Soil-structure interaction analysis of the Hualien containment model     

Todor Ganev  Fumio Yamazaki  Tsuneo Katayama  Teruyuki Ueshima 《Soil Dynamics and Earthquake Engineering》1997,16(7-8):459-470

This paper presents results from forced vibration tests, microtremor observations and earthquake response analysis of a nuclear reactor containment model constructed on stiff soil in Hualien, Taiwan. The dynamic behavior of the soil-structure system is simulated successfully with two numerical models: a sway-rocking model, whose soil parameters are evaluated on the basis of the continuum formulation method, and a finite element model, using the program SASSI with the flexible volume substructuring approach. The dependences of the soil parameters of both models on the amplitudes of the different dynamic excitations are investigated in detail. An original numerical simulation of microtremor is performed. Comparison with results of a previous study involving a rigid tower on a soft soil site in Chiba, Japan is offered.  相似文献   

Barotropic local instability and severe storm process     

Dasheng Yang  Lan Sun 《中国科学D辑(英文版)》1997,40(3):259-268

By means of barotropic model, the characteristic and initial value problems are investigated to reveal the local two-dimensional barotropic instability of the nonuniform current to the dynamic mechanism of the formation of the Yangtze-Huaihe River severe storm in July 1991. Analytical theory and numerical experiment show that (i) the unstable developing modes are chiefly the two periods of about 44 d and 10 d, which are fundamentally consistent with that of the precipitation change of the Yangtze-Huaihe River. (ii) The growth rate of the local perturbation is dominated by the meridional wave numbern = 1–5 and zonal wave numberk = 1–12, i.e. the severe storm over the Yangtze-Huaihe River results from the interaction of the systems at different latitudes and waves of different scales, (iii) The perturbation over the Yangtze-Huaihe River possesses the property of local intensification, which slowly migrates westward over the lower and middle reaches of the Yangtze-Huaihe River. (iv) The growth rate of the instability, especially the propagation velocity of the perturbation, is sensitive to the external parameters ū and α. Project supported by the National Natural Science Foundation of China.  相似文献   

Prediction of the measured response of a scaled soil-pile-superstructure system   总被引：1，自引：0，他引：1  

N. Makris  T. Tazoh  X. Yun  A.C. Fill 《Soil Dynamics and Earthquake Engineering》1997,16(2):113-124

The validity of the Winkler foundation model is investigated by predicting the experimentally measured displacement transfer functions and strain spectra of a single pile embedded in a sandbox and supporting a single-degree-of-freedom superstructure. The foundation-superstructure system is a scale model and was subjected to shake table excitations. The distributed springs and dashpots of the Winkler foundation model are frequency dependent and the calibrated model predicts satisfactorily the displacement transfer function at different depths for both fixed- and free-tip pile conditions. On the other hand, the pile-axial-strains are substantially underestimated when expressed in terms of the second derivative of the computed elastic line of the pile. It is shown that a much more dependable prediction is achieved when pile-axial-strains are expressed in terms of the inertial forces acting along the pile-superstructure system.  相似文献   

下庄铀矿田成矿热液的水源研究     

刘金辉  李学礼  史维浚  孙占学 《吉林大学学报(地球科学版)》1997,(4)

在分析下庄铀矿田成矿地质背景的基础上，根据包体水氢、氧同位素组成和水－岩相互作用原理对该矿田成矿热液的水源进行了详细探讨。其结果表明，下庄铀成矿热液的氢、氧同位素组成δ１８Ｏ＝＋６．９０‰～－９．８０‰（ＳＭＯＷ）、δＤ＝－３０‰～－８５‰（ＳＭＯＷ）位于已发生氧漂移的大气降水同位素组成范围。水－岩同位素交换后，岩石的δ１８Ｏ值明显降低，显示出与岩石相互作用的古地下水具有相当低的δ１８Ｏ值。不同水－岩比值条件下同位素交换结果证明下庄成矿古水热系统具有比较充足的水源，大气降水与岩石交换后热液的δ１８Ｏ计算（－８．２６‰～＋１．５３‰）与成矿期热液的δ１８Ｏ值（－６．５４‰～＋１．４３‰）相吻合。证据表明下庄铀矿田成矿热液的水源主要来自大气降水。  相似文献   

泌阳碱矿形成的地球化学模拟研究   总被引：2，自引：0，他引：2       下载免费PDF全文

文冬光  曾建华 《地球科学》1997,22(1):69-73

泌阳碱矿过去一直被认为是原生沉积矿床。通过综合分析泌阳凹陷的地质、石油地质、碱矿地质和水文地质条件，从不同方面论证泌阳碱矿不太可能属于原生沉积矿床。利用地球化学模拟技术，从理论上模拟了泌阳碱矿的形成过程，提出了一种水－岩相互作用成矿模式，并用大量的事实支持了这种观点。  相似文献   

Thermodynamic Modelling of Ore-Forming Mechanism of the Changkeng Gold-Silver Deposits in Guangdong Province     

Zhang Sheng  Li Tongjin  Wang LiankuiGuangzhou Institute of Geochemistry  Chinese Academy of SciencesWushan  Guangzhou 《《地质学报》英文版》1997,71(4):433-445

