Design and Analysis of Modular Steel Mould Systems for SUPERDUCT Precast Arch Drainage Structures

Based on field data, 3D modelling, and systematic capability analysis of T3, T5, and T9, the following conclusions are established: 1.  Capability improves with size — T9 delivers 3.80× the hydraulic opening at only 1.95× the mould weight of T3. Total mould weight per m³ of concrete improves 24.5%. 2.  Hydraulic capability is the strongest indicator — mould weight per m² of water opening drops 48.6% from T3 to T9 (937 → 482 kg/m²). This should be the primary criterion for mould size selection. 3.  Panel design is consistently calibrated — total mould weight per m² of surface varies only ±4% (139.9–145.4 kg/m²). No over-engineering of larger panels observed. 4.  Collar is the priority optimization target — growing 2.23× vs 1.95× for total weight. For sizes beyond T9, collar joint design must be revisited. 5.  T5 internal panel correction to 1,051 kg restores consistent progression in all capability ratios across the three sizes. 6.  Design benchmarks for future moulds — (a) Total wt/m³ concrete < 1,187 kg/m³; (b) Total wt/m² water opening < 482 kg/m²; (c) Total wt/m² surface = 141–146 kg/m²; (d) Collar fraction < 20%. 7.  Trend extrapolation (Fig. 10) projects a hypothetical T-next mould at ≈ 5,900–6,200 kg total weight with water opening per m² surface continuing to improve, guiding future design targets. 8.  AI tools show promise — Claude AI generated 2D profiles and stiffener layouts but could not complete autonomous 3D assembly. Structured AI workflows with engineering validation represent a viable future direction.

[1]  Indian Roads Congress, IRC:SP:13-2004, Guidelines for the Design of Small Bridges and Culverts, New Delhi, India, 2004. [2]  Bureau of Indian Standards, IS 456:2000, Plain and Reinforced Concrete — Code of Practice, New Delhi, India, 2000. [3]  Precast Concrete Institute, PCI Design Handbook: Precast and Prestressed Concrete, 8th ed., Chicago, IL, USA: PCI, 2017. [4]  Anthropic, "Claude AI," Conversational AI System, San Francisco, CA, USA, 2025. [Online]. Available: https://www.anthropic.com [5]  Buttibori Fabrication Yard, Nagpur, Maharashtra — Mould Component Documentation and Weight Records, 2025. (Field Data) [6]  VNIT Nagpur, Structural Test Models for SUPERDUCT Proof Loading, Dept. of Civil Engineering, Nagpur, India, 2025. [7]  National Highways Authority of India, NHAI Standard Specifications for Cross-Drainage Works, New Delhi, India. [8]  Central Road Research Institute, CRRI Technical Report on Precast Concrete Drainage Structures for Highway Projects, New Delhi, India.