RU2456421C2 - Method to control seismic load at buildings and structures - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method to control seismic load at buildings and structures includes variations of cross section area with account of building height. Seismic load is controlled by supports of 3 and more kinematic foundations, every of which is represented by a solid body with height (H) having a convex ball lower surface of radius (R) with a centre of curvature on a vertical axis of symmetry and resting against a solid flat base, at the same time control is achieved by variation of the radius (R) and height (H) values with the ratio R≥H, hardness of the used material and hinged connection of the object with an oscillating base.

EFFECT: higher seismic resistance of a building and stability of a structure.

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Description

The invention relates to the field of construction, in particular to methods for regulating buildings and structures under seismic load.

A known method in which to reduce seismic load take into account the frequency of oscillations of the metal frame. In this case, there are cutouts of floor slabs in which wall panels are fixed in the recesses (patent No. 2340751, published December 10, 2008, IPC E04H 9/02).

In the known method, wall panels with significant fluctuations do not provide sufficient fixation, which reduces the reliability and efficiency of the method.

There is also known a method where base pillows are formed, allowing to reduce seismic forces (patent 2256749, published July 20, 2005, IPC E02D 27/34, E04H 9/02).

The disadvantage of this method is that on multi-story buildings, the existing racks do not provide sufficient stability of buildings with high seismicity of the territory.

There is also a method in which seismicity is reduced due to kinematic walls having the shape of a rounding and ribbing (patent No. 2319820, published March 20, 2008, IPC E04H 9/02).

However, in the known method, the ribbed walls of two levels with a horizontal slab between them do not sufficiently reduce seismicity in multi-storey buildings.

The closest technical solution is a method in which the movable communication element is made in height with one change in the cross-sectional area and the formation of a rack connected to the lower part with a certain configuration (patent No. 2005156, published December 30, 1993, IPC E04H 9/02, E02D 27/34).

The disadvantage of the prototype method is that at the points of articulation with the object, the load is poorly regulated with significant fluctuations during the earthquake, which reduces the effectiveness of the method. The supporting surface of the lower supporting element is made flat or concave with the center of curvature. The support mobility element is performed with one change in area, which is not sufficiently reliably regulated at high seismicity.

The technical result is an increase in the earthquake resistance of the building, the stability of the structure.

The technical solution of the claimed object lies in the fact that the horizontal seismic load on aboveground objects (buildings and structures) is controlled by supports of 3 or more kinematic foundations, each of which is represented by a solid body of height (H) with a convex spherical lower surface of radius with the center of curvature on the vertical axis of symmetry and resting on a solid flat base, while regulation is achieved by changing the radius (R) and height (H) by the ratio R≥H, the hardness used material and articulation of the object with an oscillating base.

The method is as follows.

Let us imagine the building as an object standing on ball bearings that can freely roll along the plane of a solid base. In this case, the inertial, otherwise seismic load on the object with horizontal movement of the base, with any great acceleration, cannot exceed the friction forces of the balls. The magnitudes of these forces are equal to S:

S = (m ₁ + m ₂ ) / H, where: m ₁ , m ₂ are the moments of friction forces at the top and bottom of the ball, N = 2R is the diameter of the ball.

Given the limited amount of displacement during an earthquake, the balls can be replaced by their lower half, but pivotally connected to the object. Moreover, by m ₁ now we should mean the moment in the hinge, and H = 2. In addition, the supports become attached to certain points of the object.

Thus, the maximum possible seismic load on the building depends only on the parameters H, R, m ₁ , m ₂ , with some correction, taking into account the hardness of the material of the supports. The value of m ₁ depends on the adopted design solution of the technical hinge.

If a ratio of R> H is allowed, then this leads to some predictable increase in S depending on the expected bias.

The method is illustrated in the figure, which shows the foundation 1, on which the spherical surface - 2 is based, having a different radius - R depending on the height of the building - N.

Support base

1. The foundation.

2. Spherical surface of the foundation.

3. The radius of the convex ball bottom surface.

4. Seismic load on the object with horizontal movement of the base.

5. Swivel object with an oscillating base.

The method allows to increase the earthquake resistance of buildings and structures.

Claims (1)

A method of controlling seismic load on buildings and structures, including changes in cross-sectional area taking into account the height of the building, characterized in that the seismic load is controlled by supports of 3 or more kinematic foundations, each of which is represented by a solid body of height (N) with a convex ball lower surface of radius (R) with the center of curvature on the vertical axis of symmetry, and resting on a solid flat base, while the regulation is achieved by changing the value of the radius (R) and height (H) with the ratio of R≥H, the hardness of the material used and the articulation of the object with an oscillating base.

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