灌浆法在采空区地基处理工程中的应用

介绍了采空区地基处理机理及灌浆施工工艺,结合工程实例,论述了渗入性灌浆法在采空区地基处理工程中的应用,提出了灌浆施工的质量控制措施,以保证灌浆质量,实现采空区土地资源的有效利用。     

《世界建筑》100 期

《世界建筑》自１９８０年创刊以来已出版１００期，它介绍了大量的国内外的建筑信息和科技成果，为推动我国建筑科技发展起了重要的作用。     

双侧壁导坑隧道工法技术探讨

本文结合双侧壁导坑工法在广州市新光快速路新光隧道施工中的应用,指出不同条件下对双侧壁导坑施工工艺的引伸及拓展。     

A new approach to evaluating the toxicity and genotoxicity of disinfected drinking water

The aim of this study was to evaluate the formation of toxic and genotoxic compounds in surface drinking waters treated with two widely used disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO(2)), and a new disinfectant, peracetic acid (PAA). For this purpose a pilot plant was set up to add these biocides continuously to pre-filtered lake water flowing into three different basins. During three seasonal experiments, short-term in vivo tests (with plant, fish and molluscs) and in vitro tests (with bacteria, yeast and human cells) were carried out to evaluate the formation of genotoxic disinfection by-products (DBPs). Gas chromatography/mass spectrometry (GC/MS) was used to identify DBPs produced during the different treatments, microbiological analyses were performed to test the biocidal activity of the disinfectants, and chemical analyses were carried out to evaluate the quality of the water. The pilot drinking water plant under study was useful in studying the toxicity and genotoxicity of disinfected drinking water with this combined chemical/biotoxicological approach. This paper describes the setting up of the pilot plant and sets out/reports the results of the microbiological and chemical analyses.     

Assessment of wind load factors for hurricane-prone regions

We study the issue of whether the wind load factors specified in the ASCE 7–95 Standard for hurricane- prone regions on the one hand and extratropical storm regions on the other are mutually consistent with respect to risk. We consider structures or elements whose design is governed by wind loads and for which wind directionality effects are not significant. We present estimates according to which ASCE 7–95 Standard provisions for wind loads inducing the design strength result in (1) safety levels that are considerably lower for hurricane-prone than for extratropical storm regions, and (2) estimates of mean recurrence intervals of hurricane wind loads inducing the design strength of about 500 y if epistemic uncertainties are neglected, and significantly lower than 500 years otherwise.     

混凝土在多重因素作用下的氯离子扩散方程

基于Fick第二扩散定律，推导出综合考虑混凝土的氯离子结合能力，氯离子扩散系数的时间依赖性和混凝土结构微缺陷影响的新扩散方程，得到了混凝土的氯离子扩散理论基准模型。建立了考虑多种耐久性因素作用下的混凝土表面剥落氯离子扩散理论模型，混凝土冻融循环氯离子扩散理论模型和混凝土损伤氯离子扩散理论模型。借助于大量的实验和工程数据，对理论基准模型进行了实验验证和工程验证，结果表明，在海洋，除冰盐和盐湖等氯离子环境中，混凝土氯离子浓度实测值与本文理论模型预测值完全相符，取得了满意的验证效果。     

瑞利波检测土基模量的一些试验研究

根据瑞利波测试方法与工作原理，对填料为天然砂砾的土基进行了现场测试并对比了传统的承载板法，建立两种方法所测土基模量之间的关系，提出了一些结论。     

锚杆抑制临空结构面扩展的试验研究

通过试验研究受压作用下临空结构面的扩展特点以及锚杆的作用。试验中,模型材料为石膏,用钢板预制生成的裂纹来模拟结构面,采用铜丝、铝丝、保险丝来模拟不同刚度的锚杆。采用应变片来量测裂纹尖端的应力集中现象,利用电阻应变仪来读取应变与压力值。试验在压力机上完成。研究结果表明,随着压力的增大,临空结构面存在翼裂纹的张拉破坏与次生裂纹的剪裂纹破坏两种形式。结构面的倾角越大越容易产生翼裂纹的扩展;小倾角结构面更容易产生次生裂纹的剪切破坏方式;锚杆作用可增强结构体的力学性能,降低裂纹尖端的应力集中现象,提高裂纹尖端裂纹的起裂荷载;锚杆并不改变裂纹的起裂角度,但使翼裂纹扩展的方向向深部偏移,从而加大因翼裂纹而造成的剥离体的厚度,减缓翼裂纹的扩展速度。试验在一定程度上揭示了锚杆对监空结构面加固机制。     

上体场穿越段工程的安全施工

上海轨道交通明珠线二期上体场车站穿越地铁一号线施工段工程,地质条件复杂,地面环境特殊,施工中不能影响一号线地铁站和地面立交桥的正常交通运行,结构复杂,安全威胁大,对施工技术、安全、质量都提出了很高的要求。本文对上体场穿越段工程安全施工进行了介绍。     

ACPD法测量管节点中疲劳裂纹的增长过程

用交流电势能落差法(ACPD)测量了一个大型K节点在疲劳破坏过程中表面裂纹增长和破坏过程。对于评价管节点疲劳寿命经常使用的一个破坏力学参数———应力强度因子,通过试验数据和Paris公式得到了裂纹在扩展过程中其数值的变化情况。