Procedure of Life-Cycle Management

Figure 2 shows the standard procedure of LCM.For a new structure,an LCM scenario should be formulated during or after the planning stage of the structure.The scenario includes the fundamental strategy on how the structure will be managed in terms of structural performance and sustainability aspects.The structure is generally designed to keep its structural function and performance without major interventions;however,planned interventions can be included in the scenario if they are required.The scenario mediates among the stages of the structural life-cycle.Design will be carried out to satisfy the scenario initially formulated.When the design outputs do not satisfy the scenario,either the scenario is modified to be consistent with design outputs and/or design is carried out again.After the execution,initial assessment is carried out to check the conditions of the structure.When any defect is found from the assessment,interventions should be taken as required.Then,it will be judged whether the scenario is suitable for the subsequent lifecycle of the structure or not.When the scenario is found to be unsuitable,the scenario should be updated.During the use stage,the structure is periodically assessed its conditions and performance possessed,and the above procedure should be repeated.When the scenario has been updated,the updated scenario should be reflected on subsequent management.If it is judged that interventions should not be taken from the sustainability evaluation mentioned later,the structure goes to the end-of-life stage.

Figure 2　Standard procedure of life-cycle management

For an existing structure,the assessment should be carried out before starting the LCM procedure.The scenario is formulated according to the result of the first assessment and documents even they may not be enough.When the assessment results conclude that interventions are difficult to take to recover structural performance,the structure goes to the life-of-end stage;otherwise,the same procedure as that for a new structure can be followed.