JPS62288270A - Damper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) The present invention is an effective seismic isolation system for buildings such as nuclear power plant buildings, disaster prevention facilities, and buildings of high social importance. Regarding dampers.

(Prior technology) Traditionally, as a base isolation structure for buildings, laminated rubber made by stacking rubber plates and steel plates and dampers to absorb vibrations are incorporated between the upper building and the lower structure, and the whole building is seismically isolated. It is known that the system's natural period is lengthened to reduce the seismic motion input to the upper building. Since the rubber plate and the damper absorb the imaging energy, if the damper has a large damping capacity, a large seismic isolation effect can be achieved.

Although many types of dampers have been proposed, it is most economical to use hysteresis damping of steel, and a large damping force can be expected.

Therefore, a cantilever damper has traditionally been used as a damper, in which an I-rod with a wide cross section (for example, diameter 77 m) is erected on a base, and the upper end is inserted into a cylindrical body that is movable up and down at the bottom of the building. Proposed.

This steel damper absorbs imaging energy by plastically deforming during an earthquake.

(Problems to be solved by the invention) According to conventional steel dampers, the initial bending stiffness is large due to the long diameter of the steel rod, and there is a problem that the seismic input becomes large until hysteresis damping becomes effective. , the influence on the initial stiffness of the entire building system was large.

An object of the present invention is to solve the above problems and to improve the ability to absorb vibrational energy.

(Means for Solving the Problems) The present invention provides mounting on the lower structure B using a plate 1, a plurality of rods 3 erected on the plate, and mounting on each rod. For installation, a support plate 4 is placed in a position opposite to the plate,
A guide part 5 is installed upright on this support plate, and a holding part 6 is attached to the lower part of the upper building B1 and holds the guide part movably.
It consists of.

(Function) Even if the overall cross-sectional area is large, the cross-sectional area of each rod 3 can be made small, so the bending rigidity is lower than that of a single member with the same cross-section. Each rod 3 absorbs the imaging energy by plastically deforming.

(Example) In FIGS. 1 and 2, the plate 1 is fixedly installed on the foundation B using anchors 2 and bolts 2a. For installation, a plurality of rods 3° are erected on the plate 1, and each rod is made of a round steel or deformed steel bar with a short diameter. A disk-shaped support plate 4 is placed on each rod 3, and the lower surface of the support plate is fixed to the upper end of the rod by welding. As shown in FIGS. 1 and 3, a rod-shaped guide body 5 serving as a guide portion is erected at the center of the support plate 4, and a flange portion 51 is formed on the outer periphery of the upper end of this guide body. It is. The guide body 5 is movably housed in a holding frame 6, which is a holding section attached to the lower part of the building B1. This guide body can accommodate vertical movement due to deformation of the rod body 3. Holding frame 6
Fixing plate 7 attached to the socket of anchor 8 and bolt 8a
It is firmly attached to the lower part of the upper building B1.

Therefore, in the event of an earthquake, when the direction of vibration is the left-right direction in FIG. 4, the upper and lower ends of each rod 3 are plastically deformed to effectively absorb the vibration energy.

Here, experimental results regarding the damping characteristics of the damper of the present invention are shown below.

First, FIGS. 5 and 6 show experimentally obtained restoring force characteristics under static loading and dynamic loading.

As is clear from these graphs, the restoring force characteristics show the good spindle-shaped restoring characteristics seen in ordinary steel members.

Next, Figure 7 shows the relationship between the horizontal displacement and vertical displacement of the damper.As is clear from this graph, smooth vertical movement is ensured for all displacements, and the damper is absorbed.

Further, FIG. 8 shows the equivalent viscous damping constant depending on the displacement level, and a value of about 35% is secured with a deformation of about 15 cm. Note that the larger the attenuation constant, the greater the amount of energy absorbed by the damper during an earthquake.

Figure 9 shows the seismic energy absorption required for a steel damper in a full-sized building (equivalent to 50KINE: equivalent to a maximum earthquake of seismic intensity 7 class, dashed line ■ in the drawing) and the absorption capacity of the damper of the present invention. I am making a comparison, but 8c
The required amount of energy absorption was cleared by changing the mPfi degree, indicating sufficient energy absorption performance, indicating that it can be applied to actual buildings.

(Effects of the Invention) According to the present invention, since the cross-sectional area of each rod becomes smaller, the bending stiffness becomes smaller even if the cross-section is the same as that of the conventional example, and the influence on the initial stiffness of the entire building system is reduced. Also, high energy absorption capacity can be ensured by deforming the rod.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view showing the state of use, Figure 2 is the
Figure 3 is a sectional view taken along line M4 in Figure 1. Figure 4 is a front view showing the state of deformation during an earthquake. Figures 5 and 6 show the relationship between horizontal force and horizontal displacement. Graph, Figure 7 is a graph showing the relationship between vertical displacement and horizontal displacement, Figure 8 is a graph showing the equivalent viscous damping constant depending on the deformation level, and Figure 9 is a graph showing the cumulative amount of energy absorbed during an earthquake. It is. 1... Attachment to plate, 3... Rod body, 4... Support plate, 5... Guide part, 6... Holding part, B... Lower structure, B1... Upper building. Patent applicant: Shimizu Corporation) 1.21z1 Figure 5, Figure 61nu!

Claims (1)

[Scope of Claims] A mounting plate attached to the lower structure; a plurality of rods erected on the mounting plate; a support plate mounted on each rod and facing the mounting plates; A damper consisting of a guide part erected on a support plate, and a holding part attached to the lower part of an upper building to movably hold the guide part.