Pre-Positioned Deployable Mobile Tsunami Barrier System with Semicircular Battlement Wall Geometry, Hydraulic Erector Mechanism, and Integrated Civilian Survival Pod

Tsunami events represent among the most destructive natural disasters, causing catastrophic loss of life along densely populated coastlines. Existing mitigation strategies have fundamental limitations: permanent seawalls are expensive and coastline-specific, while evacuation-dependent strategies fail for near-field seismic events where warning times may be as short as 5–10 minutes. This paper proposes the Mobile Tsunami Barrier System (MTBS) — a pre-positioned deployable coastal barrier that activates automatically within 2–3 minutes of a seismic trigger signal from national early warning systems. Key innovations include: horizontal storage in promenade garage cavities with hydraulic erection to 10-metre operational height; a semicircular curved wall face that reduces net bending moment by approximately 36% relative to a flat wall; a battlement upper edge profile providing 12% pressure relief; hydraulic percussion ground anchors; vacuum interlocking between units; and an integrated civilian survival pod rated for 4 persons and 72-hour autonomous operation. The paper provides full hydrodynamic derivation of force and bending moment reduction, vehicle anchoring anti-sliding and anti-overturning analysis, material specification to Eurocode 3, a six-step deployment sequence, scalability from 60 metres to 13 km of coastline, and a structured comparison against permanent seawalls, super levees, and MOSE flap gates. An illustrative case study applies the system to Marina Beach, Chennai, India. This is a conceptual design and feasibility analysis; CFD validation and prototype testing are identified as future work.