四川省内江市东兴区地质灾害的特征、成因及防治对策

东兴区地质灾害发育广泛,以崩塌(危岩)、滑坡和不稳定斜坡(高陡边坡)为主.其宏观发育特征有明显的分区性和季节性;灾害规模不大,但是影响人群较多,危害较大.崩塌(危岩)分布最为广泛,其主要受控因素是为水平状砂泥岩互层的差异性风化;滑坡和不稳定斜坡(高陡边坡)分布较少,降雨入渗和人工开挖坡脚是造成灾害的直接原因.在查明地质灾害成因机制和影响因素后,对不同类型地质灾害采取人工清除、填沟摸缝、砌支撑柱(墙)、避让搬迁等有针对性的措施,以达到切实可行而且经济的目的.     

折射层析成像法测试隧道围岩松动圈

通过应用折射层析成像法在乌鞘岭特长隧道中的测试,说明该方法对于横向速度变化不均一,过渡带速度渐变的地质情况具有分辨率高、图像直观、易于解释,适合对隧道围岩松动圈的测试.     

某水电站地下厂房岩体质量分级研究

根据某水电站地下厂房各勘探平硐现场统计的基础数据,采用RMR分类、Q系统法、水电系统分类法(HC法)、BQ法对地下厂区围岩岩体质量进行了分析评价,然后综合4种方法的评价结果,得到了各硐段的综合岩体质量类别,使这4种分类法相互补充、相互验证,达到综合确定围岩类别的目的,以此作为围岩稳定性分类的基础.此外,还对不同方法所得的评价结果进行了相关性分析.     

阜新盆地东梁区浅层致密砂岩气气源岩特征

为了解阜新盆地浅层致密砂岩气成藏条件,应用有机岩石学和有机地球化学方法,对气源岩特征开展研究.认为该区浅层致密砂岩气气源岩为沙海组四段泥岩、沙海组三段煤层和泥岩;气源岩厚度大且埋藏浅(＜1500 m),有机质丰度高(TOC＞2%),生烃潜力强;有机质类型沙海组四段为Ⅲ(偏ⅡB)型干酪根,沙海组三段为Ⅲ型干酪根;气源对比显示沙海组三段和沙海组四段气源岩与沙海组三段浅层致密砂岩气同源,浅层致密砂岩气紧邻源岩.表明研究区气源岩能生成大量天然气,利于形成浅层致密砂岩气藏.     

辽宁省岩石环境系统信息化初探

根据辽宁省岩石环境质量现状,初步探讨岩石环境系统的信息化发展与建设设想.认为信息化是落实科学发展观的有效途径,是实现可持续发展的必由之路,是促进环境资源保护的有力武器,是环境科技水平的衡量标志,它有利于社会、经济、资源、环境更快更好地协调发展.     

山东省菏泽凸起地热田岩溶地热水水化学水平演化特征

在前人研究成果的基础上,选择A-A'和B-B'两条路径,采用Piper三线图解、Schoeller图解、Na-K-Mg平衡图解、饱和指数计算评价等方法,研究山东菏泽凸起地热田地热水沿路径上的循环演化特征.结果表明:沿A-A'、B-B'剖面岩溶冷水→岩溶热水,水化学类型由SO4?HCO3-Ca?Mg?Na或SO4?HCO...     

A well‐established Early–Middle Pleistocene marine sequence on south‐east Zakynthos island,western Greece: Magneto‐biostratigraphic constraints and palaeoclimatic implications

The chronostratigraphy of a long, onshore Early–Middle Pleistocene marine sedimentary sequence on the south‐east part of Zakynthos island, Greece, is presented. Correlation of the succession with the isotope record of Ocean Drilling Program Site 963 reveals the combined influence of tectonics and eustacy in this area. The sequence is divided into three formations by two main unconformities that apparently relate to sea‐level lowstands associated with two major northern hemisphere glaciations, those of marine isotope stages (MIS) 22 and 12. The Zakynthos sequence in many ways is comparable with the Italian Valle di Manche section. Magnetostratigraphic and rock magnetic analyses, supported by biostratigraphy, document the position of the Matuyama/Brunhes Chron boundary (0.77 Ma), the top and base of the Jaramillo Subchron (0.99–1.07 Ma), the Cobb Mountain Subchron (1.173–1.185 Ma) and the top of the Olduvai Subchron (1.78 Ma). The underlying strata are constrained exclusively by detailed nannofossil biostratigraphy extending at least to the lowermost Pleistocene at around 2.54 Ma and therefore certainly incorporating the base of the Olduvai Subchron (1.95 Ma) and possibly the Gauss/Matuyama Chron boundary (2.58 Ma). In addition, a remarkable increase in sedimentation rate (from 3.2 and 28 cm ka^?1 to 167 cm ka^?1) and hence resolution above the Matuyama/Brunhes boundary (Middle Pleistocene) reveals one short‐lived magnetic excursion, possibly 17a (0.66 Ma), within the normal polarity Brunhes Chron. Copyright © 2011 John Wiley & Sons, Ltd.     

Degradation of rock fracture asperities in unloading,reloading, and reversal

Among the constitutive models for rock fractures developed over the years, Barton's empirical model has been widely used. Although Barton's failure criterion predicts peak shear strength of rock fractures with acceptable precision, it has some limitations in estimating the peak shear displacement, post‐peak shear strength, dilation, and surface degradation. The first author modified Barton's original model in order to address these limitations. Barton proposed his model for degradation of fracture asperities in unloading, reloading, and shear displacement reversal based on just one cyclic direct shear test. In this study, a database of results of 18 cyclic direct shear tests available in the literature was collected and analyzed. Modifications were made to Barton's original model (in terms of fracture cyclic shearing) to make it consistent with the modified model proposed by the first author. Copyright © 2010 John Wiley & Sons, Ltd.     

Cavity expansion in cross‐anisotropic rock

Schistous rock can be considered—in a first approximation—as cross‐anisotropic linear elastic material. The determination of the corresponding material constants on the basis of the laboratory investigation of rock samples often fails, as the extraction of appropriate cores proves to be unfeasible (the cores disintegrate if the schistosity is pronounced). In this paper a new method is presented to determine the material constants of a linear elastic cross‐anisotropic rock on the basis of cavity expansion field tests, e.g. with a radial jack. To this purpose, an analytic approximation for the deformation of a hydrostatically loaded cylindrical cavity in cross‐anisotropic rock is derived which serves to the inverse analysis of the material parameters. Copyright © 2010 John Wiley & Sons, Ltd.