The Lihuang Road Station of Jinan Metro Line 2 constructed by China Railway Engineering Fourth Corp. Ltd was undergoing the final sprint of 4 entrances and exits construction. This project was a key transportation project in Shandong Province. The ground conditions at the entrance and exit of the station were very complicated, combined with soft soil layer, permeable layer, and boulder stratum, and the gas pipeline needed to be crossed and has 1.8 meters downwards slope , which brought tremendous difficulties to the construction. A rectangular pipe jacking construction technology had been implemented on the construction of the entrance and exit of Lihuang Road Station. Meanwhile, a 4.9m x 6.9m giant rectangular pipe jacking machine had been used for construction. This was also the largest rectangular pipe jacking machine manufactured by Tangxing Machinery.
Giant machine had remarkable technology, it was customized for the Jinan Metro Tunnel Project. Tangxing Machinery innovated the following techniques：
Mega Frame Welded Pre-deformation Controlling Technology
Separated Active Hinged Sealing Structure One-step Forming Technology
Front and Rear Shield Upper and Lower Split Welding Technology etc.
In order to guarantee the stupendous quality of the giant machine, we have innovated and constructed the optimized design of the multi-point meshing transmission of the rectangular pipe jacking machine and the combined coordinated transmission in the design. Moreover, based on the fundamentals of self-developed attitude measurement and control technology and auto-steering system, Tangxing explored and adopted the intelligent navigation measurement and control system of multi-sensor rectangular pipe jacking machine simulating underground space, using superb technology to ensure the precise construction of the giant machine.
This is the first time that the rectangular pipe jacking machine construction technology has been used in metro tunnel construction in Shandong Province. After implementation, it will greatly reduce manpower participation and shorten the construction time. Normally, the construction period of an entrance and exit could take up to half a year without considering pipeline relocation and traffic guidance. The rectangular pipe jacking machine completed the construction in only 3 months, which will greatly increase the construction speed of the station. Shandong's new infrastructure speed and efficiency had been significantly fastened up. Tangxing Machinery is manufacturing diligently, and fulfilling the slogan of "Prosperous China, Vigorous Tangxing".