Overview
ISO 18407:2018 - Simplified design of prestressed concrete tanks for potable water gives practical guidelines for planning, designing and constructing ground-supported cylindrical tanks made of prestressed concrete (PC) for potable water. The standard applies to tanks with capacities up to 30 000 m3 and a diameter-to-height ratio (D/H) from 1.0 to 3.0. It covers design principles, loadings, structural analysis, material properties, stress limits and member detailing for roofs, walls and base slabs. Where other tank types (reinforced concrete, underground, elevated) are involved, designers can still refer to ISO 18407 for common elements where applicable.
Key Topics and Requirements
The standard addresses technical topics essential for safe, economical prestressed concrete tank design:
- Scope, terms and symbols - definitions and notation for consistent design communication (Sections 1–4).
- Design principles - overall approach to simplified, reliable design (Section 5).
- Loads - comprehensive load catalogue including deadweight, imposed loads, hydrostatic water pressure, prestressing effects, creep and drying shrinkage, temperature, seismic action, wind, snow, earth and uplift pressures (Section 6).
- Prestress requirements - treatment of prestressing force immediately after stressing, effective prestress, and indeterminate forces from prestress (Section 6.5).
- Material properties - guidance on concrete and steel strength, modulus of elasticity, creep, shrinkage and steel relaxation (Section 7.2–7.3).
- Structural analysis and member design - calculation of member forces, stress limits for reinforced and prestressed members, verification methods (Sections 7–8, 11).
- Seismic verification - seismic design principles, input motions, seismic coefficient methods, dynamic analysis and safety checks (Section 9).
- Construction details - prestressing steel layout, reinforcement rules, concrete cover, joints, openings and anchorage detailing (Section 10).
- Materials and durability - selection and specification of materials suited to potable water containment (Section 12).
Practical Applications and Users
ISO 18407:2018 is intended for:
- Structural and civil engineers designing ground-supported prestressed concrete potable water tanks.
- Water utilities and municipal planners specifying tank performance and capacity (≤ 30 000 m3).
- Contractors and precast manufacturers implementing prestressing, reinforcement detailing and joints.
- Regulators and reviewers assessing compliance with recognized design practice.
Use cases include design and construction of new PC storage tanks, retrofit assessments, and as a reference for common detailing when working on other tank types.
Related Standards
Designers should use ISO 18407 alongside national building codes, local seismic regulations and relevant standards on concrete, prestressing, waterproofing and potable water systems to ensure full regulatory compliance.