lower half portion 16. [Selection diagram] Fig. 1

Description

  The present invention relates to a reverse striking method, and more particularly to a structural column used in the reverse striking method and a seismic isolation building using the structural column.

  The counter-striking method is a construction method in which the construction of the basement floor and the ground floor is performed in parallel, and is known as an effective construction method for shortening the construction period of a high-rise building having the basement floor. When implementing the reverse driving method, in general, the steel pillar of the main body of the building or the structural pillar that will be the core of the RC pillar is used as a temporary pillar in the pile hole that has been excavated by piercing the casing into the ground. After building, piles are constructed by placing concrete.

  Next, the first floor beam / floor is built in the upper part of the construction pillar, and this is used as a gantry (construction floor) to excavate the basement floor, while excavating and building down from the first basement to the bottom. Repeat the construction. After excavating to the floor level of the foundation, the foundation reinforcement is completed by placing the foundation and placing concrete. While performing these work in the basement, construction work on the ground floor is performed at the same time, so the construction period is significantly longer than the conventional construction method (ordered) where construction work on the ground floor is completed after the construction of the ground floor is completed. Can be shortened.

  On the other hand, when the reverse driving method is carried out, the underground structure is constructed downward while supporting the load of the structure on the ground floor, which is constructed in advance, on the construction pillar. For this reason, it has been considered unsuitable for building seismic isolation. Under such circumstances, as disclosed in Patent Document 1 and Patent Document 2, even if the reverse driving method is carried out, seismic isolation devices are installed on the structural pillars that make up the basement of the basement floor. Construction methods for building buildings have been proposed. In Patent Document 1, a temporary jack is arranged between the foundation of the underground frame and the foundation beam, and the axial force (weight of the building being built) is temporarily received by the temporary jack. A method of cutting and placing a seismic isolation device is disclosed.

  Further, Patent Document 2 discloses a construction column having a structure in which a steel pipe having a circular cross section is disposed between a lower half portion embedded in a foundation and an upper half portion constituting a main pillar of an underground floor. Is disclosed. An opening part in which the seismic isolation device can be inserted is provided on the side surface of the steel pipe of the stem column disclosed in Patent Document 2. Then, after constructing the underground frame, the seismic isolation device is inserted into the steel pipe from the opening, and the gap between the seismic isolation device and the upper half or the lower half is filled with a grout material. It is disclosed that after the grout material is hardened, the side wall (a part other than the opening) of the steel pipe is cut, and the axial force applied to the structural pillar is transferred to the seismic isolation device.

  Certainly, according to the construction methods disclosed in Patent Documents 1 and 2, it is possible to construct a seismic isolation building by installing a seismic isolation device on the structural pillar even when the reverse driving method is implemented. However, any of the methods disclosed in any of the documents requires cutting a part of the structural column or the steel pipe portion and replacing the load borne by the structural column with a seismic isolation device. For this reason, it takes time and labor to install the jack in a narrow space and to cut the structural pillar, and to bear the risk of subsidence due to load exchange.

  On the other hand, in Patent Document 3, it is proposed to perform the reverse driving method using a structural pillar in which a seismic isolation device is previously arranged between the lower half and the upper half. By burying a structural column that has been previously installed with a seismic isolation device, the above problems can be solved, and it is possible to safely construct a seismic isolation building by the backlash method.

Japanese Patent No. 3648651 Japanese Patent No. 3637945 Japanese Patent Laid-Open No. 11-30053

  By using a construction pillar having a configuration as disclosed in Patent Document 3, work associated with the retrofitting of the seismic isolation device is not necessary, and it is considered that the installation work can be simplified. However, the structural pillar of Patent Document 3 is not questioned about the cross-sectional shape as described in paragraph [0016], and is a pillar material constituting the lower half and the upper half separated by the seismic isolation device. There is only an example using the same member. Generally, cross-H-shaped steel with an open cross section (a member that combines steel materials with an H-shaped cross section in two directions) is used for the structural column. Since it cannot be burdened, buckling stops are provided in the middle of the floor, and the depth that can be dug in one process (cycle) becomes shallow, and the number of processes increases and the work on site increases. Precast concrete structural pillars with large axial strength have been developed, but in high-rise buildings where high axial force acts, the weight of the high-rise building increases. It becomes difficult.

