为全面认识川藏铁路隧道TBM施工地质适应性问题,分析其主要不良地质条件,系统研究TBM施工适应性特点,从岩爆、软岩大变形、涌突水、高地温4个方面论证,得出TBM施工的地质适应性为“弱适应”,并分别阐述TBM施工的关键技术: 1)岩爆及软岩大变形区域,根据地质预报及现场工作情况采取相应的支护措施及施工对策; 2)涌水段施工,针对裂隙状渗水、非裂隙状涌水,可采取“水压分流排水+灌浆封堵加固 ”进行处理; 3)高地温段施工中,除常规通风物理降温措施外,针对富热水高温段还需采取限量排水、注浆封堵以减少热水涌出量,并采取结构防热。
To fully study the geological adaptability of TBM in
SichuanTibet railway tunnel construction, the main unfavorable geological
conditions of SichuanTibet railway tunnel are
comprehensively analyzed and the adaptability characteristics of TBM are
systematically studied. With analysis of the four aspects of geological
conditions, i.e. rock burst, large deformation of soft rock, water inrush, and
high ground temperature, it is demonstrated that the geological adaptability of
TBM construction is weak. The key techniques of TBM construction are described
as follows: (1) In the area of rockburst and large deformation of soft rock,
corresponding support and construction countermeasures should be taken
according to geological prediction and field conditions. (2)For fractured
seepage and nonfractured water inrush, the
construction of water inrush section can be treated by hydraulic shunt drainage
or grouting plugging and reinforcment. (3) In addition to the conventional
ventilation physical cooling measures in the construction of high ground
temperature section, limited drainage and grouting should be adopted to reduce
the amount of hot water gushing in the hightemperature
section with rich hot water, and structural heat prevention should be adopted.