The shield tunnel section of left line from xuzhou road station to liuwei road station of tianjin metro line 4 is connected

On July 10, as the "number one" of shield machine in six weft road station of tianjin metro line 4 slowly break out, the subway line 4 of the left line of xuzhou station to six weft road station shield interval smoothly, this is the subway line in the first through the tunnel under construction in tianjin, marked the subway line 4 to achieve the goals of all taken a solid step.

The left line between xuzhou road station and liuwei road station is 722.16m in length. It was built by China railway no.4 bureau. The interval is characterized by complex geological conditions, abundant groundwater, high construction risk and great technical difficulty. Xuzhou road station of metro line 4 is located at the intersection of bengbu road and dagu north road. To minimize for subway construction seal around the impact on the surrounding commercial, through survey, many technological research in many ways, determine the shield machine in xuzhou road station line radius of 300 meters small radius, from 85 - meter long tunnel shield machine in a length of 500 meters completed about 90 degree turn, small turning radius, circular curve length, small radius of unprecedented construction difficulty.

In order to ensure the successful completion of the small radius starting of the shield tunneling machine, metro group has made a comprehensive and detailed progress plan to design the cutter disc and drive system of the shield tunneling machine, especially the small curve turning radius of 300 meters, so as to better improve the quality of the shield tunneling construction. Make special construction plan and emergency plan, invite experts to carry out detailed analysis and full demonstration on equipment selection and configuration, grouting inside and outside the tunnel, tunnel drainage, structural reinforcement, tunneling parameter selection, etc., to provide technical support for tunneling construction. In the process of tunneling, it pays attention to strengthen monitoring and parameter control, maintains a good tunneling attitude, strictly controls the settlement of the surface and surrounding buildings, and ensures the safe and stable tunneling of the shield.

In the face of many unfavorable factors such as high construction risk and difficulty, metro group organized and arranged scientifically and reasonably, and prepared the special plan of negative four-layer earthwork excavation in detail, and invited experts to review it. Detailed work before the construction, during the implementation of leadership shift, on-site technical personnel 24 hours on duty system, mobilize all positive factors, give play to party members pioneer role and young staff as a fresh force, layer by layer implementation, link to the quality control, for all shield construction provides a solid foundation.