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Z. X. Zhang T. Naarttij rvi 《Fragblast: International Journal for Blasting and Fragmentation》2005,9(2):61-78
Due to the large-scale sub-level caving in Malmberget mine and the short distance between the mine and Malmberget town, the ground vibrations in the town have reached a high level since the year 2001 when large scale caving mining started. In order to control and reduce the high vibrations, LKAB launched a research project on active reduction of vibrations in Malmberget by using the wave interference or wave superposition method with electronic detonators. By means of this method, the vertical vibrations were reduced by 10% and the total vibration time for a ring blast was reduced by 80% according to five ring tests in the mine. For a further reduction of the vibrations, a second method, named changing initiation sequence in ring blasts, was developed on the basis of stress wave theory and the geographic conditions of the town and the mine. The second method has so far been applied in all of the drifts near the town, and the vibrations measured at the town show that the vertical vibrations caused by production blasts in the mine have been reduced by more than 31% on average. In addition, a third method, dividing a ring into two parts during blasting, was developed and used to reduce the ground vibrations from a number of very large rings in the mine. The results indicate that the vibrations have been reduced by more than 33%, and a more interesting and surprising result is that ore extraction has been increased by the third method. 相似文献
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The urban fringe, which can be seen as a special form of regional ecosystem with a spatial transition from urban to rural
areas, has strong heterogeneity and is a typical ecologically sensitive area. The expansion of cities and the landscape effect
of the changes have attracted wide attention. The primary aim of this study is to obtain an understanding of the spatial patterns
of landscape conversion and the corresponding environmental sustainability. With the help of GIS and Fragstats software, the
changes of landscape patterns before and after town planning were compared in An-Ding town of Beijing, of which the sustainability
was also revealed based on the ecological footprint using social and economic statistic data. The results showed that the
landscape pattern changed greatly during its conversion from several villages to a small town and the landscape fragmentation
increased due to road construction. Meanwhile, human disturbance increased with the constructed land extension. For the gap
between the ecological footprint and the biological capacity, An-Ding town ran an ecological deficit at that period, which
means it was unsustainable. However, the environmental sustainability decreased after planning due to the degraded green land
and forest. The results suggested that ecological management should be strengthened during the town planning period. 相似文献
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曾小东 《地质灾害与环境保护》2003,14(2):76-78
西藏那曲镇是全世界海拔最高、含氧量最稀薄、最后一个安装自来水的地级城市。那曲镇海拔高度为4500m，冻土层深达2．8m，地下水丰富，基础开挖超过lm时就有地下水渗出，且土质多为流沙型，施工时容易引起塌方，施工环境恶劣。本文就那曲镇的具体情况介绍一下给水管道的安装及维修。 相似文献
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D. C. Singhal V. K. Sharma Manish Tungaria 《Journal of the Geological Society of India》2016,88(4):449-463
In the present case study, impact of urbanization and industrial development on the shallow groundwater regime of Saharanpur town of Uttar Pradesh in India is examined with the aim of planning groundwater protection for better governance. The hazardous physicochemical and bacteriological parameters and heavy metals detected in the shallow aquifer include harmful pathogens like fecal coliforms, heavy metals like cadmium, chromium, nitrates and sulphates. An assessment of ground water vulnerability using the well known DRASTIC method has confirmed that the shallow groundwater in some central and southern localities of Saharanpur town fall in the medium risk zones. Further, using field data of 32 electrical resistivity soundings, the protective capacity of the unconfined aquifer is assessed in terms of a ‘total longitudinal conductance’ of the semi-pervious to impervious sediments overlying the unconfined aquifer. However, some areas aligned along a northwest-southeast and in the western parts of the town seem to have relatively higher protective capacity against infiltrating waste pollutants. A ground water protection planning map prepared by combining the DRASTIC map and the ‘potentially hazardous pollutants’ map has brought out the need to install eleven new groundwater quality monitoring wells in the town at locations near the line sources and point sources of pollution. This approach can be readily employed by the decision makers in framing sound guidelines for groundwater protection and governance. 相似文献
