黑河右岸溢洪洞左导墙优化试验

黑河水利枢纽右岸溢洪洞为缩短引渠左导墙的长度,减少施工开挖量,降低施工难度,减少工程投资,进行优化试验.通过对7种不同的方案对比分析,选择了合适的体型,满足了工程要求.     

关于最远点判定及直径的唯一性

给出了点到有界集最远点的一些必要或充分条件，然后对直径的唯一性也给出了一些判定条件。     

Performance of a non‐load‐bearing steel stud gypsum board wall assembly: Experiments and modelling

A gypsum wall assembly was exposed to an intense real‐scale compartment fire. For the wall assembly, temperatures were measured at the exposed face, within the stud cavity, and at the unexposed face during the fire exposure. Total heat flux gauges were used to measure the temporal variation of the energy incident on the walls, and cameras, both visual and infrared, were used to image the unexposed face of the wall assembly during the fire exposure. The behaviour of the wall assembly under the fire load is discussed as are current model results for a simulation of the fire test. Copyright © 2006 John Wiley & Sons, Ltd.     

冲切成槽法在薄壁砼防渗墙施工中的应用

冲切成槽法施工薄壁砼防渗墙,是一种新型防渗墙施工方法,它是利用特制的扁钻头对风化基岩或卵石层进行冲切成槽的施工方法,在工艺上有着较强的优越性.     

地下连续墙在太钢老厂改造工程中的应用

结合某深基坑支护施工实例 ,介绍了采用多头潜水钻成槽机进行地下连续墙施工的基本原理、工艺流程及注意事项。指出该方案对于在老厂区改造工程狭窄场地条件下 ,解决深基坑施工保护附近建 (构 )筑物安全具有独特的优势     

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对于套管挤毁问题较为严重的油气水井，采用非API标准的特厚壁套管来提高其抗挤强度，是今后预防套管挤毁的重要发展方向。目前，特厚壁套管的抗挤强度计算和尺寸系列尚未形成工业标准，文章提出特厚壁套管的抗挤强度计算方法和尺寸系列，供设计者和厂家参考。API/ISO套管挤毁工作组曾对本文公式进行了测评，结果曼示具有较高的计算精度。大量计算表明，特厚壁套管的抗挤强度大大提高，约为加厚前原套管抗挤强度的1．5～4倍，甚至6倍。最后还介绍了特厚壁套管在中原油田的现场应用情况。     

Behaviour of ±45° glass/epoxy filament wound composite tubes under quasi-static equal biaxial tension–compression loading: experimental results

The primary aim of this paper is to present results describing in detail the behaviour of ±45° E-glass/MY750 (GRP) tubes, of various wall thicknesses, subjected to equal biaxial tension–compression loading, generated under combined internal pressure and axial compression. The role played by the non-linear lamina shear has also been assessed by comparing various shear stress–strain curves for embedded laminae (extracted from tests on ±45° tubes subjected to circumferential: axial stress ratios SR=1:0, 1:−1 and 2.3:−1) with that of an ‘isolated’ lamina (measured from torsion of 90° tubes). Extracted shear failure strains, for embedded laminae, were more than four fold larger than those measured at ultimate failure for an ‘isolated’ lamina. Soft characteristics were observed in the embedded lamina and these were believed to be due to interaction between early matrix damage initiation (and propagation) and shear. Factors affecting the behaviour of the tubes, such as bulging, scissoring, thermal stresses and stress variation through the thickness are discussed.     

一种基于GE90-30PLC的飞剪自动控制系统

本文介绍了调整线材轧线精轧机前专用于切头的启停式飞剪的自动控制系统。该系统以GE90—30PLC为控制核心，辅以热金属HMD、光电编码器等元件，能很好地完成飞剪的剪切及定位。其中着重阐述了飞剪控制中各个重要参数的计算原理和方法。     

混凝土骨料二维分布的模拟和应用

通过在一个矩形截面上模拟混凝土骨料的实际分布，获得了该截面上任一点的骨料分布密度和骨料分布的统计特性。模拟结果表明，当模拟次数趋向于无穷大时，截面上任一点的骨料分布密度趋向于定值，对于不同的骨料面积百分数，骨料分布密度曲线的形状十分相似，均由上升段和水平段两部分组成。基于这些模拟结果，利用数学拟合获得了骨料分布密度的解析表达式，并被混凝土实验所初步证实。作为一个应用，本文计算了混凝土截面上各点的氯离子扩散系数。     

Pile Response Adjacent to Braced Excavation

The excavation of soil for the construction of basements or cut-and-cover tunnels results in ground movements. One particular concern is that the excavation-induced lateral soil movements may adversely affect any nearby pile foundation. The lateral loads imposed by the soil movements induce bending moments and deflections in the pile, which may lead to structural distress and failure. This paper presents the results of an actual full-scale instrumented study that was carried to examine the behavior of an existing pile due to nearby excavation activities resulting from the construction of a 16 m deep cut-and-cover tunnel. The pile was located 3 m behind a 0.8 m thick diaphragm wall. Excavation to the formation level that was 16 m below the ground surface resulted in a maximum lateral pile movement of 28 mm. A simplified numerical procedure based on the finite-element method was used to analyze the pile response. Generally, the theoretical predictions were in reasonable agreement with the measured results.