汶川地震震后恢复重建工程资金分布特点浅析及应用

采用统计拟合的方法,详细分析了汶川地震震后恢复重建工程资金的分布特点,依据震后恢复重建工程资金与烈度、人口、GDP和损失的拟合关系,提出了基于人口、地震灾害损失、GDP等因素的3个震后恢复重建工程资金快速评估模型,并利用宁洱地震数据验证经验公式的可行性。震后恢复工程资金分布特点及资金评估经验公式对未来地震进行恢复重建规划有良好的借鉴作用。     

Seismic rehabilitation and analysis of Chaohe earth dam

Stability of earth dams during earthquakes has been a major concern for geotechnical engineers in seismic active regions. Liquefaction induced slope failure occurred at the upstream slope of a major earth dam in the suburb of Beijing, China, during the 1976 Tangshan Earthquake. The gravelly soil with loose initial condition liquefied under relatively small ground vibration. In recent years, a major seismic rehabilitation project was carried out on a similar earth dam nearby using dumped quarry stone. Seismic stability analysis was carried out using model test, finite element simulation, and pseudo-static slope stability program after taking into account the influence of excess pore pressure.     

西南岩溶区生态地质环境特点及其重建策略

西南岩溶区生态地质环境具有水热充沛、矿产和旅游资源丰富,但存在地上地下双层岩溶空间结构和山高水深、地形陡峻、土壤贫瘠等两重性的特点,在人为活动的干扰影响下很容易导致生态退化,产生水土流失和石漠化等生态环境问题。本文在充分论述了西南岩溶区生态地质环境的这种特点的基础上,通过生态系统退化过程的机理分析,提出了岩溶生态系统退化是脆弱的岩溶生态地质环境和人类活动共同作用的结果的成因观点,以及以将人为活动限制在岩溶生态系统环境承载允许的范围之内作为前提条件,并辅以因地制宜开发水资源、合理利用土地资源、发展立体化生态农业、挖掘地方经济增长潜力、改善农村能源结构及生态移民等工程措施的生态系统恢复重建策略。      

现代非开挖地下管线施工方法及适用范围

每一种非开挖地下管线施工方法都有其各自特点和适用范围。介绍了一些最常用的现代非开挖地下管线施工方法,包括铺设、修复或更换管线施工方法的原理、特点和适用范围     

Influence of Reinforcement Mesh Configuration for Improvement of Concrete Durability

Steel bar in concrete structures under harsh environmental conditions, such as chlorine corrosion, seriously affects its service life. Bidirectional electromigration rehabilitation (BIEM) is a new method of repair technology for reinforced concrete structures in such chloride corrosion environments. By applying the BIEM, chloride ions can be removed from the concrete and the migrating corrosion inhibit can be moved to the steel surface. In conventional engineering, the concrete structure is often configured with a multi-layer steel mesh. However, the effect of the BIEM in such structures has not yet been investigated. In this paper, the relevant simulation test is carried out to study the migration law of chloride ions and the migrating corrosion inhibitor in a concrete specimen with complex steel mesh under different energizing modes. The results show that the efficiency of the BIEM increases 50% in both the monolayer steel mesh and the double-layer steel mesh. By using the single-sided BIEM, 87% of the chloride ions are removed from the steel surface. The different step modes can affect the chloride ion removal. The chloride ions within the range of the reinforcement protective cover are easier to be removed than those in the concrete between the two layers of steel mesh. However, the amount of migrating corrosion inhibitor is larger in the latter circumstances.     

Rehabilitation of damaged reefs: Outcome of the use of recently broken coral fragments and healed coral fragments of pocilloporid corals on rocky boulders

The use of two types of coral transplants on rock boulders was evaluated as a low‐cost alternative for rehabilitation of live coral coverage in localities whose reef structure has been reduced considerably. Transplant success between recently broken coral fragments (BCF) and healed coral fragments (HCF) was compared assuming that initial fragmentation accelerates the attachment of corals by regeneration stimulation. Two sets of both types of transplants were started during the dry and rainy seasons to contrast the effect of environmental stability on transplant survival, vertical growth and horizontal growth over 12 months. The technique provided adequate conditions for coral development, as transplants responded satisfactorily. BCF showed higher success than HCF in attaching to the substrate (up to 98 ± 4% versus 86.4 ± 18.9% after 9 months) during both seasons and also showed a greater increase in height (209.63 ± 43.65% versus 124 ± 15.83%) and diameter (107.26 ± 25.75% versus 99.98 ± 19.74%) during the rainy season. Boat anchorage caused mortality in transplants started during the dry season (less than 10% for BCF versus 37.2% for HCF) while the impact of Hurricane Polo in October 2014 caused higher mortality in transplants started during the rainy season (up to 55%). We conclude that (i) coral transplantation on rock boulders is a good choice to restore damaged coral communities, (ii) BCF seems to be the best source of transplants for pocilloporid corals, and (iii) although high light availability during the rainy season enhances transplant growth, the stable, low energy conditions in the dry season facilitate initial transplant attachment and high survival.     

