准噶尔地区磁场解释及区域构造特征   总被引：6，自引：0，他引：6       下载免费PDF全文

费鼎  张新生 《地球物理学报》1987,30(5):459-468

根据准噶尔盆地及周围山区航空磁测结果,发现了5个沉积盖层厚度大于12km的拗陷,其中3个的盖层厚度可达18km,从而提高了盆地的油气远景评价。盆地内为隆拗相间的格局。 盆地内有一范围比盆地略小的以前寒武系为基底的稳定地块--准噶尔地块,它以断裂为边界。 盆地中部的北西西向长条状正异常,推断是由发育在下古生代裂陷槽中以基性为主的基性超基性杂岩体引起的。  相似文献   

南天山东段榆树沟-铜花山巨型构造混杂带的发现及意义     

陆关祥周鼎武  王居里张成立 《地质论评》2004,50(2):120-124,i003,i004

通过遥感构造综合解析，认为南天山东段榆树沟-铜花山地区为一巨型构造混杂带。该构造带可划分为南部和北部的两带变质褶皱地层系统、中带的构造混杂系统和不同期次的岩浆侵入体。结合同位素定年和岩浆侵入的综合对比与研究，认为该地区先后经历了五期构造运动，分别为：①南北向逆冲推覆，②北西西向左行走滑，⑧北西西向右行走滑，④南北向逆冲推覆，⑤北北西、北东向断裂。  相似文献   

海积软土前期固结压力与结构强度的关系及成因分析   总被引：3，自引：0，他引：3  

王冠英  肖树芳  习春飞 《世界地质》2004,23(1):69-74

通过对不同地区海积软土的大量试验，对原状土样和重塑土样的压缩曲线确定了海积软土前期固结压力和结构强度，并研究了海积软土前期固结压力及结构强度的关系。由于考虑了土的结构强度，对结构性土根据超固结比(OCR)对土的压密状态的判断与实际结果更加相符。为了定量地反映海积软土的结构强弱，首次引入反映海积软土结构性及其对扰动敏感程度的结构稳定系数，反映了海积软土结构性的稳定程度。初步分析了海积软土结构强度的成因。  相似文献   

黑龙江省虎林市幅重磁场特征及其地质解释   总被引：1，自引：0，他引：1  

林泽付  薛进  杨恕  吴东国 《世界地质》2004,23(4):397-401

以区域地质资料和物性资料为依据，对黑龙江省虎林市幅重磁场特征进行了综合分析。根据航磁△T异常以及布格异常平面等值线展布特点，对该区的杂乱磁场区、线性磁场区和平稳磁场区进行了相关的地质解释，描述了30条断裂构造带及其重力场特征；结合重力异常和航磁异常等综合资料，按结晶基底起伏形态，将虎林盆地划分为4个隆起、3个凹陷共7个构造单元。  相似文献   

Response of Concrete and Masonry Dams to Ground Vibration due to Blasting     

G. R. Adhikari  A. I. Theresraj  R. N. Gupta 《Fragblast: International Journal for Blasting and Fragmentation》2004,8(1):41-49

The safety and stability of concrete and masonry dams is a great concern when blasting has to be conducted close to these dams in order to construct small hydro-electric projects. There is a danger of ground vibration amplification to those residential-type buildings that are built close to these dams.

Responses of three concrete and masonry dams were measured directly by conducting a number of blasts and by monitoring vibration in the ground as well as on the dams. The amplitudes and frequencies of the motions were analysed and vibration attenuation relations were derived. These relations were used to compare the vibration levels on the dams with those in the ground.

Because of close-in construction blasts that produced high frequency ground vibrations, there was no amplification of the ground vibrations by these dams. The measured amplitudes of ground vibration were comparable to those of the dams.  相似文献   

热泵在多年冻土地区工程中的应用   总被引：1，自引：1，他引：1  

Sergei Guly 《冰川冻土》2004,26(Z1):220-226

The inclement climate and permafrost have a strong influence on human activities and life in cold regions. It is important to adjust to these conditions in such a way as to minimize adverse environmental impacts. In order to maintain the ecological equilibrium, various technologies have been developed which involve the use of the natural cold for solving difficult engineering problems. Heat pumps hold much promise in this context. They can help protect the environment from the thermal effects of human activities and, unlike the conventional refrigeration devices; the produced heat can be utilized. They also provide a solution to another problem vitally important for the northern regions - saving of fuel and energy resources. In case of global warming with an increasing need for artificial refrigeration, the use of heat pumps will be the most economical solution, preventing catastrophic loss of structural stability virtually without additional costs.  相似文献   

