非平稳空间相关多点地震动合成方法研究   总被引：1，自引：0，他引：1  

董汝博  周晶  冯新 《地震工程与工程振动》2007,27(3):10-14

根据地震波的传播特点,在现有的非平稳空间相关多点地震动合成方法的基础上进行了改进。通过修正随机相位角,使生成的多点地震动在局部场地上具有收敛性。给出了未知和已知相位差谱统计规律2种情况下非平稳多点地震动的合成方法。进一步提出了基于实际地震纪录的空间相关多点地震动合成方法。这些方法可用于大尺度结构的多点输入分析。  相似文献   

INTEGRATION OF THE MODELS OF ANNAGNPS AND REMM TO ASSESS RIPARIAN BUFFER SYSTEM FOR SEDIMENT REDUCTION     

Yongping YUAN Ronald BINGNER Randall WILLIAMS Richard LOWRANCE David BOSCH Joe SHERIDAN 《国际泥沙研究》2007,22(1):60-69

The United States Department of Agriculture (USDA) Annualized Agricultural Non-Point Source Pollution model (AnnAGNPS) is used to help evaluate a watershed response to agricultural management practices to control water quality. However, AnnAGNPS version 3.5 does not contain features to estimate the effect of a riparian buffer (RB) system on water quality. The Riparian Ecosystem Management Model (REMM) is used to simulate the impact of riparian buffer systems on water quality. However, frequently the lack of measured upland loadings that are required by REMM simulation limits the application of REMM. To address this data gap, a study was conducted to integrate AnnAGNPS with REMM for RB system simulation. AnnAGNPS was used to simulate water and sediment loadings from an upland field into a three-zone RB system at the Gibbs Farm located in the Georgia coastal plain. These AnnAGNPS outputs were used as the inputs to REMM. REMM was used to simulate water and sediment movement along the riparian buffers. The AnnAGNPS simulated amount of annual runoff at the edge of the field was close to observed amounts (Nash-Sutcliffe efficiency of 0.92). It is believed that a substantial portion of sand was removed from the runoff one meter into the grass buffer where the samplers were located; therefore, sand was excluded from the AnnAGNPS simulation for comparison with observed sediment. Excluding sand, the AnnAGNPS predicted amount of annual sediment matches the observed amount fairly well (Nash-Sutcliffe efficiency of 0.46). In addition, based on evaluating the percent reduction of sediment at each zonal interface, the AnnAGNPS/REMM model well simulated the function of the RB system to reduce sediment.  相似文献   

地震工程研究的科学大平台   总被引：1，自引：0，他引：1  

王自法 《地震工程与工程振动》2007,27(6):1-9

始于十九世纪末的地震工程研究,在其100多年的历史中积累了大量的理论和实践经验,随之而建设起来的各类地震工程实验设施分布于世界各地。近20年来,信息技术的飞速发展使得分布于世界各地的实验设施通过网络实现协同实验和资源共享。基于以上的信息,为了更好更快地和国际接轨,本文提出了建设一个地震工程研究领域的科学大平台设想。这个大平台包括三个方面的内容:数值模拟,网络协同实验系统和基础信息系统,将形成本领域开放性的综合科学平台。在数值模拟方面,这个科学平台将利用最新的信息技术将本领域的科学研究结果和方法集成起来,形成一个模块式的科学研究平台系统。在网络协同实验方面,将采纳美国NEES的思路,并对其改进和提高之后应用于中国。在基础数据方面,将利用最为先进的数据仓储技术,建设一个可以服务于地震工程科学研究的数据平台。最后,文章给出了建设这个科学平台的规划,以及目前的进展和资金支持等情况。  相似文献   

浮放设备地震滑移反应数值模拟研究   总被引：1，自引：0，他引：1  

郭恩栋  吴伟  胡煜文  杨克勇 《地震工程与工程振动》2007,27(6):124-129

以前人研究建立的浮放设备滑移反应分析理论为基础,给出了浮放设备在水平和竖向地震输入下滑移反应运动微分方程,选取连续型的库仑摩擦力模型,采用Runge-Kutta法求解浮放设备地震滑移反应运动微分方程,可以得到浮放设备在地震作用下的绝对加速度、相对速度和相对位移反应时程。采用编制的计算程序,进行了浮放设备地震滑移反应参数影响研究,结果表明:浮放设备水平滑移反应随着水平地震地面输入或楼层反应输入的增大而增大,随着设备与支撑面之间摩擦系数的增大而减小;当水平向输入加速度峰值大于0.3g时,需要考虑竖向激励的影响。  相似文献   

