含水层结构和地下水面形态的虚拟模拟——以苏锡常地区为例   总被引：4，自引：2，他引：2  

朱琳  苏小四  段福洲  胡卓玮  潘云  高立 《吉林大学学报(地球科学版)》2007,37(2):400-405

利用Visual C++作为虚拟苏锡常地区第四系含水层结构和地下水面形态的开发工具,采用OpenGL对它们进行三维可视化表达,研究者可采用不同的显示方式对含水层和地下水面进行观察,了解各地层间的空间分布特征、含水层间的补给关系、地下水面的形态和水平方向上地下水补给区和排泄区的分布情况,以及地下水面的动态演示过程。  相似文献   

地铁车站结构振动台试验中传感器位置的优选   总被引：3，自引：0，他引：3  

杨林德  季倩倩  杨超  郑永来 《岩土力学》2004,25(4):619-623

在对软土地铁车站结构进行振动台模型试验的过程中,对传感器设置位置的优选进行了研究,内容包括按三维问题的分析论证地铁车站结构在横向激振作用下的受力变形特征,据以确定可按平面应变问题进行分析的断面的分布范围及主观测断面的位置;按二维问题的分析论证地铁车站结构在横向激振作用下的变形趋势,据以确定观测断面上传感器设置的优选位置;以及在满足基本信息采集要求的前提下,对可供采用的信息采集通道进行优化分配的方法。成果对试验获得成功起到了保障作用,对同类试验也有参考价值。  相似文献   

Dynamic collapse analysis for a reinforced concrete frame sustaining shear and axial failures     

Kenneth J. Elwood  Jack P. Moehle 《地震工程与结构动力学》2008,37(7):991-1012

Shaking table test results from a one‐story, two‐bay reinforced concrete frame sustaining shear and axial failures are compared with nonlinear dynamic analyses using models developed for the collapse assessment of older reinforced concrete buildings. The models provided reasonable estimates of the overall frame response and lateral strength degradation; however, the measured drifts were underestimated by the models. Selected model parameters were varied to investigate the sensitivity of the calculated response to changes in the drift at shear failure, rate of shear strength degradation, and drift at axial failure. For the selected ground motion, the drift at shear failure and rate of shear strength degradation did not have a significant impact on the calculated peak drift. By incorporating shear and axial‐load failure models, the analytical model is shown to be capable of predicting the axial‐load failure for a hypothetical frame with three nonductile columns. Improvements are needed in drift demand estimates from nonlinear dynamic analysis if such analyses are to be used in displacement‐based performance assessments. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Experimental characterization,modeling and identification of the NEES‐UCSD shake table mechanical system     

O. Ozcelik  J. E. Luco  J. P. Conte  T. L. Trombetti  J. I. Restrepo 《地震工程与结构动力学》2008,37(2):243-264

This paper proposes a simple conceptual mathematical model for the mechanical components of the NEES‐UCSD large high‐performance outdoor shaking table and focuses on the identification of the parameters of the model by using an extensive set of experimental data. An identification approach based on the measured hysteresis response is used to determine the fundamental model parameters including the effective horizontal mass, effective horizontal stiffness of the table, and the coefficients of the classical Coulomb friction and viscous damping elements representing the various dissipative forces in the system. The effectiveness of the proposed conceptual model is verified through a comparison of analytical predictions with experimental results for various tests conducted on the system. The resulting mathematical model will be used in future studies to model the mechanical components of the shake table in a comprehensive physics‐based model of the entire mechanical, hydraulic, and electronic system. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

以气候变化为标志的中国第四纪地层对比表   总被引：80，自引：14，他引：66  

刘东生  施雅风  王汝建  赵泉鸿  翦知湣  成鑫荣  汪品先  王苏民  袁宝印  吴新智  邱占祥  徐钦琦  黄万波  黄慰文  安芷生  鹿化煜 《第四纪研究》2000,20(2):108-128

