探讨屋面渗漏的原因与对策

屋面渗漏是建筑工程的质量通病,产生的原因很多,牵涉的范围广,分析原因,制定对策。通过从设计→施工→使用的综合防范治理,解决屋面渗漏的问题。     

浅谈小城市特色的形成——以沂源县城为例

改革开放以来,城乡经济发展迅速,城市无论在数量上还是规模上的快速发展出人意料,建设活动也最具活力。但同时,我们也清醒地看到,大多数小城市千城一面,杂乱无章,毫无特色可言。就像一支曲子,没有自己的主旋律,让人惋惜。沂源县城作为一个新建城市,不失时机地作好城市特色规划,更好地指导城市的开发和建设,就显得十分重要了。在2002年7月批复实施的县城总体规划中,将沂源县城城市性质定义为“山水生态城市”。那么沂源县城有怎样的现实条件、如何才能达到这一目标呢?一、沂源县城市要素浅析城市的特色是指城市所在地域特有的自然风光与人工…     

Role of phosphorus in eutrophication and diffuse source control

Many lakes and some streams and estuaries are showing signs of excessive fertilization due to the input of aquatic plant nutrients from man-associated sources. The key element often found limiting aquatic plant populations is phosphorus. The attempt to control phosphorus input to natural waters as the overall approach for controlling excessive fertilization is technically sound and economically feasible for many natural waters. However, a much better understanding of the relationship between the phosphorus input to a lake and the excessive growths of aquatic plants within the lake must be developed. This development will require a combined biological and chemical approach toward assessing the role of phosphorus in eutrophication for a specific water body. The biological approach will use tissue content, enzymatic and kinetic uptake analysis of phosphorus limitations as well as bioassays of phosphorus availability in order to determine the limiting nutrient for a body of water. The chemical aaproach will utilize amounts of each of the forms of phosphorus present in the lake and the rates of interchange of phosphorus between these various forms.There will be some waters where control of phosphorus from treatment of domestic waste water input and removal of phosphorus from detergents will not result in significant improvement in water quality. This is because these waters derive their phosphorus from diffuse sources, such as urban and rural stormwater drainage, the atmosphere, and ground waters. In these instances, it may be necessary to initiate in-lake control of phosphorus by the addition of alum or iron salts.     

Use of driven piles in rammed holes during construction in soils prone to slump-type settlement

Conclusions The experiment with the use of piles cast in rammed holes in lieu of continuous foundations placed on a bed compacted by tamping produced positive results and will be expanded upon further, since the strength properties of the materials in the foundations and the soils in the foundation beds can be more fully utilized, the reliability of the structure increased, the volume of earthwork reduced, labor and material outlays diminished, and the rate of construction and the level of the industrial nature of the work increased.State Institute for the Projection of the Greenhouse Industry. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, p. 10, March–April, 1977.     

工字形铝合金偏心压杆平面外稳定承载力研究

运用ANSYS软件对工字形铝合金偏心压杆平面外稳定承载力进行了研究,分别讨论初弯曲、残余应力和截面厚度偏差等缺陷对杆件平面外稳定承载力的影响,提出稳定系数曲面的概念,指出平面外稳定系数是相对偏心率e′和相对长细比λ的二元函数,在空间上为一连续的曲面。并对不同截面尺寸杆件的平面外稳定系数进行大量计算分析,以此为基础拟合出了平面外稳定系数曲面=f(λ,e′)的函数表达式,可供设计参考。     

Fluid filling of a membrane tube with self-weight

The filling of a membrane tube with self-weight by a fluid is studied theoretically for the first time. The fundamental problem depends on two non-dimensional parameters, $\beta$ and $\gamma$ which represent the importance of internal pressure and membrane self-weight respectively. The nonlinear equations are solved by an efficient numerical integration method. It is found that membrane self-weight has considerable effect on the tube geometry and the tension of the membrane at low filling pressures.     

岩土工程档案的利用需求及管理对策

本文通过作者多年对岩土工程档案管理工作的实践,结合岩土工程档案本身的特点,总结了岩土工程档案利用需求的相关特性。     

大型商场家电类商品火灾蔓延特性研究

采用实尺实验的方法，针对模拟家电类商品的标准组件，就商品货架摆放和堆垛摆放的不同形式，研究在无水喷淋保护的条件下火灾发展和火焰传播的特性。得出该类商品发生火灾时达到旺盛期的时间、垂直方向和水平方向火焰传播速度以及火灾载荷对火灾发展影响的规律。     

CFRP筋作体外预应力束的简支梁桥设计研究

本文介绍了c筋在预应力混凝土公路梁桥建设中的应用。该桥为整体现浇25m跨径简支梁,采用CFRP筋中的碳绞线(Carbon Fiber Composite Cable)作为体外预应力束。文中论述了设计中应关注的主要问题,运用理论方法和有限元方法对结构作了全面分析,并在造价上与普通预应力混凝土梁桥作了比较。