UH模型在有限元分析中的应用   总被引：5，自引：0，他引：5  

姚仰平  冯兴  黄祥  李春亮 《岩土力学》2010,31(1):237-245

由姚仰平等提出的超固结土统一硬化模型(UH模型)能够描述超固结土的硬化、软化、剪缩和剪胀等应力应变特性以及应力路径对它的影响。通过改进,直线型的Hvorslev线由抛物线型的Hvorslev线代替,UH模型的参数与剑桥模型(Cam-clay模型)的参数相同。应用该模型,对三轴试验进行有限元模拟,分析了与应用Cam-clay模型所得应力应变关系曲线的异同点;针对刚性承压板试验,进行了地基承载力的三维有限元分析,比较了与应用Cam-clay模型和摩尔库仑模型(Mohr-Coulomb模型)等所得p-s曲线的不同,分析了地基中不同点处的应力-应变关系曲线,并与Boussinesq弹性理论计算的应力做了比较;进行了地基固结沉降数值分析,比较了孔压、沉降的变化规律,体现了UH模型的优越性。  相似文献   

利用云南水管仪观测资料检测地球自由振荡   总被引：2，自引：1，他引：1  

杨跃文  秦嘉政  任佳  杨星  杨玲英  蒋翠荣  袁曲  李丽红  和玉权 《地震研究》2010,33(2)

利用云南省数字化水管仪的观测资料,采用功率谱密度估计方法,在没有对资料进行去固体潮处理的情况下,准确获得了2004年12月26日苏门答腊大地震激发的0S4～0S30基频球型自由振荡,并与前人的观测结果进行比较,同时对照了PREM模型的理论计算周期,发现水管仪观测与这三者符合得非常好,除0S4振型的观测周期和周期1、周期2、周期3的相对误差均大于0.3%外,其余的差别在3‰以下。研究表明,利用数字化水管仪观测资料的确可以提取到苏门答腊大地震激发的地球球型振荡,这就为地球自由振荡的研究提供了一种新的观测手段。  相似文献   

微震记录的空间自相关法误差特性分析          下载免费PDF全文

文成哲  刘财  鹿琪  郑松洙  韩颜颜 《地球物理学进展》2010,25(2):439-446

本文定量研究了当面波能量分布不遵循各向均匀的假设时,运用空间自相关法（SPAC法）出现的误差.通过分析合成微震记录,研究了方位局限的入射、站台的数量对空间自相关系数的影响,明确了一些圆形排列的SPAC系数偏差空间构造.它可分为两个部分：低频域的零偏差部分和高频域的偏差部分.在高频偏差域,存在排列特色的周期特性.其角度周期是排列圆周上相邻站点之间夹角的一半.研究中要强调的是对于每种圆形排列存在一些特殊的入射方向的现象（如,对三角形排列,那些方向角度为 15°, 45°, 75°,…）.当瑞利波沿着这些角度之一传播时,在SPAC谱中,有效的无偏差频率范围扩展到先前研究结果的两倍.这个现象为提高野外SPAC法勘探精度提供了一个新的可能.  相似文献   

Torsional response of a rigid circular foundation on a saturated half-space to SH waves     

Yuan-qiang Cai  Peng Wang  Hong-Lei Sun  Chang-jie Xu 《Soil Dynamics and Earthquake Engineering》2010

An analytical approach is used to study the torsional vibrations of a rigid circular foundation resting on saturated soil to obliquely incident SH waves. Biot’s poroelastic dynamic theory is considered to characterize the saturated soil below the foundation, which is solved by Hankel transform later. In order to consider the scattering phenomena caused by the existence of the foundation, the total wave field in soil is classified into free-field, rigid-body scattering field and radiation scattering field. According to the classification of wave field and the mixed boundary-value conditions between the soil and the foundation, torsional vibrations of the foundation are formulated in two sets of dual integral equations. Then, the dual integral equations are reduced to Fredholm integral equation of the second kind to be solved. Combining with the dynamic equilibrium equations of the foundation, the expressions for the torsional vibrations of the foundation are obtained. Numerical results are presented to demonstrate the influence of excitation frequency, incident angle, the torsional inertia moment of the foundation and permeability of the saturated half-space on the torsional vibrations of the foundation.  相似文献   

