Double-track connection, railway construction heavy industry shield machine helps the world's first shield method construction of medium and low speed maglev tunnel construction

May 17, 2023

Recently，Jointly built by China Railway Construction Heavy Industry and China Railway 14th Bureau for Changsha Maglev East Extension Line“Maglev 2”The composite earth pressure balance Shield Machine was successfully disassembled and lifted out.，It marks the world's first double-track connection of medium and low speed maglev tunnel constructed by shield method.，Changsha Maglev East Extension Line MaglevTStation 2 to MaglevTThe civil works between the three stations have been successfully completed.。

“Maglev 2”The Shield Machine runs through

Access of Changsha Maglev East Extension LineT3 Total length of terminal project line 4.454 kilometers，It is the first shield underpass construction in Huanghua International Airport area.。The tunnel underpasses the airport aviation oil pipeline for six times.，Long-distance underpass airport runway glide slope sensitive area，Settlement control requirements for sensitive area of glide slope±10 mm，The accuracy of settlement control in shield construction directly affects the safety of aircraft take-off and landing.。At the same time，In the launching stage, the Shield Machine will be launched with a small radius of about 300 meters.，The requirements for the configuration and adaptability of the shield machine are extremely high.。In addition，This project is the first time that shield construction method is applied to maglev project.，The special mode of maglev transportation puts forward higher requirements for tunnel construction.。

In order to ensure that the tunneling process is stable and controllable，According to the engineering geological and hydrological conditions in the airport and the surrounding environment, China Railway Construction Heavy Industry and China Railway 14th Bureau Co., Ltd.，Specially built two earth pressure balance shield machines，It is the largest diameter shield machine in Changsha rail transit construction project so far.，The shield machine is designed accordingly.，An aperture ratio of 38 was use.%Composite cutterhead，Optimize the muck improvement system，And that slag discharge efficiency is improved.，Reduce the disturbance of surrounding strata and ensure the construction progress。The settlement value of the shield machine under the sensitive area of the airport is only 0..2 mm，Realized“Zero settlement undercrossing”，To ensure the smooth completion of the project.。

Shaped tunnel

Future，After Changsha Maglev East Extension Project is completed and put into operation,，TTerminal 2 is hereTThe transfer time of Terminal 3 is only 2 minutes.。Greatly meet the future collection and distribution needs of the airport，It is of great significance for Changsha to build a comprehensive transportation hub centered on the airport.。