On the morning of November 9th 2020, the earth pressure balance TBM produced by NHI for China Railway 12th Bureau was inspected and accepted in the assembly workshop of the tunnel boring equipment branch workshop. Before that, the TBM produced by NHI for China Railway 4th Bureau has just completed the factory acceptance. This two equipment will serve Shenyang Metro Line 2 South Extension Project.

"TBM made in Shenyang Serves Shenyang"

Speaking of TBM of Shenyang Metro and NHI, we have to talk about Shenyang Station of Shenyang Metro Line 1. The “Zhenxing No. 1” TBM produced by NHI was the one responsible for running through this station. The single-track tunneling length from Yunfeng North Street Station to Shenyang Station is 1,400 meters, and 45 train tracks need to be traversed. The vibration and impact caused by trains are the biggest test for the tunneling of TBM. In order to allow sufficient time for excavation and construction, NHI completed the "Zhenxing No. 1" production in only three months. This is also the first time that NHI TBM has served the Shenyang subway project.

With continuous deepening of urban construction and continuous improvement of the people's requirements for transportation, Shenyang's subway construction has also entered a period of rapid development, and NHI TBM has also participated more and more in the construction of Shenyang subway. On November 23th 2009, "Shenyang No. 1" TBM served the interval between Century Square Station and Xiashengou Station on Shenyang Metro Line 2; In January 2015, NHI and Shenyang Shield Equipment Engineering Co., Ltd. signed a contract to build φ6.28 soil pressure balance shield machine, serving the Shenyang Metro Line 9 Shensu West Road Station to Shengli South Street Station; In April 25th 2016, the φ6.28 soil was manufactured by NHI for the Urban Rail Branch of China Railway Shanghai Engineering Bureau. The pressure-balanced TBM started again on the left line of the interval between University of Science and Technology Station and Zhangshabu Station on Shenyang Metro Line 10, and started its second journey. This is the TBM which completed Shenyang on January 7, 2016 the section from Renjieshuian Park to Puhe Avenue Station on the northern extension of Metro Line 2 set a record of 24 meters per day and 504 meters per month before it set out again.

From 2006 to 2020, NHI successively provided 24 TBMs of various specifications for the Shenyang Metro Project, contributing to the construction and development of urban subway.

Technology Upgrades to Stabilize the Market

Focusing on users and keeping a close eye on the laws of market development, NHI takes accelerating product technology upgrades and innovations as the key to NHI's victory in dealing with fierce market competition.

The two construction companies which are responsible for the construction of the southern extension of Shenyang Metro Line 2 selected the φ6.48 earth pressure balance TBM produced by NHI at the same time, but they have very different equipment performance requirements. After understanding the technical requirements in detail, NHI design team immediately established a project research team. According to user requirements, two important indicators of driving torque and propulsion speed of TBM are customized. The project team used the technical reserves of serialization and experience accumulated in actual engineering applications, after repeated calculations and measurements, finally found a solution.

In addition, the construction companies proposed that the efficiency of segment transportation during construction was low, and hoped to improve the transportation efficiency through improved measures. After repeated demonstrations by the project team, the original secondary crane transportation was changed to double-beam crane transportation, which not only reduced intermediate links and increased space utilization, but also greatly improved the efficiency of segment transportation and greatly reduced failures. Meanwhile, incidence rate was reduced by large and efficiency of excavation was improved.

Break Through Tradition and Seek Exploration

As we all know, our country is rich in coal resources, the coal resources are in the deep buried layer, and the geological conditions are complex. The tunneling operations of coal mines basically use traditional blasting or cantilever tunneling machines. This traditional coal tunnel construction method that has remained unchanged for decades is facing progress. The shortcomings such as slow speed, high cost, high potential safety hazards, poor working environment and poor roadway forming quality have been difficult to meet the needs of modern coal mine roadway construction.

In order to solve this worldwide construction problem, Fangda Group NHI has the courage to innovate. In 2014, it developed a domestically-made 4.53m diameter coal mine rock tunnel full-face Road header (another type of TMB used in mining) test machine, which was applied to the roadway construction of Huainan Mining Group Zhangji Mine. Successfully digging 2 kilometers underground in a buried depth of 500 meters, it created a coal mine rock roadway with a maximum daily footage of 30.7 meters, an average monthly footage of 404 meters, a maximum daily footage speed 10 times higher than traditional technology, and a monthly footage 4.5 times higher than traditional method. If this equipment was a transition machine, then on April 18, 2019, the first domestically developed and fully independent IP rights of 6.33 meters large diameter coal mine rock tunnel full-face road header, which was successfully rolled off the assembly line at NHI, is the first series of products for the field of coal mine roadway construction officially matured. This equipment is customized for Shandong Xinjulong Company. The purpose is to solve the complicated geological conditions of horizontal roadways in Xinjulong mining area which has large underground depth, large tunnel diameter, long construction distance, poor construction environment and slow construction speed, etc. The 4.53m diameter roadheader used in the Xinyuan Mine of Yangmei Group in December 2019 is an effective improved and upgraded equipment for solving the actual problems encountered in the design and construction of the first two equipment. The 4.53m diameter half coal and rock road header manufactured in March 2020 has achieved a major technological breakthrough in coal mine roadway road headers. The applicable stratum of the equipment has changed from a rock layer to a half coal and half rock layer. The applicability of the equipment in coal mines has achieved significant breakthrough.

From the construction of the municipal subway to the excavation of coal mine tunnels, NHI has always kept exploring the field of tunnel engineering. As Fangda Group continues to increase its support for NHI, the future NHI will invest more research energy in unmanned and intelligent areas and continue to innovate and develop in the field of tunnel engineering, in order to lead the development direction of the industry.