July 13，The world's first large-diameter double-shield earth pressure combined shield machine independently developed by China——“Tiebing Guanghua No.6”Tiangui Intercity Railway from Guangzhou East to Huadu(Hereinafter referred to as“Guanghua intercity”)Section from Jingxi Road to Baiyun Dongping(Hereinafter referred to as“Jingbai interval”)The No.2 shield shaft started smoothly.，And apply a number of digital technologies.。So far，Cumulative completion of civil works of Guangzhou-Huadu Intercity Railway Project 11%。

The total length of Jingbai Tunnel is about 8.62 kilometers，Shield construction needs to face the underpass reservoir、Broken fracture zone、Multiple boulders and upper soft and lower hard formation、Dense buildings and other major risk points。To ensure construction safety，The technical team tailor-made“Tiebing Guanghua No.6”Shield machine。The shield machine has double shields.TBMAnd an earth pressure shield.，Have“High hard rock、High Torque、High precision tunneling capability”Three core advantages，Easily cope with excavation under various complex geological conditions。

The reporter learned from the scene.，The main structure of No.2 shield shaft in Jingbai section is only 40 meters long.、36 meters wide，It can not meet the demand of complete launching of shield machine with a total length of 131 meters.。To this，The project technical team adopts the construction method of split launching to overcome the small launching site.、Limitations such as small shield wellhead。

“Only the shield body and connecting bridge are used for downhole launching in this split launching.，All trolleys are placed on the ground.，After equipment optimization, only 5 trolleys are needed to meet the starting conditions.。”Construction unit: work area II of Guangzhou-Huadong Intercity Project of China Railway Construction South China Company(Section of China Railway 15th Bureau)Executive Manager Cao Dongjiao introduced.，The relay pump station is used to solve the pressure drop problem of the hydraulic system in the split launching stage.，Forward grouting and grease system are used to solve the injection problem，External water circulation and pea gravel system are used to solve the problem that the trolley can not go down the well，It provides conditions for the shield machine to start tunneling smoothly.。

In addition，For effective promotion“Tiebing Guanghua No.6”Operational efficiency，The engineering construction team introduced the concept of digital construction of shield tunnel.，Build a digital intelligent exhibition hall at the construction site，Includes a business profile、3DHolographic projection、VRExperience、Safety education area、Mechanical model visit、Shield construction monitoring and other plates。In the exhibition hall, the whole process of site construction can be monitored by the central control system.。

So far，Guangzhou-Huadong Intercity Railway Project(Guangzhou Dongzhi Huadu Tiangui)Civil works completed accumulatively 11%，7 stations of the whole line are under civil construction.，Civil construction in 5 sections，The rest shall be prepared in the early stage.，Three shield machines are digging.。