区域土地利用转型与土地整理

目前,我国城市土地利用结构远未达到优化的水平,农业土地利用的规模不经济等土地利用问题都可通过土地整理加以解决,我国未来土地管理的任务会更多的在"土地整理"方面。我国土地整理的根本任务是形成合理、高效、集约的土地利用结构,增加有效耕地面积,提高土地利用效率,适应社会经济发展对土地的需求。我国地域辽阔,社会经济发展程度存在明显的区域差异,正是因为社会经济发展程度的这种区域差异,它将导致在同一时段内含有不同的土地利用转型阶段。大多数区域的土地利用形态都要经历一些发展阶段,即经过一段时期的持续变化后,直至与其它类型之间达到一个新的平衡。因此,有关部门在制定有关土地整理的目标、模式及政策的过程中,也要充分考虑待整理区所处的土地利用转型阶段,因为在通常情况下这些阶段是区域发展进程中必须要经历的。然而,通过实施土地整理,调整用地结构,可加快社会经济的发展,促使区域土地利用转型阶段的转变,同时它也会向土地整理提出新的更高层次的要求,以实现土地资源的可持续利用。     

峰丛洼地自然封育过程岩溶水溶解无机碳的变化——以桂林丫吉试验场为例

以桂林丫吉试验场为例,检验植被恢复对岩溶碳汇的影响作用。上世纪80年代,丫吉试验场峰丛洼地的植被受砍伐干扰,地表以草地居多,此后施行自然封山育林,植被经二十多年的封育后,现在变成为灌木林,土壤中植物根系呼吸和微生物异养呼吸增强,土壤空气中CO2含量上升,岩溶作用增强,泉水输出的无机碳通量增加。通过建立系统的水化学混合模型,将泉水的无机碳通量分解为原水输出和降雨补给引起的新水输出。在一次典型的强降雨过程,S31岩溶泉原水输出量占总量的65%~83%,而降雨补给引起的新水无机碳输出通量较少,且不能反映生态环境的变化,因此应以原水中溶解无机碳的浓度衡量整个生态环境对岩溶作用的影响。长期的观测表明由于植被的改变导致原水输出的无机碳含量提高了27%,而原水在岩溶泉的年流量中所占的比例高达72%~84%,其中由植被演化造成岩溶碳汇增加的幅度为19%~23%。      

太湖湖滨带的生态建设

太湖湖滨带是太湖流域重点污染控制区之一。本文根据流域生态学与流域管理学的原理,提出了太湖湖滨带生态建设的途径。（1）发展生态农业,减少农田污染。（2）入湖河道沿岸两侧建设河岸林带,成为农田与河流间的缓冲带。（3）加强沿岸丘陵的水土保持。（4）充分利用湖泊湿地的净化功能,作为治理太湖富营养化的有效措施。（5）选择入湖河道河口,在试验基础上建立人工湿地。推动太湖湖滨带生态建设工程顺利开展的措施：（1）提高全社会的环境保护意识。（2）从组织和制度上加强湖滨带污染控制管理。（3）建立环境监测和信息管理系统。（4）开展湖滨带污染控制工程的试验研究。     

广西岩溶植被自然分布规律及对岩溶生态恢复重建的意义

广西的岩溶植被类型和物种多样性丰富，分为5个植被型组8个植被型共96个群系，广西岩溶植被纬度分布由南至北为季节性雨林→含热带成份的常绿落叶阔叶混交林→常绿落叶阔叶混交林，生态结构复杂，特有成分突出，形成特殊的热带亚热带岩溶植物区系。岩溶区生态建设与植被恢复过程中，需遵循植被地带性分布规律，参照区域性顶极植物群落，进行人工群落的重建设计，选择优良乡土树种尤其是速生常绿阔叶树种，模拟天然植被构建先锋植物群落，乔灌藤草优化配置，针对生境异质性的主导因子，强化岩溶山地造林与封育管理技术，有效提高生物生产效率和植被覆盖率，开发特有适生的名特优产品，带动经济发展、促进生态环境尽快改善。