高等级公路桥头差异沉降位置技术处理

分析桥头跳车机理,结合洛阳——三门峡——灵宝高速公路建设的工程实际,详细介绍防止桥头跳车、高填方路段和填挖结合部位因地基差异沉降对路面结构造成的不良影响,论述了采取的技术处理措施。     

吹泥造陆场地结合地下空间开发的地基处理方案

针对围海造地的吹泥场地基坑建设成本高、施工难度大的问题,通过台州东部新区启动吹填造陆场地基处理以及基坑工程的案例,分析吹泥场地地质条件、浅层和中厚层不同真空预压处理方案的加固效果及其对基坑支护的影响,进行基坑的稳定和总体造价分析,认为采用中厚层真空预压处理工艺,有利于基坑工程的支护和开挖,可减少工程总投资。因此,在围海造地期间改变传统造地观念,地基处理结合地下空间规划,从后续开发建设和工程整体性的角度考虑是有必要的。     

船体纵骨的热点应力分析

运用MSC.Patran/Nastran软件,对典型船舶纵向构件进行了热点应力分析,讨论了4种不同因素对节点热点处的应力集中系数的影响,并总结了其变化规律。     

基于离散条柱的三维滑体构造方法

针对三维边坡极限平衡分析中滑体构造复杂困难的问题,提出了基于离散条柱的三维滑体构造方法。该法将坡体离散成条柱,利用离散点处坡面高程和滑裂面高程判断条柱是否有效,再通过种子填充算法搜索出构成坡体的离散条柱,最后根据坡体的边界条柱求解近似滑坡周界。方法较简便并具有良好的通用性。     

On stress concentration factors for tubular Y- and T-Joints in frame structures

This paper is written as a result of some years experience with fatigue analysis of offshore jacket structures where the connections are made as tubular joints. The hot spot stresses at the tubular joints in such analysis are normally derived based on parametric equations for stress concentration factors. These stress concentration factors are normally related to the axial force in the brace. It is observed that the hot spot stresses at the crown positions of the tubular joint in some cases are significantly affected by the local loading on the chord and the bending moment in the chord. In order to use the existing formulae in these cases some engineering effort is required to derive correct hot spot stress. This work can be avoided by using the nominal stress in the chord as the basis for calculating the hot spot stress at the crown position instead of using the axial force in the brace as basis for the analysis. This also extends the validity of the equations for stress concentration factors for T- and Y- joints in design standards. The proposed modification makes it also simpler to include the effect of joint flexibility in a proper way. The basis for a proposed revision of the equations for stress concentration factors for these joints is presented in this paper. It is considered that this modification leads to minor changes of the computer code, but that it will save analysis work for engineers and reduce the possibility of calculating incorrect fatigue lives in tubular frame structures.     

喷浆法在加固黄河大坝高填土中的应用

文章结合东营黄河大桥桥头高填土跨越黄河大坝的工程实例,介绍采用喷浆法进行大坝高填土加固的设计方法及施工工艺,并对其加固效果进行了评述。     

Levels of ultrafine particles in the Taipei Rapid Transit System

Ultrafine particle number concentrations are measured at five stations and inside trains on four routes in the Taipei Rapid Transit System during October–December 2007. The results indicate that there are no additional emission sources of ultrafine particle on the platforms. Ultrafine particle levels at a ground level station were, however, adversely affected by traffic outside of the station. Moreover, particles can enter the underground stations via the subway tunnels resulting in high levels during weekdays.     

强力骨架梁腹板开孔有限元分析

针对舰船结构中强梁腹板特殊开孔引起的应力集中问题,应用有限元法分析了开孔的垂向位置、孔的宽度、孔的长度对强梁整体强度的影响,以及其最大应力发生位置的变化规律,讨论了3种常用开孔补强方法的补强效果,并提出了一些供实际结构设计的参考意见。     

小水线面双体船全船应力分布的有限元分析

该文依据有关规范和文献,针对小水线面双体船的特殊外载及结构形式,用有限元法详细分析其全船及局部的应力分布规律,并计算出在不同载荷分布,不同结构形式,不同的加强措施下的应力分布情况及相应的应力值。     

非硫酸盐高浓度有机废水酸化的可生化性指标

利用表观B/C指标和理论B/C指标评价了厌氧酸化过程对蔗糖-蛋白胨人工废水可生化性的影响.结果显示对于COD为1 064～63 900 mg/L的废水,采用表观B/C评价指标,废水的可生化性降低了0%～96%;采用理论B/C指标,可生化性提高幅度为2%～21.6%.实验结果表明用理论B/C指标评价厌氧酸化过程对蔗糖-蛋白胨人工废水可生化性的影响较之表观B/C更为科学合理;同时说明对于非硫酸盐废水类型,理论B/C作为评价其酸化过程改变废水可生化性的指标同样适用;酸化出水的理论B/C随废水COD增加呈现下降的趋势,理论分析认为其与废水的酸化度(α)有关,酸化度越低,酸化出水的理论B/C越低.