稀性泥石流的平均运动速度研究   总被引：1，自引：0，他引：1  

余斌 《地震学刊》2009,(5):541-548

泥石流的运动速度是泥石流动力学研究中最重要的参数。稀性泥石流是常见也是危害较大的泥石流类型,准确而简洁地计算稀性泥石流的运动速度非常重要。现有的稀性泥石流平均速度经验公式,在使用上和适用地区上还存在一些问题。本文通过分析一系列稀性泥石流观测资料中的体积浓度与稀性泥石流的运动速度和阻力特征的关系,得出了一个新的计算稀性泥石流平均运动速度的经验公式,该公式能适应各种类型的泥石流沟,适用于一般急流的稀性泥石流;对于缓流稀性泥石流,计算值与观测值相比偏大,但很接近;不适用于缓慢稀性泥石流。本文提出的经验公式,使用简洁,计算稳定,与其他方法计算的稀性泥石流平均运动速度很接近。该速度计算经验公式也适用于稀性泥石流堆积扇上游沟道,但对于堆积扇上的速度,计算值偏大,且越往堆积扇的下游,偏差越大。  相似文献   

双桥静力触探法判别上海薄夹层粘土地基液化研究   总被引：2，自引：0，他引：2  

张继红  顾国荣 《岩土力学》2005,26(10):1652-1656

通过对11项典型工程场地进行原位取土及双桥静力触探原位测试分析,重点研究了上海地区薄层粘性土（或粘质粉土）夹层对液化判别的影响,统计分析了锥尖阻力qc、摩阻比Rf与土层粘粒含量的相关关系,提出了完全依据双桥静力触探试验的地基液化判别方法,在工程应用中取得了显著经济效益。  相似文献   

非线性弹性地基上矩形薄板的主参数共振   总被引：20，自引：0，他引：20  

杨志安  赵雪娟  席晓燕 《岩土力学》2005,26(12):1921-1925

分析非线性弹性地基上受参数激励小挠度矩形薄板的主参数共振问题,由冯卡门方程和伽辽金方法得到系统的非线性振动方程,它是杜分-马休型方程,应用非线性振动的多尺度法得到平均方程。数值计算结果表明：阻尼系数、地基系数、几何参数对主参数共振曲线影响明显。  相似文献   

双河油田核三段Ⅱ油层组内夹层分布规律   总被引：7，自引：0，他引：7       下载免费PDF全文

张尚锋  张昌民  伊海生  郑荣才  樊中海  姜建伟  鲁国甫 《沉积与特提斯地质》2000,20(4):71-78

油层内的夹层是影响油田注水效果的因素之一,也是影响剩余油研究分布的主要因素。笔者以钻井岩心、测井等资料为基础,研究夹层的类型,成因及发育分布特征,指出各种类型的夹层与基准面变化过程中Ａ／Ｓ比值变化和沉积物补给通量变化关系密切,不同级次的基准面旋回和不同沉积微相内夹层的层次类型及发育分布规律不同。文中深入分析了夹层类型与基准面旋回的关系。  相似文献   

均匀充电矩形薄板电场复形调优反演计算     

李建林  张庆  倪根生 《物探化探计算技术》2000,22(3):254-256

针对充电电场反演计算参数较多以及复形调优算法处理约束条件的直接有效性,作者就均匀充电矩形薄板反演问题编制程序,计算地质体理深、倾角及大小。尽管迭代次数较高,计算结果颇为理想,取得了较好的效果。  相似文献   

重叠回线装置下有限导电薄板瞬变电磁响应的一种简化模型   总被引：1，自引：0，他引：1       下载免费PDF全文

李勇 《地球物理学进展》2008,23(3):948-956

在吸收前人提出的导电薄板等效电流回路模型概念的基础上,应用普通电磁学理论对其瞬变电磁法的过程作了完整的论述,并得到清晰明确的数学表达式,同时指出一次场关断时间与观测异常幅值的关系.在重叠回线装置下,模型解可进一步被简化.通过实例的具体数值计算过程,证明该简化模型为重叠回线装置下有限薄板类地质体瞬变电磁的定量分析提供了一个简捷有效的途径.  相似文献   

