GFRP锚杆在软土地区深基坑工程中的应用研究

GFRP锚杆是以玻璃纤维为增强材料,以合成树脂为基体材料,经拉挤成型技术和必要的表面处理所形成的一种新型复合材料锚杆,具有强度高、耐腐蚀性好、自重轻等优点。本文阐述了GFRP锚杆使用在软土地区深基坑工程中的特点,结合其性能分析,展示出该锚杆在软土地区广阔的应用前景。     

二苯甲胺缩水杨醛类Schiff碱的合成及其表征

以二苯甲酮为原料经过酰胺化、还原、水解得二苯甲胺盐酸盐,再与水杨醛及其衍生物5-氯水杨醛反应,生成了两种二苯甲胺缩水杨醛类Schiff碱。其中二苯甲胺盐酸盐的酰化最佳反应条件为:回流温度控制在140℃,时间为20h,收率为89%;目标产物总收率均为97%以上,并利用IR、MS、1 H NMR、UV-vis及荧光光谱等方法对产物进行了表征。     

深基坑开挖与支护施工方案案例

以具体工程基础深基坑施工为例，从组织机构、工艺流程、施工方法、管理控制措施、雨季施工措施等多方面论述超深基础开挖与支护施工方案，为此类基础开挖与支护提供指导。     

扩底钻孔灌注桩在软土地基加固中的应用

青草沙5号沟泵站工程是上海青草沙水源地原水工程三大主体工程中的1个子项,开挖深度为21.2 m,采用扩底钻孔灌注桩对泵站基坑底下的软土地基进行加固。介绍了扩底钻孔灌注桩施工的全过程及施工注意事项。工程选用特别设计的MRS800型钻头,优化工艺,运用新材料玻璃钢夹砂管,控制了扩底、成孔的质量。优良的桩基质量为后续超大深基坑开挖打下扎实的基础,同时也为上海软土地基使用扩底钻孔灌注桩积累了经验。     

二重管无收缩双液WSST法注浆技术在基坑施工中的应用

杭州益乐路过街地下通道基坑渗水处理中，采用二重管无收缩双液WSS注浆技术施做防水帷幕。该注浆法止水迅速，持效时间长，施工简便，注浆防渗效果良好。     

超细分子筛的合成和应用

综述了近年来超细沸石分子筛的合成及其结构－性能表征方面的进展，并简介超细分子筛材料在催化领域中的应用。     

Effect of NiCrAlY platelets inclusion on the mechanical and thermal shock properties of glass matrix composites

NiCrAlY platelets modified glass matrix composites were prepared. Their microstructures were characterized, their Young's modulus, fracture strength in bending, Vickers hardness, and indentation toughness were measured, and their thermal shock resistance was studied using quenching-strength and indentation-quench methods. With increasing NiCrAlY content, evident enhancements of the Young's modulus and indentation toughness were obtained. The NiCrAlY alloy inclusion could exert significant influences on the retained bending strength of the samples after quench tests, from 9.6 MPa for NiCrAlY-free glass to 32.0 MPa for 30 wt.% NiCrAlY-containing composites. The indentation-quench tests showed that NiCrAlY alloy inclusion elevated the critical quenching temperatures for propagation of pre-crack, from 150 °C for NiCrAlY-free glass to 225 °C for 30 wt.% NiCrAlY-containing composites. Inclusion debonding and intersection, crack deflection and bridging were observed, and are likely the micromechanisms accounted for the improvement of fracture resistance.     

Impact of the coating process on the molecular structure of starch‐based barrier coatings

Molecular analysis of starch structure can be used to explain and predict changes in physical properties, such as water vapor and oxygen barrier properties in packaging materials. Solution casting is a widely used technique to create films from starch formulations. This study compared the molecular properties of these standard films with those of experimental coatings applied to paper in laboratory‐scale and pilot‐scale trials, with all three techniques using the same starch formulation. The results revealed large differences in molecular structure, i.e., cross‐linking and hydrolysis, between films and coatings. The main differences were due to the shorter drying time allowed to laboratory‐scale coatings and the accelerated drying process in pilot trials owing to the high energy output of infrared dryers. Furthermore, surface morphology was highly affected by the coating technique used, with a rougher surface and many pinholes occurring in pilot‐scale coatings, giving lower water vapor permeability than laboratory‐scale coatings. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41190.