影响植筋粘结锚固性能主要因素的试验研究

采用拉拔法，通过对95个植筋拉拔试件的研究，考虑了混凝土强度、植筋直径、埋深、孔径大小、保护层厚度、钢筋外形等因素对植筋粘结锚固性能的影响，给出了考虑多种影响因素的粘结力计算公式，供设计时参考。     

地基沉降计算深度范围内压缩模量当量值_（E_s）~－的实用计算公式

本文针对《建筑地基基础设计规范》（ＧＢＪ７—８９）中地基沉降计算深度范围内压缩模量当量值的计算公式,通过理论推导,提出该值的实用计算公式,其计算结果使在沉降计算中完全等效于各分层的压缩模量,且计算十分简捷。     

建筑工程中现浇板裂缝原因及防治措施

针对现浇钢筋混凝土板普遍存在的裂缝现象，从设计和施工两方面综合分析了裂缝产生的原因，提出了有效克服裂缝的预防和处理方法，以供同行参考。     

预应力混凝土叠合受弯构件刚度评价及挠度计算

分析了二次受力情况下预应力混凝土叠合构件断面的受力特点,探讨了其刚度的评价方法和挠度计算方法。在正常使用状态下,由于预制断面上荷载预应力的存在,增大了断面的有效受压区面积,从而提高了叠合构件的初期抗弯刚度。给出的挠度计算方法合理地解决了二次受力叠合构件的挠度计算问题,其计算结果与试验结果吻合较好。     

The characterisation of friction stir welding process effects on stiffened panel buckling performance

The introduction of advanced welding methods as an alternative joining process to riveting in the manufacture of primary aircraft structure has the potential to realise reductions in both manufacturing costs and structural weight. However, welding processes can introduce undesirable residual stresses and distortions in the final fabricated components, as well as localised loss of mechanical properties at the weld joints. The aim of this research is to determine and characterise the key process effects of friction stir welding assembly methods on stiffened panel static strength performance. Utilising experimentally validated finite element modelling methods, it is demonstrated that welding induced residual stresses have a significant influence, and that collapse behaviour is less sensitive to advanced process effects and process effect magnitudes than panel initial buckling behaviour.     

Impact of the River Maine Drainage Scheme on Hydro-Power Generation

A comparison is made between pre- and post-drainage scheme river flows recorded on the River Maine, Co. Antrim. A method of using five-year reference periods has been applied to the mean daily flows to smooth and eliminate, as far as possible, variations due to climatic changes.
Any loss of energy production which might have been due to changes in river flow was examined for turbine installations at a factory at Cullybackey. The quantities of usable water, and hence potential energy production, were calculated for each of the post-scheme five-year periods and compared with a pre-scheme five-year reference period. Any potential loss was then represented by a depreciation factor. It was found that no measurable loss of potential energy production has occurred on the River Maine in the post-scheme period.     

基于煤体微裂隙演化进程的综放窄煤柱煤巷非对称支护研究

针对窄煤柱煤巷掘进完成初期出现的大变形控制难题,结合窄煤柱煤巷动静支承压力基本认识,运用CT扫描技术系统研究了窄煤柱煤巷巷道中心轴两侧煤体微裂隙的演化进程,提出双锚索桁架与单体锚索平行布置非对称支护技术,并对其组成结构、控制机理、应力场分布规律进行了系统研究。结果表明:1)窄煤柱煤巷巷道中心轴两侧煤体微裂隙数量、发育速度和贯通速度具有明显的不对称性;2)顶板和煤柱帮桁架锚索应力场沿垂直方向呈"蝙蝠形"向岩体深部扩展,应力叠加区更大范围锚固体处于受压应力状态。双锚索桁架平行布置非对称支护技术在120210窄煤柱煤巷试验成功,巷道围岩在静态支承压力和动态支承压力作用期间变形协调一致,控制效果良好,研究成果对类似工程条件的支护设计具有一定的理论意义和实用价值。     

An optimal sequential preventive maintenance policy under stochastic maintenance quality

This paper presents a sequential imperfect preventive maintenance policy for a degradation system. Two kinds of activity, called continuous preventive maintenance (PM) and minimal repair, are simultaneously considered when arranging discrete imperfect preventive maintenance schedules. In order to obtain the maximum benefit in a finite lifetime, an expected benefit model is formulated based on maximal/equal cumulative-hazard rate constraints, and the optimal PM intervals are obtained using a genetic algorithm (GA). It is usually difficult to determine fixed maintenance quality after performing maintenance activities. This problem is addressed in the present paper by assuming that the reduction factor is a stochastic variable following probability distributions at fixed times. It is more rational to describe the fluctuation and trend of quality of discrete preventive maintenance during a lifetime; this makes optimisation results more robust and insensitive to the randomness of the crucial parameters in imperfect PM models. A numerical case is presented to illustrate the proposed model and some discussions are summarised.     

Hydrocarbon stress response of four tropical plants in weathered crude oil contaminated soil in microcosms

Responses to hydrocarbon stress of four tropical plants Panicum maximum, Zea mays, Centrosema sp. and Pueraria sp. grown in crude oil contaminated soils (1%, 5% and 10% w/w) were evaluated in a green house. Plants’ percentage survival, shoot heights, biomass development, and phytotoxicity susceptibility were used as indicators of growth, stress response and hydrocarbon tolerance. Relative to control, shoot heights and biomass of plants reduced with increasing hydrocarbon concentration, but 1% w/w oil-in-soil, stimulated shoot heights (5.9% and 6.4%) and weights (21.9% and 2.3%) in P. maximum and Centrosema sp. respectively. P. maximum tolerated the contaminant stress with biomass yields of 113% and 57% of control respectively in 1% and 10% w/w oil-in-soil. All the plants had 100% survival in 1% w/w, but considerably reduced survival in 10% w/w oil-in-soil. These results show that P. maximum has great potential for phytoremediation of petroleum contaminated soil.     

FRP约束钢筋混凝土柱承载力非线性有限元分析

借助有限元分析软件ABAQUS,通过建模合理选取材料本构关系、确定单元类型、界面处理以及网格划分的设置,建立FRP约束钢筋混凝土柱在轴心压力作用下的非线性有限元计算模型,得出各个阶段试件的承载能力。与试验结果进行比较,结果表明,有限元计算的极限承载力和荷载-挠度曲线与试验结果较好吻合,验证了有限元分析模型的适用性。