JP3186519B2 - Lift-up method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lift-up method in which a foundation at a lower part of an existing building such as a building is separated from a ground-side foundation and lifted up to a required height.

[0002]

2. Description of the Related Art In recent years, in order to improve the seismic performance of an existing building, a seismic isolation device has been introduced into the lower part of the foundation of the existing building, or the existing building has been further lifted up by a further amount and the lower part has a basement. There is a request to use it.

[0003] In order to perform such a construction, it is necessary to lift an existing building to a required height and maintain the state, and the lift-up method is as follows.
It is considered that the foundation of the lower part of the existing building is separated from the ground side foundation such as foundation piles and pushed up by jacks.

[0004]

However, in the conventional lift-up operation using a jack, the building is simply pushed up with a jack inserted underneath to hold the building at a required height, or after being pushed up. Since it is only placed on the shoring, it cannot withstand horizontal forces such as strong winds or earthquakes, and there is a concern that displacement may occur if an excessive horizontal force is received.

[0005] In the case of short-term work, it is unlikely that such a situation as to cause such displacement will be encountered. However, the construction period of the substructure is long, and is applicable during the construction period. In order to maintain the lift-up state while the building is in service, it is necessary to adopt a construction method that takes into account the maintenance measures for these.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lift-up method capable of sufficiently resisting a horizontal force applied to a lifted existing building.

[0007]

In order to achieve the above object, in the lift-up method according to the present invention, the foundation at the lower part of the existing building is separated from the foundation on the ground side such as foundation piles. Is lifted up to the required height while taking a reaction force on the temporary frame through the hanging material suspended from the upper part of the temporary frame constructed so as to straddle the upper part of the temporary frame. While connecting these between, and surrendered by the application of horizontal force
By providing a base that exhibits a seismic isolation function by being deformed , and supporting the existing building on the ground-side foundation via the base, resistance to horizontal force due to wind or the like is obtained. Also, when a horizontal force such as an excessive seismic force greater than the wind load is applied,
The pedestal yields and deforms to provide seismic isolation, reducing input to existing buildings being lifted. At this time, even if the gantry yields, the load of the existing building is supported by the temporary frame via the hanging material (claim 1).

When an existing building is moved by an excessive horizontal force, it can be received by a buttress frame disposed around the existing building or the temporary frame via a damper for buffering. The displacement can be suppressed as much as possible while absorbing the horizontal energy acting on the existing building by the damping action of the damper.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a case where seismic isolation work is performed under an existing building will be described below with reference to the accompanying drawings. 1 (a) to 1 (d) show a construction procedure of the present invention method.

[0010] First, as shown in FIG.
The temporary frame 2 is constructed in a state of straddling the area from above and above. Here, the upper part 2a of the temporary frame 2 is set at a height that allows for the lift-up margin h of the existing building 1.

A plurality of lifting jacks 3 are arranged on the upper part a of the temporary frame 2.
A hanging material 4 such as a steel material or a PC strand is suspended, and a lower end thereof is connected to a lower portion of the existing building 1. Although only two lifting jacks 3 are illustrated in the figure, the number of the jacks 3 is actually determined according to the size and weight of the existing building 1, and one of the hanging members 4 is accordingly determined. The support load per book is set.

The foundation 1a of the existing building 1 is disposed above the foundation pile 5 in the ground E. After the suspension members 4 are connected, the foundation 1a is separated from the foundation pile 5, and The temporary foundation 6 is constructed.

In parallel with this, a plurality of buttress frames 7 are constructed around the existing building, and are opposed to the existing building 1 with a slight gap therebetween through the viscous damper 8 for buffering. This completes the lift-up preparation work. The damper 8 may be arranged on either the building 1 side or the buttress frame 7.

Next, the existing building 1 is raised as shown in FIG. 1 (b) by driving the lifting jack 3 and pulling up the hanging members 4 while taking a reaction force on the temporary frame 2.

The lifting operation is not performed once as shown in the figure, but is performed step by step while maintaining the level of the existing building 1 in small steps, and a temporary mounting base 10 is added to the upper part of the temporary foundation 9 every time the lifting operation is stopped. By connecting the upper part to the foundation 1a, the lower part of the existing building 1 is kept connected to the temporary foundation 9 via the temporary gantry 10.

FIG. 2 shows the details of the connection between the foundation 1a, the temporary foundation 9 and the temporary gantry 10.
The temporary gantry 10 installed on the top is a truss assembly in which vertical and horizontal frames 10a and 10b made of H-shaped steel are assembled in a tower shape to cover the periphery of the foundation 1a, and a brace material 10c is wrapped around the base. By vertically extending the vertical frame 10a in advance, the ascent of the foundation 1a is guided. The number of the temporary mounts 10 is set to the number and the support strength corresponding to the required strength against the assumed horizontal force such as wind and earthquake.

