Design of PST / FST / Humus Tank (RCC) using Robot Structural Analysis (part 2)

​Design of Underground RCC Primary Settlement Tank (Eurocode Standards) ​In this tutorial, we demonstrate the professional workflow for designing a Preliminary Settlement Tank (PST) using Autodesk Robot Structural Analysis according to Eurocode (EN 1992-3 for liquid retaining structures and EN 1997 for geotechnical design). ​We move beyond simple stress analysis to cover essential stability verifications, including buoyancy and soil-structure interaction. ​Design Scenarios & Limit States: ​Condition 1: Hydrostatic Test (STR/GEO Set B) - Tank is full, representing maximum internal liquid pressure with no external soil support. ​Condition 2: Maintenance & High Groundwater (UPL/GEO) - Tank is empty, but subjected to maximum external soil pressure and groundwater table, triggering the Uplift (UPL) stability check. ​Objectives: ​Eurocode Modeling: Full 3D FEA modeling of a rectangular settlement tank using RSA, adhering to EN 1992-1-1 and EN 1992-3. ​Uplift Verification (UPL): Performing the buoyancy check (Vdst,d ≤ Vstb,d) considering the safety factors for destabilizing vs. stabilizing permanent actions. ​STR & GEO Analysis: Distinguishing between Structural (STR) failure of the RCC walls/slabs and Geotechnical (GEO) failure of the supporting ground using Eurocode Design Approaches. ​Crack Width Control: Designing for Tightness Class as per EC2 Part 3, ensuring the PST is liquid-tight and durable against effluent. ​Dynamic Soil Interaction: Modeling the base slab using the coefficient of subgrade reaction (Kz) to simulate realistic soil behavior. ​Load Combinations in RSA: Setting up automatic combinations for ULS and SLS specifically for underground tanks. ​FEA Result Interpretation: Extracting reinforcement requirements and analyzing panel maps for moments (Mxx, Myy). ​Efficiency in RSA: Using the "Required Reinforcement" and "Provided Reinforcement" modules to automate Eurocode compliance for liquid retaining panels. ​#RobotStructuralAnalysis #Eurocode #CivilEngineering #StructuralDesign #WastewaterTreatment #ACI350 #EC2 #StructuralAnalysis