变质岩区深埋长大隧道初始地应力场反演研究

摘要

初始地应力场是岩土工程设计和施工所要考虑的首要因素.依托十房(十堰至房县)高速通省隧道地应力量测资料,调整不同组合的侧压系数,获得了隧址区岩体多组地应力.利用残差函数,分别计算了各向同性与各向异性本构关系下每一组侧压系数的残差,并进行了对比分析,确定了不同本构关系的最优侧压系数.利用获得的侧压系数,反演计算测试点的地应力,通过与实测结果的对比分析确定了与隧址区岩体适宜的本构关系,最终得到了隧道的初始地应力场分布规律.研究表明,初始地应力场与隧道的埋深和地形地貌有关,且通省隧道更适于在各向异性本构关系下进行地应力场反演,误差幅值约为10%.%Initial in-situ stress is a primary factor for the design and construction in rock engineering.According to the data of Tongsheng tunnel of Shiyan-Fangxian express highway, different groups of in-situ stress in the tunnel site were acquired by adjusting lateral pressure coefficient.The residuals of different lateral pressure coefficients in isotropic and anisotropic constitutive relations were calculated by constructing a residual function.Through comparing and analyzing the results, the optimal lateral pressure coefficient for the tunnel site was confirmed.Furthermore, the in-situ stress of metamorphic rock at test points was retrieved.The constitutive relation of rock mass at the tunnel site was determined through comparison with measured values.Finally the distribution of in-situ stress field of the tunnel was obtained.The research shows that the initial in-situ stress field is related to the buried depth and the topography of tunnel.The anisotropic constitutive relation is adaptive for Tongsheng tunnel and the error is about 10%.