After the ascending operation and the assembling of the temporary gantry 10, after the suspension members 4 are locked at the ascending position, as shown in FIG. 1 (c), an improvement work is performed in the lower space of the existing building 1. In this construction, the seismic isolation base 11 was constructed in the ground E,
A plurality of seismic isolation dampers 12 that serve as seismic isolation structures are arranged on 1. If the existing building 1 is to be used during this construction period, a temporary staircase or the like may be provided at the entrance so that people can enter and exit.

After the completion of the seismic isolation work, the existing building 1 is lowered by dismantling the temporary gantry 10 from the top in the reverse order, and lowering the suspension members 4. It is installed and distributes its load to the seismic isolation structure. When the connection between the existing building 1 and the seismic isolation structure is completed and the existing building 1 becomes self-supporting, the hanging material 4 is removed from the existing building 1, the lifting jack 3, the buttress frame 7, and the temporary frame. If the demolition and removal work in step 2 is performed, the improvement work on the existing building will be completed.

In the above steps, the construction period shown in FIG. 1C is the longest, during which the horizontal force F such as a strong wind or an earthquake is applied.
Is added to the existing building 1, the temporary gantry 10 holds the existing building 1 on the ground E against the horizontal force F. In addition, when a horizontal force F larger than expected is applied, the temporary gantry 10 itself yields and reduces rigidity, thereby producing a kind of seismic isolation effect and reducing input to the existing building 1. Further, as a result, when the existing building 1 moves, it is received by the buttress frame 7 via the damper 8, and
The displacement of the building 1 is suppressed while the horizontal energy acting on the existing building 1 is reduced by the damping action of the damper 8.

In the above-described embodiment, the case where the lift-up method of the present invention is applied to the seismic isolation construction at the lower part of the existing building 1 has been described. The present invention can be widely applied to a case where an object is held in a lift-up state and construction is performed below the object.

In the case where the existing building is lifted up by an additional amount and the lower part is newly used for a basement or the like, the temporary gantry can be used as a main pillar as it is.

The horizontal movement may be suppressed by a temporary frame instead of the buttress frame.

[0023]

As described in detail in the above embodiments, according to the lift-up method according to the present invention, when a horizontal force such as a strong wind or an earthquake is applied during a lift-up period of an existing building, the existing structure is not affected. A gantry located at the bottom of the foundation of the building receives this horizontal force and acts as a resistance to the horizontal force. When an excessive horizontal force is input, the gantry yields and the rigidity decreases, and it functions as a kind of seismic isolation structure that absorbs energy by deformation. The input of force can be reduced as much as possible, and at this time, the load of the existing building can be continuously supported by the temporary frame via the suspension members. Therefore, even when the existing building is held in the lift-up state for a long time, safety can be ensured, and the existing building can be used during the construction period.

When the existing building is moved by an excessive horizontal force, it can be received by a buttress frame or the temporary frame arranged around the existing building via a damper for buffering. The displacement can be suppressed as much as possible while absorbing the horizontal energy acting on the existing building by the damping action of the damper, so that double safety can be obtained.

[Brief description of the drawings]

FIGS. 1 (a) to 1 (d) are explanatory views showing construction steps of the present invention method.

FIG. 2 is a detailed view showing a connection relationship between a foundation of an existing building and a temporary gantry.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Existing building 1a Foundation 2 Temporary frame 3 Elevating jack 4 Suspension material 7 Buttress frame 8 Viscous damper 10 Temporary stand

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) E04G 23/06 E04G 23/02 E04G 21/14-21/16 E04H 9/02 331

Claims (2)

(57) [Claims] 1. A method of separating a foundation at a lower part of an existing building from a foundation on a ground side and lifting up the existing building to a required height, comprising: constructing a temporary frame that straddles above the existing building; While raising the existing building while taking a reaction force on the temporary frame through the hanging material suspended from the upper part of the frame, while connecting these between the foundation of the existing building lower part and the ground side foundation , Yield by applying horizontal force
A lift-up method comprising: providing a base that exhibits a seismic isolation function by deforming the base; and supporting the existing building on a ground-side foundation via the base. 2. The horizontal movement of the existing building,
2. The lift-up method according to claim 1, wherein the control is performed by a buttress frame or the temporary frame disposed around the existing building via a damper for damping.