Recently, with the slow rotation of the red cutterhead of the "Haihe No. 1" shield machine, the right line shield of the rail transit line B1 Jinlindao Station - Tianjin Avenue Station (hereinafter referred to as the Jintian section) constructed by the rail company successfully crossed the Haihe River.
The right line of the shield in the Jintian section started
The Jintian section is constructed by shield method, with a length of about 850m on the right line and a length of 225m across the Haihe River, which is the longest subway shield tunnel crossing the Haihe River in Tianjin. Since the cutterhead of the shield machine arrived on the south bank of the Haihe River on March 28, it officially began to cross the Haihe River, and after 16 days, it successfully arrived at the north bank of the Haihe River, with an average daily construction of about 14m.
The forming tunnel line is smooth and leak-free
This project is the first subway tunnel with a shield crossing the Haihe River within the Binhai New Area. There are many problems such as shallow overburden, high water pressure, small radius, complex geological conditions, etc., the section is located on the right-turn small radius circular curve and is located in the uphill section, the underpass river channel covers the soil shallowly, the shield construction is difficult, the safety risk is large, and the construction technology requirements are extremely high.
Wang Yong, deputy secretary of the party committee and general manager of the group, went deep into the scene to guide the work
In order to solve the above problems, the railway company organized the project to set up a test section before crossing the Haihe River, and selected the best tunneling parameters through summary analysis. In the process of traversing, strictly control the shield tunneling parameters such as earth pressure and grouting pressure, and issue a tunneling instruction table every 10m according to the geological conditions, the thickness of the crossed soil and the groundwater level, etc., focusing on controlling the cutterhead speed, cutterhead torque and slag output to reduce the disturbance to the surrounding soil, and control the shield to advance at a uniform speed to ensure that the shield is effectively filled after passing through the formation, and at the same time, it will not break through the riverbed due to excessive pressure, resulting in water and sand gushing at the tail of the shield.
The right line shield of the Jintian section successfully crossed the Haihe River
The parties involved in the construction took a number of targeted measures during the crossing: inviting external experts to guide them, and the internal experts of the construction unit monitored the whole process during the crossing. Hold a regular meeting every day to analyze and study the shield parameters and monitoring situation, and immediately analyze the causes and rectify any subtle problems. Strictly check the incoming materials, check the maintenance of the shield machine and the allocation of vulnerable spare parts every day, improve the attendance rate of the equipment, and ensure the continuity of the crossing construction. In view of the shield leakage water, emergency drills were organized before the crossing, and surprise emergency drills were carried out during the crossing process, and an inspection team was set up to inspect the river every hour. With the joint efforts of all parties, the construction of the shield crossing the Haihe River was successfully completed.
The surface of the Haihe River
Emergency drills
The smooth crossing of the first-class risk source of the Haihe River by the right line shield in the Jintian section is a great encouragement to all parties involved, and it has also accumulated rich experience for the next shield construction. All participants are confident that the rail transit line B1 will be built into a high-quality, safe and efficient high-quality project, and create a safe, convenient, comfortable and sustainable rail transit line for the people of the new area.
Source: Binhai Construction Investment