【作者】 李宏； 安其美； 王海忠； 毛吉震；

【Author】 Li Hong An Qi-mei Wang Hai-zhong Mao Ji-zheng (Institute of Crustal Dynamics,CEA,Beijing 10008,China)

【机构】 中国地震局地壳应力研究所；

【摘要】 为了研究"V"型河谷区岩体应力的大小、方向及其分布,采用水压致裂地应力测试技术对河床和山体内的平面和三维地应力进行了现场测量。实测最大水平主应力方向为N40°～60°W,最大水平主应力值最高近40MPa,最小水平主应力值为20MPa;在河床谷底浅部80m以上,受河谷卸荷影响地应力有所释放,形成卸荷带;孔深90～130m产生应力集中,形成"V"型峡谷典型的"应力包"分布特征;三维主应力值随水平埋深的增加而增大,最大主应力倾角随硐深增加变陡。对原地应力实测结果进行解析,得到了隧道横截面的最大主压应力和最小主压应力及相关的应力参量,结合岩爆判据对隧道发生岩爆的可能性进行了分析,隧道横截面内最大差应力的大小是控制岩爆发生的主要因素。更多还原

【Abstract】 To study the distribution of rock stresses value and direction around"V"shape river valley,the plane stresses and 3-D stresses measurement was carried out by hydraulic fracturing stress measured technique on the riverbed and mountain massif.The maximum stress direction is about N40°～60°W,the highest value of maximum stress is near to 40MPa,the minimum stress is near to 20MPa.The in-situ stress had been released as river valley unloaded,formed unloaded zone above 80m around river valley shallow depth.The depth of 90～130m were stresses concentrated zone,formed typical"stresses fold"distribution of"V"shape river valley.3-D stresses and the maximum principle stress obliquity were increased as the horizontal burying depth increased.The maximum compression stress and minimum compression stress within the tunnel cross section were obtained by stress analysis.The possibility of rock-burst was analyzed considering the rock-burst criterion.The rock-burst were controlled by different stress within the tunnel cross section.更多还原