Application of caustic method to determining stress intensity factor of compressive shear crack   总被引：1，自引：0，他引：1  

陈顺云  许昭永  杨润海  赵晋明  王  熊秉衡  王正荣 《地震学报(英文版)》2005,18(4):483-489

Introduction The caustics method has been introduced into seismology in recent years and preliminary in- vestigation indicates that it is effective to study the compressive stress (strain) of transparent sam- ples such as plexiglass (XU et al, 2001, 2002; Xu et al, 2000, 2002; XIONG et al, 2000, 2002). Especially, as a seismological concept, earthquake nuclei, becomes clearer according to the caustic shadow, which combines plastic area, nucleation area and crack concentration area together …  相似文献   

基于Visual Basic及Access的工程资料档案管理系统开发     

熊良宵  李天斌 《中国地质灾害与防治学报》2005,16(3):148-151,155

在社会日趋发展和信息技术取得巨大进步的今天，许多勘查设计单位原有的工程资料管理方法已不能完全满足社会各方面工程实践的要求，使用先进的工程资料管理系统是必不可少的。因此，工程资料档案管理系统是一卜具有重要理论研究意义及广阔应用前景的研究课题。文章结合鹧鸪山隧道这一重大工程，利用visual Basic和Access开发了一个适用于广大工程建设资料管理的软件。在系统开发过程中，解决了以下问题，即利用WinRAR软件实现文，牛的压缩及解压缩，利用SQL语言实现文件多种查询方法。通过调用文件存放地址实现文件的打开功能。工程资料卡当案管理系统的使用将解决工程实际中存放、保管资料的各种问题，消除了传统资料保存方式的弊端。工程资料档案管理系统具有使用方便、查询快捷等优点，具有实用价值和推广价值。  相似文献   

树根桩治理不均匀沉降厂房的实例     

欧高军 《化工矿产地质》2006,28(2):117-120

由于厂房桩基础设计为“洛阳铲”成孔灌注桩,不适宜该地基土且未考虑填土负摩擦的影响,加上部分桩基施工过程中未达到持力层,从而导致厂房发生不均匀沉降,引起上部结构沉降开裂。通过在原厂房承台中置入树根桩,并对承台进行了加固处理,使厂房不均匀沉降得到有效控制。  相似文献   

Dynamic rupture on a bimaterial interface governed by slip-weakening friction   总被引：3，自引：0，他引：3  

Zheqiang Shi  Yehuda Ben-Zion 《Geophysical Journal International》2006,165(2):469-484

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Theoretical and numerical analyses of pore-fluid flow patterns around and within inclined large cracks and faults   总被引：6，自引：0，他引：6  

Chongbin Zhao  B. E. Hobbs  A. Ord  P. Hornby  Shenglin Peng  Liangming Liu 《Geophysical Journal International》2006,166(2):970-988

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华北东部上地幔破裂带   总被引：5，自引：0，他引：5       下载免费PDF全文

杨文采张学民  于常青 《地质学报》2007,81(10):1305-1313

利用天然地震的走时和S波震相的层析成像方法可以提供上地幔S波速度扰动精细图像。我们对华北东部(32°～44°N,114°～126°E)进行了高分辨率S波地震层析成像研究,揭示了苏鲁及环渤海地区上地幔速度结构的差异,为研究该区域深部构造演化提供新的地球物理证据和制约。本次成像取得的最醒目的成果是揭示了由波速剧烈变化指示的两条上地幔破碎带,它们分别出现在渤海湾裂谷区与苏鲁超高压变质带下方。苏鲁超高压变质带下方上地幔破碎带包含多个有序排列的高速团块,推测与扬子走滑并向前俯冲、以及前锋超高压变质块体拆沉及折返作用有关。地幔地震S波速的成像结果支持华北东部渤海湾地区发育地幔热羽柱体系的观点,并对地幔热羽柱的鉴识提供了新的标识。  相似文献   

Discrete‐like crack simulation by smeared crack‐based FEM for reinforced concrete     

Yuichi Sato  Kazuhiro Naganuma 《地震工程与结构动力学》2007,36(14):2137-2152

A numerical process that simulates crack propagation in reinforced concrete through post‐crack stress redistribution is presented. This process is developed within the context of the smeared crack approach. Continuity and orientation of the reinforcing bar components are automatically recognized in the pre‐processing stage. The process explicitly outputs crack widths by computing the bond slips along reinforcement, without imposing any additional nodes between the reinforcement and concrete. The process is incorporated with a finite element algorithm, and the validation is investigated through sample 3D static analyses of nine concrete specimens subjected to monotonic shear and flexure loads. These specimens contain relatively well‐distributed steel bars and fiber reinforced polymer (FRP) sheets of reinforcement ratio from 0.11 to 0.57%. The analyses predict the crack patterns and crack widths well, although some disagreements are found between the test and the analysis results. The proposed process outputs discrete, continuous in crack directions, and element boundary‐free crack patterns. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

钻杆失效理论分析方法初探          下载免费PDF全文

吕建国桂暖银  胡远彪 《探矿工程》2001,(5):55-57

从有限元分析构件裂纹周围的应力分布出发,导出钻杆中常出现的Ⅰ－Ⅲ型复合裂纹的失稳条件,通过编程计算了不同深度秒同倾角裂纹尖端处的应力强度因子,计算得到的临界裂纹深度可作为钻杆检测仪精度选择的参考,同时也为钻杆寿命评估提供了理论依据。  相似文献   

彬长矿区采陷裂缝影响因素分析     

田军 《中国煤炭地质》2008,(9):47-49

对彬长矿区地面裂缝进行了详细调查,指出该矿区地面裂缝的主要为开采塌陷引起的采陷裂缝,并对采陷裂缝的发育特征进行了归类。分析认为：采深增大,基岩厚度增大,覆岩的稳定性增强,对地面裂缝的规模控制也增强,60°～70°为塌陷裂缝边界范围圈定的指标值;工作面变宽,采厚变大,会加剧地面裂缝的产生和发展;“上硬下软”的地层结构,有利控制地表移动变形,关键层厚度增大,可以明显减缓地表移动;松散层厚度愈大,抗变形能力愈大的土层,其裂缝愈不发育;V型沟谷对裂缝的形成和发展影响较小,斜坡则对裂缝的发育有加剧作用;降雨对裂缝的发育有明显的加速作用。  相似文献   

Incorporating spatial variation in housing attribute prices: a comparison of geographically weighted regression and the spatial expansion method   总被引：10，自引：3，他引：7  

Christopher Bitter  Gordon F. Mulligan  Sandy Dall’erba 《Journal of Geographical Systems》2007,9(1):7-27

Hedonic house price models typically impose a constant price structure on housing characteristics throughout an entire market area. However, there is increasing evidence that the marginal prices of many important attributes vary over space, especially within large markets. In this paper, we compare two approaches to examine spatial heterogeneity in housing attribute prices within the Tucson, Arizona housing market: the spatial expansion method and geographically weighted regression (GWR). Our results provide strong evidence that the marginal price of key housing characteristics varies over space. GWR outperforms the spatial expansion method in terms of explanatory power and predictive accuracy.

Christopher BitterEmail:

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