Consolidation analysis of saturated multi‐layered soils with anisotropic permeability caused by a point sink     

Zhi Yong Ai  Wen Ze Zeng 《国际地质力学数值与分析法杂志》2013,37(7):758-770

This paper presents the analytical layer‐element method to analyze the consolidation of saturated multi‐layered soils caused by a point sink by considering the anisotropy of permeability. Starting from the governing equations of the problem, the solutions of displacements and stresses for a single soil layer are obtained in the Laplace–Hankel transformed domain. Then, the analytical layer‐element method is utilized to further derive the solutions for the saturated multi‐layered soils in the transformed domain by combining with the boundary conditions of the soil system and continuity conditions between adjacent layers. The actual solutions in the physical domain can be acquired by the inversion of Laplace–Hankel transform. Numerical results are carried out to show the accuracy and stability of the proposed method and evaluate the influence of sink depth and anisotropic permeability on excess pore pressure and surface settlement. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Fractal characteristics of sand grain group changes under freeze-thaw cycles and its correlation with long-term strength北大核心CSCD     

刘启  张泽  张圣嵘  恽晴飞  付峻松 《冰川冻土》2022,44(6):1820-1832

Seasonally frozen soils are widely distributed in China in terms of area,and the freeze-thaw cycle effect generated by the alternation of cold and warmth is one of the causes of engineering damage in cold areas during construction,and it is particularly important to restore the nature and state of the soil when it is subjected to freeze-thaw action. Therefore,sandy soil specimens with different numbers of freeze-thaw cycles were prepared,and the long-term strength of frozen sandy soil was tested using a spherical template indenter. Using fractal theory and the microstructure image processing software ImageJ,the change law of grain group and long-term strength of two frozen sandy soils under different numbers of freeze-thaw cycles were studied. The results show that：for fine sand（FS）,the fractal dimension DB has a highly significant positive correlation with the long-term strength variation,among which ≥0. 15~0. 20 mm and ≥0. 25~0. 40 mm have the best fit with the long-term strength,and are the dominant grain classes of FS. For medium sand（MS）,the fractal dimension DB is slightly positively correlated with the long-term strength,and the variation shows a“vertical N”trend,in which the grain size content of ≥0. 30~0. 40 mm and ≥0. 40 mm fits better with the long-term strength,and is the dominant grain class for MS. The content of other grain groups did not correlate significantly with the long-term strength change. The freeze-thaw action changed the content ratios of coarse and fine grain agglomerates in the soil. With the increase of the overall particle size interval,the dominant particle size also increases,which shows that the long-term strength of frozen sandy soil tends to decrease and then increase with the increase of the content of some particle sizes. The results of the study can provide theoretical reference for the determination of long-term strength in areas subject to freeze-thaw action. © 2022 Science Press (China).  相似文献   

Eddy formation and surface flow field in the Luzon Strait area during the summer of 2009     

刘泽  侯一筠  谢强 《中国海洋湖沼学报》2015,33(5):1320-1333

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基于精密单点定位的岛礁控制测量研究     

洪泽  王国举 《全球定位系统》2015,(3):51-54

本文利用静态精密单点定位技术解算海岛礁控制点的位置坐标,并利用高精度长基线解算软件GAMIT／GLOBK的结果作对比,结果显示其精度可达到厘米级别。在数据解算过程中分析影响误差的主要来源,并重点讨论了多路径效应对精度的影响,提出相关的处理手段,最终达到提高精度的目的。  相似文献   

微板块与大板块：基本原理与范式转换     

李三忠  索艳慧  周洁  钟世华  孙国正  刘洁  王光增  朱俊江  姜素华  李玺瑶  郭晓玉  刘丽军  刘永江  曹现志  郭玲莉  赵淑娟  王鹏程  关庆彬  陈龙  刘勃然  周建平  姜兆霞  刘琳  曹花花  戴黎明  于胜尧  刘博  王秀娟  王程程  王玺  刘泽  管红香  李晓辉  胡军  段威  于雷  刘晓光  王誉桦  钟源  刘鹏  张文超  李洛阳  赵彦彦  许淑梅 《地质学报》2022,96(10):3541-3558

