厚表土薄基岩非对称开采多场耦合作用下井筒偏斜机理研究

Shaft of coal mines play a critical role as “throat” in transportation between surface and underground working site in mining operations, and it is crucial in safety production of mines. In recently years, a new damage form of shaft which is co-existing of shaft deflection and vertical compress deformation in alluvium portion of thick alluvium and thin bedrock strata were found in Juye coalfield, Shandong, China, the damage of shaft seriously threated safety production of mines. This project aiming at the research gaps on mechanism of above mentioned problems of shaft damage, the hydrogeology, engineering seepage mechanics, mining engineering, underground structure mechanics and other relative theories are applied, the theoretical analysis, numerical simulation and in-situ monitoring will be conducted and thick alluvium strata (over 400 m) is planned to be taken as research object, the mechanical characters of permeability and concretion of soil layers will be studied and the constitutive model will be established; moreover, the subsidence and deformation characters of double-medium overburden under effects of mining induced deformation of rock layers and subsidence of soil layers under concretion will be studied and the stress and deformation condition of ground within surface plant will be obtained; in addition, the interaction deformation mechanism of close distance dissymmetric mining and ground subsidence under water drainage around shaft will be revealed and the main reason of shaft deflection will be found. The research results will show its important theoretical significance and application value on optimizing protective coal pillar design of surface plant within thick alluvium (over 400 m) and thin bedrock strata, as well as safety operation of shafts under similar geological conditions.

煤矿井筒是矿山开采地面与井下运输的“咽喉”，对矿井安全生产至关重要。近年来，山东巨野矿区厚表土薄基岩地层井筒出现一种表土段井筒偏斜与竖向压缩变形共存的新破损形态，严重威胁矿井生产安全。本项目针对导致上述井筒新的破损形态机理研究空白，综合运用水文地质学、工程渗流力学、采矿学、地下结构力学等理论，采用理论分析、数值模拟、模型试验、现场实测相结合的研究方法，以厚表土（400m以上）薄基岩为研究对象，研究高应力作用下土层的渗透与固结力学特性，建立其本构模型；探究开采覆岩移动与土层固结沉降叠加形成的双介质上覆地层沉陷移动与变形规律，获得工广内地层受力与移动变形特征；揭示厚表土薄基岩近距离非对称开采和井筒周围地层疏水沉降移动与井筒相互作用变形机理，获得导致井筒偏斜主因。研究成果对今后合理留设厚表土（400m以上）薄基岩地层工广保护煤柱，确保类似地质条件矿井井筒运行安全，具有重要的理论意义和应用价值。

煤矿井筒是矿山开采地面与井下运输的“咽喉”，对矿井安全生产至关重要。近年来，山东巨野矿区厚表土薄基岩地层井筒出现一种表土段井筒偏斜与竖向压缩变形共存的新破损形态，严重威胁矿井生产安全。本项目针对导致上述井筒新的破损形态机理研究空白，综合运用水文地质学、采矿学、开采沉陷学、土力学、渗流力学等多学科交叉，采用水文地质勘探、理论分析、试验研究、数值模拟和工程实践相结合的方法，以厚表土（400m以上）薄基岩为研究对象，研究了高应力作用下土层的渗透与固结力学特性，建立其本构模型；探究厚表土层底含直覆薄基岩煤层开采地层移动变形规律，建立其移动变形计算模型，分析上覆地层移动变形特征及其影响因素，揭示了该类地层立井井筒偏斜机理；揭示了在役偏斜立井井筒受力状态，提出了深孔地面高压注浆安全治理偏斜井筒预警值确定方法，构建了特厚松散层地面高压注浆在役井筒监控与预警系统，攻克了在役井筒不停产运营下深孔高压注浆井壁安全预警的技术难题；提出了在役偏斜井筒不停产地面注浆治理方法，首次提出在役井筒四周布置高压注浆泄压孔控压技术，研发了保护在役井筒“泄压-预警”双控地面高压注浆技术；揭示了特厚松散层地面高压注浆浆液扩散规律及其影响因素，获得了该类地层注浆压力与静水压力定量关系，得到了特厚松散层注浆技术参数，提出了特厚松散层地面注浆参数工程化确定方法，创新了特厚松散层单孔多层段注浆新型套管与施工工艺。研究成果对今后合理留设厚表土（400m以上）薄基岩地层工广保护煤柱，确保类似地质条件矿井井筒运行安全，具有重要的理论意义和应用价值。