March 9th saw the CREG Double Shield TBM CREC 241 passing 6km drive for Lanzhou Water Source Project.
The total drive of the project is 12. 235km and the expected geology for the Φ5.48m machine mainly comprises of rock mass class II and class III. Since its launching on February 28th 2017, CREC 241 has encountered serious gushing in certain sections, fallen surrounding rocks on its way and crossed fractured zone as well. The complicated geology posed great challenges for the TBM operation. In early February, the machine had to be stopped due to sudden gushing. However, thanks to the smooth and close cooperation between the project contractor SINOHYDRO ENGINEERING BUREAU 4 CO., LTD and CREG in technical solutions and execution, CREC 241 has sustained steady and fast advance regardless of the unfavorable geotechnical conditions. It set a monthly record of 792m drive from October 6th to November 5th 2016. On January 23rd, 2017 and January 29th 2017 respectively, it set daily record of 43.5m. The impressive performance of CREC 241 is well recognized by the project contractor.