Civil engineering systems such as a Buildings, sump pits, playgrounds and fibers are designed for a very long lifetime. These products serve as supporting infrastructure for private and business transactions of our society. Various factors such as daily usage, weather conditions and severe events (such as earthquakes, floods or landslides) and their combination contribute to systems deterioration and sometimes to their failure.
Maintenance actions typically classified as preventative and substantial. Preventative maintenance actions taken to prevent deterioration and keep the structure fully operational while substantial maintenance actions are taken to repair an existing damage and improve the condition. Substantial maintenance work is usually comprehensive while preventative maintenance work is relatively small scale.
Preventative maintenance activities on sump pits, concrete slab or column, playground and fiber cables are typically focused to reduce the impact of water and usage capacity from the people and children. The main goals are as follows:
- Ensuring proper drainage of water in the structure from to the sump pits.
- Sealing with proper materials of structural concrete slab or columns elements from exposure to water
- Improving the surface conditions in playground area to prevent accelerated deterioration
- Providing proper matetrial for fiber optic cables
Substantial maintenance activities on sump pits, concrete slab, playground and fiber optic, on the other hand, are as follows:
- Repair
- Replacements
INDIVIDUAL MAINTENANCE PLANS OF SUBSYSTEMS
An efficient intervention plan for each component is required to obtain an efficient integrated system plan. Individual plans are shown below:
Fig 1. Individual timelines of Subsystems
| Type of Intervention | Abbreviation | Duration(days) | Ideal Frequency(years) |
| Precast sump pit Maintenance | PS-M | 30 | 10 |
| Precast sump pit Replacement | PS-R | 60 | 30 |
| Steel Minor Repair (Surface) | S-M | 10 | 20 |
| Steel Structural Repair | P-R | 40 | 50 |
| Cable Addition -> Inserting another wire into the tube | C-A | 4 | 20 |
| Cable Replacement | C-R | 10 | 20 |
| Maintenance of Steel Concrete Slabs | SC-M | 15 | 20 |
| External Inspection of Steel Concrete Slabs | SC-I | 10 | 10 |
| Asphalt Surface for walkway around playground area Replacement | AS-R | 8 | 25 |
| Playground Intermediate and Base Layer Replacement | PIB-R | 18 | 60 |
| Playground Surface Maintenance | PS-M | 4 | 10 |
| Playground Intermediate and Base Layer Mainenance | AIB-M | 4 | 20 |
INTEGRATED STRATEGY
Maintenance of a civil system rely on information collected on its components, which can provide the us an accurate assessment of the overall condition state.
Our aim is to minimize the duration of the interventions and to maximize the gap between them. We can attain this goal by aligning the maintenance strategies of the subsystems. After integrating the maintenance plans of all subsystems, the following timeline and pareto plots are obtained:
Fig 2. Integrated Timeline
The optimal option would be obtained by is minimizing the duration of the interruptions and maximizing the distance between interventions. We can rank the alternatives to evaluate and select the best alternative which is the best for our preference. 320 alternatives are ranked in the plot below based on our preference.
Fig 3. Ranking of Alternatives
Our preference is visualized by the Pareto frontier in the first graph below. The blue line represents the Pareto frontier and the dark black point in the top-left corner represents the best alternative based on the preferences. In the second graph, the opposite case is represented, which is low distance and high duration.
Fig 4. Lowest Duration – Highest Distance and Highest Duration – Lowest Distance Alternatives