JP2013185369A - Method of making structure earthquake-resistant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a structure earthquake-resistant without using large-scale equipment such as a seismic isolator which supports the entire structure or a vibration control device which drives a weight, by utilizing a vibration control mechanism of a five-storied pagoda.SOLUTION: An elevator device and a get-on/get-off lobby part to be installed inside a structure which is an object to be made earthquake-resistant are structurally cut off from the other parts, made independent, integrated and turned to a columnar structure. It is defined as an elevator core. Also, the part other than the elevator core is defined as an outer shell part. When the elevator core is at one part, it is provided near the center of the structure which is the object to be made earthquake-resistant as much as possible. A difference between a natural frequency of the elevator core and a natural frequency of the outer shell part is made as large as possible, and the elevator core and the outer shell part are connected through a shock absorber such as an oil damper. Thus, the phenomenon that the structure resonates with earthquake waves and the amplitude of a shake is enlarged is blocked and the structure is made earthquake-resistant.

Description

The present invention relates to a technique for making a building earthquake resistant.

Recently, the influence of long-period vibration on high-rise buildings has attracted attention. During the Great East Japan Earthquake, the earthquake that occurred in the Tohoku region has been attracting attention because it caused great damage to high-rise buildings in Osaka. This is said to be due to the fact that the period of the earthquake and the natural period of the high-rise building are equal and the amplitude is expanded by resonance.
As a countermeasure against earthquakes, [Patent Document 1] and others disclose a method of supporting an entire building with a seismic isolation device using laminated rubber. However, in this method, a building having an enormous weight is supported by the seismic isolation device. Therefore, it is considered that the requirements for the seismic isolation device must be extremely strict and become very expensive, and the performance is lowered due to deterioration of the rubber.

In addition to the above problems, this method can absorb vibrations for short-period earthquakes, but it is difficult to absorb vibrations for long-period earthquakes. It is considered that it is not so effective as an earthquake resistance method, particularly as an earthquake resistance method for long period earthquakes.

As another method, a method of damping vibration by driving a weight with a linear motor is disclosed in [Patent Document 2]. However, since the shaking of the earthquake does not always coincide with the driving direction of the linear motor, in order to cancel the shaking of the high-rise building due to the earthquake, two devices are installed so that the driving directions are orthogonal to each other. It is necessary to drive so as to cancel the movement due to the above, but if the phase of the seismic wave and the vibration direction are misread, the amplitude may be increased. Furthermore, it is necessary to use a heavy weight with a large weight in a large high-rise building, but providing such extra heavy weight on the top of the high-rise building may adversely affect the strength of the high-rise building. Conceivable.

Japanese Patent Laid-Open No. 05-010386 Japanese Patent Laid-Open No. 08-226252

The vibration amplitude of the building is expanded by resonating with the seismic wave without using a large-scale facility such as a seismic isolation device that supports the entire building or a vibration control device that drives the weight to cancel the shaking of the building. The challenge was to develop a method to prevent this.

By applying the vibration control mechanism of a five-storied pagoda to the elevator part of a high-rise building, the high-rise building was made earthquake resistant by a relatively simple method. By utilizing this technology, we believe that high-rise buildings can be made earthquake resistant at a very low cost.

The present invention eliminates the need for large-scale equipment required for earthquake resistance of high-rise buildings, and avoids damage to long-period earthquakes by making slight changes to this design using equipment that is essential for high-rise buildings called elevators. It became possible. This method can be applied not only to a high-rise building but also to a lower building if it is a building having an elevator.

Hereinafter, detailed embodiments of the seismicizing means according to the present invention and problems and points to be noted in implementation will be described.
The five-storied pagoda is a typical example of an old high-rise building, but this five-storied pagoda has never been destroyed by an earthquake so far, and its seismic performance is drawing attention. I presume why the five-storied pagoda is strong against earthquakes as follows.

