深水大直径超长桩基础施工技术

结合工程概况及其地质条件,对钢护筒的制作和埋设、水上桩位的测量与控制、钻孔要点、钢筋笼的制作与安装、导管安装等施工环节的施工技术进行了介绍,为今后潮汐地区深水大直径超长钻孔灌注桩的施工提供了宝贵的经验。     

现浇钢筋混凝土裂缝分析及预防

近年来,非标准模数和造型复杂的建筑大量出现,其结构形式大多以现浇钢筋混凝土结构为主.由于采用现浇钢筋混凝土结构,房屋的整体性、抗不均匀沉降和结构安全性均比以往有了很大程度的提高.但现浇钢筋混凝土结构易产生裂缝.如何避免或减少混凝土裂缝的产生,作者根据工程实践,提出简述,供工程人员分析参考.     

办公楼工程基坑围护设计方案

通过上海某公司办公楼工程,介绍了同一工程基坑在周边环境不同的情况下,采用多种基坑围护结构形式的设计思路。叙述了围护方案的比较及选择,施工流程及土方开挖及降水的要求等。     

某特大桥超长大直径钻孔灌注桩桩底压浆施工

结合某特大桥超长大直径钻孔灌注桩采用桩底压力注浆,介绍了压力注浆施工方法及施工的注意事项,探讨了压力注浆技术在超长大直径钻孔灌注桩的施工技术,以提高桩基承载力。     

定向爆破抛掷距离研究与分析

定向爆破抛掷距离计算常采用体积平衡法或抛体堆积法,这2种计算方法的理论基础和设计原则各不相同.为了验证其客观性、准确性,通过选取不同爆破参数和布药结构,进行系列模拟试验并加以分析和研究,研究证明体积平衡法更加符合客观规律,该结论有助于指导定向爆破设计与实践.     

Five-layer reverse tape casting of IT-SOFC

Tape casting is a well-established method for manufacturing thin ceramic layers with controllable thickness and porosity. This study investigates the potential of 10Sc1CeSZ material for the electrolyte and anode layers for intermediate-temperature solid oxide fuel cells (IT-SOFC) in an anode-supported cell (ASC) geometry. In order to use La_0.6Sr_0.4Co_0.2Fe_0.8 Oxide (LSCF) cathode material, a Gd_0.2Ce_0.8 Oxide (GDC) barrier layer is needed; however, thermal expansion coefficient mismatch results in delamination of the GDC from the electrolyte during high temperature sintering when fabricated by conventional tape casting procedures. For the first time, ASCs have been manufactured by a five-layer tape casting technique; barrier layer, novel composite layer, electrolyte, anode functional layer, and anode substrate. Ni-ScCeSZ composite cells were tested between 650 and 800°C in H₂:N₂ fuel (85% H₂) on the anode and air on the cathode to yield a maximum power density of .46 W/cm². These results demonstrate the feasibility of this new five-layer tape casting technique to produce IT-SOFC.     

Properties of phyllosilicate-based porous ceramics shaped by conventional tape casting and freeze tape casting

Silicate ceramics were shaped using tape casting (TC) and freeze tape casting (FTC) processes from three clays labeled HCR, KORS, and KCR. These clays exhibited mass content of 77% halloysite–10 Å, 29% kaolinite, and 98% kaolinite minerals, respectively. After casting the slurries, the dried tapes were sintered at 1200°C. The microstructure changes were characterized before and after sintering using scanning electron microscopy. The apparent porosity of TC samples was lower (36–47 vol.%) compared to values obtained with FTC samples (67–79 vol.%). The latter samples exhibited a highly textured porosity, with micron-sized pores aligned perpendicular to the tape surfaces. Upon sintering, the porosity of TC samples tended to decrease conversely to the case of FTC samples. Such behavior seemed related to the simultaneous effect of organic additives and ice templating. Consequently, the FTC samples showed a relatively low mechanical strength of 3–7 MPa and thermal conductivity of .14– .22 W m⁻¹ K⁻¹. After sintering, the mullite crystallization contributed to strengthen the bulk materials, helping to compensate for the detrimental effect of porosity on the stress to rupture and on thermal conductivity values.     

阳泉市地下商业街基坑支护设计与施工

阳泉市地下商业街（人防工程），其基坑距两侧建筑物基础仅2．0m-4.0m。为保证周边建筑物的安全，需进行基坑支护。结合场地工程地质条件，经反复论证，决定采用悬臂式结构的稀疏单排灌注桩，并在灌注桩间注入水泥浆加固基坑周边土体。经实践检验，支护工程安全可靠，达到了预期目的。     

桥梁分层施工的结构分析

通过对桥梁支架法施工的简支梁桥分层浇筑混凝土形成的组合构件结构形式的分析讨论,提出设计和施工中应注意的结构问题。     

Influence of high pressure and manganese addition on Fe-rich phases and mechanical properties of hypereutectic Al−Si alloy with rheo-squeeze casting

The influence of high pressure and manganese addition on Fe-rich phases (FRPs) and mechanical properties of Al?14Si?2Fe alloy with rheo-squeeze casting (RSC) was investigated. The semi-solid alloy melt was treated by ultrasonic vibration (UV) firstly, and then formed by squeeze casting (SC). Results show that the FRPs in as-cast SC alloys are composed of coarse β-Al₅(Fe, Mn)Si, δ-Al₄(Fe, Mn)Si₂ and bone-shaped α-Al₁₅(Fe, Mn)₃Si₂ phases when the pressure is 0 MPa. With RSC process, the FRPs are first refined by UV, and then the solidification under pressure further causes the grains to become smaller. The peritectic transformation occurs during the formation of α phase. For the alloy with the same composition, the ultimate tensile strength (UTS) of RSC sample is higher than that of the SC sample. With the same forming process, the UTS of Al?14Si?2Fe?0.8Mn alloy is higher than that of Al?14Si?2Fe?0.4Mn alloy.