A THREE-DIMENSIONAL NUMERICAL BOTTOM-HOLE TEMPERATURE STABILIZATION MODEL*

The heat flow equation in cylindrical coordinates is solved numerically for any general distribution of thermal diffusivity. The temperature stabilization of a borehole is considered, and solutions for the case where thermal diffusivity is a function of radial distance from the borehole are obtained and compared to solutions for uniform diffusivity. The results are discussed in terms of thermal diffusivities that are different for the well contents and for the surrounding material. It is found that the approach to formation temperature is affected by differences between well contents and the surrounding region.     

A NUMERICAL METHOD TO COMPUTE THE RESISTIVITY TRANSFORM FROM WENNER SOUNDING DATA*

A numerical technique to compute the resistivity transform directly from the observed Wenner sounding data has been developed. In principle, the procedure is based on a decomposition method and consists of two steps: the first step determines a function that approximates the apparent resistivity data and the second step transforms this function into the corresponding kernel by an analytical operation. The proposed method is tested on some theoretical master curves. A high degree of precision is achieved with very little computer time. The applicability is shown on two field examples.     

浅议震后厂房地基基础沉降的处理方法

新疆是个多震区 ,破坏性地震常引起房屋的破坏和财产的损失。本文分析了房屋在震后产生地基失稳和不均匀沉降等破坏现象的原因 ,并提出了处理方法和补救措施 ,可供震区有类似图 1　车间柱网平面图Fig.1　 Plan of the colonnade in the work- shop的现象房屋的补救处理参考使用。1　工程概况新疆喀什地区某车间建于 195 8年 ,柱网平面图如图 1所示。 1996— 1999年喀什地区连续发生多次 6级以上地震 ,致使 EA 列柱产生不均匀沉降 ,影响了车间的正常使用。测量表明 ,34、36、38、4 0、4 2号列柱中沉降量分别为 :13.1、12 .8、12 .2、11.9及…     

ON THE NUMBER OF FRACTIONS TO COMPUTE TRANSPORT OF SEDIMENT MIXTURES

1 INTRODUCTIONMany hydro-momhological mathematical models neglect the innuence of river bed maerialheterogeneity and its time and space changes during transport and related erosion/dePosition processes. Inthese models a rePresentative diameter of the river bed grain-size distribution (for examPle d5o) isspecified as initial data in each comPutational point of the modeled domain. Different d5o can be assignedto each ghd point but temPoral changes in bed material gradation cannot be simula…     

不同地震烈度下边坡稳定性计算实例

按照工程场地地震安全性评价的有关规定，在充分研究场地工程地质，地震地质背景等工作的基础上，采用ＢＩＳＨＯＰ法以某拟建工程场地在不同地震烈度下其边坡的稳定性进行了计算。     

A CONTROL OF TWO-DIMENSIONAL MAGNETIC INTERPRETATION BY THREE-DIMENSIONAL MODEL BODY ANOMALIES*

In magnetic routine interpretation the comparison of two-dimensional model curves with measured magnetic anomalies is widely used for an approximate evaluation of the position and depth of magnetic models. Before starting an interpretation of a survey by means of two-dimensional models, it is very useful to have an idea of the shape of anomalies caused by extended but finite bodies, taking into account various strike directions: Three sets of anomalies of thin plates (horizontal length 19, downward length 9, width 1) dipping 30°, 60°, and 90° resp. for various strike directions and an inclination of 20° were computed. Some of these anomalies, e.g. those with nearly N-S strike direction look rather complicated, and at the first glance one would not expect that they are caused by such simple bodies. Several profiles crossing the computed anomalies perpendicularly were interpreted two-dimensionally. For less extended anomalies the depths determined for the top of the plates are 10-20% too small, the magnetization amounts to 50–75 % of the value of the finite bodies. The interpretation of the profiles covering more extended anomalies gave very accurately the same values for the position, depth and magnetization for the two-dimensional body as for the original three-dimensional model. Anomalies of vertical prisms with varying extensions in the y-direction were computed. Their differences in amplitude and in the distance maximum-minimum show that interpretation of short anomalies by two-dimensional methods yields depth errors of up to 20 percent. To see the possibilities of the separation of superimposed anomalies dike anomalies were added to the anomaly of a broad body in great depth and several attempts were made to interpret parts of the composite anomalies. The interpreted bodies lie too deep. In complicated cases the depth values can have large errors, but experienced interpreters should be able to keep the errors in the range of one third of the depth values.     