  Therefore, in the present invention, there is a structural pillar provided with a seismic isolation device that solves the above-described problem, a structural pillar that can bear a high axial force and can suppress an increase in weight, and the structural pillar. The purpose is to provide a base-isolated building using columns.

  The structural pillar according to the present invention for achieving the above object is a structural pillar used in the reverse driving method, and has an upper half portion having a closed cross section constituting a permanent pillar in the basement floor, and a deeper foundation. And a lower half portion having an open cross section embedded therein, and a seismic isolation device is interposed between the upper half portion and the lower half portion. In this way, the main body column part is a solid cross-section member, and the part embedded in the foundation or pile is composed of an open cross-section member, thereby suppressing an increase in crane load during lifting, A pillar that can bear power can be reasonably constructed.

  Further, in the structural pillar having the above-described features, the upper half is composed of a steel pipe column having a base plate at the lower end, and the lower half is a cross H-shaped steel column having a base plate at the upper end. Constructed, the upper half is filled with concrete after installation. With such a feature, the axial force borne by the upper half can be efficiently transmitted to the lower half via the seismic isolation device. Moreover, the upper half part can raise the tolerance with respect to an axial force by being filled with concrete after installation, suppressing the weight at the time of lifting.

  Further, in the structural pillar having the above-described features, the base plate joined to the lower half is configured to be thicker than the base plate joined to the upper half. As a result, the axial force dispersion effect in the base plate is increased, and even if the bearing area (cross-sectional area) of the lower half is smaller than that of the upper half, the axial force (stress) is transmitted to the lower half. It can be done smoothly. As a result, the amount of steel in the lower half can be reduced, leading to cost reduction.

  In addition, the base-isolated building according to the present invention is characterized in that any one of the above described structural pillars is applied to a core portion where elevators are concentrated. Thus, since the elevator does not pass through the seismic isolation layer, a special mechanism for causing the rail and the support member to follow the deformation at the time of the earthquake is not necessary.

  According to the structural pillar having the above-described features, even when a super high-rise building has a base-isolated structure underground, it can be reasonably constructed by a reverse driving method.

It is a figure which shows the structure of the construction pillar based on embodiment. It is a figure which shows the mode at the time of constructing | isolating a seismic isolation building using the construction pillar based on embodiment, and is a figure which shows the state which embedded the construction pillar. It is a figure for demonstrating the process of burying a true pillar. It is a figure which shows the mode at the time of constructing a seismic isolation building using the structural pillar based on embodiment, and is a figure which shows the state which installed the gantry in the upper part of the structural pillar. It is a figure which shows the mode at the time of constructing a base-isolated building using the structural pillar according to the embodiment, and is a diagram showing a state in which the excavation of the underground part is completed and the construction of the underground floor frame and the ground floor frame is advanced It is. It is a figure which shows the state which has arrange | positioned the temporary fixing member to the true pillar.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the structural pillar and the seismic isolation building of the present invention will be described in detail below with reference to the drawings. In addition, the form shown in the following embodiment is a part of a preferred form for carrying out the present invention, and the form and constituent members of each element can be appropriately changed without departing from the characteristics thereof. it can.

  First, with reference to FIG. 1, the structure of the construction pillar based on this invention is demonstrated. FIG. 1A is a diagram showing a side surface form of the stem column, and FIG. 1B is a diagram showing a planar form of the upper half part. Moreover, the figure (C) is a figure which shows the planar form of a seismic isolation apparatus, and the figure (D) is a figure which shows the planar form of a lower half part.

[Structure of construction pillar]
The structural pillar 10 according to the present embodiment includes an upper half 12 and a lower half 16 and a seismic isolation device 14. The upper half 12 is an element constituting the main pillar of the basement floor, and is constituted by a member having a closed cross section. Specifically, it can be a steel pipe column. The column material that constitutes the upper half 12 of the structural pillar 10 is such a member and is configured to be filled with concrete after installation, so that the structural pillar 10 is buried, and after striking the underground floor, It becomes possible to configure the main pillar without replacement. Moreover, the resistance with respect to an axial force can be improved after installation, suppressing the weight at the time of lifting.