传统板块构造理论50多年来一直是占统治地位的地学理论，是理解固体地球运行的基本范式，但遇到三大难题：板块起源、板内变形和板块驱动力。针对这三大难题，微板块构造理论试图开拓一个全球构造研究的新范式。本文通过与传统板块构造理论中基本原理的逐条对比，阐明了微板块构造理论的基本原理和优势及其对传统板块构造理论的拓展。微板块构造范式既不同于传统板块构造范式，又不同于地幔柱范式，是两者的重要补充与拓展。文中着重从几何学、运动学、动力学、适用范围、理论出发点、理论假设与预测的角度，阐明了大板块与微板块的异同，并探讨了两者的转换关系及其转换机制的多样性，介绍了微板块生长成为大板块的4种途径、大〖JP2〗板块破碎为微板块的3种转换模式，探索了前板块构造体制下微地块在非线性地球系统中通过自组织、自生长等方式，进化为板块体制下微板块的自然选择过程。本文还提出陆壳型微地块是密度选择的结果，其密度决定了其保存机制，这是陆壳起源的根本；〖JP〗微地块向微板块的转变是刚性选择的结果，其刚性是初始板块构造体制起始的必要条件；微板块不对称俯冲或对流型式的转变是热选择的结果，其热不对称性是现代板块构造体制起始的必要条件。  相似文献   

网络GIS信息安全研究     

王泽根  张毅赵斌张鹏  韩应明 《测绘学院学报》2004,21(1):66-68,72

分析了保障网络GIS信息安全的必要性和网络GIS信息可能受到的安全威胁及其物理入侵点，提出了保障网络GIS信息安全的技术策略。  相似文献   

宁夏回族自治区的湿地资源及其保护建议   总被引：5，自引：0，他引：5  

姜全飞  闫泽 《湿地科学与管理》2006,2(2):34-37

介绍了宁夏回族自治区湿地资源现状、面临的主要威胁和问题,提出了加强湿地立法和管理机构建设、保护湿地资源的建议。  相似文献   

元谋干热河谷区水土流失现状及治理对策   总被引：12，自引：0，他引：12  

张建平  杨忠  庄泽 《云南地理环境研究》2001,13(2):22-27

元谋干热河谷区气候炎热干燥、植被稀疏、生态环境脆弱,加之人类活动的干扰,水土流失严重,流失面积1080.79km^2,占总面积的53．5％。通过对水土流失特征、危害、水土保持存在问题的分析,提出了该区水土流失的治理措施和建议。  相似文献   

由降雨侵蚀引起的山坡面水土流失预测的数学模型   总被引：3，自引：1，他引：3  

刘阳  王锡魁  彭泽州 《吉林大学学报(地球科学版)》2002,32(2):174-176

数学模型包括：坡面水流连续方程、水流运动方程、泥沙连续方程（水土流失方程）、坡面变形方程。考虑到坡面流的流速及非线性双曲型方程，采用迎风有限差分显格式来离散方程，编制计算程序，进行了计算。研究成果可以描述动态坡面降雨侵蚀过程，并可将研究成果扩展到整个小流域，从而为治理水土流失提供依据。  相似文献   

古气候变化吸引子维数对比研究     

袁林旺  周春林  刘泽纯 《地理与地理信息科学》2002,18(3):94-96

对世界上不同地区的多条古气候曲线 ,采用相同的间距和同一种算法进行关联维数计算 ,结果表明各系统均具有非线性作用产生的混沌现象。与太阳辐射曲线关联维数对比表明 ,太阳辐射控制了气候变化的基本格局 ,在此基础上叠加了区域性特征。  相似文献