随着新技术方法的不断引入和地层学多元划分理论的提出,除了传统的岩石地层、生物地层和年代地层,又开拓了地貌地层、磁性地层、土壤地层、同位素地层、事件地层和旋回地层等新的分支。高分辨率古气候研究的需要,促使我们去探索第四纪地层,特别是陆相地层新的划分方案。本文作者在各自对不同的成因类型的第四纪沉积物的研究中,都或多或少参照深海氧同位素阶段进行过地层的划分和对比的尝试,自然就产生了以氧同位素阶段为参照的划分和对比第四纪地层的设想。我们“抛砖引玉”,提出了中国第四纪ＭＩＳ地层表,只求“有”,尚不能求“准”,希望我们的工作能够推进我国第四纪地层的研究,对第四纪科学的发展作出贡献。  相似文献   

大连水师营地下水初始水位的计算及地下水流场的预测   总被引：1，自引：0，他引：1  

赵培迎  王彦  刘健 《水文》2000,20(3):5-9

利用对偏微分方程逆问题的数值求解,给出了由一组抽水产测水位值计算地下水初始水位以及由二组抽水井实测水位值估算总补给量的方法。在此基础上建立了对地下水流场进行预测的数值方法。并对水师营地下水流场进行了预测,其预测结果与实测值基本吻合。此方法可在类似地下水资源评估和地下水流场计算中推广应用。  相似文献   

Modal control of seismic structures using augmented state matrix     

Lyan‐Ywan Lu  Lap‐Loi Chung 《地震工程与结构动力学》2001,30(2):237-256

In conventional methods of modal control, the number of controllable structural modes is usually restrained by the number of sensors that feedback the structural signals. In this paper a modal control scheme where the feedback gain is formulated in an augmented state space is proposed. The advantage of the proposed method is that it increases the number of the controllable modes without adding extra sensors. The method is verified experimentally by an earthquake simulation test with a full‐scale building model. The proposed modal control was also compared with the conventional ones in the test. For the building model tested, the performance of the proposed control with only one feedback signal can be as efficient as that of modal control with full state feedback. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

空间钢筋混凝土框架结构的非弹性地震反应   总被引：3，自引：0，他引：3  

杜宏彪  沈聚敏 《地震工程与工程振动》1999,19(2):81-86

对两个缩比为十五分之一的三层、双跨、两开间的钢筋混凝土框架模型进行了振动台试验,一个模型模拟质量中心与刚度中心不一致的偏心结构,另一个模型模拟承受双向地面运动的结构。研究了结构的空间非弹性地震反应。计算结果表明,理论分析与实测结果有较好的吻合性。  相似文献   

Groundwater in a coral island   总被引：4，自引：3，他引：1  

V. S. Singh  C. P. Gupta 《Environmental Geology》1999,37(1-2):72-77

 Freshwater aquifers in small coral islands usually occur as thin lenses which are significantly influenced by stresses such as groundwater pumping, sea tides, etc. Kavaratti, a coral island, is one of the 36 such islands in the Arabian Sea off the western coast of India. Detailed hydrogeological investigations were carried out to determine the quantity of freshwater that could be pumped in addition to the present usage. Salinity of groundwater must remain within permissible limits and a 2-D solute mass transport model with a vertical section of the island was constructed by the computer code SUTRA. The model was calibrated by obtaining a match of computed and observed values of the water table, tidal efficiency, and salinity of groundwater at the water table. The model analysis showed that the salinity of groundwater continues to increase unless groundwater pumping is kept below a certain rate. Groundwater potential can be augmented by reducing the subsurface outflow to the sea and by raising the water table by a subsurface dam. Received: 8 September 1997 · Accepted: 27 April 1998  相似文献   

未来海平面上升激化地基变形的研究     

杨红禹  田春德 《上海国土资源》2000,(4)

未来上海地区海平面上升将引起地下水位抬升,将会对多层建筑地基产生影响。文章在研究探讨地基变形激化程度的同时,也进行了土压缩模量Es的预测分析工作,并提供分析结果。  相似文献