深部原岩应力场有限元反演与工程应用研究

Study on finite element method inversion of deep in-situ rock stress field and its engineering application

【目的】构建基于实测数据的深部原岩应力场有限元多元回归反演分析模型,为实际工程设计和科学研究提供基础数据。【方法】针对有限测点原岩应力数据仅能反映局部应力场,远不能表达原岩应力场分布规律的缺陷,在分析霍州矿区地质条件的基础上,应用大型通用软件ANSYS12.0建立了最大埋深达930 m的研究区域原岩应力场数值计算力学模型,并利用4个测点的实测数据进行了原岩应力场有限元多元回归反演分析。【结果】多元回归的复相关系数为0.904 0,接近于1.0。研究区域内煤岩体3个主应力几乎全为压应力,原岩应力分布均匀,但分层现象明显,且受断层影响较大;310水平上2#煤顶板最大主应力为15.0~17.0 MPa,由于地质构造差异,在距离边界250~450 m处存在一个应力相对增高的地带。【结论】建立了原岩应力有限元反演分析模型,其计算结果与实测结果的拟合程度较高,可为矿井建设和安全生产提供原岩应力基础资料,有较强的工程实用性。

【Objective】 The finite element inversion analyzing numerical mechanics model based on measured data was built to provide fundamental data for the practical engineering design and scientific research.【Method】 On the basis of analyzing geological conditions in the mining area,the numerical computing mechanics model was built by using the large general software ANSYS12.0,in the research region where the maximum burial depth was about 930 m,and the finite element multivariate regression inversion analysis about deep in-situ rock stress field was done by utilizing four measurement points data,because the in-situ rock stress data of limited measure nodes only reflected the local ground stress fields,and could not express the whole ground stress distribution law.【Result】 Multiple correlation was equal to 0.904 0,very close to 1.0,in the multivariate regression calculation results.The three principal stresses of coal and rock mass in the research area were almost compressive stress,and in-situ rock stress distributed uniformly in the whole,but the layering phenomenon was remarkable,and the rock stresses were greatly influenced by faults.The maximum principal stress in the 310 m level of No.2 coal roof changed in the range of 15.0-17.0 MPa.At the same time,there was one stress relative heightening zone in the distance between 250 m and 450 m of calculating model left boundary.【Conclusion】 The calculation results of the finite element inversion analyzing model are very close to the measured results,the basic in-situ rock stress information can be provided to mine construction and safety production,and the model has strong engineering practicability.