@arit_china: Precast concrete tunnel segments are standardized curved concrete components manufactured in factories, transported to the construction site, and then assembled ring by ring at the tail of a tunnel boring machine (TBM) to form the permanent lining structure of the tunnel, serving to withstand surrounding rock pressure, prevent water and soil seepage, and ensure the long-term stable operation of the tunnel.#concrete #construction #constructionlife #civilengineering #concretelife