Ridge subduction and porphyry copper-gold mineralization:An overview   总被引：35，自引：0，他引：35  

SUN WeiDong    LING MingXing    YANG XiaoYong  FAN WeiMing  DING Xing & LIANG HuaYing CAS Key Laboratory of Isotope Geochronology  Geochemistry  Guangzhou Institute of Geochemistry  Chinese Academy of Sciences  Guangzhou  China  Research Center for Mineral Resources  School of Earth  Space Sciences  University of Science  Technology of China  Hefei  Graduate University of Chinese Academy of Sciences  Beijing  Key Laboratory for Metallogenic Dynamics  ... 《中国科学:地球科学(英文版)》2010,(4)

Many large porphyry Cu-Au deposits are connected to adakitic rocks known to be closely associated with ridge subduction. For example, there are several subducting ridges along the east Pacific margin, e.g., in Chile, Peru, and South America, most of which are associated with large porphyry Cu-Au deposits. In contrast, there are much fewer ridge subductions on the west Pacific margin and porphyry Cu-Au deposits are much less there, both in terms of tonnage and the number of deposits. Given that Cu and Au are...  相似文献   

贵州喀斯特聚落文化类型及其特征研究   总被引：1，自引：0，他引：1  

赵星 《中国岩溶》2010,29(4):457-462

从喀斯特环境人地关系的角度出发,探讨贵州喀斯特聚落文化的组成因子和文化层;依据地域分异规律、相似性原则、综合分析原则,将贵州喀斯特聚落文化分为谷地聚落、半坡村聚落、溪边村聚落、丘原区聚落、洞穴聚落和屯堡聚落六种主要类型。谷地聚落因峰丛洼地环境容量小,形成散珠状小聚居的形态和独特的垦殖文化景观;半坡村聚落因喀斯特山地环境的影响,形成依山而建、聚族而居、典型的吊脚楼民居建筑等特征;溪边村聚落因峰林坝地环境容量较大,沿河形成串珠状聚族而居的形态;丘原区聚落因丘原盆地环境容量大、地域环境开放,形成多民族杂居、村寨密集分布、文化交融强等特征;洞穴聚落因岩洞环境的特殊性,形成依洞而建的小聚居形态;屯堡聚落因喀斯特环境和历史的影响,形成典型的集聚型村落,将石文化、江南文化、军事文化有机结合。通过探讨各类型聚落文化在聚落规模、聚落布局、聚落环境、建筑、生活习俗等方面的特征,可为合理开发贵州喀斯特聚落文化提供依据。   相似文献   

Nitrogen and phosphorus intake by phytoplankton in the Xiamen Bay     

林彩  林辉  贺青  许焜灿  吴省三  张元标  陈金民  陈宝红  林力斌  卢美鸾  陈维芬  汤荣坤  暨卫东 《中国海洋湖沼学报》2010,28(1):99-105

This paper describes a time series experiment examining the nitrogen and phosphorus intake of natural phytoplankton communities by a microcosms approach.Seawater samples containing natural phytoplankton communities were collected from waters around Baozhu Islet in inner Xiamen Bay and around Qingyu Islet in the outer bay.The goal was to elucidate the relationship between phytoplankton population enhancement,the biological removal of nitrogen and phosphorus from the seawater,and the phytoplankton nitrogen an...  相似文献   

Detection of lymphocystis disease virus in Japanese flounder Paralichthys olivaceus and other marine teleosts from northern China     

