磨损随机过程建模及实例分析

针对磨损过程的动态性和随机性,提出一种构件磨损随机过程建模方法,为磨损构件的可靠性分析和寿命预测提供基础。基于平稳随机过程,给出了磨损随机过程建模基本流程;以Ar-chard磨损公式为例,推导了任意时刻磨损量的分布函数,从而能够评估磨损构件的动态可靠度和概率失效时间;结合活塞气环的实测数据,建立磨损随机过程模型,并给出抗磨损可靠度随行驶里程的变化规律。通过算例发现,磨损随机过程模型与实际相符,而考虑稳态磨损过程的磨损率为随机变量,计算结果偏保守。这样,为工程构件磨损的定量评估探索新的途径。     

农村及偏远地区饮用水除氟研究

研究了农村及偏远地区地下饮用水的除氟方法及其工艺流程、发展中的除氟新方法及新材料;分析了现有饮用水除氟设施存在的问题及其原因;提出了适合于农村及偏远郊区的除氟方法及其设施的发展方向.     

某超贫钒钛磁铁矿选矿试验研究

对某超贫钒钛磁铁矿开展了选矿试验研究,在工艺矿物学研究的基础之上,采用预选和再磨弱磁选工艺,获得了铁精矿铁品位58.32%,回收率60.76%的试验指标。     

高原铁矿选矿厂预选工艺的研究与应用

主要介绍了金钢矿业乔普卡铁矿新建高原铁矿选矿厂预选工艺的研究与应用情况,通过对预选工艺的设计和优化,使生产流程更加顺畅,提高了生产效率,实现了流程运行的科学性、高效性与稳定性,形成了一套具有高原特色的新型铁矿选矿生产工艺,可为高原铁矿的选矿提供借鉴。     

湖南某铜矿选矿无碱新工艺研究

针对铜品位0.850%的湖南某铜矿,进行了矿石多元素分析和物相分析,进行了各种条件试验,确定了无碱新工艺优先浮铜流程,可获得铜精矿含铜22.338%、铜回收率89.09%的选矿指标。     

Optimal intervention strategies for multiple objects affected by manifest and latent deterioration processes

In the existing infrastructure management systems, optimal interventions strategies (OISs) are determined for objects that deteriorate gradually (manifest deterioration process, MDPs), under the assumption that with appropriate inspection and intervention strategies the probability of failure of object can be neglected. Objects that deteriorate suddenly (latent deterioration process, LDPs), for example, due to scouring during a flood or earth movements during an earthquake are not considered. The determination of OISs for an object that deteriorates due to both MDPs and LDPs requires the consideration of both. The latter, however, means that the probability of failure of the object must be considered. In this article, a Markov model is presented that can be used to determine OISs for multiple objects of multiple types affected by uncorrelated MDPs and LDPs. The model is an extension of the model proposed by Mayet and Madanat (Incorporation of seismic considerations in bridge management systems. Computer-Aided Civil and Infrastructure Engineering, 17:185–193, 2002). In the model, a set of condition states (CSs) is used to describe the condition of objects of each type, where each set is composed of non-failure CSs and failure CSs. The probabilities of going from each non-failure CS to each failure CS are estimated using normalised fragility curves, and the probabilities of going from each non-failure CS to each non-failure CS are initially estimated using the Markov deterioration prediction model of Kobayashi, Kaito, and Lethanh (A Bayesian estimation method to improve deterioration prediction for infrastructure system with Markov chain model. International Journal of Architecture, Engineering and Construction, 1:1–13, 2012a) and later adjusted taking into consideration the probabilities of entering the failure CSs. The use of the model is demonstrated using a road link comprising one road section and one bridge.     

悬浇梁施工工艺

悬浇梁施工是桥梁施工项目当中的重难点,其施工工艺的特点就是在没有支架的施工场地、大型移动的吊装机械又不适用的情况之下,对较大跨径连续梁桥进行浇筑。在这种施工工艺当中,需要采用悬浇梁施工的工艺方法。     

Sustainable construction: life cycle energy analysis of construction on sloping sites for residential buildings

In 2010, the Australian residential construction sector contributed about 28% of the value of all construction and was responsible for 8% of the total energy consumption. Residential construction will continue to increase to cope with the demand due to population growth. Owing to land scarcity, construction on sloping sites has become a common construction method for residential development in Australia. This method has economic benefits but poses environmental issues as it damages topsoil, disturbs natural drainage and groundwater pathways and imposes additional stress on soil under fill. The life cycle energy consumption of the construction process is examined in relation to residential projects on sloping sites on a range of slopes and soil types in New South Wales, Australia. Forty-one detached dwellings were selected and a service life of 60 years assumed for the study. The research findings reveal that the slope for each type of soil has a positive correlation with life cycle energy consumption. As part of the onsite construction process, the results also show that the energy consumption of construction on sloping sites plays a significant factor in the life cycle energy analysis of a building.     

上海中心大厦塔冠外露钢结构防腐涂装体系的研究与实践

上海中心大厦塔冠是国内房屋建筑史上第一次达到600 m以上高度的塔顶建筑,由于其结构复杂、关联设备众多、环境条件严酷、施工难度大,常规的钢结构防腐经验难以适用。通过对塔冠自然条件和施工条件的深入分析,陈述了原方案的否定、调整和再否定,并在大量工程调研的基础上,提出了新的长效防腐体系。通过试验检验,结合严格的工艺质量控制,使这一新的组合配套防腐体系在大厦塔冠钢结构防腐实践中得到落实应用。