  The upper half 12 having such a configuration is provided with a base plate 12a at the lower end thereof. The base plate 12a is configured such that the planar shape matches or approximates the upper plate 14a constituting the seismic isolation device 14. By setting it as such a structure, it becomes possible to make the seismic isolation apparatus 14 support the axial force which this installation pillar bears efficiently.

  The lower half portion 16 is an element embedded in the foundation (pile deeper than the foundation) within a foundation and a pile embedded in the foundation (contained by filling the casing 22 with concrete 22 (see FIG. 2)). It is comprised by the member which has an open cross section. Specifically, a cross H-shaped steel column can be used. By setting the column material constituting the lower half portion 16 of the structural pillar 10 to such a configuration, the weight of the structural pillar 10 as a whole can be reduced (suppressed). For this reason, when carrying out the reverse driving method, it is possible to lift the built-up pillar 10 in a suspended state, and to load and embed it in the casing 20.

  The lower half 16 having such a configuration is provided with a base plate 16a at the upper end thereof. The base plate 16a is configured such that the planar shape matches or approximates the lower plate 14c constituting the seismic isolation device 14. By having such a configuration, the axial force borne by the main pillar (upper half 12) transmitted through the seismic isolation device 14 can be efficiently transmitted to the lower half 16 and supported. Is possible.

  The seismic isolation device 14 is an element that bears the edge of vibration between the upper half 12 and the lower half 16, and may be an element that can at least edge vibration in the horizontal direction. Specific examples include a laminated rubber type structure, a sliding support structure, and a rolling support structure. For example, the seismic isolation device 14 of the example shown in FIG. 1 is a laminated rubber type structure, and a laminated rubber 14b is provided between the upper plate 14a and the lower plate 14c.

  By providing the seismic isolation device 14 between the upper half 12 and the lower half 16, even when the upper half 12 and the lower half 16 have different cross-sectional shapes and sizes, a large axial force can be transmitted. The seismic isolation device 14 can be made to play the role of the buffer region for achieving.

  Further, in the structural pillar 10 of the present embodiment, the base plate 16a of the lower half portion 16 is configured to be thicker than the base plate 12a of the upper half portion 12. With such a configuration, the axial force dispersion effect in the base plate 16 a is increased, and the area (cross-sectional area) of the support surface of the open cross-section member constituting the lower half portion 16 constitutes the upper half portion 12. Even when the member or the lower plate 14c of the seismic isolation device 14 is significantly smaller, the axial force (stress) can be smoothly transmitted to the lower half 16. Further, there is no possibility of damaging the lower plate 14c of the seismic isolation device 14 due to the stress concentration.

[Action, effect]
According to the true pillar 10 having such a configuration, since the base isolation device 14 is interposed in the column, it is not necessary to install the base isolation device 14 after the base pillar 10 is installed. Moreover, since the upper half part is comprised with the pillar material which can be comprised as a permanent pillar of an underground frame, it is not necessary to replace a pillar material after excavating an underground floor. Furthermore, since the lower half part 16 is comprised with the steel frame of an open cross section, the weight reduction as the whole structure pillar 10 can be achieved. Thereby, the embedding work of the structural pillar 10 becomes easy.

  Further, since the seismic isolation device 14 is interposed between the upper half 12 and the lower half 16, it is possible to efficiently transmit the axial force between the two.

[Example of application to seismic isolation buildings]
Next, a base-isolated building that employs a structural pillar having the above-described configuration will be described with reference to FIGS. In constructing a high-rise building, the seismic isolated building according to the present embodiment is such that the above-described structural pillar 10 is arranged in a core portion where elevators are concentrated and arranged. In a high-rise building having a basement floor, the elevator shaft is a space extending from the basement housing 32 to the upper part of the ground basement 30. For this reason, when the seismic isolation device is arranged at the boundary between the underground floor and the ground floor, a phase shift occurs between the underground floor housing 32 and the ground floor housing 30 when an earthquake occurs, and the elevator shaft There is a risk of distortion. For this reason, the rail and support member which comprise an elevator require a special mechanism which makes it follow the deformation | transformation of the elevator shaft at the time of the occurrence of an earthquake.

  By arranging the seismic isolation device 14 at the lower end of the elevator shaft as in the present embodiment, the elevator shaft can obtain the seismic isolation effect in the same manner as the chassis on the ground floor, and damage when an earthquake occurs. Can be reduced. Therefore, the special mechanism as described above is not necessary.