战文斌  李永芹  绳秀珍  邢婧  唐小千 《中国海洋湖沼学报》2010,28(6):1213-1220

We isolated a strain of lymphocystis disease virus (LCDV) from Japanese flounder (Paralichthys olivaceus) cultured in northern China. Based on published sequences of major capsid protein (MCP) gene of LCDV-cn (GenBank: AF126405), we designed two primer sets P1/P2 and P3/P4. We then used one-step or nested PCR and in-situ hybridization (ISH) to detect LCDV and identify the target tissues or cells in infected Japanese flounder. The PCR products were positive in purified viral supernatant, skin nodules, gut, gill, kidney, spleen, stomach, heart, and liver of Japanese flounder. We compared the DNA sequence with 14 MCP nucleotide sequences from GenBank, including Megalocytivirus (OFIV and RSIV), Iridovirus (CzIV and WIV), Ranavirus (TFV and FV3), and Lymphocystivirus (8 LCDV). Based on the alignment, we confirmed the PCR product was from Lymphocystivirus (GenBank accession number DQ279090 (LCDV-HD)). Using ISH, we noted the presence of LCDV in the skin nodules, gut, gill, spleen, stomach, and heart of spontaneously infected Japanese flounders. We successfully amplified LCDV fragments from Schlegel’s black rockfish (Sebastes schlegeli Higendorf), redwing sea robin (Lepidotrigla microptera Günther) and turbot (Scophthalmus maximus) using the one-step and nested PCR, suggesting the target genes can be widely detected in fish using this method.  相似文献   

The effects of large and small-scale topography upon internal waves and implications for tidally induced mixing in sill regions     

Jiuxing Xing  Alan M. Davies 《Ocean Dynamics》2010,60(1):1-25

A free surface non-hydrostatic model in a cross-sectional form, namely, two-dimensional, in the vertical is used to examine the role of larger-scale topography, namely, sill width, and smaller scale topography, namely, ripples on the sill upon internal wave generation and mixing in sill regions. The present work is set in the context of earlier work and the wider literature in order to emphasise the problems of simulating mixing in hydrographic models. Highlights from previous calculations and references to the literature for detail, together with new results presented here with smooth and “ripple” topography, are used to show that an idealised cross-sectional model can reproduce the dominant features found in observations at the Loch Etive sill. Calculations show that on both the short and long time scales, the presence of small-scale “ripple” topography influence the mixing and associated Richardson number distribution in the sill region. Subsequent calculations in which the position and form of the small-scale sill topography is varied show for the first time that it is the small-scale topography near the sill crest that is particularly important in enhancing mid-water mixing on the lee side of the sill. Both short-term and longer-term calculations with a reduced sill width and associated time series show that as the sill width is reduced, the non-linear response of the system increases. In addition, Richardson number plots show that the region of critical Richardson number, and hence enhanced mixing, increases with time and a reduction in sill width. Calculations in which buoyancy frequency N varies through the vertical show that buoyancy frequency close to the top of the sill is primarily controlling mixing rather than its mean value. Hence, a Froude number based on sill depth and local N is the critical parameter rather than one based on total depth and mean N.  相似文献   

大容量气枪震源长江定点激发信号检测   总被引：3，自引：2，他引：1  

徐嘉隽  蔡辉腾  金星  王善雄  夏季  李培 《中国地震研究》2016,30(3):418-429

地学长江计划“安徽段实验”是大容量气枪震源在长江的首次激发。本文针对布设在气枪固定激发点附近的流动台和周边固定台接收到的气枪信号进行线性叠加分析近场和远场信号的时频特性,利用叠加结果检测气枪信号的传播特性,分析不同环境因素对信号传播距离的影响。结果表明：①近岸首台可以接收到清晰的压力脉冲、气泡脉冲的体波和面波信号;②气枪信号主频为5Hz左右,随震中距的增加,压力脉冲信号衰减很快,信号主频频带变窄;③对信号传播距离进行初步检测,最近的传播距离为180km,最远共有3个激发点传播达到260km,夜晚激发信号传播距离较远。  相似文献