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研究玉树地震灾区4县27乡镇的灾后重建工程地质与水文地质条件,选定了地形地貌、地层岩性、水文地质条件、场地地震烈度4个因素作为评价分区指标,构建了单因素指标评价准则,并利用层次分析方法确定了各因素的权重。在此基础上,结合模糊数学理论与方法,分别给出了基于自然单元、乡镇以及各乡镇工程建设用地、特别是极重灾区结古镇镇址的工程地质与水文地质评价结果。结果表明,除奔达乡、真达乡、洛须镇、正科乡、尕多乡等5乡镇所在地分布在工程地质条件较差和极差区,不具备重建工程地质与水文地质条件外,其余各乡镇所在地均处于工程地质较好和良好区,具备重建工程地质及水文地质条件。结古镇原镇址85%的建筑用地分布在工程地质与水文地质条件比较好的地区,只有零星的建筑用地分布在工程地质与水文地质条件较差和极差区,活动断裂穿越,距离地质灾害易发地较近,重建时要注意避让。 相似文献
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This paper deals with the landslide susceptibility zonation of Tevankarai Ar sub-watershed using weighted similar choice fuzzy
method in a GIS environment. There has been a rapid increase in landslide occurrences in the Kodaikkanal town and area surrounding
the town specially in the settlements around the town and road links leading to and from the town. This necessitates a detailed
study of slope instability problems in this area. It is observed that these incidences occur frequently during the monsoon
and summer showers. Rainfall is identified as the prime triggering factor. Eleven physical factors that cause instability
are identified as causative factors from the field investigations and landslide occurrences. Land use pattern, slope gradient,
curvature and aspect, weathering index which are evaluated from the weathering ratios of different chemical constituents of
the three major lithological variations, soil type, hydraulic conductivity of soil and soil thickness, geomorphology, drainage,
and lineament have been utilized to prepare the spatial variation. A weighted similar choice fuzzy model which ranks a set
of alternatives by identifying the similarity between the outcome of alternatives and outcome of ideal alternatives is used
to rank the causative factors. Each causative factor is classified into sub-categories and rated based on their effect on
stimulating the landslide event using qualitative judgment derived from field studies and landslide history. The prepared
thematic maps of causative factors are integrated, utilizing the GIS software Arcmap. The outcome has projected the low, moderate,
high, and very high landslide susceptibility zones. The high-hazard and very high-hazard areas fall in the northwestern part
characterized by croplands and agricultural plantations, while the moderate hazard zones are seen in prominent settlements
and low-hazard zones are observed in the sparse settlements and zones of less agricultural activity. The model is verified
using the relative landslide density (R) index, and the susceptibility map is found to be consistent with the mapped landslide
incidences. The results from this study illustrate that the use of weighted similar choice fuzzy method is suitable for landslide
susceptibility mapping on regional scale in growing hill towns as Kodaikkanal town. 相似文献
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山东临胸县中新世山旺组地层中的硅藻土不仅以化石门类丰富保存精美著称于世,而且具有重要的开采经济价值。山旺组在山东省分布十分局限,仅分布临胸县东25公里的山旺村一解家河村一带,是一套由泥岩、页岩、硅藻土及油页岩、煤层间夹玄武岩组成的湖泊沉积。它分布在大片基性火山熔岩发育区,岩性简单,产状平缓,厚度不大。由20-100米不等,地层出露面积不足0.5平方公里,化石极为丰富,尤其是硅藻。 相似文献
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Comparative analysis of bacterial contamination in tap and groundwater: A case study on water quality of Quetta City,an arid zone in Pakistan 
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下载免费PDF全文 Water is an essential element on earth, which provides human a variety of services in domestic use, agriculture, or industries. However, some serious health risks of drinking water are associated with microbial contamination, particularly with fecal matter. Therefore, microbial quality assessment is considered to be a necessary component of water quality assessment. This study investigates microbial contamination of water distributary system around the city by comparing groundwater (GW) and tap water (TW) quality in Quetta city. 31 GW samples and 31 TW samples were collected in the study area during the months of September, October, and November. Fecal coliform test was carried out in laboratory and their average total coliform contamination was computed. Results showed that the