The Changkeng gold-silver deposits consist of a sediment-hosted, disseminated gold deposit and a replacement-type silver deposit. The mineralizations of gold and silver are zoned and closely related to the silicification of carbonate and clastic rocks, so that siliceous ores dominate in the deposit. The mineralizing temperature ranges mainly from 300 to 170℃, and K+, Na+, Ca2+, Mg2+, and Cl- are the major ions in the ore-forming fluid. Calculations of distribution of metal complexes show that gold is mainly transported by hydrosulphide complexes, but chloride complexes of silver, iron, lead, and zinc, which are transformed into hydroxyl and hydrosulphide complexes under neutral to weak-alkaline circumstances in the late stage, predominate in the ore-forming solutions. Water-rock interaction is confirmed to be the effective mechanism for the formation of silver ores by computer modelling of reaction of hydrothermal solution with carbonate rocks. The solubility analyses demonstrate that the precipitation  相似文献   

大型水域水岩相互作用及其环境效应研究   总被引：26，自引：0，他引：26  

王士天  王思敬 《地质灾害与环境保护》1997,8(1):69-89

以大量实际资料及深入的研究成果，较全面地论述了人工大型水域水岩相作用及其导致的主要地质灾害，包括水库诱发地震，库岸崩滑，水岩作用导致的大坝溃决，以及水库淤积导致的大面积环境恶化等问题。  相似文献   

筒桩基础的地震反应分析     

董金明  刘春原  郝厉  刘平 《东北地震研究》2004,20(2):8-14

本文基于Biot动力固结方程，在BDWF模型的基础上，通过等价线性迭代不断修正土体模量以逼近土体的非线性动态响应，对建筑筒桩基础的地震反应进行了动力分析。为了分析筒桩基础的地震反应，考虑桩-土-结构的动力相互作用，将桩-土-结构地震反应分析的空间体系简化为二维问题计算。结果表明，筒桩基础桩基相对桩基于桩基有较好的抗震性能，筒桩基础的柔性改善了结构的基本周期。  相似文献   

Interactive behavior of soil–pile-superstructure system in transient state to liquefaction by means of large shake table tests     

Shintaro Yao  Koichi Kobayashi  Nozomu Yoshida  Hiroshi Matsuo 《Soil Dynamics and Earthquake Engineering》2004,24(5):572-409

Shaking table tests were conducted by means of a large-scale laminar box with 4 m in length, 2 m in width and 2 m in height in order to investigate behavior of a soil-pile-superstructure system in liquefiable ground. A model two-storey structure, supported by a pile group, was set in a saturated sand deposit, and subjected to a sinusoidal base motion with increasing amplitude. Discussions are focused on the transient behavior until soil liquefaction occurs. Main interests are characteristics of springs used in a sway-rocking model and a multi-freedom lumped mass (MFLM) model that are frequently used in soil–pile interaction analysis. The spring constant in the sway-rocking model is represented by restoring force characteristics at the pile head, and that in the MFLM system is represented by an interaction spring connecting the pile to the free field. The transient state prior to soil liquefaction is shown to be important in the design of a pile because dynamic earth pressure shows peak response in this state. The reduction of the stiffness due to excess porewater generation and strain dependent nonlinear behavior is evaluated.  相似文献   

In-plane and anti-plane strong shaking of soil systems and structures     

G. Gudehus  R. O. Cudmani  A. B. Libreros-Bertini  M. M. Bühler 《Soil Dynamics and Earthquake Engineering》2004,24(4):319-342

The concept of in-plane and anti-plane shaking is introduced with a rigid block on a plane surface with Coulomb friction. Using a hypoplastic constitutive relation to model the mechanical behaviour of the soil, numerical solutions for a rigid block on a thin dry or saturated soil layer are obtained. The coupled nature of dynamic problems involving granular materials is shown, i.e. the motion of the block changes the soil state—skeleton stresses and density—which in turn affects the block motion. Motions of the block as well as soil response can be more realistically calculated by the new model. The same constitutive equation is applied to the numerical simulation of the propagation of plane waves in homogeneous and layered level soil deposits induced by a wave coming from below. Experiments with a novel laminar shake box as well as real seismic records from well-documented sites during strong earthquakes are used to verify the adequacy of the hypoplasticity-based numerical model for the prediction of soil response during strong earthquakes. The response of a homogeneous earth dam subjected to in-plane and anti-plane shaking is investigated numerically. In-plane and anti-plane shaking is shown to cause nearly the same spreading of a sand dam under drained conditions, whereas under undrained conditions anti-plane shaking causes stronger spreading of the dam. The dynamic behaviour of a breakwater founded on rockfill and soft clay during the 1995 Kobe earthquake is back-calculated to show the good performance of the proposed numerical model also with a structure. Section 9 deals with buildings on mattresses of densified cohesionless soils or fine-grained soils with granular columns, slopes with ‘hidden’ dams and structures on piles traversing clayey slopes to show the suitability of hypoplasticity-based models for the earthquake-resistant design and safety assessment of geotechnical systems.  相似文献