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151.
在剖析区域及城市空间对深圳市铁路布局要求的基础上,分析了既有铁路存在的不足之处。提出了提升深圳在高速铁路网中的枢纽地位,构建以深圳为核心的城际铁路网,发挥铁路对城市空间支撑作用的三大规划策略;构建“高铁+城际”为骨干的区域交通组织模式,支撑“粤港澳”建设为世界一流湾区、深圳建设为全球一流城市的计划。 相似文献
152.
伴随着粤港澳大湾区正式上升为国家战略,区域经济发展重心的新变化会对深圳港发展产生重要影响。通过系统梳理大湾区发展目标与战略部署,选取地区生产总值、产业结构、生态环保、固定资产投资与集疏运体系5个重要指标,分别与港口吞吐量构建双变量VAR模型进行脉冲响应分析,进而对深圳港提出发展建议。结果表明,地区生产总值、产业结构以及集疏运体系能够对港口吞吐量产生长期正向影响,生态环保能够对港口吞吐量产生长期负面影响,而固定资产投资对于港口吞吐量的影响较弱;优化港区布局、注重生态环保、加强通道建设等发展建议,可加快促进深圳港建设成为符合大湾区发展特色的新港口。 相似文献
153.
Katherine M. Busse 《Coastal management》2013,41(4):291-301
The contamination of shellfish by pathogenic bacteria and viruses is a concern of shellfish producers, distributors, and consumers. To address these water quality concerns, the National Shellfish Sanitation Program has classified shellfish growing waters as approved, conditionally approved, or prohibited. The Tillamook estuary is one of Oregon's primary shellfish harvest areas. Degradation of water quality in Tillamook Bay has been linked to oyster bed closures, declines in salmonid populations, and decreases in recreational use of estuarine resources. In this study, water quality concerns related to shellfish management are addressed by examining the patterns of fecal coliform bacteria (FCB) concentration in Tillamook Bay. A oneway analysis of variance was used to compare log‐transformed FCB concentrations in prohibited, restricted, and conditional shellfish management areas. We found (I) a difference in Tillamook Bay water quality between all three areas and (2) a change in FCB concentrations through time in each management area. Since the designation of shellfish management areas affects the economy and public health, monitoring practices need to be reevaluated in order to draw more refined conclusions about water quality trends in Tillamook Bay. 相似文献
154.
Tom Crandall 《Coastal management》2013,41(4):451-466
Abstract The San Diego Coast Regional Commission, faced with the responsibility of approving, approving with conditions, or denying permits for development proposed along the scenic coastal bluffs of San Diego county, has adopted guidelines for bluff‐top development which assures retention of scenic vistas and provision of public access while permitting private landowners “reasonable use”; of their property. These unique guidelines delineate certain environmental and aesthetic parameters within which bluff‐top development may take place. Portions of the guidelines are presented, and some of the factors leading to their formulation and adoption are discussed. 相似文献
155.
Over $3.5 billion were spent toward nutrient controls in the Chesapeake Bay watershed between 1985 and 1996. These expenditures were based on cost-shares between federal, state, local, and private sources and should be considered conservative. A comparison of point and nonpoint nutrient control expenditures in the Bay basin showed that about 50% of the funds were directed toward agricultural best management practices and 45% were allocated for point source nutrient reductions and combined sewer overflows (20% and 25%, respectively). The remainder was spent on various other estuarine-targeted programs. Maryland was responsible for 79% of the total expenditures, 16% was expended by Virginia, and the remainder was attributable to the District of Columbia and Pennsylvania (4% and 1%, respectively). The most costly basin was the Patuxent (over $125 per kilogram of total nitrogen removed) and the least costly was the Eastern Shore of Virginia, where the cost was just under $21 per kilogram of nitrogen removed. For the control practices examined, the analysis found that nutrient management was the least costly. Animal waste control and low tillage were the second and third most economical nutrient management strategies. Significant reductions were achieved from point sources for both total nitrogen (16%) and total phosphorus (53%) by 1996. Virtually all of the large reduction in point source phosphorus was a result of the phosphorus detergent ban implemented basinwide in the late 1980s. Nonpoint source nutrient reductions were more modest. An approximate 12% reduction in phosphorus was accompanied by an 8% reduction in total nitrogen loadings. Despite these nutrient reductions, no significant improvements in bottom-dissolved oxygen levels were detected along the Bay mainstem during the warmer months, and the mouth of Chesapeake Bay showed marginally significant degradation during the 11-year period. It was determined that dissolved oxygen conditions were influenced more by nitrogen than phosphorus reductions and that nutrient controls aimed at the mid-Bay region had the greatest potential for improving low dissolved oxygen conditions in the Bay's bottom waters. 相似文献
156.
杭州湾跨海大桥南通航孔桥为A形单塔双索面三跨连续半漂浮体系钢箱梁斜拉桥,其钢箱梁安装过程中,先后发生了临时固结松动、支架脱离时梁端标高异常、悬臂梁端竖向标高变化大、轴线横向偏差增加等问题.针对其安装线形控制问题进行分析和讨论,施工中采取相应措施控制钢箱粱安装线形,完成主跨合龙,取得了较好的效果. 相似文献
157.
158.
根据杭州湾跨海大桥南岸接线软土地基试验段的实际数据,详细分析了软土的各项指标及压缩特性,为软基处理提供依据。 相似文献
159.
通过采用自平衡测试法对杭州湾跨海大桥南岸滩涂区基础试桩进行测试,转换以后得到了荷载~位移曲线、桩周土的侧摩阻力和端阻力的分布。转换以后的数据表明,实测桩周土摩阻力要远大于地质报告给定的摩阻力,说明了由地质报告确定桩长较保守,最后给出了优化以后桩的持力层。 相似文献
160.
杭州湾跨海大桥海中承台采用钢套箱工艺,结构混凝土一次性浇筑的施工技术,文中对符合工况管理及时机选择、封底握裹措施、混凝土配合比及温控措施等的关键技术进行了介绍。 相似文献