TW sample were all contaminated by coliform except for Chiltan town, hence are not considered suitable for drinking without any treatment according to WHO drinking water quality standards. The average coliform concentrations were 12 in Quetta main city, 11.6 in Jinnah town, 5.3 in Satallite town, 10 in Shahbaz town and 5 in Brewery town (0/100 mL CFU) and the TW samples from the three towns were even more contaminated with E.coli. Whereas among the GW, average microbial concentrations were 1.8 in Quetta main city, 2 in Satallite town, 1.4 in Shahbaz town, and 0.4 in Chiltan town (0/100 mL CFU), respectively, which shows that the contamination is occurring within the water distributary pipeline system when the water flows through the pipelines. Moreover, this research will be valuable for researchers and administrative authorities to conduct elaborative studies, and develop new policies to prevent further deterioration of drinking water in the water distribution system by pathogenic microorganisms and ensure safe drinking water to the public of Quetta city. 相似文献
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Matera is an ancient city located at the top of Italy's high heel that has been anointed the European Capital of Culture 2019 and which, since 1993, has been included in the UNESCO World Heritage list. The close relationship between the urban development of the old town and its geology offers the unique opportunity to discover, in one shot, the cultural and geological history of a wonderful city that is often left out of the spotlight. As a corollary to this, the rupestrian old town of Matera and nearby areas are known also for having been the location of several movies (e.g. Bond 25 ‘No time to die’). Accordingly, media and tourists alike are showing a growing interest in Matera. 相似文献
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广东贵屿土壤Cd、Hg潜在威胁评价 总被引：1，自引：0，他引：1
通过表层土壤、深层土壤、水稻样品及水样的采取与分析,结果表明,水俣病的元凶Hg在广东省贵屿镇土壤中具有极高的富集系数,易在酸性条件下向有效形态转化的弱有机结合态Hg占全Hg的17.74%;痛痛病的元凶Cd在部分土壤中的含量已超过环境承受的极限,且最易与生命体发生作用的水溶态Cd和离子交换态Cd占全Cd的比例高达16.2%。Hg、Cd的块金系数均大于70%,具明显的表层富集特征,与家电拆解作坊表层土壤重金属元素同源性较好,说明Cd、Hg的分布、富集受人类活动影响强烈,其对生态环境和居民健康存在极强的潜在威胁,在特定条件下有可能引发各类地方病。 相似文献
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以吉林省江源县石人镇泥石流观测资料为背景,对该区泥石流形成及活动条件进行了较为全面的分析研究。提取出11项影响泥石流危险性的评价因子,利用灰色关联方法计算出评价因子间的关联度,并运用模糊数学综合评判法对石人镇13条泥石流沟进行了危险性评价,评价结果较为可信,对监测和整治泥石流具有较高的参考价值。 相似文献
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上海郊县松江是一个古城,文物古迹甚多,其第四纪全新形地层发育,属典型软土,从而引发了诸多与建筑学有关的奇异地质事件,吸引着地质旅游者前去探秘,成为尚待开发的富有潜力的地质旋游资源。 相似文献
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Landslide risk assessment and management by decision analytical procedure for Dereköy, Konya, Turkey
The Dereköy landslide threatening the town of Dereköy, Konya, Turkey is investigated in order to assess and manage the associated risk. Dereköy town, located 12 km west of Konya city center, which is the second largest city in central Anatolia, has been extending due to the demand for new settlement places in Konya for the last decade. As most of the town is situated on the slopes of Meram river valley, on which the slope movements are observed, the risk of landslide has been increasing due to these new settlements. In this study, the landslide risk in Dereköy is assessed by following the so-called decision analytical procedure. The risk is defined by multiplication of hazard and consequences of the hazard. The hazard, which is the probability of slope failure, is computed by using the first-order second-moment (FOSM) method. The possible consequences of a landslide in Dereköy are analyzed and their costs are assessed relative to each other. A decision tree for choosing among the possible alternatives for reducing the risk is constructed in order to manage the risk. 相似文献
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受岩溶及采空区的影响,湖南某煤矿附近出现了几个塌陷坑,危及居民的生命财产安全。为了查明附近的岩溶分布范围,采用等值反磁通瞬变电磁法进行探测。通过在调查区开展了6条线的等值反磁通瞬变电磁法工作,发现已知塌陷坑在探测结果中为低阻异常,其探测结果与已知情况吻合。结果表明,该方法在城镇中的探测效果较好,能够为城镇地质灾害调查提供详实的资料。 相似文献
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西南地区许多滑坡,位于深切峡谷地区的人类活动密集区,具有坡形陡、变形快、危害性大的特点。丹巴特大型滑坡就是一个典型,它位于丹巴县城南街。2004年起,该滑坡就处于加速运动阶段。滑坡一旦下滑,半个丹巴县城将遭到毁灭,数千人的生命、数亿元的国家和人民财产将毁于一旦。通过对丹巴县建设街滑坡特征及形成机理分析,为后来来的滑坡综合治理提供设计、施工、工程处理提供依据。 相似文献
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清江隔河岩水库杨家槽滑坡稳定性工程地质研究 总被引：2，自引：0，他引：2
杨家槽滑坡现已成为一个现代化的新型城镇,基建费用已花掉数千万元,在滑体上居民上千人。新镇址是未经正规地质勘察而定下来的,后经清江地质大队勘测认定为滑坡时,地方政府和市民极为关注。为安定民心,长江水利委员会清江地质大队进行滑坡治理前的地质详勘工作。经过一年多的详查勘探与科学研究,基本查清了滑坡形成的年代（２．２－２．４万年前）、形成机制、滑坡的物质组成与结构以及滑带的特性等,并在滑体内发现一个规模较 相似文献