Dynamic response of road pavement resting on a layered poroelastic half‐space to a moving traffic load     

Xue‐Qian Fang  Shao‐Pu Yang  Jin‐Xi Liu  Xiao‐Song Zhang 《国际地质力学数值与分析法杂志》2014,38(2):189-201

This paper is dedicated to study the dynamic response of a thin‐plate resting on a layered poroelastic half‐space under a moving traffic load. Based on the dynamic poroelastic theory of Biot, the general solutions of the homogeneous poroelastic foundation are obtained by Fourier translation. By using the transmission and reflection matrices method in the frequency domain, the equivalent stiffness of the layered poroelastic half‐space is presented. Kirchhoff's hypotheses are applied to obtain the vertical displacement of the thin plate. By using the inverse Fourier transform, the time domain solution is obtained. As an example of three layers, the influences of the load velocity, the material properties of poroelastic layers, and the flexural rigidity of the plate on the response of the pavement system are examined. Analyses show that a soft intermediate layer results in the significant increase of vertical displacement of road pavement. Comparison with the existing work validates the present model. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

An iterative algorithm for removing the effect of thin cloud cover from LANDSAT imagery     

B. Chanda  D. Dutta Majumder 《Mathematical Geology》1991,23(6):853-860

In this paper, we propose an iterative algorithm for removing the effect of thin cloud cover from LANDSAT imagery. It is seen that the noise in such images is multiplicative as well as additive. The recorded image is first processed to update different parameters of the image formation model to known values. Processing algorithm and knowledge of parameter values are developed by considering the physics of the situation. A low-pass filter is then applied to the processed image to remove the effect of the cloud. The filter is of a tapered shape, and its parameters are adjusted to minimize the estimation error.  相似文献   

岩石薄片资料的有序和无序模糊聚类及其沉积学意义     

龚一鸣 《矿物岩石》1990,10(1):87-93

笔者对岩石薄片资料进行了有序和无序模糊聚类，岩石薄片资料象沉积构造一样与沉积作用、沉积环境有密切的联系。但是，由于大多数的岩石薄片资料具有模糊性和灰色性，因此，这种联系一般说来不甚明显。但模糊聚类能使隐藏在这些资料中的沉积学信息清楚、白化。在沉积学和岩相古地理的研究过程中，不同类型、不同特征的资料必须用不同的理论和方法进行整理、分析，只有这样才能揭示隐藏在这些资料中的特征和规律。  相似文献   

An Innovative Approach to Meteorite Analysis by Laser‐Induced Breakdown Spectroscopy          下载免费PDF全文

Giorgio S. Senesi  Gioacchino Tempesta  Paola Manzari  Giovanna Agrosì 《Geostandards and Geoanalytical Research》2016,40(4):533-541

An innovative approach of double pulse laser‐induced breakdown spectroscopy (DP‐LIBS) coupled with optical microscopy was applied to the characterisation and quantitative analysis of the Agoudal iron meteorite in bulk sample and in petrographic thin section. Qualitative analysis identified the elements Ca, Co, Fe, Ga, Li and Ni in the thin section and the whole meteorite. Two different methods, calibration‐free LIBS and one‐point calibration LIBS, were used as complementary methodologies for quantitative LIBS analysis. The elemental composition data obtained by LIBS were in good agreement with the compositional analyses obtained by traditional methods generally applied for the analysis of meteorites, such as ICP‐MS and EDS‐SEM. Besides the recognised advantages of LIBS over traditional techniques, including versatility, minimal destructivity, lack of waste production, low operating costs, rapidity of analysis, availability of transportable or portable systems, etc., additional advantages of this technique in the analysis of meteorites are precision and accuracy, sensitivity to low atomic number elements such as Li and the capacity to detect and quantify Co contents that cannot be obtained by EDS‐SEM.  相似文献