JP2002327491A - Earthquake-resistant design method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake-resistant design method by taking the earthquake loss index into consideration as an evaluation index of the earthquake- resistant performance which permits an efficient earthquake-resistant design. SOLUTION: This design method features each stage described below; (1) A preliminary design stage determining the preliminary plan for the structure described above in such a manner that the predetermined approximate earthquake loss required can be satisfied by using a presumed earthquake motion and basic specification information for the structure. (2) Final design stage determining the detailed plan for the structure so as to satisfy the detailed earthquake loss value requested by using the presumed earthquake motion, basic specification information of the structure and the results of preliminary plan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic design method for various structures.

[0002]

2. Description of the Related Art In Japan, there are many earthquakes due to its geographical conditions. Therefore, when designing major structures (building structures and civil engineering structures), it is general that seismic design is performed. . Conventionally, in seismic design of structures, the seismic motion input to the structure is determined, the behavior of the designed structure when the seismic motion is applied is examined, and the safety of the structure against horizontal strength and toughness is evaluated. Was to be done. At that time, in order to ensure the safety of the designed structure, the input seismic motion and the safety factor were extraly evaluated to evaluate the safety and the like.

On the other hand, in recent years, real estate securitization has attracted attention for the purpose of contributing to the construction of efficient structures in urban areas and the like. At that time, the maximum expected loss value (PML)
Attempts have been made to evaluate the seismic performance of structures (real estate) using seismic loss indices such as values). This seismic loss index is an index that quantitatively evaluates the damage of a structure by examining the seismic damage specific to the structure and using a probabilistic method. Indicates that the structure has high seismic performance. Therefore, when designing the structure, the value of the seismic loss index (hereinafter referred to as the "seismic loss value")
In many cases, it is required to satisfy the upper limit.

[0004]

FIG. 5 shows an existing seismic design method. Specifically, a basic design and a practical design of a target structure (hereinafter, referred to as a “target structure”) are performed so as to satisfy a predetermined proof stress index (S
1 ′, S2 ′), calculate the earthquake loss value after the end of the implementation design. Then, the calculated earthquake loss value (hereinafter referred to as “calculated earthquake loss value”) is compared with a predetermined required earthquake loss value (S3 ′). At this time, if the calculated earthquake loss value satisfies the required earthquake loss value, the design is terminated, but if the calculated earthquake loss value does not satisfy the required earthquake loss value, it is necessary to continue the operation again. Here, if the calculated earthquake loss value does not greatly differ from the required earthquake loss value,
Again, design the implementation to satisfy the required earthquake loss value.
If the calculated earthquake loss value is significantly different from the required earthquake loss value, the basic design is re-designed, and then the practical design is performed (S4 '). Therefore, if the calculated earthquake loss value is significantly different from the required earthquake loss value, the efficiency becomes extremely low.

The seismic loss value is an index that depends not only on the structural design of the structure but also on the overall structure of the structure, which fluctuates depending on the arrangement of the equipment provided in the target structure. By devising the design, the value can be improved. For example, when the structure is a high-rise building structure, if the shaking of the lower part is smaller than the shaking of the upper part, the equipment is damaged by providing the equipment at the lower part of the structure. The probability can be reduced. As described above, when the earthquake loss value is used as an index, it is particularly important to consider this at the basic design stage. Therefore, by taking the above measures, the earthquake loss value can be reduced efficiently. But,
At present, the seismic loss value is not evaluated between the basic design and the actual design.Therefore, in the actual design stage, the design must be designed to satisfy the required seismic loss value only with the structural design of the structure. And efficient design could not be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and considers an earthquake loss index as an evaluation index of the seismic performance of a structure, and enables an efficient seismic design. It aims to provide an earthquake-resistant design method.

[0007]

In order to solve the above-mentioned problems, a seismic design method of the present invention is characterized by including the following steps. (1) A basic design stage in which a basic plan of the structure is determined so as to satisfy a predetermined required approximate earthquake loss value, using the ground motion assumed in advance and basic specification information of the structure. (2) An implementation design step of determining a detailed plan of the structure so as to satisfy a required detailed earthquake loss value by using the presumed earthquake motion, the basic specification information of the structure and a result of the basic plan. .

