连续悬索桥受横桥向船撞力的分析

应用平面有限元计算程序代替空间有限元计算程序,解决了连续悬索桥受横船撞力的分析问题,通过对具体算例的分析,得到了有益的启示。     

设计阶段控制工程项目成本的几种方法

对设计阶段工程项目成本控制存在的问题及其对工程项目造价的影响进行分析，提出设计阶段工程项目成本控制的方法，使工程成本在设计阶段得到有效的控制。     

适应清单计价模式加强施工企业管理

在深入分析工程量清单计价方式的实施对施工企业影响的基础上，结合目前企业发展中存在的问题，提出了企业应对工程量清单计价的若干措施。     

客运专线隧道衬砌施工质量常见问题分析及处理措施

隧道衬砌是隧道施工的重要工序,其质量影响着隧道的使用功能。总结隧道衬砌施工中常见的质量问题,研究分析影响质量问题的原因和关键因素,从理论和实践上提出改善混凝土施工工艺、提高混凝土性能品质等的处理措施或建议,尤其在防水板挂设、衬砌拱顶灌注、钢筋保护层施工方面有新的观点,可供以后施工借鉴和研究。     

A study on seepage field in subgrade slope subjected to various rainfall patternsEI北大核心

Research purposes: Rainfall is one of the most important factors for subgrade slope failure, and rainfall patter is one of the most primary influence parameters. Based on the two-dimensional saturated-unsaturated seepage theory, numerical analyses are conducted to investigate the change rules of seepage field in subgrade slope subjected to rainfalls with four different patterns, i.e. delayed, uniform, central and advanced rainfall patterns. Research conclusions: (1) Both the maximum pore-water pressure umax and the maximum saturated depth Hsmax at shoulder are affected by rainfall intensity and rainfall duration observably. (2) There is a sensitive range of coefficient of permeability influencing on the maximum saturated depth, only within the sensitive range increasing coefficient of permeability could reduce Hsmax and subgrade surface pore-water pressure effectively. (3) Under central and advanced rainfall patterns, the most dangerous time stage of slope stability is obvious affected by coefficient of permeability, within the sensitive range and the less side outside the sensitive range, the starting point of the most dangerous time stage is not affected by coefficient of permeability, but the end time is advanced with coefficient of permeability increasing. (4) The stability of subgrade slope is the best under advanced rainfall pattern and the worst under delayed rainfall pattern. (5) The research results can provide basis and reference for slope protection and reinforcement design.     

EA4T车轴钢热处理冷却转变特性的研究

本文采用金相分析方法,系统地研究了EA4T钢在不同介质连续冷却、等温冷却下的组织转变。在860℃～920℃加热淬火时,随着加热温度降低,淬火所得的显微组织细小,这种工艺更有利于获得合格的晶粒度;该钢具有很强的贝氏体形成能力,即使空冷也能得到贝氏体组织;此钢在520℃以下等温,可抑制先共析铁素体的析出,得到粒状贝氏体组织,随着等温温度的降低,转变速度加快,在450℃下等温300s就可得到完全的贝氏体组织。     

高压共轨式电控柴油机电子油门故障自诊断策略研究

根据电子油门传感器的特点闸述了其故障自诊断的原理,介绍了电子油门诊断法中的极值诊断法和逻辑性诊断法,对油门传感器发生故障后的失效处理工作模式进行了讨论。建立了电子油门故障诊断的仿真模型,其仿真结果表明该控制策略能及时地发现故障。     

State Wetland Protection: A Matter of Context?

Models of integrated management emphasize the role of the surrounding socioeconomic and political environment in influencing management choices for natural resources. In this study, we explore a model that examines the influence of socioeconomic and political variables on the wetland management programs of U.S. states. Logistic regression was used to identify environmental, socioeconomic, and political variables that explained variation in state wetland programs. The likelihood of strong planning, nonregulatory, regulatory, and overall programs increases as the importance of fisheries in the state increases (p < 0.05), but decreases as population density increases (p < 0.15). Furthermore, there is an increasing likelihood of stronger regulatory and overall programs as environmental group activity and industry importance increases (p < 0.05). These findings provide empirical evidence to support the contention that management approaches used in one state often must be adapted to fit the realities of another given state.     

安庆长江大桥3号墩钢套箱围堰施工技术

宁安铁路安庆长江大桥主桥为101.5＋188.5＋580＋217.5＋159.5＋116（m）三索面钢桁梁斜拉桥。桥梁主塔墩3号墩位于主河槽通航航道上,施工水位深,河床覆盖层浅,覆盖层下面为强风化光板岩,岩面高低不平;承台为圆形,直径大,桩基础为3.0 m/3.4 m变直径摩擦型钻孔桩。3号墩基础施工采用双壁钢套箱围堰方案,先围堰,后钻孔。钢套箱外径56 m,高42.88 m,属大型钢围堰。从围堰组拼、下水、浮运、定位、下沉等方面,详细介绍了宁安城际铁路安庆长江大桥3号墩钢套箱围堰的施工技术,为以后同类工程的施工提供借鉴。