Here is a concise summary of the provided text:
**Project Overview**
* **Tokyo Bay Crossing Road**: A massive infrastructure project connecting Tokyo, Kawasaki, and Kisarazu
* **Started**: 1989
* **Length**: 15.1 km (9.5 km from Kawasaki, 4.4 km from Kisarazu, and 1.2 km underwater tunnel)
* **Goal**: Alleviate traffic congestion and reduce travel time (e.g., ~15 minutes to Ryonan Gum by car)
**Construction Challenges & Innovations**
* **Soft ground and high water pressure**: Utilizing the "Base Conscious Shield Construction Method"
* **World's largest shield tunnel machine** (14.14m outer diameter) for underwater excavation
* **Super-large crane ship** (4,100-ton lifting capacity) for transporting massive tunnel segments
* **Automatic assembly system** for efficient and safe tunnel construction
* **Freezing method** for stabilizing soft earth during excavation
**Construction Process**
* Excavation from Kawasaki artificial island towards Kisarazu
* Tunnel segments assembled using robotic assistance
* Temporary and final lining construction simultaneously
* Waterproofing and completion of the two-lane road tunnel
Here are the key facts extracted from the text, each with a number and in short sentence form, excluding opinions:
**Project Overview**
1. Construction work on a crossroads in Tokyo Bay began in 1989.
2. The project connects Tokyo with a bridge, making it the largest offshore civil engineering project worldwide.
3. The project spans from Ukishima (Kawasaki side) to Sera and artificial islands, then through an undersea tunnel to Kisarazu.
**Construction Details**
4. The project's total length is approximately 15.1 km.
5. 9.5 km of the project are on the Kawasaki side.
6. 4.4 km on the Kisarazu side will be a narrow tunnel.
7. A 10 km long shield tunnel section includes a Kawasaki artificial island.
8. Two tunnels will be constructed in each section, divided into 8 sections.
**Technical Specifications**
9. The shield tunnel's inner diameter is 98 meters.
10. The depth of the earth retaining wall reaches 114 meters below sea level.
11. A sealed muddy shield machine with an outer diameter of 14.14 meters is used for excavation.
12. The machine is propelled by 48 500-ton jacks, generating 24,000 tons of power.
**Innovative Methods**
13. An automatic assembly system is introduced to save labor and ensure safety.
14. A super-large crane ship with a 4,100-ton lifting capacity is used for transportation and assembly.
15. The project utilizes a freezing method to stabilize ultra-soft ground and prevent seawater inflow.
**Tunnel Completion**
16. The tunnel's tertiary lining construction begins simultaneously with temporary reconstruction.
17. The tunnel's final structure includes reinforced concrete for the invert, side walls, middle wall, and floor slabs.
18. A waterproofing sheet is added between the temporary and final reconstructions.