[0008] Here, the basic specification information of a structure is a basic condition for designing a target structure, such as a location position and a ground condition (hereinafter, may be referred to as a "location condition or the like"), a structure, or the like. Basic data such as the external dimensions of an object. The basic plan of a structure is the structure type, structure type,
Determining the basic form, arrangement of structural members, presence / absence of seismic isolation / damping structure, arrangement of major equipment, etc.
The detailed plan of the structure is the design of the members of the target structure, and
This refers to determining the detailed structure such as the detailed specifications of the equipment to be arranged on the target structure.

The seismic loss index of a structure is an index that quantitatively evaluates the seismic damage of a structure by using a stochastic method. An index calculated based on the amount of physical loss of finishing materials and equipment. For example, the expected loss value for the predetermined non-exceeding probability [the amount of loss at the time of the predetermined non-exceeding probability caused by an earthquake during a predetermined reproduction period (an earthquake that occurs once during a predetermined reproduction period), An index expressed as a ratio to the replacement cost (cost of constructing a similar structure), and the damage risk value for a specified period (average amount of damage caused by an earthquake during a specified period)
Are typically used.

When the expected loss value with respect to the predetermined non-exceeding probability is used, the value when the reproduction period is 475 years and the non-exceeding probability is 90% is the maximum expected loss value (hereinafter, referred to as the maximum expected loss value).
The value in the case where the recall period is 475 years and the non-exceeding probability is 50% is called an average expected loss value (hereinafter, referred to as “NEL value”). Further, in the above-mentioned predetermined period damage risk value, when the period is set to one year, it is called an annual risk value. In addition, the loss value may include an economic loss amount due to being unable to perform economic activities due to the earthquake. In addition, it is possible to add the loss amount for secondary damage such as human life and fire.

Further, the evaluation of the earthquake loss value is performed in two stages, a basic design stage and a practical design stage. For this reason, it is preferable to calculate and evaluate earthquake loss values in the basic design stage in a simple manner and to perform detailed evaluation of earthquake loss values in the implementation design stage in order to perform efficient design. . However, the required approximate earthquake loss value and the required detailed earthquake loss value need to be set to matched values, but may be set in any manner as long as the conditions are satisfied. Therefore, the required general earthquake loss value and the required detailed earthquake loss value may be the same value, or the required general earthquake loss value may be a value having a predetermined range, and the required general earthquake loss value may be the required general earthquake loss value. The value may be set to satisfy a stricter condition than the value.

In the basic design stage and the practical design stage,
As in the conventional case, it goes without saying that the basic plan and the design of the structural members and the like are designed so as to satisfy the target response value (allowable strength, allowable displacement amount, etc.) of the structure with respect to the given earthquake motion.

According to the seismic design method of the present invention, the basic design is carried out for the target structure after satisfying the required approximate seismic loss value, and the practical design is performed. The method of calculating the seismic loss value is adopted. Therefore, since the earthquake loss values in the basic design stage and the practical design stage do not greatly differ from each other, it is possible to avoid the inefficient work of performing the basic design after the practical design as in the related art.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. The structure targeted in the present embodiment is a multi-story building structure.

[Earthquake Loss Index] First, before describing the seismic design method of the present invention, an earthquake loss index of a structure will be described. Various indexes can be used as the earthquake loss index. For example, when the annual risk value is used, it is calculated by calculating the total of the product of the earthquake occurrence probability in a predetermined period for each earthquake scale and the amount of earthquake loss in the corresponding target structure for each earthquake scale. can do.

Since the probability of earthquake occurrence differs depending on the location of the target structure, ground conditions, and the like, the probability of earthquake occurrence is stored in a database in association with the location conditions of the target structure and the like, and the location conditions and the like are stored. It is preferable to output the earthquake occurrence probability by inputting it when performing data processing.

Further, since the amount of earthquake loss differs depending on the earthquake scale and the detailed structure of the target structure, it is stored in a database in association with the earthquake scale and the corresponding detailed structure of the target structure. It is preferable to output the amount of the earthquake loss by inputting the input data, which is suitable for performing data processing. In the present embodiment, the amount of earthquake loss is calculated as the amount of physical loss or the sum of the amount of physical loss and the amount of economic loss. The physical loss is the amount of loss when the structure itself and its associated finishing materials, equipment, or equipment are damaged. For example, restoration (repair, replacement) of a damaged structure, etc. ) Can be determined by the cost required. In addition, the economic loss amount is the loss amount due to the suspension of business due to the earthquake,
As an example, it can be obtained by multiplying the number of days of business suspension by the unit operating loss (operating loss per day).

