岩爆灾害研究与进展

为阐明岩爆机理,减少岩爆灾害,对岩爆的定义、分类、研究方法、特征、形成条件、预测方法及防治措施进行了系统的阐述。在前人工作的基础上,结合国内外已有的工程实例,对岩爆的时空特征和发生部位的岩性特征进行了剖析,对已有的岩爆研究方法和预测方法进行了合理分类和简要介绍,指出了部分研究方法的不足之处和预测工作的发展趋势。综合现有研究表明:岩爆分类采用的标准各有不同,其研究方法还具有改进的空间;适用于大部分工程的岩爆预测方法仍在探索和完善中;有效的岩爆防治措施有待进一步研究和优化。     

地铁盾构隧道施工对周边环境影响的监测

地铁盾构隧道在通过不良地质条件地段施工过程中会对地层产生扰动,可能引起地表及周边建筑物变形或沉降,尤其是隧道穿过正在施工的基坑止水幕墙时,可能会拉裂幕墙危及基坑及附近建筑物安全,因此必须进行监测。文章介绍了广州地铁盾构隧道施工过程中的第三方监测的经验和体会,可供同类工程施工中借鉴。     

岩体温度法隧道施工掌子面前方含水体预报模型试验研究

文章从岩体温度影响因素及岩体温度场出发,详细介绍了室内模型的制作、实验应注意的问题、试验成果及分析计算,初步探讨了岩体温度与隧道施工掌子面前方含水体的关系及隧道施工掌子面前方含水体的预报原理和可行性.     

大直径泥水盾构施工引起的地表沉降分析和对策

鉴于武汉长江隧道工程复杂边界条件,为了确保盾构施工安全,保护周边建筑物,因此在施工过程中,必须根据隧道覆土厚度、地质条件、周边环境条件,合理设置与控制泥水压力,确定合适的同步注浆量等,以控制非正常的地层损失、避免灾害性地层损失、控制地表沉降、避免开挖面坍塌。本文结合武汉长江隧道盾构施工经验,对大直径泥水盾构推进中对周边环境的影响因素进行分析,并就地表沉降控制和预防灾害事故及事故处理的一些体会进行总结。     

A link-node complementarity model and solution algorithm for dynamic user equilibria with exact flow propagations

In this paper, we propose a link-node complementarity model for the basic deterministic dynamic user equilibrium (DUE) problem with single-user-class and fixed demands. The model complements link-path formulations that have been widely studied for dynamic user equilibria. Under various dynamic network constraints, especially the exact flow propagation constraints, we show that the continuous-time dynamic user equilibrium problem can be formulated as an infinite dimensional mixed complementarity model. The continuous-time model can be further discretized as a finite dimensional non-linear complementarity problem (NCP). The proposed discrete-time model captures the exact flow propagation constraints that were usually approximated in previous studies. By associating link inflow at the beginning of a time interval to travel times at the end of the interval, the resulting discrete-time model is predictive rather than reactive. The solution existence and compactness condition for the proposed model is established under mild assumptions. The model is solved by an iterative algorithm with a relaxed NCP solved at each iteration. Numerical examples are provided to illustrate the proposed model and solution approach. We particularly show why predictive DUE is preferable to reactive DUE from an algorithmic perspective.     

农村道路客运发展研究

文章基于当前农村道路客运发展实际,分析了影响农村客运发展的主要因素,并从加大投入、抓好规划和建设、规范管理、建立完善的机制、加强安全监管等方面提出了促进农村道路客运持续健康发展的对策。     

Large-scale evacuation network optimization: a bi-level control method with uncertain arterial demand

To improve the efficiency of large-scale evacuations, a network aggregation method and a bi-level optimization control method are proposed in this paper. The network aggregation method indicates the uncertain evacuation demand on the arterial sub-network and balances accuracy and efficiency by refining local road sub-networks. The bi-level optimization control method is developed to reconfigure the aggregated network from both supply and demand sides with contraflow and conflict elimination. The main purpose of this control method is to make the arterial sub-network to be served without congestion and interruption. Then, a corresponding bi-objective network flow model is presented in a static manner for an oversaturated network, and a Genetic Algorithm-based solution method is used to solve the evacuation problem. The numerical results from optimizing a city-scale evacuation network for a super typhoon justify the validity and usefulness of the network aggregation and optimization control methods.     

满足欧Ⅲ排放标准的摩托车尾气催化剂研制

制备满足欧Ⅲ排放标准的摩托车尾气净化催化剂,制备需求的高性能稀土储氧材料和耐高温高比表面材料,在此基础上制备出密耦催化剂和三效催化剂。催化性能测定表明,密耦催化剂具有优异的低温活性和抗高温老化性能,三效催化剂具有优异的三效性能和抗高温老化性能,能满足欧Ⅲ排放标准的需求。     

铅蓄电池的合理使用与维护

汽车用铅蓄电池是汽车等机动车辆发动机起动时的主要供电电源,其使用与维护的正确与否,直接影响到蓄电池寿命的长短,进而关系到运输成本的增加和车辆的正常使用。下面介绍铅蓄电池的合理使用与维护方法。a.正确选用蓄电池的额定电压、额定电荷量和蓄电池的外形尺寸应与车辆生产     

生米大桥移动模架施工技术

结合南昌生米大桥50m跨箱梁施工实例,介绍在江西省首次使用的115m下行式移动模架的构造和在预应力箱梁施T中的应用。