A unique characteristic of the five-storied pagoda, which is not seen in other buildings, is that a central pillar is placed in the center of the tower, which is independent from the outer part of the tower. Since the shape and rigidity of the outer portion of the five-storied pagoda and the portion of the core column are different, the natural frequency when vibrating is naturally different. Even if a seismic wave with the same frequency as or close to the natural frequency of the outer part of the tower comes and the outer part of the tower resonates and starts to shake, the frequency of the seismic wave is calculated from the natural frequency of the core column. The core column does not resonate and the shaking does not become so great. For this reason, even if the outer portion of the tower tries to sway further, it hits the central pillar of the center and prevents further amplitude expansion.

On the other hand, the same can be said for the core column. If an earthquake wave with the same frequency as or close to the natural frequency of the core column comes and the core column resonates and the vibration starts to increase, the vibration frequency of the seismic wave Therefore, the outer part of the tower does not resonate and the fluctuation does not increase so much. For this reason, even if the core column sways further, it hits the outer portion of the tower and prevents further amplitude expansion. In this way, even if an earthquake wave having a frequency that is the same as or close to any natural frequency comes, they interfere with each other and the expansion of the amplitude is prevented, and the five-storied pagoda is not damaged.

However, in the case of the five-storied pagoda, it does not live inside and it does not get in the way even if there is a heart column in the center, but in the case of ordinary high-rise buildings, humans live or act in this In general, if a central pillar is provided in the center, it will be a hindrance to use and the central pillar cannot be provided. Therefore, the seismic mechanism of the five-storied pagoda cannot be applied to high-rise buildings as it is. The inventor has completed the present invention by conducting various investigations and researches on how to make earthquake resistance relatively inexpensive without impeding the use of high-rise buildings.

A high-rise building can be seen as a giant vibrating piece with one end fixed, but its natural frequency is much smaller than that of a small tuning fork. However, in the case of a long-period earthquake, the period may coincide with the period of the natural frequency of the high-rise building, and the vibration of the high-rise building will increase with time due to resonance, and eventually the high-rise building will be destroyed. It has been found that there is a problem and its countermeasures are currently being studied. Increasing the steel structure of a high-rise building and strengthening the structure will increase the earthquake resistance, but simply increasing the structure and strengthening the structure will increase the cost and is a practical measure. It is hard to say.

Ordinary high-rise buildings are made as a whole. When high-rise buildings are integrated in this way, the high-rise building has a single natural frequency as a whole, but if an earthquake wave with a period that matches the natural frequency comes, the above-mentioned As a result, it will be greatly damaged by resonance. As a countermeasure, it is necessary to provide a large pillar in the center of a high-rise building if the vibration control principle of a five-storied pagoda is to be adopted. Or it can be said that the situation is not allowed due to restrictions on the ground. Therefore, the most difficult point in the present invention is how to secure a thing that performs the same function in place of the main pillar without occupying a special area in a high-rise building.

Next, the contents of the present invention and specific methods and cautions for implementing the contents will be described.
As described above, the present invention applies the vibration damping action of the five-storied pagoda, but uses an elevator that is indispensable for a high-rise building as an equivalent to the five-storied pagoda. In addition, the earthquake resistance can be improved without increasing the cost so much.

Usually, elevators and boarding / exiting lobbies are built as a part of a building without being separated from other parts. On the other hand, in the present invention, the elevator apparatus including the hoistway and the entrance / exit lobby are structurally separated and made independent so that only this part is integrated, and this is used as a substitute for the five-storied tower. The elevator device mentioned here is an elevator drive device, a car, a car frame, lighting equipment, communication equipment, ventilation equipment, other equipment attached to the car, hoistway where the car moves up and down, guide rail, pulley, wire rope, electric This refers to equipment and related equipment required for normal operation and emergency, such as cables, emergency stop devices, and shock absorbers.

The elevator device and the entrance / exit lobby are structurally separated from each other and made independent and integrated into a single vertically elongated columnar structure. The reason for including the entrance / exit lobby is to increase the bottom area for stabilization.
The columnar structure composed of the elevator apparatus and the entrance / exit lobby integrated in this manner is defined as an elevator core, and a portion other than the elevator core of the building is defined as an outer portion, and will be referred to as such in the future.
Although it seems that there are various restrictions, it can be said that it is desirable to install this elevator core as close to the center of the building as possible in the case of only one place because it is used as a substitute for the core column. If it is inevitably difficult to provide near the center of the building, it is inevitable to provide it at the end, but in that case the vibration damping effect is slightly reduced.

