U.S. patent application number 09/681612 was filed with the patent office on 2002-11-14 for earthquake-protective building buffer.
Invention is credited to Shustov, Valentin N..
Application Number | 20020166295 09/681612 |
Document ID | / |
Family ID | 24736038 |
Filed Date | 2002-11-14 |
United States Patent
Application |
20020166295 |
Kind Code |
A1 |
Shustov, Valentin N. |
November 14, 2002 |
Earthquake-protective building buffer
Abstract
A manufacture called "earthquake buffer" to protect a building
structure from destructive earthquakes as well as to secure its
stability under strong winds, comprising two non-resonant rolling
friction slide layers positioned above each other on a building
footing and consisting of a plurality of cylindrical rollers
stretched parallel in a direction of one of the main building axes
while being orthogonal to the bars in an alternative slide layer.
The slide layers are interlaid with a distributive plate and topped
with an inertia block connected to a rigid first floor diaphragm
and the building superstructure. With a magnitude of earth movement
exceeding a certain threshold, the earthquake buffer permits
practically unlimited horizontal excursions of the footing relative
to the superstructure while transmitting a dramatically reduced
shearing force upwards and preventing any sizable lateral resonant
effects in the protected building.
Inventors: |
Shustov, Valentin N.; (La
Crescenta, CA) |
Correspondence
Address: |
VALENTIN SHUSTOV
2423 FOOTHILL BLVD, #B103
LA CRESCENTA
CA
91214
US
|
Family ID: |
24736038 |
Appl. No.: |
09/681612 |
Filed: |
May 8, 2001 |
Current U.S.
Class: |
52/167.5 ;
52/167.1; 52/167.4 |
Current CPC
Class: |
E04H 9/023 20130101 |
Class at
Publication: |
52/167.5 ;
52/167.1; 52/167.4 |
International
Class: |
E04H 009/02 |
Claims
What is claimed:
1. A system of properly manufactured earthquake buffers adapted to
separate a building superstructure from its foundation for
protection against damaging effect of strong earthquakes and, at
the same time, to prevent such separation under a strong wind or
minor earthquakes, each of said devices comprising: two
non-resonant rolling friction horizontal slide layers positioned
above each other on a building footing and consisting of a
plurality of identical cylindrical rollers distanced from each
other and running parallel in a direction of one of the main
building axes, said rollers in one of said layers are orthogonal to
said rollers in another said layer in order to provide an adequate
separating effect for any horizontal component of earth movement; a
horizontal distributive plate between said two slide layers to
provide a better gravity load application to contacting surfaces of
said layers; an inertia block located on top of the upper of said
slide layers and supporting a rigid first floor diaphragm and said
superstructure, said inertia block together with said floor
diaphragm having a mass comparable to a mass of said superstructure
in order to prevent any higher frequency pulses to be transmitted
from said footing to said superstructure and to create a friction
force that can resist any possible strong wind pressure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to earthquake protection of
building structures. More particularly, the invention relates to
seismic isolation techniques.
[0003] 2. Description of the Prior Art
[0004] The concept of suppression or diverting the seismic energy
flow from entering a building structure is known as a seismic or
base isolation. Normally, this technique needs some pads to be
inserted into all major load-carrying elements in a base of the
building. It also requires creating additional rigidity diaphragms
in the basement of the building and a moat around the building, as
well as making additional provisions against overturning and/or P-D
effect. Potential benefits of the base isolation technique should
not be taken for granted: they depend on many factors and are,
sometimes, questionable (visit
http://www.ecs.csun.edu/.about.shustov/Topic4.htm).
[0005] There are the following major reasons why the existing
buildings, which incorporating seismic isolators, performed below
the expectations during the recent earthquakes:
[0006] 1. Predictions of their earthquake performances were made in
assumption of the whole building structure acting as an absolutely
rigid body rocking on their seismic isolators, while the higher
natural modes of vibration were, practically, neglected.
[0007] 2. Possibility of a negative effect of a heavy damping
mechanism of those isolators, that could generate short pulses of a
high intensity, was overlooked.
[0008] 3. The buildings that were erected on seismic isolators
remained essentially resonant systems in a wide range of earthquake
frequencies.
[0009] However, if the existing buildings on seismic isolators
happen to do their job properly and survive the earthquake impacts
successfully, there is the opposite challenge: an earthquake safe,
due to a perfect seismic isolation, structure may become vulnerable
to a strong wind.
BRIEF DESCRIPTION OF THE DRAWING
[0010] In the description of invention herein presented, references
are made to the accompanying drawings, in which:
[0011] FIG. 1 is a perspective view of an earthquake buffer on a
footing.
[0012] FIG. 2 depicts an exploded perspective view of an earthquake
buffer divided into several functional strata.
DESCRIPTION OF THE PREFERED EMBODIMENT
[0013] The present invention will be described with reference to
the accompanying drawings. As illustrated at FIG. 1 and FIG. 2, the
earthquake buffer according to the invention is positioned on each
individual column footing (1) of a building and has two
non-resonant and low friction horizontal slide layers consisting of
a plurality of identical cylindrical rollers, namely, a lower layer
(2) and upper layer (4), which are interlaid with a horizontal
distributive plate (3) and are topped with an inertia block (5)
that supports the first floor diaphragm (6) and the building
superstructure (7). The cylindrical rollers of the layers (2) and
(4) are distanced from each other and running parallel in a
direction of one of two main building axes. The direction of
rollers in the layer (2) is orthogonal to the direction of rollers
in the layer (4). The rollers of the lower layer (2) rest on a flat
top surface of the footing (1) that supports the particular
earthquake buffer. The weight of the inertia block (5) of the
buffer should be enough to suppress the potentially damaging higher
frequency pulses of vibration being transmitted from the footing
(7) into the superstructure (7) and to create a friction force that
can resist a lateral strong wind pressure.
[0014] During an earthquake, any two-dimensional horizontal
movement of the footing (7) is resolved, while transmitted upwards,
into two orthogonal components, by the following steps: first, the
plate (3) will slide up in one of the orthogonal directions
relative to the footing (1); then, the block (5) will slide up in
another orthogonal direction. Finally, a two-dimensional
acceleration will be developed and applied to the bottom of the
building superstructure (7) but being dramatically scaled down due
to a low value of the rolling friction in the layers (2) and
(4).
[0015] The material, length, diameter and a number of rollers in
each layer should satisfy both a requirement of sufficient vertical
load bearing capacity and that of an adequate shearing force being
transmitted through the earthquake buffer into the
superstructure.
* * * * *
References