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291.
小山水电站导流洞出口边坡其地质结构为下部中侏罗世安山岩(αJ2),其上覆盖了第三纪末第四纪初的玄武岩(βN~Q),两者间为不整合接触,不整合面夹有0.1~0.6m厚的粘土状及碎石粘土状夹层,产状倾向河床,倾角±25°。在上覆玄武岩层中见有高倾角的宽张裂隙带,与不整合面一起构成松动岩体,不整合面为底滑面。通过边界条件的分析和稳定计算,松动岩体的抗滑系数K=3.102,边坡是稳定的。在施工过程中采取了相应的安全保护措施,导流洞出口提前28m进洞,节约挖方量60000m3,提前了工期。经三年多的施工到运行,边坡无异常变化,表明该项优化设计是可行的。  相似文献   
292.
导水裂隙带高度预测途径探讨   总被引:3,自引:0,他引:3  
邹海  桂和荣 《江苏地质》1997,21(2):98-102
导水裂隙带高度是设计防水煤(岩)柱尺寸的主要技术参数,是煤矿防治水工作的重要内容。详细论述了其研究现状及发展趋势,并提出了履岩体地质环境,履岩体力学环境和数值模拟技术三位一体的综合预测评价方法。  相似文献   
293.
The Mount Raymond transverse zone (MRTZ) forms the east-west-trending boundary between the Wyoming salient of the Sevier fold-thrust belt and the Uinta/Cottonwood arch in north-central Utah. Major faults in the zone dip 40° to 45° north. Our structural analysis indicates that the MRTZ contains both contractional and extensional structures. The contractional structures (thrusts and related folds) initially formed as part of a southeast-verging, northeast-trending thrust system. This system gradually curved and merged to the north with the east-verging Absaroka thrust system in the apex of the Wyoming salient. The contrast in trend between structures in the MRTZ and those in the apex of the Wyoming salient reflects the initial curvature of the salient. This curve formed because the stratigraphic sequence involved in thrusting thinned gradually southward, toward the axis of a proto-Uinta arch. The present east-west trend of the MRTZ developed during Laramide uplift of the Unita/Cottonwood arch, an event which tilted the faults into their present position. Cenozoic crustal extension subsequently reactivated segments of the MRTZ. In sum, the evolution of the MRTZ illustrates how post-thrusting processes can affect the map-view geometry of thrust belts to create transverse zones.  相似文献   
294.
On the basis of S wave information from Tai’an-Xinzhou DSS profile and with reference to the results from P-wave interpretation, the 2-D structures, including S-wave velocity V s, ratio γ between V p and V s; and Poisson’ s ratio σ, are calculated; the structural configuration of the profile is presented and the relevant inferences are drawn from the above results. Upwarping mantle districts (V s≈4.30 km/s) and sloping mantle districts (V s≈4.50 km/s) of the profile with velocity difference about −4% at the top of upper mantle are divided according to the differences of V s, γ and σ in different media and structures, also with reference to the information of their neighbouring regions; the existence of Niujiaqiao-Dongwang high-angle ultra-crustal fault zone is reaffirmed; the properties of low and high velocity blocks (zones) including the crust-mantle transitionalzone and the boudary indicators of North China rift valley are discussed. A comprehensive study is conducted on the relation of the interpretation results with earthquakes. It is concluded that the mantle upwarps, thermal material upwells through the high-angle fault, the primary hypocenter was located at the crust-mantle juncture 30.0∼33.0 km deep, and additional stress excited the M S=6.8 and M S=7.2 earthquakes at specific locations around 9.0 km below Niujiaqiao-Dongwang, the earthquakes took place around the high-angle ultra-crustal fault and centered in the brittle media and rock strata with low γ and low σ values. This subject is part of the 85-907-02 key project during the “8th Five-Year Plan” from the State Science and Technology Commission.  相似文献   
295.
New40Ar/39Ar plateau ages from rocks of Changle-Nanao ductile shear zone are 107.9 Ma(Mus), 108.2 Ma(Bi), 107.1 Ma(Bi), 109.2 Ma(Hb) and 117.9 Ma(Bi) respectively, which are concordant with their isochron ages and record the formation age of the ductile shear zone. The similarity and apparent overlap of the cooling ages with respective closure temperatures of 5 minerals document initial rapid uplift during 107–118 Ma following the collision between the Min-Tai microcontinent and the Min-Zhe Mesozoic volcanic arc. The40Ar/39 Ar plateau ages, K-Ar date of K-feldspar and other geochronologic information suggest that the exhumation rate of the ductile shear zone is about 0.18–1.12 mm/a in the range of 107–70 Ma, which is mainly influenced by tectonic extension.  相似文献   
296.
熔体及其活动在造山带的演化中发挥了重要作用。熔体活动发迹了地壳应力作用方式而诱发形成剪切带或断层;熔体活动调整块体间的位移而影响造山带的变形;  相似文献   
297.
The structural feature shown on a remote sensing image is a synthetic result ofcombination of the deformations produced during the entire geological history of an area.Therefore, the respective tectonic stress field of each of the different stages in the complexdeformation of an area can be reconstructed in three steps: (1) geological structures formed atdifferent times are distinguished in remote sensing image interpretation; (2) structuraldeformation fields at different stages are determined by analyzing relationships betweenmicrostructures (joints and fractures) and the related structures (folds and faults); and (3)tectonic stress fields at different stages are respectively recovered through a study of the featuresof structural deformation fields in different periods. Circular structures and related circlular and radial joints are correlated in space to con-cealed structural rises. The authors propose a new method for establishing a natural model ofthe concealed structural rises and calculating the tectonic stress field by using quantitative dataof the remote sensing information of circular structures and related linear structures.  相似文献   
298.
巷道围岩松动圈的地质雷达探测及应用   总被引:9,自引:1,他引:9  
在简述地质雷达探测原理的基础上, 分析了巷道围岩松动圈雷达探测的可行性。结合华丰矿巷道围岩松动圈探测实例, 提出了松动圈雷达探测方法、图像分析及探测结果应用。结果表明, 采用地质雷达探测巷道围岩松动圈是可行的, 可以用于指导巷道围岩的锚杆支护设计。  相似文献   
299.
岩体结构力学岩体工程地质力学的新发展   总被引:6,自引:1,他引:6  
本文从岩体工程地质力学角度, 研讨了岩体结构力学的意义, 地位与作用。作者就个人的认识, 将岩体结构力学的理论特点, 概括为五个方面, 即再变形和再破坏, 岩体结构的控制作用、岩体结构控制论、赋存环境以及关于岩体的多种力学介质和力学模型构成的力学体系。  相似文献   
300.
我国北方农牧交错带的环境演变   总被引:60,自引:2,他引:60  
中国北方农牧交错带在10~8.5kaB.P.经历了三次阶段性增暖后进入全新世暖期。8.5~8.0kaB.P.和4~3.5kaB.P.暖期的开始与结束事件中降水变化落后于温度变化300~500a;暖期盛期时的年均温较现代高2~3℃,降水多100mm左右;暖期中存在多次短期寒冷事件,年均温最冷时较现代低3℃以上。3.5kaB.P.以来冷干趋势之上叠加着大致由300a稳定与500a波动构成的约800a的周期性变化。全新世暖期原始农业文化的阶段性发展与暖期内环境波动相对应;暖期结束时发生了由农业向牧业文化转换的事件;暖期以后的冷干期为农牧交错文化时期,农业经济随冷干程度的变化而兴衰  相似文献   
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