JP2006336280A - Maintenance management method for concrete structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a maintenance management method for reducing the risk of a concrete structure by repairing preferentially from a high risk part or structure. <P>SOLUTION: Risk evaluation is performed using RBM (risk based maintenance) to the concrete structure having a plurality of parts or structures. The plurality of structures are concrete foundations for supporting various devices in a plant facility, and repair is carried out preferentially from the concrete foundation evaluated to be running a high risk. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for maintaining and managing a concrete structure.

In a large facility such as a plant, a life cycle management system has been developed for the purpose of optimizing maintenance costs such as inspection, repair and replacement while ensuring the safety of the facility.
The life cycle management system was mainly intended for steel structures, but it is now being studied for concrete structures.
For example, because concrete structures deteriorate due to various factors such as the natural environment, concrete materials, and construction methods, there is a technology to accurately calculate the costs related to the maintenance and management of concrete structures while taking into account such deterioration factors. It has been proposed (Patent Document 1).
Japanese Patent Laid-Open No. 2001-200355

By the way, in the case of concrete structures that have exceeded the diameter for several decades after construction, the maintenance management method is used to formulate inspection, repair, and renewal plans so that all parts or structures of the structure are below a certain risk. Realization is desired. In other words, it is necessary to clarify a part or structure having a high risk of destruction or the like and to repair the entire concrete structure efficiently by preferentially repairing the part or structure.
However, the above-described technology accurately and optimally calculates the costs related to the maintenance and management of concrete structures. For this reason, a high-risk part is clarified and repaired with priority from that part or structure. There is a problem that the method has not been clarified.

  The present invention has been made in view of the above-described circumstances, and proposes a maintenance management method capable of reducing the risk of a concrete structure by preferentially repairing from a high-risk part or structure. Objective.

In the maintenance management method according to the present invention, the following means are employed in order to solve the above problems.
In the maintenance management method for concrete structures, risk evaluation is performed using RBMs for concrete structures having a plurality of parts or structures.
According to the present invention, in a concrete structure having a plurality of parts or structures, it is possible to perform risk assessment on each part or structure based on “ease of destruction” and “the magnitude of damage”. Therefore, a high-risk part or structure becomes clear. Thereby, it becomes possible to repair with priority from a high-risk part or structure.

In addition, in selecting a target (site or structure) to be subjected to risk assessment from among the plurality of sites or structures, it is not necessary to perform risk assessment for all of the plurality of sites or structures. In addition, it is possible to evaluate the risk of concrete structures.
For example, the present invention can be applied to a structure in which the structure is a concrete foundation that supports (places) various devices in a plant facility.

According to the present invention, the following effects can be obtained.
In a concrete structure having a plurality of parts or structures, since it becomes possible to perform repairs preferentially from a part or structure having a high risk, it is possible to efficiently reduce the risk of destruction of the concrete structure. it can. In addition, appropriate maintenance management costs can be achieved.

Hereinafter, an embodiment of the maintenance management method for a concrete structure of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing an example of a concrete structure to which the method for maintaining and managing a concrete structure of the present invention is applied, and is a view showing a concrete foundation 10 that supports a gas tank 1 in a large plant P.
In a large plant P (for example, an LPG plant or the like), many and many types of devices are installed on a coastal portion in a state of being supported on a concrete foundation 10. The concrete foundation 10 on which these various devices are placed has an increased risk of breakage due to deterioration with age, salt damage, and the like.
For this reason, in order to operate the large plant P safely and efficiently, it is necessary to perform maintenance on all these concrete foundations 10 at an appropriate time. That is, there is a need to perform maintenance management on a concrete structure including a plurality of concrete foundations 10.

FIG. 2 is a flowchart showing the maintenance management method for a concrete structure according to the present embodiment.
As a maintenance management method for the concrete foundation 10, a technique called RBM (Risk Based Maintenance) is used. The RBM may be referred to as RBI (Risk Based Inspection).

The RBM defines the “risk” of a concrete structure composed of a plurality of concrete foundations 10 as the product of “Likelihood” and “Consequence”. And based on the obtained risk evaluation, the final risk of a concrete structure is determined, and a maintenance plan is drawn up based on the risk determined in this way.
The RBM is described in detail in, for example, the magazine “Pressure Technology” Vol. 39, No. 1 (January 2001).

Specifically, first, concrete to be diagnosed is selected from all the concrete foundations 10 (step S1).
Although it is possible to perform risk assessment on all concrete foundations 10, the large-scale plant P or the like has a large number of concrete foundations 10 to be diagnosed. This is because real risk assessment is difficult to achieve.
For this reason, the quality of concrete materials (cement type, type of aggregate, presence / absence of coating material), design specifications, use environment, inspection frequency, deterioration status, etc., from the owner of the large plant P, etc. for all concrete foundations 10 Get the information. And the concrete foundation 10 which needs to perform risk evaluation from these information, ie, the concrete foundation 10 with high possibility that the damage has generate | occur | produced by secular change, is selected.
Thus, efficient risk evaluation becomes possible by selecting in advance the concrete foundation 10 (concrete to be diagnosed) for risk evaluation.

