石油深井地震观测中“井管突升,地面崩裂”异常机理及其社会影响对策研究

１９７９年以来,天津地区先后有９口石油深井出现了“井管突升,地面崩裂”异常现象,本文通过这９口井的基本情况,分布特点,异常类型等方面的分析,对这一现象产生的机理进行了研究;认为;这一现象的发生是由于地面局部沉降的结果,并对其进行数值模拟,力学解释,同时提出了安定社会的三项对策。     

2001年11月14日昆仑山口西M 8.1地震前的缓慢地震事件

2001年11月14日昆仑山口西M8．1地震前发生了缓慢运动事件，新疆地震台网记录分析结果表明，这次事件在大震前3．5天开始出现，长周期前驱波持续约47小时，波列呈现规则的正弦波形，视周期约为8．8秒。笔者认为，该慢地震事件是M8．1大震前中昆仑断裂临震预滑动引起的。事实表明，慢地震的观测与研究对深入了解断层失稳过程和实现地震短临预报具有重大意义，同时也显示了宽频带数字地震台网的优越性。     

中国大陆中轴构造带及其两侧的现今地壳垂直运动

利用中心年代分别为1964、1979及1993的3期精密水准复测资料研究中轴(构造)带及其两侧(东经90.5°至113.5°,北纬21.5°至42.0°)的现代地壳垂直运动。结果表明中轴带及其两侧近30多年的运动趋势与最近十几年运动趋势十分一致。而且与该地区的地势地貌有良好的相关性,几个垂直形变的高梯度带均分布在本区两个大盆地(四川盆地与柴达木盆地)周边。整个形变态势表现出明显的继承性运动特征。但在70年代,该区的垂直运动经历了一次明显的变化或反向。联系到同一时期中轴带南部的一系列7级以上强震的发生,提示大区域的垂直形变的趋势变化可能是强震活跃的一种指示。文中还利用得到的地壳垂直形变图研究了区内南—北、东—西向穿切几个主要构造单元的9条剖面的地壳垂直运动特征和它们的时空演化,结果进一步证明1969～1979年间,我国中西部比较强烈的地壳垂直运动与我国地震活动高潮期一致。纬向剖面的运动特征清楚地显示出东经100～105度的经向带内,整个研究区可分为地壳垂直运动速率西高东低的东、西两区;而经向剖面又可将这东、西两区分出以某些纬向高变化窄带为界的纬向区块。文中还详细讨论了这些区块所对应的构造单元的现今运动特征。     

一种特殊的地貌现象——碟形洼地群及其成因的探索

使用1926年出版的五万分之一顺直地形图作历史地貌分析，在河北平原西部白洋淀流域地区发现有数量众多、形态奇特的地貌——碟形洼地。用计算机数字地形模拟(DTM)方法对该洼地的个体形态和总体分布特征进行研究，并与国内外其他地区已报道的陨石雨冲击坑对照，判断白洋淀流域的碟形洼地群可能是分布在第四纪松散沉积物上的陨石冲击坑的遗迹。推测冲击可能发生在全新世中—晚期，洼地群是一次规模巨大的陨石雨冲击所形成的。     

Coupling Effect of Riser on Integrated FPS in Deepwater Area

The main challenge in predicting global responses of floating vessels in deepwater and ultra-deepwater areas comes from the system's coupled effect.In this paper,the coupled approach is used to analyze effects of riser on floating system in deepwater.The analysis results show that the coupling effects of risers will mainly affect the low frequency (LF) motions of the system.That is because risers will provide the system with a significant low frequency (LF) damping which will vary with the sea states.Under ...     

A Three-Dimensional Nearshore Hydrodynamic Model with Depth-Dependent Radiation Stresses

For the simulation of the three-dimensional (3D) nearshore circulation,a 3D hydrodynamic model is developed by taking into account the depth-dependent radiation stresses.Expressions for depth-depeedent radiation stresses in the Cartsian coordinates are introduced on the basis of the linear wave theory,and then vertical variations of depth-dependent radiation stresses are discussed.The 3D hydrodynamic model of EICIRC (Eulerian-Lagrangian CIRCulation) is extended by adding the terms of the depth-dependent or depth-averaged radiation stresses in the momentum equations.The wave set-up,set-down and undertow are simulated by the extended ELCIRC model based on the wave fields provided by the experiment or the REF/DIF wave model.The simulated results with the depth-dependent and depth-averaged radiation stresses both show good agreement with the experimental data for wave set-up and set-down.The undertow profiles predicted by the model with the depth-dependent radiation stresses are also consistent with the experimental results,while the model with the depth-averaged radiation stresses can not reflect the vertical distribution of undertow.     

Numerical Simulation of Wave Field at the Kemena River Mouth in Kalimantan Island

-By use of the parabolic equation of numerical simulation of wave which is suitable forlarge-angle propagation and Crank-Nicolson differential method,the wave field at the Kemema Rivermouth has been studied for analysis of sediment movement in the area.In order to reflect wave energy lossaccurately,the Bretchneider-Reid formula is quoted and the friction coefficient in the formula is discussedin this paper.The calculation results indicate that the wave becomes a little damped at the mouth ofKemena River influenced by the topography and bottom friction,and the wave at the east beach is higherthan that at the west beach,because the east beach extends out.     

A Numerical Model for Mixing Areas of Pollutant Discharging into Tidal Flows

- A combined numerical model for computing mixing areas of pollution vertical jet discharging into tidal flows has been developed. This numerical model is composed of a 2-D depth-averaged dynamic far-field numerical model and a 2-D vertical dynamic near-field numerical model. The former uses finite node method to compute velocity, and improved finite node method to compute pollutant concentration distribution; the latter is a k-e turbulence model, and uses SIMPLE (Semi-Implicit Method for Pressure Linked Equations) method to compute velocity. At the same time, the former provides boundary conditions for the latter. This model can simulate both far- field pollutant concentration distribution and near-field vertical recirculation quickly and precisely. This model has been verified by measured data of pollutant F of the Dachang reach of the Changjing River and test data presented by Chen el al. (1992). On the basis of verification, the authors use a designed hydrograph to compute this mixing area for a cer     

Coupled BEM-FEM Analysis of the Large-Diameter Cylinder Structure System

A method of coupled BEM-FEM analysis for the elastic spatial structure system is presented. It can be applied to the calculation of the stress and deformation of the large-diamater cylinder structure system and it is suitable for symmetric or non-symmetric structures under the distributed or concentrated load. Numerical examples show that the proposed method and computer program BEFEM are quite efficient in the analysis of the large-diameter cylinder structure problems in ocean engineering.     

Wave Transformation and Breaking in Diagonal Opposing Current

- When waves propagate into diagonal opposing current from non-current area, not only the wave parameters but also the direction of wave propagation will change, that is, wave refraction will occur. The authors have calculated the changes of wave parameters, including wave refraction, by Linear Wave Theory, and have also done systematic study on wave transformation and breaking in opposing current by means of experimental analysis and theoretical calculation. In order to know the effect of wave refraction, computation is done in this paper about wave transformation and breaking on gentle slopes in diagonal opposing current.