宿州市地下水含铁量高浅析

宿州市地下水中铁的含量在1.12～8.50 mg/l之间,超过<生活饮用水标准>(GB5749-85)(＜0.3mg/L)的4～28倍,本文根据含水层的沉积特征、铁的水文地球化学特性,通过采样分析了地下水含铁量高的原因,并提出了相应的解决方法.     

A study on the duration and amplitude characteristics of earthquake ground motions

The duration, total power, rms amplitude, and peak ground acceleration (PGA) are examined using the data from the KiK-net digital borehole accelerograph arrays in Japan during three large earthquakes. We investigate correlations between the duration, PGA on the surface and hypocentral distance, instrumental seismic intensity, and the local site conditions. Also considered in this paper, are correlation between the duration and PGA. This present study suggests that PGA is inversely proportional to the duration.Comparing the duration, total power, rms amplitude, and PGA on the surface with those at the bottom of borehole, the duration and maximum amplitude characteristics of earthquake ground motions are investigated with emphasis on site amplification due to the local site conditions. The difference of amplification factors is not only site-dependent but also event-dependent. The comparison of the site amplification factors and the average shear-wave velocity in the upper 30-m showed a good agreement.This paper indicated that the duration and amplitude characteristics suffer a reciprocal effect due to the local site conditions and the site dependency of maximum amplitude PGA is greater than that of the duration. In view of the results, the duration is not less important than the maximum amplitude and frequency content in earthquake engineering. Moreover, this study provided meaningful information of input motion available to earthquake-resistant design.     

辽宁省岫岩县香炉沟金矿床的地质特征

辽宁香炉沟金矿为金、银、铅、锌多金属矿床,位于NW向棒棰沟-苏子沟-长甸断裂带与NE向卧龙泉-抚顺构造-岩浆活动带交汇部位、牧牛-东胜多金属矿化集中区的中部.该区具有较好的成矿地质条件和控矿、聚矿构造环境,位于韩家岭岩体最佳成矿空间位置,地球化学异常范围大、强度高、并与已发现的金矿化带吻合良好.预测香炉沟金矿资源前景可达到中-大型规模.     

TBM掘进技术的发展应用及相关工程地质问题探讨

阐述了TBM(隧道掘进机)半个世纪以来的发展及其在国内外隧道建设中的应用，指出优先采用TBM掘进技术进行隧道开挖已成为未来隧道建设总的发展趋势；并在分析大量国内外工程实例的基础上，结合TBM施工中的经验及教训，对TBM掘进过程中存在的诸如断层破碎带、挤压地层、地下水、岩溶等相关工程地质问题进行了探讨，并提出了相应的处理措施。     

浅论西部边疆五省区的发展

西部大开发战略的实施为西部地区的发展提供了历史性机遇.西部边疆五省区在西部经济发展中扮演着重要的角色,加快其发展对于西部大开发具有重要意义.西部边疆五省区具有显著的资源优势、区位优势和政策优势,经济发展的潜力巨大;同时,它们在人口、经济、生态环境等方面所面临的一系列共同的问题,又严重阻碍了其发展步伐.因此,如何抓住西部大开发的机遇,制订有效的对策和措施,扬长避短、进一步加快其发展,是西部边疆五省区应认真面对的问题.     

Knowing Your Place: an Australasian perspective on catchment-framed approaches to river repair

Australia and New Zealand have been at the forefront of many advances in river management through policy and legislative initiatives and the introduction of participatory frameworks. In part this leadership role is a response to the pervasive extent and impact of post-colonial societies on Australasian environments. Core geographical concepts have contributed significantly to the increased recognition of a ‘sense of place’ in management practice. Grounded and authentic applications recognise explicitly the complexity of interactions across an array of biophysical and social scales. The contribution of geography to river management is particularly significant in the implementation of catchment-framed programmes, the development of generic scientific tools that can be used on a catchment-by-catchment basis, and the application of adaptive management principles that are operationalised within participatory frameworks. Failing to acknowledge geographical concepts can lead to a placeless universalism in river management that is unsustainable and unacceptable in biophysical and social terms.     

内蒙古东胜砂岩型铀矿床形成条件与成矿作用

鄂尔多斯盆地是中国煤、油、气、铀四大能源集一体的最大能源盆地之一,是统一在华北地台的太古宙、元古宙古老结晶岩系及古生代海、湖相台盆基础上,于中生代从华北地块分异出来并发育的中—新生代山前凹陷盆地。中—新生代盆地经历了台盆发育、断块活动及盆后活动阶段。本文分析了中—新生代盆地放射性铀成矿盆地地质及地球化学有利条件,铀的丰度(4.71×10-6～34.3×10-6)是上地壳平均丰度,甚至高出一个数量级。阐述了东胜铀矿容矿层的岩石学特征,成岩—后生—低温热液矿化蚀变特征。分析了与铀成矿作用密切相关、呈面型展布、分别产于矿体上、下盘的绿色化及漂白色蚀变形成与深盆气密切成因关系。矿床矿化蚀变作用具有:多期次多阶段成矿特点、矿化矿物组合复杂、矿化形式多样、成矿温度具低温热液特点(70～120℃)、绿色化及漂白色蚀变具面型分布,矿床属于沉积预富集—古层间氧化淋滤—后生二次还原与交代砂岩型铀矿床。     

金川二矿区1178分段巷道变形破坏特征及原因

金川二矿区1178m分段巷道位于矿体上盘,采用直墙半圆拱断面,巷道建成后变形严重,经过多次返修,仍未解决其稳定性问题。为了查明巷道破坏状况,对变形严重地段进行了监测,得到巷道变形规律,并进行了原岩应力实测工作,查明了工程的地应力环境,在此基础上结合工程地质条件对巷道变形破坏原因进行了初步探讨。     

湖南省界牌岭矿区水文地质条件的认识

文章论述了界牌岭矿区水文地质条件,并且根据原有资料对矿山开采中暴露的地质环境问题进行综合分析,取得了对矿区水文地质条件较全面的认识。     

Study on strength reduction factors considering the effect of classification of design earthquake

Introduction The strength reduction factor is defined as the lateral yielding strength required to avoid yielding in the system when subjected to a given ground motion, to the lateral yielding strength required to maintain the displacement ductility ratio demand equal to a pre-determined target duc-tility ratio under the same ground motion. The strength reduction factors are not only the key fac-tors in determining seismic action for force-based seismic design, but also one of the key parame-t…