Next, a primary investigation (non-destructive inspection, coring investigation) is performed on “ease of breakage” for each concrete to be diagnosed (step S2).
Specifically, visual inspection (presence / absence of cracks, floating position, etc.), anchor bolt soundness, scale measurement, compressive strength estimation by Schmidt hammer, ultrasonic cracking, rebar thickness / pitch investigation by radar, We will conduct simple investigations such as compressive strength investigation, neutralization depth (especially exposed steel bars), chloride ion content measurement, and alkali aggregate reaction.
And based on these investigation results, for example, four-level evaluation is performed. Specifically, the four-stage evaluation is performed such that the estimated compressive strength by the Schmitt hammer is 15 MPa or less, 15 to 20 MPa, 20 to 25 MPa, or 25 MPa or more.
Then, based on the stage evaluation of all the survey results, a four-stage comprehensive evaluation of “Likelihood” of each diagnosis target concrete is performed (step S3).

In parallel with steps S2 and S3, the “damage magnitude” is investigated for each concrete to be diagnosed (step S4).
Specifically, the properties of various equipment (such as possession of flammable liquid), weight, height, and risk of each equipment (temperature, pressure, momentum ( Investigate the number of revolutions).
And based on these investigation results, the "consequence" of each diagnosis object concrete is evaluated, for example in four steps (step S5).
For example, when the gas tank 1 contains a large amount of high-temperature flammable liquid, the “damage magnitude” of the concrete foundation 10 that supports the gas tank 1 becomes high.

Then, as shown in FIG. 3, for each of the concretes to be diagnosed, the evaluation indexes of “ease of breakage” and “severity of damage” are mapped on the risk matrix, and the risk of each diagnosis target part is mapped. Evaluate (step S6).
Thereby, for example, in the case of FIG. 3 (mapped to the dot-hatched area of the risk matrix), this concrete to be diagnosed (concrete foundation 10) is evaluated as “monitoring required”.
In addition, the concrete to be diagnosed (mapped in the cross-hatched area) is evaluated as “immediate repair”. The hatched area is evaluated as “repair as soon as possible”, and the non-decorated area is evaluated as “no problem”. Is done.

And based on the risk evaluation performed about all the diagnostic object concrete, the final risk of the concrete foundation 10 of the large plant P is determined, Based on the risk determined in this way, the maintenance plan of the concrete foundation 10 is determined. Is planned (step S7).
Then, based on the planned maintenance plan, it is determined whether to perform the repair (step S9), the repair (step S9), and the detailed investigation (step S10).

  As described above, by applying RBM to a plurality of concrete foundations 10 in the large plant P, the priority order of the concrete foundations 10 to be repaired becomes clear, and a concrete maintenance plan for the concrete foundations 10 is drawn up. can do. Thereby, the maintenance cost can be optimized.

  Note that the procedures and the like shown in the above-described embodiment are merely examples, and various modifications can be made without departing from the gist of the present invention.

Although embodiment mentioned above demonstrated the example which provides the process of selecting previously the concrete foundation 10 which should perform risk evaluation from the some concrete foundation 10 in the large sized plant P, it is not restricted to this.
When the number of parts of the concrete structure is relatively small, risk assessment may be performed for all parts.

Moreover, although embodiment mentioned above demonstrated the several concrete foundation 10 which supports (mounts) various apparatuses of a large sized plant as a concrete structure, it is not restricted to this.
Since the present invention can be applied to any structure that basically includes concrete, it may be, for example, a bridge or building made of concrete. In this case, the risk evaluation may be performed by dividing the concrete structure into a plurality of parts such as columns and beams.

It is a figure which shows an example of the concrete structure to which this invention is applied. It is a flowchart which shows the maintenance management method of the concrete structure concerning one embodiment of this invention. It is a schematic diagram which shows the risk matrix color-coded by the risk category in one Embodiment of this invention.

Explanation of symbols

P ... Large plant 1 ... Gas tank 10 ... Concrete foundation (structure)

Claims (3)

  A method for maintaining and managing a concrete structure, wherein a risk evaluation is performed using an RBM for a concrete structure having a plurality of parts or structures.   2. The maintenance management method for a concrete structure according to claim 1, wherein an object to be subjected to risk evaluation is selected from the plurality of parts or structures. The said structure is a concrete foundation which supports the various apparatuses in a plant facility, The maintenance management method of the concrete structure of Claim 1 or Claim 2 characterized by the above-mentioned.

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