高瓦斯隧道过煤段安全爆破技术研究

爆破掘进是我国隧道施工中普遍采用的技术，在隧道建设中发挥着不可替代的作用，当隧道穿越煤系地层过煤段时，由于地质条件复杂，瓦斯涌出量大，采用不合理的爆破技术易产生安全事故或延误工期，如何安全快速有效地实现爆破掘进，是隧道安全施工和缓解施工工期压力的前提。基于水菁沟高瓦斯大断面隧道过煤段进行爆破试验，通过采用五段式毫秒电雷管二次起爆技术，提高了爆破的安全性和可靠性，实现了零瓦斯燃烧和零瓦斯爆炸等事故，并达到预期爆破效果。为科学有效地制定安全技术措施提供依据，对相似条件下高瓦斯大断面隧道爆破技术具有借鉴意义。     

复杂岩基地质海上风电高桩承台基础关键技术研究及应用

本文针对福建海域复杂的地质特点,以岩基海床高桩承台基础为研究对象,对基础的承台选型、承台结构设计进行分析,结合基础的载荷计算、结构的内力建模、基础的实际监测数据,研究表明高桩中承台嵌岩基础满足设计规范要求。同时,以嵌岩基础施工为例,从桩基施工、承台施工2方面详细阐述了基础施工工艺,实践表明,采用打桩架固定式沉桩、整体式嵌岩平台、装配式预制钢套箱工艺可显著提高施工效率,满足工程建设要求。该高桩承台基础设计和施工方案可为东南沿海类似工程提供参考。     

典型碳酸盐岩渗透力学行为特征及其对储、盖性质的判定

目前对碳酸盐岩的研究主要关注其油气的储集空间，针对含油气盆地中碳酸盐岩的勘探也主要是为了寻找优质的油气储集体。然而，随着油气勘探向深层更古老的地层拓展，有效的碳酸盐岩储—盖配置显得至关重要。勘探证实，深埋条件下碳酸盐岩有利相带仍然发育高孔渗的优质储集体，然而是否发育与之配置的碳酸盐岩盖层就成为了制约深层碳酸盐岩油气勘探的关键因素。首次系统全面地通过对典型碳酸盐岩开展不同温度条件下三轴应力加载全过程渗透力学试验，得出了碳酸盐岩在破坏变形过程中渗透率随温度、围压的演化过程。试验分析结果显示，典型白云岩和典型灰岩在深埋应力作用过程中渗透力学行为特征具有明显差异，白云岩更多地显示出储集性能的特征，表现为脆—塑转换临界围压较大，岩石更容易形成裂缝，渗透率随温度的增加而增大等；而灰岩则表现出盖层的属性，体现在脆—塑转换临界围压小于白云岩，岩石相对容易形成密闭，渗透率随温度的增大逐渐减小。综合分析认为，白云岩和灰岩的纵向叠置能够形成有效的油气藏储—盖组合。     

Generation mechanism and prevention method of secondary molybdate phase during vitrification of PUREX wastes in liquid-fed ceramic melter

ABSTRACT

In order to develop a glass production method that inhibits formation of the Mo-bearing secondary phase, the so-called yellow phase (YP), and also to clarify its formation behavior, vitrification tests using a small-scale liquid-fed ceramic melter (LFCM) were conducted. Chemically simulated PUREX liquid waste containing Na, Mo and other fission elements was fed into a molten glass pool in the melter together with several sizes of feed glass. When the glass beads with a diameter of around 2 mm were fed, some YP was contained in the vitrified glass products at 25 wt% waste loading. While, almost no YP was detected in the glass products when glass powder with a diameter of less than 63 μm was used. The microscopic analysis of the cold-cap samples revealed that powderization of the feed glass contributed to the facilitation of Na dissolution to the feed glass in the cold-cap. This quick intake of Na to the feed glass prevented the formation of liquid Na₂MoO₄ aggregation and provided homogeneous Mo dispersion in the cold-cap with forms of alkali earth and/or rare earth molybdates. The homogeneous dispersion of Mo resulted in the fast and complete dissolution of Mo in the glass melt.     

Pin-cap和NDW对延迟计算精度的影响

由于仿真工具本身及外部一些因素的限制,在特征化时序库时不可能产生出与理想器件完全一致的时序库延时计算模型。为了建立更为精确的延时计算模型,cadence将多输入引脚电容模型与规范化驱动波形的概念引入到有效电流源模型。文中通过使用时序分析工具对时序库进行关键路径仿真,并将分析结果与Spectre仿真结果进行对比,研究在ECSM中标准单元的接收端建立多输入引脚电容模型所带来的时序差异,以及NDW对延迟计算精度的影响。研究表明,ECSM 库若同时结合pin-cap与NDW的使用,将会更有利于延迟的精确计算,从而得到更为实际的时序分析结果。     

Viscosity of glass-forming melt at the bottom of high-level waste melter-feed cold caps: Effects of temperature and incorporation of solid components

During the final stages of conversion of melter feed (glass batch) to molten glass, the glass-forming melt becomes a continuous liquid phase that encapsulates dissolving solid particles and gas bubbles that produce primary foam at the bottom of the cold cap (the reacting melter feed in an electric glass-melting furnace). The glass-forming melt viscosity plays a dominant role in primary foam formation, stability, and eventual collapse, thus affecting the rate of melting (the glass production rate per cold-cap area). We have traced the glass-forming melt viscosity during the final stages of feed-to-glass conversion as it changes in response to changing temperature and composition (resulting from dissolving solid particles). For this study, we used high-level waste melter feeds—taking advantage of the large amount of data available to us—and a variety of experimental techniques (feed expansion test, evolved gas analysis, thermogravimetric analyzer-differential scanning calorimetry, X-ray diffraction, and viscometer). Starting with a relatively low value at the moment when the melt connects, melt viscosity reached maximum within the primary foam layer and then decreased to its final melter operating temperature value. At the cold-cap bottom—the boundary between the primary foam layer and the thermal boundary layer—where physicochemical reactions of a melter feed influence the driving force of the heat transfer from the melt to the cold cap, the melt viscosity affects the rate of melting predominantly through its effect on the temperature at which primary foam is collapsing.     

考虑土反力的桩基承台受冲切承载力塑性极限分析

利用承台底实测土反力分布和塑性极限分析方法 ,假定钢筋和混凝土均为理想的刚塑性材料 ,导出桩基承台受冲切承载力的上限解 ,计算公式与规范公式相似 ,与试验结果的吻合程度比规范公式好。     

关于桩基承载力确定的反思与选型的简化计算

本文着重论述单桩承载力确定的正确途径。提出几种有代表性桩型的单桩承载力的建议值。并在上述认识的基础上提供一种桩型比较经济的简化计算方法。     

机场道面的地基反应模量及承载力分析

基于Winkler弹性地基板理论,提出机场道面在静力荷载作用下的挠度计算和运动荷载作用下的响应分析,并将各自计算的理论挠度曲线与实测的挠度曲线应用最小二乘准则进行曲线拟合,从而识别出机场道面的地基反应模量K,继而进一步分析机场道面的承载力。通过某一机场的实测数据进行计算,表明本文所得结果具有较好的精度。     

深水高桩承台基础施工技术

结合工程概况，介绍了深水高桩承台基础的设计及施工要点，着重从钢便桥修建、水上作业平台及钻孔灌注桩施工、钢吊箱施工等方面进行了阐述，从而为同类工程提供了参考。