钻孔压水试验水压式栓塞排水泄压问题研究          下载免费PDF全文

裴熊伟 《探矿工程》2016,43(3):56-59

压水试验水压式栓塞较其他类型栓塞可靠、灵活,但一直存在试验结束后排水泄压难题,使该类型栓塞使用局限于浅孔及地下水位高的钻孔。本文对该问题进行了研究,提出了解决方案,设计了新型水压式栓塞结构。解决了一直以来水压式栓塞的排水泄压难题,突破了试验孔深限制,使水压式栓塞能得到广泛应用。介绍了该新型水压式栓塞的结构和工作原理以及工程应用效果。  相似文献   

基岩水井压裂增水机理分析          下载免费PDF全文

李炳平  何计彬  康志鸿 《探矿工程》2016,43(1):61-65

基岩地层压裂增水与岩层性质密切相关,不同岩性其力学性质及其裂隙构造不同,压裂机理与工艺方法就不同。根据基岩地下水岩层特点,结合水力压裂增水试验,着重分析了水力压裂的形成机制,探寻了不同岩层及其力学性质与压裂的关系。  相似文献   

北方某经济开发区地下水污染调查评价     

江岳  马宏  石思宇  肖寒  赵杰  张洁 《城市地质》2016,(4)

本文应用污染指数法,对北方某经济开发区及周边地下水水质进行了污染评价,结果表明研究区地下水水质以轻污染和中污染为主,局部地区出现较重污染,主要指标为硝酸盐氮、三氯甲烷和三氯乙烯。通过对工业废水、再生水、河水水质的检测,发现研究区地表水水质与污水处理厂再生水排放密切相关,地下水污染很可能与开发区企业排污有关。由于开发区所处位置的环境敏感性和脆弱性,建议今后在开发区及附近继续开展相关研究,进一步查明地下水的硝酸盐氮及有机污染物来源、污染途径,建立完善的监测体系,以便及时切断污染源,保障城市及当地供水安全。  相似文献   

河北牛驼镇地热田高温地热水成因分析   总被引：1，自引：0，他引：1  

王永波  丁文萍  田月  王婧  丁蕊 《城市地质》2016,(3):59-64

牛驼镇地热田以基岩热储层最优,是目前地热田开发利用条件最好的热储层。牛驼镇基岩热储水温60℃~100℃,顶板埋深最浅处小于500m,一般为800~1500m,涌水量50~110 m3/h。基岩地热水水化学类型为Cl—Na型水,偏硅酸浓度46~92mg/L,偏硼酸浓度5.0~33 mg/L,氟浓度5.41~11 mg/L,是优质的理疗矿泉水。本文着重从构造运动的角度分析了牛驼镇高温地热水的形成。阐述了自元古代的吕梁运动开始至二叠纪期间,研究区在经过"三降两升"的五个地史发展期中不仅沉积了良好的基岩热储层,亦储藏了丰富的水源。随着新生代喜山运动的活跃,在牛东等断裂的控制下,牛驼镇凸起发育成熟,在此过程中,牛驼镇凸起暴露地表,沉积了新近系和第四系,构成基岩热储的良好盖层。另外,由于基岩热储岩性的热导率较高及埋藏深度较浅,使得牛驼镇地热田拥有相对较高温度的地热水资源。  相似文献   

扎龙湿地藻类植物群落结构特征及水质初步评价     

巴秋爽  李雪  刘妍  代存芳  范亚文 《海洋与湖沼》2016,47(5):924-934

扎龙湿地是我国北方同纬度地区保留最完整、最原始、最开阔的湿地生态系统,地处中温带,属大陆性季风气候。为了探究其藻类植物群落的变化特征及其与水环境的关系,本文于2011年春、夏、秋季对扎龙湿地的藻类植物群落进行调查分析,共发现藻类植物349个分类单位(包括变种、变型),隶属于8门105属,藻类植物群落全年均以绿藻为主导,其组成呈绿藻-硅藻型。优势种中绿藻门主要以镰形纤维藻(Ankistrodesmus falcatus)和四尾栅藻(Scenedesmus quadricauda)为主,硅藻门以弯棒杆藻(Rhopalodia gibba)和隐头舟形藻(Navicula cryptocephala)为主,优势种组成具有明显的季节演替现象。藻类植物细胞密度呈现明显的单峰型,夏季最高,平均为10.74×10~4ind./L。湿地研究区域分为开阔型水域、小型封闭水域、湿地型水域和湖泊型水域四个生态类型,不同水域藻类植物群落结构特征明显不同。经聚类和多维尺度分析,将不同采样点的藻类植物群落分为四组,多样性指数表明湿地水体处于轻度污染或无污染状态。综合研究结果可以认为扎龙湿地的水体基本处于贫营养-中营养状态,只有极少数水域处于富营养状态。  相似文献   

An experimental investigation into the influence of the damage openings on ship response     

《Applied Ocean Research》2016

Ship motions after damage are difficult to evaluate since they are affected by complex phenomena regarding fluid and structures interactions. The possibility to better understand how ship behavior in damage is influenced by these phenomena is important for improving ship safety, especially for passenger vessel.In this paper an experimental campaign is carried out on a passenger ferry hull, to show the effects of the water dynamics across damage openings on ship motions. Novel aspects of this research include the study of the effects of the damage position on the ship roll response. The study is carried out for still water and for beam regular waves at zero speed.Results from the experiments carried out underline that the roll behavior of a damaged ship is affected by the position of damage opening and not only by its size. Assuming the same final equilibrium conditions after flooding but characterized by different damage openings it is possible to observe how motions RAOs and roll decay characteristics modify according to the opening locations.  相似文献   

