关键词: 深中通道, 沉管隧道, 钢壳混凝土管节, 智能建造, 浮运安装, 最终接头

Abstract: At the beginning of steel-shell concrete immersed tunnel project of the Shenzhen-Zhongshan Link, the technical gaps in the industrial chain and the bottlenecks of traditional processes were encountered. The goal was to overcome world-class challenges in structural theory, intelligent equipment, and process systems for extra-wide, deep-buried, and variable-width immersed tunnels, and to develop a replicable and promotable Chinese solution for intelligent construction. An innovative “bridge-island-tunnel-underwater interchange” four-in-one engineering scheme was proposed. Based on this scheme, systematic research was conducted on structural theory innovation, intelligent equipment development, and process system construction. The load-bearing mechanism of the steel-shell concrete composite structure was revealed. A bidirectional strengthening flexural design method and a three-mechanism shear design method were established. A “four lines and one system” intelligent manufacturing base was built for steel shells. High-stability self-compacting concrete preparation technology and the world’s first intelligent pouring equipment were developed. The world’s first integrated floating transport and installation vessel was developed. An in-tube push-out final joint smart closure technology was created. A full-process electronic archive management system was also established. The results show that the new structure increased the bearing capacity by 30%, reduced the section height by 16%, and cut the dredging volume by 15 million m³. The measured void ratio with a steel-concrete interface gap of less than 5 mm was no more than 0.05%. A high-efficiency prefabrication goal of “one section per month” was achieved. The integrated vessel and smart installation technology solved the problems of long-distance floating transport and millimeter-level docking of extra-wide and ultra-heavy tunnel elements. The final joint technology saved three months of construction time and about 240 million yuan in costs. The conclusions are as follows: The Shenzhen-Zhongshan Link has fully achieved intelligent construction of offshore steel-shell concrete immersed tunnels, overcome the gaps in the entire industrial chain and technical bottlenecks, and provided complete technical references and demonstrations for subsequent similar super-large cross-sea cluster projects.

Key words: Shenzhen-Zhongshan Link, immersed tunnel, steel-shell concrete tunnel element, intelligent construction, floating transport and installation, final joint