盆因拉隧道高地应力成因及岩爆防治措施研究

盆因拉隧道位于雅鲁藏布江峡谷区,受构造板块影响,地应力分布特殊,隧道的施工遇到较强烈的岩爆影响。本项目通过对隧道通过区的构造应力场进行分析,采集实测地应力数据,通过仿真技术分析预测隧址区的地应力分布特征;采用室内试验对隧道洞身处闪长岩进行矿物组分、结构特征分析;采用单轴压缩、三轴试验测试岩体力学指标,结合地应力数据及岩体力学参数、隧道开挖断面形状分析岩爆灾害发生机理,对隧道岩爆进行预测、评价,并提出采取"水压爆破、应力释放、加强支护"的措施,有效控制了岩爆造成的危害,为类似隧道的施工积累了经验。

Research on the Causes to High Geological Stress and Rockburst Prevention of Pengyinla Tunnel

Penyinla Tunnel, located in the Yarlung Zangbo River valley subjected to special plate influence, has a unusual distribution of geological stress. Its construction is greatly affected by the severe rockburst, stress field of the tunnel excavation area is analyzed to obtain the measured stress data; simulation technology is used to predict the ground stress distribu- tion of tunnel area; through the tunnel by tectonic analysis, acquisition of measured stress data, prediction of through simu- lation analysis ; mineral composition, structure characteristics of diorite are analyzed through indoor experiments; the mechanical indices of rock mass obtained by the uniaxial compression test and the three axis experiments combined with field measurement of stress data and rock mechanics parameters of tunnel excavation section shape analysis are employed to analyze the occurrence mechanism of rock burst to evaluate and predict tunnel rock burst. And ＂Hydrolie pressure blasting, stress release, strengthening support＂ measures are proposed, which effectively control the damage of rock burst, and provides reference for construction of similar tunnel.