March 2，Jinan Rail Transit Line 4 Project“Guangxing No.9”The earth pressure balance shield machine started smoothly.。At this point，By China Railway Construction Heavy Industries、Jinan Heavy Industry Co., Ltd. and China Railway 20th Bureau Co., Ltd. jointly built the first domestic double-helix earth pressure balance shield machine without feeder.，The construction of Jinan Rail Transit Line 4 project has begun.。

“Guangxing No.9”Shield machine

“Guangxing No.9”Shield machine excavation diameter 6.68 meters，The length of the whole machine is 92 meters，Total weight about 500 tons，The installed power is 2300 kilowatts，It is the first double-helix earth pressure balance shield machine without sheet feeder in China.。

Jinan Rail Transit Line 4 from Provincial Sports Center Station to Quancheng Park Station is 698.535 meters，The main crossing stratum is gravel.、Completely weathered diorite、Cemented conglomerate，The water depth is 2-23.5 meters，Formation fracture is developed，And that problem of bee prone to gushing.，At the same time, the tunnel passes through the Yuhan highway interchange.、Square Xigou、Overpass foundation and numerous underground pipelines，High requirements for land subsidence control。

Starting site of shield machine

The R & D team of China Railway Construction Heavy Industry Co., Ltd. cooperated with China Railway 20th Bureau to solve the construction risk of the project.，Many technical difficulties have been overcome.，In order to better control the excavation face pressure,，Maintain surface stability，Feederless double helix technology is first proposed.，While effectively reducing the risk of ground settlement caused by spouting in shield construction,，But also realize that continuous and rapid transportation of materials.，And that construction efficiency is improve.，For this time“Guangxing No.9”Safe and efficient tunneling has laid a solid foundation.。