顶管施工技术在我国的历史与发展

文章对我国的顶管施工技术的发展历程进行了回顾与总结，对现状和存在的问题进行了分析，并预测了将来的发展趋势。     

预应力混凝土管桩螺纹机械快速连接接头技术

本文主要介绍预应力混凝土管桩螺纹机械快速接头的构造、连接技术,并探讨其发展应用前景。     

石油化工碳钢管线氩弧焊用国产焊丝的选择

通过国内近年研制的可用于低碳钢的氩弧焊丝TIG－J50、TIG－LD与国产H08Mn2SiA以及日本神钢的TGS－50焊丝在化学成分、机械性能、可焊性、耐腐蚀性等方面的对比，认为TIG-LD是国产较理想的低碳钢氩弧焊专用焊丝。     

Behavior of Open- and Closed-Ended Piles Driven Into Sands

Both the driving response and static bearing capacity of open-ended piles are affected by the soil plug that forms inside the pile during pile driving. In order to investigate the effect of the soil plug on the static and dynamic response of an open-ended pile and the load capacity of pipe piles in general, field pile load tests were performed on instrumented open- and closed-ended piles driven into sand. For the open-ended pile, the soil plug length was continuously measured during pile driving, allowing calculation of the incremental filling ratio for the pile. The cumulative hammer blow count for the open-ended pile was 16% lower than for the closed-ended pile. The limit unit shaft resistance and the limit unit base resistance of the open-ended pile were 51 and 32% lower than the corresponding values for the closed-ended pile. It was also observed, for the open-ended pile, that the unit soil plug resistance was only about 28% of the unit annulus resistance, and that the average unit frictional resistance between the soil plug and the inner surface of the open-ended pile was 36% higher than its unit outside shaft resistance.     

Analytical Solution for Fluid-Structure Interaction in Liquid-Filled Pipes Subjected to Impact-Induced Water Hammer

In this paper, an analytical solution for the four-equation model describing fluid-structure interaction in liquid-filled pipes subjected to impact-induced water hammer is presented. The analytical solution is derived for the case of both Poisson coupling and junction coupling. The results obtained from the analytical solution are in good agreement with experimental measurements and with numerical solutions determined by the method of characteristics. Taking advantage of the analytical solution, some features of coupled wave propagation are presented and discussed.     

WLF泥浆脱水机的研制

该 项研究成果将３项核心技术融为一体 :(１)采用了絮凝剂管道添加系统添加絮凝剂。该技术是在用絮凝法提取味精废水中的有用物质 ,并进行综合利用的研究中产生的 ,同时也进行了絮凝技术去除发酵液菌体的研究［１］和絮凝技术强化锰精矿浓缩脱水的研究。后一研究成果已应用于遵义选矿厂矿浆固液分离工艺中 ,已取得工业试验的成功［２］ ;(２)絮凝后的泥浆用复合固液分离器［３］浓缩 ,使浓度达４０%～５０ %;(３)浓泥再经特制的螺旋挤滤机提升、挤滤 ,浓度达５０ %～５５ %。绝大部分泥水得以澄清 ,达到排放标准并可在钻井中循环利用 ,最终…     

浅谈预应力钢筒混凝土管生产过程中的质量控制

即将开工的引黄工程国际Ⅳ标工程将采用国际上已广泛应用的预应力钢筒混凝土管，为了搞好该工程的管理工作，作者结合ＰＣＣＰ生产工艺的考察情况，提出了ＰＣＣＰ生产 的质量控制点及相关指标，以使工程管理人员对ＰＣＣＰ生产工艺及其质量控制有所了解，便于将来质量控制工作的开展。     

石化装置内管廊的布置与设计

结合工程设计实践经验,阐述石化装置管廓的布置与设计,主要包括管廓的高度、跨度和荷载的计算等方面的内容。     

四川高含硫气井集气管道的施工

四川卧－63井天然气含硫化氢32％，其含硫量目前是四川气田最高的。本文阐述高含硫集气管道的施工准则，介绍卧－63井集气管道的施工概况，其中包括管道的敷设、检验、阴极保护的设置及吹扫试压。     

Prediction of concentration and temperature profiles for non-isothermal ethane cracking in a pipe reactor

Thermal crackers are mostly modeled as plug flow systems, disregarding the lateral gradients present. In this paper, a 2-dimensional model has been established for ethane cracking in a thermal cracker in laminar flow, using a molecular mechanistic model for ethane cracking. The model, consisting of 9-coupled partial differential equations, is solved using the backward implicit numerical scheme. The resulting product distribution and temperature profiles are predicted throughout the reactor. The concentrations of acetylene and propylene show a maximum within the reactor. The effect of certain operational parameters — tube radius, wall temperature and mass flow rate — is also studied on these profiles. The parameters are varied in the range of 0.005–0.0125 m for tube radius, 1.25 kg/hr-2.5 kg/hr for mass flow rate and 850–1,050 ‡C for tube wall temperature. It is observed that an increase in wall temperature and an increase in tube radius or decrease in flow rate favours the conversion of ethane.