rock mass assessment and corresponding tbm operation optimization for tbm tunneling at depth - a case study of jinping ii hydropower station
Therefore, in the face of these unfavorable geological conditions, it is necessary to modify and optimize the boring machine to improve the performance of the boring machine.
In China, two of the four water diversion caves of Jinping secondary hydropower station project were constructed by two tunnel boring machines.
There are about 16 race tunnels.
The length is 7 km and the maximum depth of coverage is 2,525 m.
In this paper, the rock blocks along the water diversion tunnel of Jinping secondary hydropower station are evaluated, and then according to the main control factors of shield excavation, they are divided into three typical excavation sections.
The three typical excavation sections are normal excavation sections, excavation sections controlled by high altitude stress and excavation sections controlled by large inflow of groundwater.
In order to overcome the unfavorable geological conditions of these typical export sections, the corresponding improvement and operation optimization are proposed in this paper.
The experience gained by Jinping secondary hydropower station can provide useful reference and guidance for the in-depth construction of shield tunneling.