Improved assessments of wave-induced fatigue for free spanning pipelines     

《Applied Ocean Research》2016

For subsea pipeline projects, the costs related to seabed correction and free span intervention are often considerable. Development of reliable methods for fatigue analyses of pipelines in free spans contributes to minimize costs without compromising pipeline integrity. Assessment of wave-induced fatigue damage on multi-span pipelines is investigated, and improved analysis methods are suggested in this paper. A time-domain (TD) algorithm is developed, which accounts for non-linear hydrodynamic loading and dynamic interaction between adjacent spans. The proposed TD approach is employed to evaluate linearized frequency-domain (FD) solutions from recognized design standards and to study the dynamic response of multi-span pipelines to direct wave loading. Differences between multi- and single-span analyses are described for the first time, and the common assumption that the main fatigue damage contribution comes from the fundamental mode is demonstrated not to hold for multi-spans. An improved FD solution capable of predicting multi-mode response is derived and demonstrated to give accurate fatigue life estimates for multi-span pipelines.  相似文献   

Life after death: shallow‐water Mediterranean invertebrate communities associated with mammal bones          下载免费PDF全文

Sergi Taboada  Maria Bas  Carlos Leiva  Mariona Garriga  Rafael Sardá  Conxita Avila 《Marine Ecology》2016,37(1):164-178

Invertebrate and microbial marine communities associated with mammal bones are interesting and poorly understood habitats, mainly known from studies on deep‐water whale remains. In order to characterize these communities in the shallow‐water Mediterranean, we present here the results of a pioneering experiment using mammal bones. Minke whale, pig and cow bones were experimentally deployed on three different background communities: rocky substrate, soft‐bottom and a Posidonia oceanica meadow. Bones were deployed for a year at about 20 m depth and collected every 3 months, and the invertebrate fauna colonizing the bones was identified to the lowest possible taxonomic level. As expected, mammal bones showed remarkable differences when compared with background communities. Within bones, four different clusters could be identified, primarily on the basis of the polychaete fauna, the most abundant and diverse group in the survey. Clusters A1–A3 corresponded to high to moderately altered successional stages composed by a fauna closer to that of anthropogenically enriched shallow‐water environments. These clusters were characterized by the occurrence of the opportunist polychaetes Ophryotrocha puerilis, Neanthes caudata (Cluster A1), Protodorvillea kefersteini (Cluster A2) and Ophryotrocha alborana (Cluster A3). Cluster B was characterized by the presence of the polychaete Oxydromus pallidus together with typical invertebrate background fauna, which suggests that this community, after a year of deployment, was closer to that found in natural conditions. As opposed to similar shallow‐water studies in other geographic areas, no occurrence of the polychaete Osedax (commonly known as bone‐eating worms) was reported from our experiments. Apart from the study on the invertebrate communities, insights about the population dynamics of three of the most abundant species (O. puerilis, O. alborana, N. caudata) are given as well as remarks on a hypothetical trophic network based on fecal pellet analysis.  相似文献   

Crustacean decapod assemblages associated with fragmented Posidonia oceanica meadows in the Alboran Sea (Western Mediterranean Sea): composition,temporal dynamics and influence of meadow structure          下载免费PDF全文

Ángel Mateo‐Ramírez  Javier Urra  Pablo Marina  José L. Rueda  José Enrique García Raso 《Marine Ecology》2016,37(2):344-358

The decapod assemblage associated with a Posidonia oceanica meadow located near its western limit of biogeographic distribution was studied over an annual cycle. Fauna samples were taken seasonally over a year (five replicates per season) in two sites located 7 km apart, using a non‐destructive sampling method (airlift sampler) for the seagrass. The dominant species of the assemblage, Pisidia longimana, Pilumnus hirtellus and Athanas nitescens, were associated with the protective rhizome stratum, which is mainly used as a nursery. The correlations between decapod assemblage structure and some phenological parameters of the seagrass shoots and wave height were negative or null, which reflects that species associated with the rhizome had a higher importance than those associated with the leaf stratum. The abundance and composition of the decapod assemblage as well as the ecological indexes displayed a seasonality trend with maximum values in summer‐autumn and minimum in winter‐spring, which were related to the seawater temperature and the recruitment periods of the dominant species. The spatial differences found in the structure and dynamics of the assemblages may be due to variations in the recruitment of the dominant species, probably as a result of the influence of local factors (e.g. temperature, currents) and the high dispersal ability of decapods, together with the patchy configuration and the surrounding habitats. The studied meadows are fragmented and are integrated within a mosaic of habitats (Cymodocea nodosa patches, algal meadows, rocky and sandy bottoms), which promotes the movement of individuals and species among them, maintaining a high species richness and evenness.  相似文献   

An experimental study on water entry of asymmetric wedges     

《Applied Ocean Research》2016

The aim of the paper is to provide an experimental reference for investigation of asymmetric water entry of wedges. Parameters of the study include initial deadrise angle, inclination angle and impact speed. Initial deadrise angles of the wedges were 20° and 30° with inclination angles ranging from 0° to 15° in 5° increments. Wedges were freely fallen from three different heights. Time histories of impact pressure and body acceleration were recorded. Sampling rate of measurements were set to 25 KHz. Main configuration of each test including mass of the wedge and water level were kept unchanged during all experiments. Additionally, several calibration tests were conducted to assess the repeatability and accuracy of the recorded data. The experimental results are compared with different entry theories and other available experiments. The comparison shows a reasonable agreement and indicates that the inclination angle can dramatically affect the impact pressure experienced by the wedges. Finally, the results show that the traditional asymmetric theories are not appropriate for all inclination angles.  相似文献