一类统计模型在地震预报中的应用

本文提出了一类用于地震预测的统计模型,该模型包括地震活动的趋势部分、周期成分及随机波动部分,并据该模型对小华北地区的地震趋势进行了估计。     

三维粘弹性LDDA方法及其在地学中的初步应用

在二维弹性LDDA方法的基础上提出了三维粘弹性LDDA方法，并开发了相应的计算机软件．通过两个三维块体的摩擦滑动数值实验，证明了这个方法的理论和程序是正确和可靠的．用该程序研究了印度板块碰撞引起的东亚地区的现今速度场和沿主要断裂带的相对位移速率．初步结果表明，碰撞边界附近的速度最大，向内部衰减很快．青藏高原向北东方向运动，华北平原向东运动，东南亚向东南运动．在祁连山西南和东北速率变化的衰减梯度分别为0.05和0.007mm/a/km，衰减是非线性的，运动方向由北东转向近东西方向，变化很大．穿过龙门山断裂的速度衰减基本是线性的，其值为0.01 mm/a/km，运动方向为南东．印度板块碰撞对于东经115以东和北纬45以北的区域影响很小．由计算得到的速度场与GPS观测结果基本一致．计算得到的班公湖——怒江——澜沧江断裂带在近1Ma以来的相对滑动速率平均约0.5mm/a；金沙江断裂带相对滑动速率最大，为0.8 mm/a；郯庐断裂带基本不动．理论和计算表明，三维粘弹性LDDA方法可以用于研究具有断层的地球动力学问题．      

一种应用于地震长期预报中的概率增益模型

由推导的前兆存在时强震发生的条件概率表达式，讨论了地震发生的概率增益模型。同时，由空间地震活动和地震资料的不均一性，研究了平稳条件概率的各种计算方法。最后，以华北地区的各地震带为例，用多种方法计算了它们的平稳无条件概率和河北北部区域未来１０年的强震发生概率     

地震孕育体源流变模型（一）-位移场

为了研究地震孕育过程，在弹性包体理论的基础上建立了流变介质的体源包体模型理论．本文基于弹性包体模型的位移场的解析解，运用流变力学理论中的对应原理，导出流变体介质中，包体在任意一点的3个方向分别产生的位移的粘弹性解析解.      

1605年7月13日琼州历史地震陆沉原因

本文通过地震史料考证,野外地质调查,钻孔土层力学性质分析,场地震害考察等资料的研究,认为琼州历史地震在滨海地带第四纪软弱土层中诱发了砂土液化、软土流滑、造成地基失效、场地不均匀沉陷的情况,是导致震区内特殊地段“陆地沉陷”的主要原因     

地幔内变粘度的滞弹性流体运动的三维有限元模型

建立了描述具有无限大Ｐｒａｎｄｌｔ数，变粘度的滞弹性流体运动的稳态和动态三维有限元公式，其中运动方程的有限元公式是由用应力分量表示的平衡方程，再利用牛顿流体的本构关系导出的。这种处理方式，不仅能够分析流体粘度变化所起的动力学作用，而且还能够直接计算温度分布和由流体运动所引起的扰动压力。最后，论证了导出的有限元公式和程序的正确性和可靠性，并给出了具有三维流动特征的算例     

老旧房屋震害预测的一个数学模型

本从云南城市建筑的实际出发，给出一个老旧房屋震害预测的数学模型。     

THREE-DIMENSIONAL DYNAMIC RESPONSE OF LINED TUNNELS DUE TO INCIDENT SEISMIC WAVES

Formulae are developed to determine the three-dimensional response of twin lined tunnels buried in an infinite medium subjected to seismic loadings using the method of successive reflection. The convergence of the method has been demonstrated both analytically and numerically. The dynamic interaction of the twin tunnels subjected to seismic waves is investigated numerically. It is found that the three-dimensional response of twin tunnels may differ significantly from the two-dimensional response, and that through-soil interaction between the tunnels may also be significant.     

FITTING OBSERVED PROFILES TO A MAGNETIZED DYKE OR FAULT-STEP MODEL*

The symmetry shown, by the function describing the magnetic anomaly due to a dyke or vertical fault step leads to a method by which an observed profile may be adjusted to conform with that symmetry. By making these adjustments a minimum the ideal dyke or fault profile closest to the observations is constructed. In three of four possible situations this is interpreted by simple geometry. Parallelpiped models may be transformed into two dykes for symmetry analysis. Depth limited models are not so amenable, even in special cases.     

APPLICATION OF A GROUPED RESPONSE UNIT HYDROLOGICAL MODEL TO A NORTHERN WETLAND REGION

Applications of hydrological models to northern wetland-dominated regions have been limited in the past to a few case studies on small basins employing ‘lumped’ models. Only recently have there been attempts to apply the grouped response unit (GRU) distributed modelling approach using terrain classifications to these same basins. This study summarizes recent efforts in applying such a model. For the purposes of implementing the GRU approach, terrain types that are hydrologically significant and characteristic to the wetland-dominated regime were successfully discriminated using a principal component analysis and a hybrid unsupervised/supervised classification technique on Landsat–Thematic Mapper imagery. The terrain classifications were then used as input into a distributed hydrological model for calibration and validation using recorded spring runoff events. Preliminary model applications and results are described. Calibration to a historic spring runoff event yielded an r² value of 0.86. Model validation, however, yielded much poorer results. The problems of model applicability to this region and limitations of sparse data networks are highlighted. The need for more field research in this type of hydrological regime, and associated improvements to the model parameter set are also identified.     

祁连山中东段三维构造物理模型及其在地震预报中的应用

利用近年来在祁连山中东段地区取得的丰富、完整、系统、可靠的地表活动构造定量化数据和测震学资料建立了本区新世活动构造的三维构造物理模型,定性或半定量地描述了该区活动的块的运动状态,解释了不同活动块体的运动性质及块体之间的运动转换关系,归纳总结了不同块体内前兆异常及地震活动性特点。