  When the seismic isolation building having such a configuration is constructed by adopting the reverse driving method, for example, the structural pillar according to the above-described embodiment may be applied as follows. First, as shown in FIG. 2, the true pillar 10 is buried in the ground. The embedding of the structural pillar 10 can be performed in the same manner as a normal reverse driving method. Specifically, as shown in FIG. 3A, the casing 20 is driven into the ground and the inside is excavated. Next, as shown in FIG. 3 (B), a reinforcing bar (not shown) is arranged, and the construction medium 10 is inserted into the pile hole filled with the concrete 22 in the casing 20, and the concrete 22 is awaited to be cured (FIG. 3 (C). )). After the concrete 22 is hardened, the inside of the casing 20 is refilled as shown in FIG.

  Here, the structural pillar 10 a embedded in a portion other than the core portion indicated by the broken line A in FIG. 2 may be a normal structural pillar that does not include the seismic isolation device 14.

  Next, as shown in FIG. 4, beams and floor surfaces constituting the floor of the first floor portion are constructed on the upper part of the structural pillars 10 and 10 a to constitute the gantry 24. Here, the seismic isolation device 14 is arranged at the upper end of the structural pillar 10a embedded in a portion other than the core portion (boundary portion with the frame on the ground floor), and the gantry 24 is positioned above the seismic isolation device 14. To be configured. After constructing the gantry 24, the construction of the ground floor housing 30 is advanced, and excavation work for constructing the underground floor housing 32 is performed.

  As shown in FIG. 5, excavation work on the basement floor is performed so that the seismic isolation device 14 provided in the structural pillar 10 is exposed and the lower half 16 is embedded in the foundation. A housing 32a serving as a core is constructed on the upper part of the device. When the seismic isolation building 40 is constructed by such a method, temporary fixing as shown in FIG. 6 is performed on the seismic isolation device 14 disposed between the lower half portion 16 and the upper half portion 12 constituting the structural pillar 10. It is preferable to bury the structural pillar 10 in a state where the member 18 is installed.

  The temporary fixing member 18 prevents the lower half portion 16 and the upper half portion 12 from being displaced relative to each other in the horizontal direction, and when the stem 10 is suspended, due to its own weight and the weight of the lower half portion 12, It plays a role of preventing the seismic isolation device 14 from extending in the vertical direction. For this reason, by providing the temporary fixing member 18, even when the structural pillar 10 according to the embodiment is lifted in a suspended state and inserted into the casing 20, the upper half 12 and the lower half 16 are displaced. There is no possibility that an adverse effect will occur due to the occurrence of a tensile load on the seismic isolation device 14.

  According to the construction of the seismic isolation building 40 by carrying out the reverse driving method using the structural pillar 10 according to the above embodiment, it is not necessary to replace the load of the structural pillar 10, and the seismic isolation device 14 Installation can be facilitated. In addition, since the construction proceeds in a state where the seismic isolation device 14 is loaded with an axial force, the risk of abrupt settlement due to the compression of the rubber portion is less than a method of changing the load.

10, 10a ......... structural pillar, 12 ... upper half, 12a ... base plate, 14 seismic isolation device, 14a ... upper plate, 14b ... laminated rubber, 14c ... Lower plate, 16 ......... Lower half, 16a ......... Base plate, 18 ......... Temporary fixing member, 20 ......... Case, 22 ......... Concrete, 24 ...... Gantry, 30 ...... Housing, 32 ……… Housing, 32a ……… Housing, 40 ……… Seismic isolation building.

Claims (4)

It is a structural pillar used in the reverse driving method,
An upper half having a closed cross-section constituting the main pillar of the basement,
A lower half portion having an open cross section buried deeper than the foundation,
A structural pillar comprising a seismic isolation device interposed between the upper half and the lower half. The upper half is composed of a steel pipe column with a base plate at the lower end,
The lower half is composed of a cross H-shaped steel column having a base plate at the upper end,
The construction pillar according to claim 1, wherein the upper half is filled with concrete after installation.   The base column according to claim 2, wherein the base plate joined to the lower half is thicker than the base plate joined to the upper half.   A seismic isolation building, wherein the structural pillar according to any one of claims 1 to 3 is applied to a core portion where elevators are concentrated.

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