织金区块煤层气合采生产特征及开发策略

针对南方煤层层数多、单层薄,煤层气有效开发难度大的问题,以贵州织金区块煤层气井实际生产数据为基础,分析定向井不同煤组合采、薄煤层水平井生产特征及产气影响因素,并提出相应开发建议。分析表明,不同煤组合采产气差异较大,受地层供液能力、解吸液面高度及合采跨度影响,中、下煤组合采效果好于上、中、下煤组合采效果,其中16/17/20/23/27/30号煤层合采是区块最优合采层位;压裂规模显著影响煤层气井产气效果,压裂规模越大产气效果越好,增大压裂规模,提高压裂改造效果是多煤层煤层气有效开发的重要手段之一;水平井产气效果是定向井3~4倍,薄煤层水平井适应性得到证实,根据地质及地表条件采用水平井、定向井组合开发,可提高多煤层煤层气开发效果。综合认为,在地质条件有利的区域优选合采层位,增大压裂规模,优选实施水平井,可提高多薄煤层煤层气开发效果。     

江苏某材料厂周边农田土壤钼污染特征及农作物健康风险评价（84）

为了解江苏某材料厂金属冶炼活动引发的重金属污染风险,采集周围农田土壤、小麦和水稻籽实样品,确定Mo含量及其在土壤中的形态,采用地质累积指数和富集因子指标评价土壤中钼的污染风险,采用健康风险指数评价小麦、稻米中Mo的健康风险。结果表明,农田土壤中Mo含量在0.50～63.2 mg/kg之间,其平均值5.70 mg/kg远高于全省平均值0.65 mg/kg,表层土壤出现了中度—高度富集,近70%的样点受到不同程度的钼污染,污染范围距该厂300 m,污染深度>1.5 m。土壤中的Mo具有较高的生物有效性,在小麦、水稻籽实中显著富集,主要与土壤具有较高的全Mo含量以及土壤呈碱性有关。基于EPA的健康风险评估方法,食用当地稻米、小麦会产生较大的健康风险。     

GIS-based hazard mapping and zonation of debris flows in Xiaojiang Basin,southwestern China

Debris flow sites were identified at 140 locations in the Xiaojiang Basin in Yunnan province, southwestern China. Their spatial distribution and catchment characteristics are described in detail on the basis of previous research, air photo interpretation, field investigation and mapping using Geographical Information Systems (GIS). Using a statistical approach, a quantitative model of hazards assessment and zonation was developed through synthesis analysis of basin areas, gradients, and the relative reliefs of these debris flow sites. In terms of debris flow hazard assessment, areas within the Xiaojiang Basin can be classified as severe, heavy and light hazard regions.     

河北省涿鹿县大河南岩体中A型花岗岩特征及构造意义

分布在大兴安岭-太行山构造岩浆活动带上的大河南岩体,是多期岩浆活动的产物,划分为晚侏罗世、早白垩世早期和早白垩世晚期三期.早白垩世侵入岩由细粒正长花岗岩、中粒正长花岗岩、花岗斑岩组成.本文通过对早白垩世侵入岩地球化学特征进行系统研究,发现该期岩体主量元素具有富硅、富碱、富铁,低镁、贫钙特征;稀土元素配分曲线为右倾“海鸥型”,负铕异常明显;微量元素以Ba、Sr、P、Ti强烈亏损,K富集为特征.Y/Nb-Ce/Nb图解上,岩体具A1型花岗岩特征,形成于非造山环境的张性环境,是早白垩世华北东部岩石圈减薄、华北克拉通破坏的具体实例.     

FLAC3D在复杂工程条件下的应用

利用建筑垃圾堆山造景是现代城市的一个新方向。但由于堆山工程占地范围大,荷载大,往往会产生一系列的工程地质问题,在软土地区这个问题更为突出。为使堆山工程能顺利进行,必须对地基进行一定的处理,而常规计算只能选择典型剖面或者地段进行局部分析,不能反映真实的三维影响特征,但数值分析可以有效解决这一问题。利用有限差分软件FLAC3D,对天津某堆山工程进行分析,为优化地基处理方案提供有力依据。     

Analysis of boundary friction effect on the homogenization process of compacted bentonite/claystone mixture with technological voids upon hydration

Pre-compacted MX80 bentonite/Callovo-Oxfordian (COx) claystone mixture has been proposed to backfill and seal the underground galleries for radioactive waste disposal in France. While emplacing these pre-compacted blocks, technological voids are created between the blocks and the host rock and among the blocks themselves. It is expected that homogenization process will take place over time for the structure constructed with pre-compacted blocks upon hydration. This study investigated the boundary friction effect on such a process. Results showed that after the filling of technological voids, the soil far from the technological voids would swell further, while those near the voids would be compressed under the welling pressure generated by the soil behind, resulting in an increase in homogeneity in terms of dry density distribution. However, this homogenization process would stop after a certain time. Further examination showed that the homogenization process ended when the maximum boundary friction force became equal to or higher than the vector sum of swelling forces in the radial direction. Based on the force equilibrium and the mass conservation, the final dry density distribution was estimated. Comparison between the estimation and the measurement showed a good agreement, indicating the relevance of the identified mechanism related to boundary friction.

     

四川盆地东部垫江盐盆早三叠世嘉陵江组四段杂卤石成因及对成钾的指示

四川盆地三叠纪是主要的成钾期,目前发现的主要含钾矿物为杂卤石,有关早三叠世嘉陵江组四段石盐岩中杂卤石成因一直存在争议.采用薄片鉴定、扫描电镜、稀土元素和锶同位素等手段,分析了四川盆地东部垫江盐盆长寿地区嘉陵江组四段石盐岩中杂卤石矿物形态特征,初步探讨了该杂卤石成因及对寻找海相钾盐的指示意义.扫描电镜下与石盐岩共生的杂卤...     

西南某水电站坝基岩体质量分级研究

坝基岩体质量分级关系到大坝工程的安全性和经济性.通过对坝基岩体质量分级要素及各要素之间的联系进行研究,得出岩体分级各要素界限指标的对应值.在此基础上提出适用于本工程坝基岩体质量分级的单因素和双因素标准.并应用此标准对该坝基进行岩体质量分级.