Thrust and Torque Characteristics Based on a New cutter-head Load Model

Full face rock tunnel boring machine(TBM) has been widely used in hard rock tunnels, however, there are few published theory about cutter-head design, and the design criteria of cutter-head under compl...     

Performance characteristics of tunnel boring machine in basalt and pyroclastic rocks of Deccan traps–A case study简

A 12.24 km long tunnel between Maroshi and Ruparel College is being excavated by tunnel boring machine (TBM) to improve the water supply system of Greater Mumbai, India. In this paper, attempt has been made to establish the relationship between various litho-units of Deccan traps, stability of tunnel and TBM performances during the construction of 5.83 km long tunnel between Maroshi and Vakola. The Maroshi–Vakola tunnel passes under the Mumbai Airport and crosses both runways with an overburden cover of around 70 m. The tunneling work was carried out without disturbance to the ground. The rock types encountered during excavation are fine compacted basalt, porphyritic basalt, amygdaloidal basalt, pyroclastic rocks with layers of red boles and intertrappean beds consisting of various types of shales. Relations between rock mass properties, physico-mechanical properties, TBM specifications and the corresponding TBM performance were established. A number of support systems installed in the tunnel during excavation were also discussed. The aim of this paper is to establish, with appropriate accuracy, the nature of subsurface rock mass condition and to study how it will react to or behave during underground excavation by TBM. The experiences gained from this project will increase the ability to cope with unexpected ground conditions during tunneling using TBM.     

第三系弱成岩砂岩TBM卡机蠕变机理分析

以引洮9号隧洞为例,利用国际通用的Burgur蠕变模型,对卡机事故围岩蠕变进行了定量分析,分析结果表明,在第三系弱成岩砂岩中围岩蠕变是导致卡机事故的重要原因。卡机段围岩含水率增加了2%左右,强度参数下降了30%~50%,围岩强度的变化使得蠕变加速,卡机风险增加。     

On the combination and normalization of interval-valued belief structures

This paper investigates the issues of combination and normalization of interval-valued belief structures within the framework of Dempster-Shafer theory (DST) of evidence. Existing approaches are reviewed, examined and critically analysed. They either ignore the normalization or separate it from the combination process, leading to irrational or suboptimal interval-valued belief structures. A new logically correct optimality approach is developed, where the combination and the normalization are optimised together rather than separately. Numerical examples are provided throughout the paper.     

设备维修策略的合理选择与决策流程

在事后维修、定期维修和状态维修这3种维修策略中，应该从设备运行可靠性及经济性的更高要求出发，合理选择维修策略来降低设备使用的费用，提高生产经济效益，从而增强企业的竞争能力和发展能力。对于关键设备，首选采用状态维修策略，不可行时也必须采取定期维修策略；对于主要设备，除故障突发特殊情况下，都应采用定期维修策略；对于次要设备，采用事后维修的策略。现代企业中各种维修模式纷呈，所以要对设备采取钊’对性的、动态的、灵活的维修策略。     

预制箱梁混凝土冬季施工质量控制措施

针对预制箱梁混凝土冬季施工易受冻害损伤这一情况,从材料储备、配合比设计、运输和浇筑、养护与拆模等方面介绍了预制箱梁混凝土的冬季施工质量控制措施,以保证混凝土的施工质量。     

Regenerable sorbent for natural gas desulfurization

Sulfur-containing odorants are normally added to propane and natural gas supplies to facilitate leak detection. The sulfur in these fuels can poison the catalysts used in fuel-cell fuel-processing systems, thereby inactivating the surfaces of the fuel-cell anodes and resulting in degraded power generation performance. The sulfur content of natural gas or any hydrocarbon fuel needs to be reduced to very low levels to ensure long-term stable electrochemical performance for both high- and low-temperature fuel cells. This paper presents the development and test results of a new physical adsorbent for natural gas desulfurization. The sorbent effectively removes all sulfur-bearing compounds at ambient temperature with very high capacity. The new sorbent can also be fully regenerated by the temperature swing. In a series of tests, the sulfur adsorption capacity of the new material is compared with other commercially available and specially prepared sorbents. The results of the comparison tests are also summarized in this paper. This paper was presented at the ASM Materials Solutions Conference & Show held October 18–21, 2004 in Columbus, OH.     

地面综合防空对中低轨道预警卫星的需求应用分析

首先阐述了现代信息化条件下地面综合防空面临的空中威胁．进而引出天基卫星预警系统在防空作战中的作用；接着对天基卫星预警系统中中低轨道预警卫星的探测区域和探测方式等技术进行了分析；最后就地面综合防空对中低轨道预警卫星的应用需求这一问题．按照技术发展趋势分三个阶段进行了的讨论。     

双护盾全断面掘进机施工管片安装衬砌技术要点

介绍了双护盾全断面掘进机(以下简称TBM)预制管片洞内安装衬砌支护模式的原理,并对其施工方法和技术要点进行了详细阐述。     

大伙房水库引水隧洞TBM掘进段围岩稳定性分析

利用ANSYS软件对大伙房水库引水隧洞TBM掘进段进行了二维数值模拟.采用平面应变模型.针对不同的上覆岩层厚度和围岩类别,计算得出围岩的应力场和位移场,从这两个角度对围岩的稳定性进行评价,得出的结论对大型隧洞工程的设计和施工具有指导意义.