Cones to model foundation vibrations: incompressible soil and axi-symmetric embedment of arbitrary shape     

John P. Wolf  Andrew J. Deeks   《Soil Dynamics and Earthquake Engineering》2004,24(12):963-978

The recently streamlined strength-of-materials approach using cones to calculate vibrations of foundations embedded in layered half-spaces and full-spaces is applied to incompressible and nearly-incompressible soil and to axi-symmetric embedments of arbitrary shape. For incompressible soil the axial-wave velocity in the cones is limited to twice the shear-wave velocity and a trapped mass for the vertical motion and a trapped mass moment of inertia for the rocking motion moving as a rigid body with the under-most disk of an embedded foundation are introduced. In the case of a fully embedded foundation, a mass and a mass moment of inertia are also assigned to the upper-most disk. For an axi-symmetric embedment of arbitrary shape, the disks have varying radii. No modifications to the formulation are, however, required. For these two extensions the strength-of-materials approach using cones leads to the same sufficient engineering accuracy as is achieved in other more conventional cases. This is demonstrated in a vast study. Thus the same other advantages also apply: physical insight with conceptual clarity, simplicity and sufficient generality.  相似文献   

L'île Crémieu (Jura,France), un plateau calcaire épargné par la tectonique ?     

Muriel Rocher  Marc Cushing  Francis Lemeille  Stéphane Baize 《Comptes Rendus Geoscience》2004,336(13):1209-1218

The ‘Île Crémieu’, a plateau of Jurassic limestones located in the southern border of the Bresse and at the Jura front, is generally considered as non-deformed. Quaternary ice sheets and drainage have underlined and cleaned out some fracture planes trending NNE and NW–SE that border and crosscut the ‘Île Crémieu’. The analysis of seismic profiles reveals NNE-trending normal faults and NW–SE-trending strike-slip faults, crosscutting the basement to Late Miocene layers. Microtectonic fieldwork shows that these faults exist and were activated during the main Cainozoic tectonic events. To cite this article: M. Rocher et al., C. R. Geoscience 336 (2004).  相似文献   

结构性对上海软土渗透系数影响的试验研究          下载免费PDF全文

顾中华  高广远  王结虎 《探矿工程》2004,31(5):1-3

对在不同固结压力下原状土、重塑土的渗透系数进行试验研究，对比分析渗透系数的变化规律，研究上海软土结构性对渗透系数的影响。该试验的研究结果对上海软土渗透系数的确定有重要的工程指导意义。  相似文献   

Principal axes of M-DOF structures Part Ⅱ: Dynamic loading     

Zach Liang  George C.Lee 《地震工程与工程振动(英文版)》2003,2(1)

This paper is the second in a two-part series that discusses the principal axes of M-DOF structures subjected to static and dynamic loads. The primary purpose of this series is to understand the magnitude of the dynamic response of structures to enable better design of structures and response modification devices/systems. Under idealized design conditions, the structural responses are obtained by using single direction input ground motions in the direction of the intended response modification devices/systems, and by assuming that the responses of the structure is decoupleable in three mutually perpendicular directions. This standard practice has been applied to both new and retrofitted structures using various seismic protective systems. Very limited information is available on the effects of neglecting the impact of directional couplings (cross effects of which torsion is a component) of the dynamic response of structures. In order to quantify such effects, it is necessary to examine the principal axes of structures under both static and dynamic loading. In this two-part series, the first paper is concerned with static loading, which provides definitions and fundamental formulations, with the conclusion that cross effects of a statically loaded M-DOF structure resulting from the lack of principal axes are of insignificant magnitude. However, under dynamic or earthquake loading, a relatively small amount of energy transferred across perpendicular directions is accumulated, which may result in significant enlargement of the structural response. This paper deals with a formulation to define the principal axes of M-DOF structures under dynamic loading and develops quantitative measures to identify cross effects resulting from the non-existence of principal axes.  相似文献