利用地层空间的相对稳定性、井资料、地震资料模拟高分辨率波阻抗资料

由于地震资料是带限的,而井资料约束反演过程中的地震反演频带的展宽也是有一定限度的,使得反演地震波阻抗也是带限的。如何进一步拓宽反演地震波阻抗的频带宽度,提高地震资料的分辨率是文中研究的内容。利用井约束下的地震反演波阻抗资料、地震资料及井资料,借鉴地质模拟技术,研究如何利用地层的空间相对稳定性特征,通过相关函数的分析,估计反演更高分辨率的地震波阻抗资料。考虑到地质体空间的相关性及分辨率,相关半径取相关函数从最大点到第1个极值点的范围。在目标函数的计算过程中,既考虑当前计算点的权系数信息,又考虑井外推时的权系数信息,这样使计算结果更加稳定可靠。通过综合模拟计算,能够识别较小砂体     

辽宁省北沟地区金矿地球化学特征及成矿预测

通过对北沟地区地球化学异常和已知矿体的研究,结合地质成矿环境,确定地球化学找矿指标,预测该区金矿找矿远景.     

武隆隧道岩溶地质超前预报综合技术

武隆隧道全长9418m,为渝怀铁路第二长大隧道。该隧道的施工地质条件非常复杂,存在浅埋段、断层破碎带、岩溶暗河、非煤系地层瓦斯和岩爆等不良地质现象。其中,岩溶、暗河以及岩溶涌水是本隧道施工的最主要地质问题。根据岩溶垂直分带结果,武隆隧道处于混流带中,特别是多在季节变动带与水平迳流带之间。自隧道开挖揭露以来,多次发生大型、特大型岩溶涌水灾害。作者根据武隆隧道施工的特点,以地质法为基础,以HSP声波反射法为主要手段,结合TSP203系统和钻探等的超前预报综合技术,进行岩溶地质超前预报。实践证明,武隆隧道综合地质预报技术的应用是基本成功的,值得在同类隧道施工地质预报中借鉴。     

Mapping landslide susceptibility from small datasets: A case study in the Pays de Herve (E Belgium)

A landslide susceptibility map is proposed for the Pays de Herve (E Belgium), where large landslides affect Cretaceous clay outcrop areas. Based on a Bayesian approach, this GIS-supported probabilistic map identifies the areas most susceptible to deep landslides. The database is comprised of the source areas of ten pre-existing landslides (i.e. a sample of 154 grid cells) and of six environmental data layers, namely lithology, proximity to active faults, slope angle and aspect, elevation and distance to the nearest valley-floor. A 30-m-resolution DEM from the Belgian National Geographical Institute is used for the analysis. Owing to the small size of the sample, a special cross-validation procedure of the susceptibility map is performed, which uses in an iterative way each of the landslides to test the predictive power of the map derived from the other landslides. Four different sets of variables are used to produce four susceptibility maps, whose prediction curves are compared. While the prediction rates associated with the models not involving the “proximity to active fault” criterion are comparable to those of the models considering this variable, strong weaknesses inherent in the fault data on which the latter rely suggest that the final susceptibility map should be based on a model that excludes any reference to fault. This highlights the difference between a triggering factor and determining factors, and in the same time broadens the scope of the produced map. A single reactivated slide is also used to test the possibility of predicting future reactivation of existing landslides in the area. Finally, the need for geomorphological control over the mathematical treatment is underlined in order to obtain realistic prediction maps.     

A Combined Three-Dimensional Geological-Geostatistical-Numerical Model of Underground Excavations in Rock

Summary. This paper exploits geological and borehole geotechnical data obtained in the exploratory phase of a tunneling project to investigate in a first place if the kriging interpolation scheme may effectively reproduce the spatial variability of rock mass quality (Rock Mass Rating, RMR) in the vicinity of tunnels. For this purpose a quick solver in Fortran has been developed that performs variography analysis of 3D spatial data, fast kriging estimations of RMR between borehole sampling locations at the centroids of the elements of the numerical model, and model validation. For the purpose of an integrated underground excavation design, a step further is made by incorporating into the 3D mechanical numerical model of the rock mass, the three-dimensional (3D) solid geological model, thus coupling the geology with the ground (geotechnical) model (i.e. each element of the numerical model is assigned a geological material). The mechanical properties of each finite difference cell (or Representative Elementary Volume) of the ground model were then prescribed according to its geological type, the spatial heterogeneity of the rock mass expressed quantitatively with the kriging model, and the upscaling calculations of the mechanical properties of the intact rocks determined in the laboratory, based on the size-effect (strength dependence on size) and Damage Theory. Furthermore, a preliminary numerical simulation of the advance of unsupported tunnels in the model of the heterogeneous rock mass was performed for illustration purposes.     

Digital Image Based Approach for Three-Dimensional Mechanical Analysis of Heterogeneous Rocks

Summary This paper presents a digital image based approach for three-dimensional (3-D) numerical simulation and failure analysis of rocks by taking into account the actual 3-D heterogeneity. Digital image techniques are adopted to extract two-dimensional (2-D) material heterogeneity from material surface images. The 2-D image mesostructures are further extrapolated to 3-D cuboid mesostructures by assuming the material surface as a representation of the inner material heterogeneity within a very small depth. The iterative milling and scanning system is set up to generate the 3-D rock mesostructures. A Hong Kong granite specimen is used as an example to demonstrate the procedure of 3-D mesostructure establishment. The mechanical responses and failure process under the conventional Brazilian tensile test condition are examined through numerical analyses. The stress distribution, crack propagation process and failure model of heterogeneous material cases are simulated with a finite difference software. The numerical results indicate that material heterogeneity plays an important role in determining the failure behavior of rocks under external loading.     

新一代天气雷达在泥石流灾害中的应用探讨

天气雷达的发展大致经历了4个阶段，其主要用于监测强对流天气、定量估计降水，是气象部门的重要探测和监测手段之一。新一代天气雷达观测的实时回波强度（Z）、径向风速（V）、速度谱宽（W）的回波图像中，提供了丰富的有关强对流天气的信息，综合使用Z、V、W的图像分析，有利于较准确和及时地监测灾害性天气。云南滑坡泥石流灾害高发区与云南暴雨中心有很好的对应关系，云南滑坡泥石流灾害空间分布与暴雨空间分布的空间相关系数为0．19，通过了0．05的显著性水平检验，也进一步说明云南暴雨在滑坡泥石流灾害发生中起着重要作用。以2004年7月5日德宏州特大山洪泥石流灾害为例子，探讨了新一代天气雷达在泥石流灾害的临阵预警中的应用。     

利用天气数值预报产品建立贵州黔西南州分县温度预报方程的方法及应用

利用2002～2004年1～12月EC、T213天气数值产品的温度格点实时分析资料、预报资料以及贵州省黔西南州8个测站观测资料,从160个样本中筛选出相关较好的因子,利用多元回归统计模型,以及根据地理环境,天气形势分型造成的温度差值(ΔT)为逐步订正值,建立黔西南州分县温度预报方程。在2005年11月～2006年2月应用中取得较好效果,预报误差小于±3.0℃,平均误差1.3℃。