断层上方第四系覆盖层中氡气运移规律的数值模拟     

王晓丽  刘菁华  王祝文  张玉龙 《物探与化探》2007,31(2):149-152

在前人研究的基础上,建立了稳定条件下断层上方第四系覆盖层中氡气的运移方程,给出了相应的边界条件,对断层上方覆盖层中的氡浓度分布进行了数值模拟,并对其影响因素进行了讨论.结果表明,断层上方第四系覆盖层中存在明显的氡浓度异常,其分布与覆盖层的厚度、断层的宽度、氡的扩散系数和对流速度等因素有关.  相似文献   

西部某水电站坝区采空区的工程效应研究          下载免费PDF全文

魏放  魏义亮 《地质与勘探》2007,43(3):112-115

通过对西部某水电站的地质环境分析,揭示了采空区分布特征.对溢洪道进行数值模拟,研究采空区上覆岩层的影响范围,分析采空区对溢洪道的影响.最后综合分析采空区对水电站不同工程部位的危害,提出相应的处理措施.  相似文献   

Estimation of Block Sizes for Rock Masses with Non-persistent Joints   总被引：2，自引：3，他引：2  

B. H. Kim  M. Cai  P. K. Kaiser  H. S. Yang 《Rock Mechanics and Rock Engineering》2007,40(2):169-192

Summary  Discontinuities or joints in the rock mass have various shapes and sizes. Along with the joint orientation and spacing, the joint persistence, or the relative size of the joint, is one of the most important factors in determining the block sizes of jointed rock masses. Although the importance of joint persistence on the overall rock mass strength has long been identified, the impact of persistence on rock strength is in most current rock mass classification systems underrepresented. If joints are assumed to be persistent, as is the case in most designs, the sizes of the rock blocks tend to be underestimated. This can lead to more removable blocks than actually exist in-situ. In addition, a poor understanding of the rock bridge strength may lead to lower rock mass strengths, and consequently, to excessive expenditure on rock support. In this study, we suggest and verify a method for the determination of the block sizes considering joint persistence. The idea emerges from a quantitative approach to apply the GSI system for rock mass classification, in which the accurate block size is required. There is a need to statistically analyze how the distribution of rock bridges according to the combination of joint orientation, spacing, and persistence will affect the actual size of each individual block. For this purpose, we generate various combinations of joints with different geometric conditions by the orthogonal arrays using the distinct element analysis tools of UDEC and 3DEC. Equivalent block sizes (areas in 2D and volumes in 3D) and their distributions are obtained from the numerical simulation. Correlation analysis is then performed to relate the block sizes predicted by the empirical equation to those obtained from the numerical model simulation. The results support the concept of equivalent block size proposed by Cai et al. (2004, Int. J. Rock Mech. Min. Sci., 41(1), 3–19).  相似文献   

On the quantitative evaluation of metamorphic fluid composition: Verification of the results of physicochemical simulations for water-mineral-rock reactions     

V. O. Khudolozhkin 《Russian Journal of Pacific Geology》2007,1(3):290-301

This paper reports the results of a comparison of the qualitative physicochemical simulations (by the Winsel program complex) of the composition of the reacting fluid with experimental data on the water-electrolyte (NaCl, HCl, NaOH, and KOH)-mineral (quartz, corundum, microcline, and plagioclase) system and the water-electrolyte-rock (granite and pelite) system at 400–800°C and 1–10 kbar. Constraints are proposed for the temperature, pressure, and the composition of the electrolyte at which the simulation results are consistent with the experimental data.  相似文献   

起伏地表条件下地震波场数值模拟有限积分变换有限差分方法     

李健  孙建国 《吉林大学学报(地球科学版)》2007,(Z1)

针对起伏地表条件下的地震波数值模拟问题,提出将起伏的地表映射到一个规则的长方形网格坐标系中,并在此基础上推导出变换域中的波动方程。根据导出来的波动方程应用有限余弦变换有限差分方法进行地震波场的数值模拟,以解决起伏地表条件下的数值模拟。  相似文献   

海岸地形作用在青岛一次晚秋暴雨过程中的数值模拟分析          下载免费PDF全文

邰庆国  汤剑平  高留喜  石莹  裴洪芹 《气象科学》2007,27(6):633-640

利用常规资料和卫星、雷达观测,分析了2004年11月9日至10日山东青岛地区一次暴雨的中尺度结构特征,并在初步分析的基础上进行了数值模拟和地形的敏感性对比试验,结果表明:此次暴雨是冷锋前暖区的浅层对流性强降水;西太平洋的水汽是这次暴雨的主要水汽源;模式对这次强降水具有较强的模拟能力;海岸地形作用所产生的次级环流和中尺度重力波,可能是这次对流性强降水的触发机制,同时对这次降水有很大的增幅作用。  相似文献