岩体演化的非线性动力学模型与稳定性分析     

孙瑛琳  许传华  韩绍瑛 《岩土工程技术》2008,22(6):286-288

以时间序列为基础,应用支持向量机建立岩体演化的非线性动力学模型,依据Lyapunov指数给出最长可预报时间,并通过函数拟合、变量代换将其化为标准的尖点突变模型,利用突变理论对其进行稳定性分析。结果表明,该模型预测效果理想,并具有良好的推广能力。  相似文献   

大直径、高置换率振冲碎石桩复合地基桩土应力特征试验分析   总被引：1，自引：0，他引：1  

李华伟 《岩土工程技术》2008,22(1):51-54

结合一次试桩案例,探讨分析了大直径、高置换率振冲碎石桩处理东部沿海地区填海地基的桩土应力分布特征和一般规律,并提出了一些新的理论和见解。  相似文献   

MapInfoGIS应用系统二次开发技术     

吕丽英  耿云峰 《北京测绘》2008,(2):16-19

对MapInfo基本产品进行了介绍,系统阐述了三种利用MapInfo产品进行的二次开发模式：MapInfo作为独立开发平台,利用MapBasic进行二次开发模式;将MapInfo作为OLE对象的开发模式;利用基于ActiveX的MapX控件所进行的开发模式。  相似文献   

利用VBA开发数字线划图质量控制与检查软件   总被引：1，自引：0，他引：1  

许中彬  宋智慧 《北京测绘》2008,(1):59-61

大比例尺数字线划图的质量检查方法是测绘行业共同关注的焦点。本文结合我院实施石家庄市1：1000数码航飞数字线划图的生产工作实践．介绍了基于SCAS平台制作大比例尺数字线划图质量控制、检查的办法,阐述了利用VBA＋SCAS作二次开发,控制数据质量的思路及应用。  相似文献   

动态规划法确定灌溉用水定额   总被引：2，自引：0，他引：2  

王二英  刘小山 《地下水》2008,30(4):80-83

农作物灌溉用水定额是实现水资源优化管理的重要组成部分,随着经济社会的发展,农业灌溉用水面临着水资源不足和保证粮食安全的双重压力,因此科学地确定农业灌溉用水定额,是实行微观定额管理的重要基础资料,也是今后水行政主管部门科学核定取水许可数量、建立水权分配制度的重要依据。本文采用动态规划的方法确定各种作物的灌溉用水定额。  相似文献   

拓扑变换法在平面直角坐标近似变换中的应用     

陈群国  陈永立  赵根庄 《地理空间信息》2008,6(3):107-109

简要介绍了对平面直角坐标进行近似变换的几种方法,重点讨论了拓扑变换法对平面直角坐标进行近似变换的原理。并对其变换的精度情况进行了实践分析。提出了提高其变换精度的处理方法及在建立变换模型时应注意的问题。  相似文献   

塑料土工格栅拉伸特性试验研究   总被引：6，自引：2，他引：4  

杨广庆  庞巍  吕鹏  周乔勇 《岩土力学》2008,29(9):2387-2391

进行土工格栅加筋土结构现场试验时,如何将实测应变有效地转换成拉应力对正确分析结构的作用机制具有重要影响。通过室内试验,研究了不同拉伸速率对3种强度的HDPE土工格栅拉伸性能的影响。试验结果表明：土工格栅的拉伸强度和拉伸模量随拉伸速率的降低而降低,峰值应变随拉伸速率的降低而增加。土工格栅强度越高,受拉伸速率的影响越小。在特定的拉伸速率条件下,同一种土工格栅对应2％,5％,10％应变和峰值应变的拉伸强度依次增大,而拉伸模量却依次减小。试验结果具有较强的实用价值。  相似文献   

Source of ore-forming material for the Huangtuliang gold deposit,Hebei Province and ore prospecting in the deep periphery   总被引：3，自引：1，他引：2  

Shuyin Niu  Aiqun Sun  Baode Wang  Yuchou Han  Minghui Wei  Hai Zhang  Ge Zhang  Ping Shi  Wenxing Wang 《中国地球化学学报》2008,27(3):225-234

The Huangtuliang gold deposit is characterized by its wide and large ore belt, stable extension and closely spaced orebodies. Unfortunately, no orebody was found by deep drilling. As a result, ore prospecting in this region was once put into dilemma. Detailed analysis of ore-forming and ore-controlling structures in the mining district by the authors has revealed that the ore-forming and ore-controlling structure in this mining district is a steeply dipping （85°-110°/∠70°-85° N-NNE）, spade-shaped ductile shear zone, and the ore-controlling structures are a series of nearly erected second-ordered faults which are developed in the upper part of the ductile shear zone, inter-secting with the ductile shear zone. Deep cutting of the ductile shear zone made it possible the ascending of ore fluids from the mantle plume at depth and these ore fluids would migrate upwards along the ductile shear zone under certain temperature and pressure conditions. Along their ascending path, the ore fluids would extract ore-forming elements from the country rocks and the extracted ore-forming elements would be deposited as ores in the hang- ing-wall second-ordered faults. The reason why no orebody was found in early prospecting at depth is that north- ward-dipping drilling in the southern part of the shear zone extended so deeply as to be beneath the shear zone. Only shallow-level orebodies could be found by southward-dipping drilling practice in the northern part of the shear zone. The location where deep-seated orebodies occurred shifted northwards and the orebodies occurred at greater depth. Therefore, it is natural that no orebody could be found when drill core passed through the shear zone. After the ore-forming and ore-controlling structures were well understood, the focus of ore prospecting was placed on the deep-level, northward-penetrating veins. In this way a number of new blind orebodies of great thickness have been found. On the basis of research development in the mining district, a prospecting plan has been made  相似文献   

Platinum and Palladium in Coal Rock and Geochemical Anomaly in Eastern Yunnan Province,Southwest China     

夏庆霖  赵鹏大  成秋明  陈永清  张生元 《中国地质大学学报(英文版)》2008,19(4):354-362

A series of geochemical anomalies of Pt and Pd were found in 1 358 recombined samples from a geochemical stream sediment survey in eastern Yunnan (云南) Province, China. Chemical optical emission spectroscopy, X-ray fluorescence analysis, and inductively coupled plasmas atomic emission spectrometry analyses of 22 elements and chemical compositions of 21 samples from coal-bearing strata from the Late Paleozoic, Mesozoic, and Cenozoic show Pt and Pd concentrated to some extent in coal rocks, with Pd/Pt相似文献   

河北平原地裂缝产生的微观机理研究   总被引：1，自引：0，他引：1  

孙强  杨继红  秦四清  刘天霸  胡秀宏 《工程地质学报》2008,16(2):201-205

分析了降雨和微结构失稳诱发的河北平原地裂缝机制。根据研究发现:(1) 根据近40a来华北平原的降雨量曲线图与地裂缝发生的时间图对比发现地裂缝多干旱年份的6-8月,地裂缝与农业灌溉用水密切相关。 (2)通过微结构突变失稳理论发现当应力状态满足孔隙微结构失稳判别式时,微结构元的变形状态将产生一个跳跃,即会诱发微结构失稳崩塌。(3)地下水的抽取造成原饱和带土体颗粒之间有效接触力的增加,同时造成地下隐裂隙和空洞的形成。同时灌溉入渗引起的非饱和带土体含水量增加,不仅改变了颗粒的受力情况,更重要的是导致了颗粒间连接刚度的降低,导致微结构的失稳。  相似文献