The lithology of the strata in the Gobi region of the Xinjiang autonomous region of China is mainly composed of mudstone,silty mudstone,and other soft rocks.Because of the low strength of the rock mass and the serious...The lithology of the strata in the Gobi region of the Xinjiang autonomous region of China is mainly composed of mudstone,silty mudstone,and other soft rocks.Because of the low strength of the rock mass and the serious effects of physical weathering in this area,the slope stability in open-pit mines is poor,and creep deformation and instability can readily occur.Taking the Dananhu No.2 open-pit mine as a typical example,the creep test of a mudstone sample under different stress levels was studied.Then,based on a bottom friction experiment and a FLAC3D numerical simulation,the deformation and failure processes of the slope were analyzed.The stress–displacement curve and the displacement–time curve for the monitoring points were plotted to obtain the relationship between the stress and displacement for the slope of the soft rock.The results showed that the long-term strength of the mudstone was between 8.0 and 8.8 MPa,and that stable creep occurred when the slope was under low stress.The potential failure mode for this type of slope is that the front edge creeps along the weak layer and then a crack is formed at the trailing edge of the slope.When the crack penetrates the weak layer,cutting bedding and bedding sliding occur.The deformation process of the stable creep slope includes an initial deformation stage,an initial creep stage,a constant velocity creep stage and a deceleration creep stage.展开更多
东戈壁地区分布的成矿有利地质单元为下石炭统雅满苏组(C1y)安山岩、砂岩、灰岩、凝灰熔岩、凝灰岩,和北东向、近东西向断裂构造,以及闪长玢岩等。使用FieldSpec Pro FR地面光谱测试仪,对地面高光谱蚀变矿物进行识别,同时结合野外实地...东戈壁地区分布的成矿有利地质单元为下石炭统雅满苏组(C1y)安山岩、砂岩、灰岩、凝灰熔岩、凝灰岩,和北东向、近东西向断裂构造,以及闪长玢岩等。使用FieldSpec Pro FR地面光谱测试仪,对地面高光谱蚀变矿物进行识别,同时结合野外实地观测和化学分析测试,分析和总结了各成矿有利地质单元的蚀变矿物组合特征。在雅满苏组凝灰熔岩区地面高光谱蚀变矿物组合分布地段圈定了找矿预测区,经查证,发现钨钼等多金属矿化线索,地表云英岩化、褐铁矿化、绿泥石化等蚀变发育,表明石英+绢云母+褐铁矿+黄钾铁矾+绿泥石等地面高光谱蚀变矿物组合可为钨钼等多金属矿化线索的找寻提供重要指示性矿物标志。展开更多
基金The work was Supported by State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Beijing(No.SKLGDUEK1923)National Key Research and Development Program(No.2018YFC0808301).
文摘The lithology of the strata in the Gobi region of the Xinjiang autonomous region of China is mainly composed of mudstone,silty mudstone,and other soft rocks.Because of the low strength of the rock mass and the serious effects of physical weathering in this area,the slope stability in open-pit mines is poor,and creep deformation and instability can readily occur.Taking the Dananhu No.2 open-pit mine as a typical example,the creep test of a mudstone sample under different stress levels was studied.Then,based on a bottom friction experiment and a FLAC3D numerical simulation,the deformation and failure processes of the slope were analyzed.The stress–displacement curve and the displacement–time curve for the monitoring points were plotted to obtain the relationship between the stress and displacement for the slope of the soft rock.The results showed that the long-term strength of the mudstone was between 8.0 and 8.8 MPa,and that stable creep occurred when the slope was under low stress.The potential failure mode for this type of slope is that the front edge creeps along the weak layer and then a crack is formed at the trailing edge of the slope.When the crack penetrates the weak layer,cutting bedding and bedding sliding occur.The deformation process of the stable creep slope includes an initial deformation stage,an initial creep stage,a constant velocity creep stage and a deceleration creep stage.
文摘东戈壁地区分布的成矿有利地质单元为下石炭统雅满苏组(C1y)安山岩、砂岩、灰岩、凝灰熔岩、凝灰岩,和北东向、近东西向断裂构造,以及闪长玢岩等。使用FieldSpec Pro FR地面光谱测试仪,对地面高光谱蚀变矿物进行识别,同时结合野外实地观测和化学分析测试,分析和总结了各成矿有利地质单元的蚀变矿物组合特征。在雅满苏组凝灰熔岩区地面高光谱蚀变矿物组合分布地段圈定了找矿预测区,经查证,发现钨钼等多金属矿化线索,地表云英岩化、褐铁矿化、绿泥石化等蚀变发育,表明石英+绢云母+褐铁矿+黄钾铁矾+绿泥石等地面高光谱蚀变矿物组合可为钨钼等多金属矿化线索的找寻提供重要指示性矿物标志。
