四川省溪口滑坡运动特征的离散元模拟

通过离散元分析拟合了溪口滑坡碎屑流的运动过程和主要特征,认为滑坡解体后是以碎屑流方式完成运移和停积过程。     

强震地面运动的理论地震学研究

本文从理论地震学的角度概述了强震地面运动研究中关于震源过程、场地效应和地面运动预测等方面的研究进展,提出了一些进一步的研究课题.     

LOCAL POTENTIAL AND PRINCIPLE OF VORTICITY CONSERVATION

In this paper,the local potential of nondivergent flow on beta plane is derived from the motion equa-tion.The conservation principle for vorticity is obtained when the local potential tends to be minimumwith the variational technique.Some other properties st,ch as Lagrangian of vorticity equation,energyetc.are also discussed briefly in the paper.     

成都平原东部地震动小区划研究

场地的区域工程地质条件决定了场地土结构及土动力学参数的区域性差异,对强震地面运动起着重要的控制作用。为了考虑这种控制作用,以便合理地进行成都平原地震动小区划,本文根据一定数量的地震反应分析结果和所处的区域工程地质条件,建立了地貌单元、土层厚度和土层结构等因素与各类地震反应谱和各档峰值加速度的统计直方图。并引入分量分析方法,对原始因素进行正交变换,用产生互不相关的新因素来代替它们。正交变换之后,根据因子得分矩阵建立模糊关系矩阵 R,根据反映新因素重要程度的因子载荷矩阵生成新因素权重矩阵 A,然后采用模糊综合评判方法,判别成都平原东部各点的地面地震动类型,并由判别结果勾划了本区地震动小区划图。     

Ultrasonic modelling research of earthquake response of underground lifeline engineering

Earthquake response of underground lifeline engineering is investigated by the method of ultrasonic model experiments in this paper. From general field conditions, two models of underground lifeline engineering, one for non-uniform field and the other for uniform field, are designed based on the similarity principle. Besides analysis of seismic phases, a series of analyses especially on particle vibration are carried out. The results show that: The shorter the epicentral distance, the greater are the intensity variation and the change rate of intensity variation of earthquake ground motion, so the more disadvantageous to underground pipelines. In soft covering layer, compressional waves mainly cause radial flexures deformation, but shear wave result in axial dilation deformation of the pipelines; when the thickness of the covering layer is smaller (less than seismic wave length), the rhythmic variation of the intensity of earthquake ground motion is controlled mainly by the wave length of seismic waves in the bedrock. The property of the covering layer has considerable effect on earthquake ground motion. For different covering layers, their effect on each component of earthquake ground motion is not the same. Owing to the effect of wave propagation, the ground is in different states of particle vibration at different times, and there is considerable difference in phase and intensity of particle vibration between two different covering layers near their junction line or surface. Because underground lifelines tend to vibrate with the particles of the earth around it, this results in different deformation of underground pipelines under different conditions. So, it is necessary to take corresponding anti-seismic countermeasures for pipelines according to their practical situations. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 104–110, 1992. This paper is part of the research supported by Funds of Doctoral Faculty of National Education Committee.     

Temporal and spacial analysis of regional composite nodal plane solutions for small earthquakes

A method is proposed in this paper for the analysis of temporal and spatial characteristics of composite nodal plane solutions for small earthquakes. With this method, the interested region is devided into small areas according to the geological features of the region. As an example, 107 composite nodal plane solutions are calculated for the adjoining region of Shaxi, Hebei and Neimenggu. The temporal and spatial characteristics of the variations of the solution parameters before and after the great Tangshan main earthquake in 1976 have been analysed and some interesting results are obtained. The Chinese version of this paper appeared in the Chinese edition ofActa Seismlogica Sinica,13, 9–20, 1991.     

中国及邻区现代地块运动的数值模拟

本文利用板块几何学的方法研究中国及邻区地块间的相对运动,用数值方法计算了地块运动的角速度及边界断层的滑动速率。计算结果与活断层数据相当吻合,本文还利用地块运动速度讨论了我国现代构造活动     

Chaos in the solar system

We have accumulated thousands of orbits of test particles in the Solar System from the asteroid belt to beyond the orbit of Neptune. We find that the time for an orbit to make a close encounter with a perturbing planet, T _c ,is a function of the Lyapunov time, T _ty .The relation is log (T _c /T _o )= a + b log (T _ly T _o )where T _o is a fiducial period which we have taken as the period of the principal perturber or the period of the asteroid. There are exceptions to this rule interior to the 2/3 resonance with Jupiter. There, at least in the restricted problem, for sufficiently small Jupiter mass, orbits may have a positive Lyapunov exponent and still be blocked from having a close approach to Jupiter by a zero velocity curve. Of more serious concern is whether the relation holds for purely secular resonances, and if it does, how to choose T _o .This is the case of interest for the planets in the solar system.     

Expansions of (r/a)m cos jv and (r/a)m sin jv to high eccentricities

Expansions of the functions (r/a)^cos jv and (r/a)m ^sin jv of the elliptic motion are extended to highly eccentric orbits, 0.6627 ... <e<1. The new expansions are developed in powers of (e–e*), wheree* is a fixed value of the eccentricity. The coefficients of these expansions are expressed in terms of the derivatives of Hansen's coefficients with respect to the eccentricity. The new expansions are convergent for values of the eccentricity such that |e–e*|<(e*), where the radius of convergence (e*) is the same of the extended solution of Kepler's equation. The new expansions are intrinsically related to Lagrange's series.