盾构通用衬砌环楔形量计算及应用

本文结合长沙地铁通用衬砌环拼装实例，分析了单环衬砌环不同点位拼装对平曲线、竖曲线所提供的空间转角矢量及楔形量的影响值，希望对拼装时点位选择、盾构姿态调整有一定的意义。     

地面出入式盾构法隧道施工技术研究综述

地面出入式盾构(GPST)由日本株式会社大林组研发,作为一种新型盾构隧道施工方法,无需传统盾构的端头工作井,明显减小对周围环境的影响,同时缩短工期。该技术目前的实践工程较少,存在多方面工程技术难题。根据已有研究资料,阐述地面出入式盾构的相关技术难题,主要从隧道衬砌、盾构姿态、同步注浆等几个方面进行总结,分析现有研究不足之处,提出需要进一步研究的方向和研究思路。     

Geosynthetics for waterways and flood protection structures – Controlling the interaction of water and soil

The interaction of water and soil has been both a blessing and a curse in all times within living memory. Water is the origin of life but is also threatening life when appearing unboundedly. Therefore mankind has always worked hard to benefit from water resources on one hand and to deal with the threat of flooding on the other hand. For both, to protect the land and to allow for beneficial uses like irrigation or navigation, often special measures are necessary to keep the water within certain bounds. Structures to achieve a permanently stable situation like irrigation and navigational canals, river training or flood protection measures need suitable material, carefully thought out design and accurate execution. Often a decision has to be made among competitive approaches to optimize such structures. In many cases, geosynthetics can support or improve the functionality and sometimes only with geosynthetics the desired result can be achieved.     

Studies of the combined effects of some important factors on the likelihood of flashover

Among those factors that affect the likelihood of flashover in enclosure fires, the thermal inertia of lining materials, ventilation factor of door openings, heat release rate of fuel, and internal dimensions of the enclosure are the most important. The effects of the four factors are related, so it is very necessary to study their combined effects. In the present study, based on analyzing the approximate heat balance on the control volume similar to that in the MQH method, a dimensional relationship was derived that facilitates the estimation of pre‐flashover temperatures, which is used in the popular guidance literature as the key parameters for practical methods of predicting flashover. By correlating a vast amount of data gained in both small‐scale and large‐scale enclosure fire experiments, an important equation was obtained, which can embody explicitly and quantitatively the combined effects of the four important factors on the likelihood of flashover. According to the temperature criteria of 600°C identifying flashover, a new ‘combined method of predicting flashover’ was put forward. The validity of the method was verified in small‐scale experiments, and the results showed that it could be applied to predict well whether flashover occurs in enclosure fires or not. Copyright © 2010 John Wiley & Sons, Ltd.     

催化裂化装置再生斜管优化设计

对国内某催化裂化装置再生斜管的支撑方案进行了分析,详细阐述了支撑方案中支撑碟簧的选型设计,包括计算壳体壁温和两器系统各部分热膨胀值,并对设置碟簧前后的斜管两固定端受力进行了对比:膨胀节前后设置碟簧支撑比未设置时受力减少78％以上.同时也对再生斜管的衬里结构进行了分析,衬里的设置既要考虑到隔热,又要考虑到耐磨,并提出了确保衬里施工质量的措施.再生斜管优化设计后,该装置开车2 a,再生斜管运行良好,未出现振动及局部过热现象.     

水利衬砌工程中混凝土裂缝控制技术的应用

在混凝土建筑物当中,往往会出现裂缝等诸多问题。而裂缝的产生,主要归咎于水泥水热化、荷载、地基冻胀、干缩、钢筋锈蚀、温度、砼的质量、地基形状变化大、碱骨料反应等缘故。     

含圆柱形衬砌直角域压电体的动力反平面特性

探讨了直角域附近一圆形衬砌对压电材料的反平面动力学行为的影响.通过利用镜像法对直角域情况进行等效处理到全空间中,在复数域中利用衬砌周围的边界条件构造方程求解未知系数,并通过编程进行最终的数值计算得出压电材料在衬砌周围的动应力和电场集中系数.在数值计算中,重点讨论了衬砌和基体为不同材料、衬砌和基体电极化方向相同和不同时,它们随压电材料物理系数、结构几何参数,以及入射波的频率变化的计算结果.结果表明,在SH波的作用下,压电材料在衬砌周围的动应力集中系数和电场集中系数都有一定的相似性,并且沿衬砌周围有规律的分布,然而在入射波的频率较低时二者的值相对较大,同时计算结果还与全空间衬砌下的计算结果有一定的相似性.     

Application of the pressure grouting in the hydraulic tunnels

Present paper presents the application of pressure grouting in hydraulic tunnels subjected to high internal pressure of water. Structural analysis of the pressure grouting used for pre-stressing of concrete lining is shown along with the methods used to control the pressure grouting effects. The paper also presents a new experimental method for measuring the loss of water along the complete tunnel under operating conditions and a mathematical model for the evaluation of tunnel impermeability and functionality. All presented test methods have been developed and all measurements were performed by the “Jaroslav Cerni” Institute for Development of Water Resources in Belgrade (Serbia). These methods are presented on the example of a hydraulic tunnel of the “Bajina Basta” pumped storage plant in Serbia, during the stages of its construction and operation.     

基于扩展有限元的隧道衬砌裂缝开裂数值分析

分别通过对浙江区域48条公路隧道衬砌裂缝病害的现场调查和大量裂缝病害实例的统计分析,获得了公路隧道衬砌裂缝的分布特征规律和衬砌开裂的主要影响因素。通过与衬砌原型试验的对比,验证了衬砌开裂扩展有限元分析方法的适用性。在这些研究的基础上,采用扩展有限元研究了衬砌在主要影响因素作用下的裂缝分布规律、裂缝扩展过程、裂缝外观表现形式及发生机制。该研究为衬砌裂缝产生原因的分析提供了借鉴,同时也为隧道衬砌裂缝病害的防治与加固修复打下了基础。