地下通道的清洁与维护：面材耐久性

Render a pedestrian underpass detailed specifically for ease of cleaning and long life, showing the maintenance logic. Show the walls in large-format porcelain panels with minimal joints, coved at the base into the floor so there is no dirt-collecting internal corner anywhere, and a stainless trim protecting every external arris. Detail the floor as a seamless terrazzo falling gently to a slim linear channel drain running along one wall, with a removable stainless grating and a visible washdown point with a hose bib in a lockable recess. Show the ceiling panels as demountable with quarter-turn fasteners, one panel lifted to reveal the services above — cable trays, a sprinkler main and a duct — with a maintenance operative on a small platform working there. Detail an anti-graffiti coating implied by a wall surface being wiped clean, with one small tag half removed. Show all fittings as flush and impact-resistant, with no surface-mounted boxes at hand height. Include a cleaning trolley and wet floor sign. Photorealistic, clean, pale and hard-wearing, eye-level view.