镶嵌试件表面位移场的全息显示

用激光全息干涉法研究了在单轴压力下的镶嵌试件的表面形变,显示了离面位移场的可见图象。发现在载荷达到破裂载荷的90%左右时,沿镶嵌边界出现剧烈形变带和宏观裂纹;当岩芯强度低于或等于外围介质强度时,这种剧烈形变带集中在岩芯以外的一侧;当岩芯强度高于外围介质强度时,这种剧烈形变带形成围空图象。镶嵌试件在一定程度上模拟了地壳的横向不均匀结构,观察它的表面形变过程有助于探讨震前地震活动图象的物理含义。     

京津唐张地区震级频度关系的空间扫描

对京津唐张地区地震震级频度关系进行空间扫描后,发现该区的震级频度关系有三种类型:第1类符合线性b值模型,第Ⅱ、第Ⅲ类符合特征震级模型。近22年来未发生大震的地区往往属第1类。大震区往往属第Ⅱ、Ⅲ类。岩石力学实验结果表明,在岩石破裂及破裂连结过程中声发射事件的震级频度关系符合高b值线性模型。在岩石伴有粘滑的摩擦滑动过程中声发射事件的震级频度关系符合低b值线性模型。但是在一个完整岩石的破裂和失稳错动全过程中声发射事件震级频度关系符合特征震级模型。由此说明某一区域的震级频度关系可能反映了该区构造变形所处的阶段。一个地区震级频度关系上的多次转折可能包含了地区构造几何信息。一些未发生大震的地区,在中等震级段出现b值非线性现象,这可能意味着它更接近失稳前的临界状态     

西南极菲尔德斯半岛长城站地区深部电性结构

本文分析了1992年12月长城站附近三个测点的大地电磁测深资料(1s到4096s的低频信号数据),得出菲尔德斯半岛风谷断裂电性主轴为北东110°,半岛地壳厚度为22.3km,壳内含四个主要电性层,厚度分别为:1.3km,6.7km,1.2km和13.3km,其中上地壳为9.2km,下地壳为13.1km。     

14C测定地质年代数据(六)及14C年代数据库

本文公布14C年代数据151个,存入国家地震局地质研究所14C年代数据库内。该数据库已验收通过。现录入数据资料1500条,对各地区、各层位的宏观年代分布及对避免野外重复性工作有着参考价值     

辽宁省水氡点基本特征的研究

本文比较详细地总结了辽宁主要水氡点的基本特征(包括特征参量),并汇成总表。在占有多年水氡数据资料的基础上,研究了各主要水氡点的正常动态特征,认为一旦打破年变,在干扰排除基础上可考虑为前兆异常。同时,对每种动态类型的干扰因素做了初步分析,发现流量或抽水是多数水氡点的主要干扰因子。结合海城震例(或部分邻区震例资料),笔者探索了灵敏观测点应具有的水文地球化学条件,并初步得出一些结论。     

鄂尔多斯盆地东北部中侏罗世延安组双壳类生态组合

依据详细的剖面资料,将鄂尔多斯盆地东北部中侏罗世延安组双壳类分为4个生态组合:Ferganoconcha—Sibireconcha组合、Margaritifera组合、Unio组合、Pseudocardinia?组合;通过化石形态功能分析、现双壳类生态对比分析、产出化石的围岩沉积特征分析,认为上述组合生存环境依次分别为:开阔湖环境、前三角洲(或三角洲间湾)环境、分流间湾环境、三角洲平原小型湖或泛滥平原小型湖环境。     

Numerical simulation of elasto-plastic electro-osmosis consolidation at large strain

In this paper, a numerical solution for the electro-osmosis consolidation of clay in multi-dimensional domains at large strains is presented, with the coupling of the soil mechanical behaviour, pore water transport and electrical fields being considered. In particular, the Modified Cam Clay model is employed to describe the elasto-plastic behaviour of clay, and some empirical expressions are used to consider the nonlinear variation of the hydraulic and electrical conductivities of the soil mass during the consolidation processes. The implementation of the theoretical model in a finite element code allows for analysis of the evolution of the transient response of the clay subjected to electro-osmosis treatment. The proposed model is verified via comparison with data from a large strain electro-osmosis laboratory test, to demonstrate its accuracy and effectiveness. Various numerical examples are also investigated to study the deformation characteristics and time-dependent evolution of the excess pore pressure. Finally, a well-documented field application of electro-osmosis is simulated to provide further verification. The results show that the numerical solution is effective in predicting the nonlinear behaviour of clay during electro-osmosis consolidation.     

Migration and transformation of manganese during the artificial recharging of a deep confined aquifer

Field tests and laboratory experiments were performed, using an artificial groundwater recharging site in Southeast China as an example, to investigate the migration and transformation of manganese during the artificial recharging of a deep confined aquifer. The migration and transformation of total manganese and divalent manganese (Mn(II)) were influenced by mixing, oxidation reactions, and the dissolution of minerals containing manganese, and increasing the dissolved oxygen (DO) concentration was found to promote the dissolution of minerals containing manganese. The laboratory experiments showed that the retardation factors were higher upstream than downstream of the recharging hole. The amount of dissolution that occurred decreased, and the amount of mixing that occurred increased as the distance from the recharging hole increased. The DO concentration decreased as the amount of dissolution of minerals containing manganese that occurred decreased. A high temperature, a high DO concentration, and the presence of microorganisms were found to promote the dissolution of minerals containing manganese, which caused the total manganese and Mn(II) concentrations to increase.