[Seismic Design Method] The seismic design method of the present invention comprises two stages, a basic design stage and a practical design stage.

(1) Basic Design Stage In the basic design stage, a predetermined required approximate earthquake loss value is determined by using a presumed earthquake motion (hereinafter referred to as “assumed ground motion”) and basic specification information of the target structure. The operation for determining the basic plan of the structure is performed so as to satisfy the following conditions, and includes the following steps (see FIG. 1).

(Step 1 (S1)) In this step, the expected ground motion of the target structure with respect to the seismic target, the location conditions (basic specification information), the external dimensions which are the basic specifications of the structure, the standard floor area And the like to determine basic specification data. Here, the assumed ground motion determines an epicenter position and an earthquake magnitude. In addition, the location of the structure is appropriately selected and used at the prefectural level, the municipal level, or at a smaller level.
As the ground condition, data of a classification such as hard, normal, or soft, or more detailed data is appropriately selected and used.

(Step 2 (S2)) In this step, a basic plan of the target structure is determined.
Here, the basic plan of a structure means a structure type (reinforced concrete structure, steel frame structure, steel frame reinforced concrete structure, steel pipe concrete structure, etc.), a structure type (truss, ramen, shell, etc.), a foundation type (solid foundation, footing foundation, Pile foundation, etc.), the arrangement of structural members, the presence or absence of seismic isolation and vibration control structures, and the outline of the layout of major equipment, etc., are determined in advance so that the calculated response values meet the seismic target. It is necessary to perform so as to satisfy the target response value of the determined target structure.

(Step 3 (S3a, S3b)) In this step, an approximate earthquake loss value is calculated using the strength index of the structure or the presence or absence of a seismic isolation structure or a damping structure, and its evaluation is performed. . Here, if the calculated approximate earthquake loss value is equal to or less than the required approximate earthquake loss value, the basic design is terminated,
We will move on to the implementation design. When the calculated approximate earthquake loss value exceeds the required approximate earthquake loss value, the basic plan is again appropriately corrected so as to satisfy the above condition.

In this step, in order to easily calculate the approximate earthquake loss value, it has been found based on past knowledge.
It is characterized by using a relation that exists between the strength index or the presence or absence of the seismic isolation structure and the damping structure and the earthquake loss value. For example, as the strength index, when the deformation performance of the structure is plotted on the horizontal axis and the strength of the structure is plotted on the vertical axis, the same level point of the seismic loss value of the structure having the corresponding deformation performance and strength is plotted as contour. ), A relationship as shown in FIG. 2 (curved rightward with respect to the origin) can be found. Therefore, by storing the relationship between the strength index of the structure and the earthquake loss value in the database in advance, the approximate earthquake loss value can be immediately calculated based on the strength index of the structure after the basic plan is determined. .

As shown in FIG. 3, between the input energy (hereinafter referred to as "earthquake input energy") and the earthquake loss value for the structure of the earthquake motion, the smaller the earthquake input energy is, the smaller the earthquake loss value becomes. There is a predetermined relationship of becoming smaller. In general, for structures
The seismic input energy decreases when the seismic isolation structure and the damping structure are adopted. (Fig. 3 shows that the seismic input energy decreases when the seismic isolation structure is adopted than when the seismic isolation structure is adopted.) ), The relationship between the seismic input energy to the structure and the various seismic structures is stored in a database in advance, so that when the seismic structure of the structure specified in the basic plan is given, The approximate earthquake loss value can be calculated immediately.

In the above description, an example of calculating the approximate seismic loss value is shown, and the strength index of the structure and the presence or absence of the seismic isolation structure and the vibration control structure are closely related. Therefore, in actuality, the approximate earthquake loss value is simply calculated by comprehensively judging the strength index of the structure and the presence or absence of the seismic isolation structure and the vibration control structure.

(2) Implementation Design Stage The implementation design stage uses the assumed ground motion, the basic specification information of the target structure, and the result of the basic plan so as to satisfy the required detailed earthquake loss value. The work for determining a detailed plan is performed by the following steps (see FIG. 4).