In an elevator to which a counterweight is attached, the counterweight, a guide rail for the weight, and a shock absorber are also integrated as a part of the elevator core.
In principle, the elevator drive unit is integrated as a part of the elevator core. However, if it is difficult to integrate it structurally as described in paragraph [0023], it must be forcibly included in the elevator core. There is no.
When two or more elevators are provided, these multiple elevators and the entrance / exit lobby may be integrated together. Further, when elevators are provided in two or more places in a wide building, a plurality of elevator cores may be formed independently and integrated for each elevator installation location. The seismic resistance is improved compared to the case where this is only one place.

If the elevator is interrupted and connected to another elevator, as in the Sky Lobby method, the elevator and the elevator are integrated from the bottom to the top so that the elevator to be connected is installed in the same boarding lobby. . If they cannot be integrated together, the elevator parts can be made as long as possible and integrated within the range that can be obtained, but it can achieve a certain effect even if it is not the best.

Although the elevator core and the outer portion are structurally separated, the foundation of the elevator core and the outer portion may be made common and it is not necessary to separate the foundation. The reason for this is that when the foundation is cut off, the strength of the foundation will be weakened, and even if two vibrating pieces with different natural frequencies are attached to a common base and vibrated, they will only resonate if their natural frequencies match. This is because the basic part does not affect the resonance, as can be seen.

Since the elevator core and the outer part are structurally separated, there is a gap between the elevator core and the outer part, but people and objects may fall because people pass through this gap. It needs to be blocked. When closing the gap, it is necessary to keep the gap lightly so that the elevator core and the outer portion are not strongly coupled by closing the gap. Of course, it goes without saying that the lid must be treated so that it does not fall off and be damaged. In addition, pipes such as water and gas pipes, conduit pipes and air-conditioning ducts in the elevator core must be connected to the outer part, but these should be applied to each other as much as possible. It is desirable to connect using a flexible joint.

The elevator core corresponds to the core column of a five-storied pagoda, and its natural frequency needs to be higher than the natural frequency of the outer portion, and the difference should be as large as possible. In order to increase the natural frequency, it is necessary to make the elevator core lightweight and tough. By making the elevator core light and tough, the natural frequency increases and the difference from the natural frequency of the outer portion can be increased. For this purpose, I think that there is a cost limitation, but make the elevator system as strong as possible, and use pillars and beams in the entrance / exit lobby with thicker steel than usual and use high-strength concrete. Is effective. Making the elevator core strong in this way causes a canned accident that the elevator car, car frame, guide rail, etc. are deformed and do not move during the earthquake and are left in the elevator car in the middle of the floor. This is also desirable in that it reduces the risk of

In the sense of increasing the natural frequency, the lower machine room system with heavy objects below is more advantageous than the upper machine room system with heavy objects such as motors and gears that drive elevators on top. In some cases, it may be necessary to use the upper machine room method. Although it is not desirable from the aspect of seismic effect, it is unavoidable.
Even in the case of the lower machine room type, this part is provided adjacent to the hoistway and can be easily incorporated into the elevator core. However, if it is difficult, the machine room should be placed in the outer part. May be. Strictly speaking, the elevator core and the outer part are connected by a wire rope and are not strictly independent. However, the force is small compared to the gravity and inertial force acting on the building, and its influence can be ignored.

As explained above, the elevator core and the outer part, which are structurally independent and have different natural frequencies, resonate in the fundamental mode at the same time even if they are built on a common foundation. It can't happen. Since this resonance is an open-end resonance, when the natural frequency of the elevator core becomes an odd multiple of 3 times, 5 times, etc. with respect to the natural frequency of the outer portion, both the elevator core and the outer portion Although resonance may occur, the amplitude of the odd-number mode resonance is smaller than the resonance with respect to the wave with the natural frequency. For this reason, even if one side resonates and shakes greatly when an earthquake occurs, the other shake is small, and both do not resonate together and a large shake occurs.
If the natural frequencies of the elevator core and the outer shell part are equal and both resonate, the distance between the two will remain constant, and both will swing as well, and even if they are tied with a string, the force acting on the string is weak. However, if the natural frequency is different, one of the two will sway greatly, but the other will not sway so much. Will stretch or shrink and sometimes break. Thus, if the natural frequency is different, both can be made to interfere strongly. The present invention attempts to improve the earthquake resistance by absorbing the energy of the shaking of the high-rise building by absorbing the elevator core and the outer part that have different ways of shaking in this way, and converting them into heat to prevent the growth of amplitude. To do.

