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71.
介绍斗轮挖泥船水下泥泵组基本结构、分析定位安装的可行性,在水下泥泵组中采用设备及管路的预装、环氧树脂垫片及激光经纬仪等工艺安装方案。 相似文献
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以斜坡式潜堤为研究对象,通过物理模型试验的方法,选取相对淹没水深、护面结构形式的糙渗系数、坡度等因素的变化对潜堤消浪特性的影响进行了研究。首先,分析了在规则波作用下相对淹没水深、护面结构形式的糙渗系数、坡度等因素对潜堤透射系数的变化规律,得到了各因素对潜堤透射系数影响程度,同时给出了波浪在潜堤附近传播时沿程波高变化情况。其次,采用与规则波相同的研究方法,分析了在不规则波作用下相对淹没水深、护面结构形式的糙渗系数、坡度等因素对潜堤透射系数的变化规律,得到了各因素对潜堤透射系数的影响程度,并给出了波浪在潜堤附近的沿程变化情况。 相似文献
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考虑边界土体性质悬浮隧道地震响应分析 总被引:1,自引:0,他引:1
晁春峰 《浙江交通职业技术学院学报》2014,(2):29-35
悬浮隧道地震响应研究是确保该新型交通结构物安全的重要内容,现有的研究往往忽视了驳岸结构的影响,将其简化为铰支、固支等简单约束形式。考虑了悬浮隧道驳岸结构周围岩土性质对其边界条件的影响,研究在横向地震作用下悬浮隧道的地震响应特性;采用大质量法,以Messina海峡悬浮隧道方案为基本模型,结合我国东部海域海床岩土性质,计算得到了地震作用下悬浮隧道管体位移、弯矩、扭矩和锚索索力,并对驳岸段长度Lsh和粘性土剪切模量G进行了参数分析。研究表明,悬浮隧道管体最大位移和弯矩出现于跨中、最大扭矩出现于两端、索力增量最大值出现于短索;弹性支撑有利于管体受力,但不利于锚索索力控制;驳岸段计算长度和粘土剪切模量的变化会对悬浮隧道地震响应特性带来显著影响,且影响规律较为复杂,可能与悬浮隧道结构动力特性、地震波的特性等相关参数具有耦合关系,需要进一步的研究探索。 相似文献
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A numerical analysis based on the boundary element method (BEM) was presented for the hydrodynamic performance of a high skew propeller (HSP) which is employed by an underwater vehicle (UV). Since UVs operate at two different working conditions (surface and submerged conditions), the design of such a propeller is a cumbersome task. This is primarily due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different. Therefore, some factors are necessary for the design of the optimum propeller to utilize the power at the mentioned conditions. The design objectives of the optimum propeller are to obtain the highest possible thrust, minimum torque, and efficiency. In the current study, a 5-bladed HSP was chosen for running the UV. This propeller operated at the stern of the UV hull where the inflow velocity to the propeller was non-uniform. Some parameters of the propeller were predicted based on the UV geometrical hull and operating conditions. The computed results include the pressure distribution and the hydrodynamic characteristics of the HSP in open water conditions, and comparison of these results with those of the experimental data indicates good agreement. The propeller efficiency for both submerged and surface conditions was found to be 67% and 64%, respectively, which compared to conventional propellers is a significantly higher efficiency. 相似文献
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A fuzzy model was presented to predict the weldment shape profile of submerged arc welds(SAW) including the shape of heat affected zone(HAZ).The SAW bead-on-plates were welded by following a full factorial design matrix.The design matrix consisted of three levels of input welding process parameters.The welds were cross-sectioned and etched,and the zones were measured.A mapping technique was used to measure the various segments of the weld zones.These mapped zones were used to build a fuzzy logic model.The membership functions of the fuzzy model were chosen for the accurate prediction of the weld zone.The fuzzy model was further tested for a set of test case data.The weld zone predicted by the fuzzy logic model was compared with the experimentally obtained shape profiles and close agreement between the two was noted.The mapping technique developed for the weld zones and the fuzzy logic model can be used for on-line control of the SAW process.From the SAW fuzzy logic model an estimation of the fusion and HAZ can also be developed. 相似文献
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本文根据葛洲坝船闸管理局对葛洲坝2号船闸下闸门附近淤积的冲沙经验,分析研究了其冲沙机理,并利用园形淹没射流的基本原理计算出了最大冲沙范围,分析讨论了喷咀的布置原则. 相似文献
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依托原云南楚大高速公路筛选试验小区,观测了28个单播组合及10个混播组合8年间生长表现,在利用常规生态学研究方法的基础上借鉴了景观生态学的斑块格局研究方法,对观测期末演替形成的植物种类、斑块数、多样性指数及盖度高度综合优势比进行了测定,从应用方式角度根据植物持续性、植物竞争力与扩散强度等方面将适用植物划分为混播先锋种、伴生种及建群种3种类型。指出单播群落具有均质化、多样化发展的趋势,提出在新建公路植被建植中,采用分斑块建立单播植物群落方式,最终建立目标混交植物群落的新思路。 相似文献