(Step 4 (S4)) In this step, the member design (number of members, member cross section, etc.) is performed based on each data obtained from the result of the basic plan created in the basic design and information on the equipment to be installed. , Used materials, etc.) and a detailed plan such as detailed specifications of the equipment to be arranged in the structure.

(Step 5 (S5)) In this step, the response value of the target structure when a simulated seismic wave is applied is evaluated (detailed seismic response analysis). The simulated ground motions are based on the assumed ground motions described above, and use data of reference ground motions (energy, amplitude, phase, etc.) accumulated mainly from past ground motion studies. , And can be created using conventional methods. In this step, it is determined whether or not the response value calculated based on the detailed plan satisfies the target response value. If the target response value is not satisfied, the detailed plan is set so as to satisfy the condition. It needs to be modified appropriately. This step is to perform a general response analysis of the target structure.

(Step 6 (S6a, S6b)) In this step, the detailed earthquake loss value of the target structure is calculated and its evaluation is performed. As described above, this detailed earthquake loss value is calculated by using the earthquake occurrence probability and the amount of earthquake loss as main data.For example, when the annual risk value is used, the By calculating the sum of the product of the one-year earthquake occurrence probability for each earthquake scale at the site and the corresponding amount of earthquake loss of the target structure (including equipment and equipment installed inside) for each earthquake scale It is calculated.

When the calculated detailed earthquake loss value is equal to or smaller than the required detailed earthquake loss value, the practical design is terminated. Further, when the calculated detailed earthquake loss value exceeds the required detailed earthquake loss value, it is necessary to appropriately correct the detailed plan again so as to satisfy the above condition.

As described above, according to the seismic design method of the present invention, the basic design is performed so as to satisfy the required approximate earthquake loss value, and further, the practical design is performed to satisfy the required detailed earthquake loss value. The method of calculating the earthquake loss value in two stages, the stage and the implementation design stage, is adopted. Therefore, the inefficient work of performing the basic design after the actual design as in the related art can be avoided without the seismic loss values at the actual design stage and the basic design stage differing greatly. Also, at the basic design stage, a basic plan was created to satisfy the required rough earthquake loss value,
By performing the implementation design so as to match the required approximate earthquake loss value, it is possible to efficiently suppress the detailed earthquake loss value.

As described above, an example of the preferred embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and it goes without saying that the design of each of the above-described components can be appropriately changed without departing from the spirit of the present invention. In particular, the structure is not limited to a building structure, but can be applied to various structures such as civil engineering structures. The earthquake loss index is a PML value, N
Various indices such as the EL value can be used. Furthermore, various seismic loss indices can be calculated by various methods according to the importance of the structure and the like. Also,
In determining a detailed plan, a plurality of detailed plans can be assumed, and the required detailed earthquake loss value can be selected by selecting a detailed plan that is an optimum value that satisfies the required approximate earthquake loss value. .

[0033]

According to the present invention, it is possible to provide a seismic design method capable of considering a seismic loss index as an evaluation index of the seismic performance of a structure and enabling an efficient seismic design.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a basic design stage in a seismic design method of the present invention.

FIG. 2 is a graph showing a relationship between a proof strength and a deformation performance of a structure and an earthquake loss value.

FIG. 3 is a graph showing a relationship between an input energy to a structure subjected to an earthquake motion and an earthquake loss value.

FIG. 4 is a flowchart showing an implementation design stage in the seismic design method of the present invention.

FIG. 5 is a flowchart showing a conventional seismic design method.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaharu Takayama 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Yuichi Kimura 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation (72) Inventor Toshiharu Nakamura 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Corporation (72) Inventor Takaaki Nakamura 4-5-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Stock Company Shinozuka Research Laboratory

Claims (1)

[Claims] 1. A seismic design method comprising the following steps. (1) A basic design stage in which a basic plan of the structure is determined so as to satisfy a predetermined required approximate earthquake loss value, using the ground motion assumed in advance and basic specification information of the structure. (2) An implementation design step of determining a detailed plan of the structure so as to satisfy a required detailed earthquake loss value by using the presumed earthquake motion, the basic specification information of the structure and a result of the basic plan. .