Dynamic stress concentration and scattering of SH-wave by interface elliptic cylindrical cavity

In this paper, the dynamic stress concentration and scattering of SH-waves by bi-naterial structures that possess an interface elliptic cavity are investigated. First, by using the complex function method, the Green‘s function is constructed. This yields the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface. Then, the problem is divided into an upper and lower half space along the horizontal interface, regarded as a harmony model. In order to satisfythe integral continuity condition,the unknown anti-plane forces are applied to the interface. The integral equations with unknown forces can be established through the continuity condition, and after transformation, the algebraic equations are solved numerically. Finally, the distribution of the dynamic stress concentration factor (DSCF) around the elliptic cavity is given and the effect of different parameters on DSCF is discussed.     

基于非等间距泊松曲线在沉降预测中的应用

泊松曲线是一种精度较高的沉降预测方法，但是它只能在等时距数据条件下方能使用，在工程实际中很难满足这一要求。本文采用插值法将非等时距数据转化成等时距数列，并结合高层建筑沉降监测工程实例分析，结果表明，用泊松曲线模型预测建筑物沉降量与实际沉降量比较接近，具有较高的应用价值。     

爆破动力作用下边坡稳定性的积分解法与应用

岩质边坡在爆破开挖过程中的稳定问题是一个亟待解决的重要问题。对实际工程进行监测,得到适合该地区的能反应高程效应的爆破地震波传播规律,并采用拟静力法计算爆破地震惯性力,提出边坡在爆破动力作用下稳定安全系数的新计算方法———积分法,同时使用MATLAB程序搜索边坡最危险滑裂面并计算最小安全系数。实例证明,此方法是分析边坡动力稳定性的有效方法之一。     

积分方程法三维模拟井地电法并行算法研究

在积分方程法模拟三维电磁响应原理的基础上,对井地电法三维正演模拟并行算法做了研究。同时,还利用Fortran 6.5和消息传递接口(MPI)开发了井地电法三维正演模拟并行计算程序。在求解大型线性方程组时,采用的是稳定的双共轭梯度(BICGSTAB)算法,单机正演程序与并行正演程序的计算结果有着很好的一致性,这说明了并行算法的正确性,为进一步开发井地电法三维反演并行程序奠定了基础,也为井地电法三维正、反演程序实用化提供了技术支持。     

起伏地表条件下地震波场数值模拟有限积分变换有限差分方法

针对起伏地表条件下的地震波数值模拟问题,提出将起伏的地表映射到一个规则的长方形网格坐标系中,并在此基础上推导出变换域中的波动方程。根据导出来的波动方程应用有限余弦变换有限差分方法进行地震波场的数值模拟,以解决起伏地表条件下的数值模拟。     

Modeling errors in upward continuation for INS gravity compensation

Accurate upward continuation of gravity anomalies supports future precision, free-inertial navigation systems, since the latter cannot by themselves sense the gravitational field and thus require appropriate gravity compensation. This compensation is in the form of horizontal gravity components. An analysis of the model errors in upward continuation using derivatives of the standard Pizzetti integral solution (spherical approximation) shows that discretization of the data and truncation of the integral are the major sources of error in the predicted horizontal components of the gravity disturbance. The irregular shape of the data boundary, even the relatively rough topography of a simulated mountainous region, has only secondary effect, except when the data resolution is very high (small discretization error). Other errors due to spherical approximation are even less important. The analysis excluded all measurement errors in the gravity anomaly data in order to quantify just the model errors. Based on a consistent gravity field/topographic surface simulation, upward continuation errors in the derivatives of the Pizzetti integral to mean altitudes of about 3,000 and 1,500 m above the mean surface ranged from less than 1 mGal (standard deviation) to less than 2 mGal (standard deviation), respectively, in the case of 2 arcmin data resolution. Least-squares collocation performs better than this, but may require significantly greater computational resources.     

MCZT在气枪震源信号频谱分析中的应用

气枪震源信号是短时非平稳信号,采用频谱细化算法能提高频谱分析的准确性。首先进行了改进线性调频Z变换(MCZT)和FFT两种频谱分析算法的误差仿真计算,然后进行气枪震源的水下子波信号和地震波信号的对比计算。结果表明MCZT计算误差较小、计算时间较少,能有效提高气枪震源信号频率和幅度特征提取的准确性,是气枪震源信号频谱特征分析的一个有效方法。     

河南省地热资源开发利用现状及展望

河南省地热资源丰富,在开封、周口、舞阳、济源、南阳盆地以及濮阳凹陷、汤阴地堑有望找到很好的热储层。现已开发的热储层为埋深８００～１３００ｍ的第三系中细砂层,水温４０～５０℃,水质优良。如果加深钻井深度至２０００ｍ,则有望找到７０℃以上的高温地热水,届时省内地热资源开发利用将上一个新台阶,达到供热采暖水平。文中对河南省地热资源的开发利用现状作一简要介绍,并对如何提高开发利用水平和资源保护提出建议。     

Closed Form Solutions of the Two-Dimensional Turning Bands Equation

The turning bands method generates realizations of isotropic Gaussian random fields by means of appropriately summed line processes. For two-dimensional simulations the relation between the isotropic correlation function of the random field and the correlation function to be simulated along the lines is given by an integral equation of Abel type. We present closed form solutions of this integral equation for almost all two-dimensional correlation models encountered in practice and discuss their numerical implementation. As an additional benefit, our tables and illustrations serve as a concise guide to correlation models useful in geostatistics.     

On Some implications of the Poisson relation

The potentialities of the so-called 'Poisson relation', which holds for uniformly magnetized bodies of constant density, for showing the connections between the gravitational and the magnetic fields of such bodies are considered. In particular, it is seen that the same characteristic ratios occur among the components of the magnetic field intensity and the components of the gradient tensors of the two fields, both locally and non-locally. It is also shown that along the magnetization axis of the body the gradient tensor of the magnetic field displays a 'tidal' structure.