The simplest way to cause interference is to make it collide. However, in ordinary high-rise buildings mainly made of concrete, there is a risk that the concrete may be damaged by the collision, or because the interference only occurs at the moment of collision. Not very recommended. It is effective to connect the two via a shock absorber as a method of effectively absorbing and suppressing the energy of shaking of a high-rise building by gently interfering with the concrete and avoiding damage to the concrete. Adopt the method.
This shock absorber is intended to suppress shaking by absorbing the energy of the building that is shaking due to the earthquake and converting it into heat. Various types of shock absorbers are possible. Although it is effective to use the friction force generated when the plates move by moving the plates, the adjustment of the friction force is difficult, so it is not a good method. A spring by itself has little ability to convert energy into heat and is not suitable for this purpose. A generally used piston cylinder type oil damper (dashpot) has a stable performance as a shock absorber and can be recommended as a reliable one that operates reliably. Of course, other liquids such as water, or those using alcohols such as glycol or glycerin may be used instead of oil, and an appropriate liquid may be selected from the viscosity and stability.

When connecting the elevator core and the outer part with an oil damper, it is not possible to use a universal joint or a joint instead of a normal bracket at both ends of the oil damper so that earthquake vibrations can be dealt with in either the vertical, front-rear, or left-right direction. It is desirable to attach an object whose connection part can move freely, such as a ball joint. This is because it is possible to cope with movements occurring in any of the vertical, front-rear and left-right directions by the pivoting movement of the universal joint or the ball joint and the expansion / contraction movement of the oil damper.

In general, universal joints minimize the friction of moving parts to avoid power loss. However, the universal joints have some friction to absorb the energy of earthquakes. Is more effective in absorbing shaking. However, since it is counterproductive to rust and lock, a universal joint with less friction is better in that sense.

The shape of the cross section of the elevator core is generally considered to be a quadrangle. A shock absorber for absorbing vibration may be provided near both ends of each side of the upper part of the elevator core where the amplitude is the largest. However, if the elevator core is large and the length of the side is long, this alone is insufficient in the buffering capacity. Therefore, the number of shock absorbers is increased according to the length.

It is also effective to provide the shock absorber not only at the top of the elevator core but also at a height of one third from the bottom. This is because vibration resonating at a frequency three times the fundamental frequency can be absorbed. However, as described above, the amplitude when resonating at a frequency that is three times the fundamental frequency is not so large, and it can be said that the meaning of supplementing the capacity of the upper shock absorber is stronger. Of course, it is desirable from the standpoint of performance to install more shock absorbers by providing other places such as, for example, each floor, although the economic burden increases. However, care must be taken so that the number does not increase so much that the coupling force between the elevator core and the outer portion connected by the shock absorber increases and the two do not shake together.

With the method described above, the earthquake resistance of high-rise buildings can be implemented at a very low cost without impairing convenience. This method can be applied not only to a high-rise building but also to a lower building if it is a building having an elevator. In this case, since the height of the building and the elevator core is lowered, the natural frequency is increased, and the vibration that resonates with the short-period seismic wave is prevented as compared with the case of the high-rise building.

Claims (1)

The elevator core installed in the building subject to earthquake resistance and the entrance / exit lobby part are structurally separated from other parts and made independent and integrated into a columnar structure, which is defined as an elevator core. With respect to the elevator core and the outer part in which the part other than the elevator core of the building is defined as the outer part, the difference between the natural frequency of the elevator core and the natural frequency of the outer part is increased as much as possible. A method of making a building earthquake resistant by connecting the outer shell part via a shock absorber.