PPP项目工程造价管理存在的问题及应对

在我国工程建设迅猛发展下,资金运作方式越发多样化。当前,我国很多大型工程建筑,特别是基础设施建筑项目频繁运用PPP模式,而政府付费、项目自身资产运营收益、使用者付费等等属于PPP项目贷款的主要还款来源,其工程项目收益是尤为关键的一部分,所以应从整体上做好造价管理,确保最大化项目建设投资效益。基于此,本文主要对PPP项目工程造价管理存在的问题及应对进行了探讨。     

Analysis of the Superconducting Cable Transposition in Low Resistance CICC Joint

1. IntroductionWhen making an integrated structure CICC joint,only a part of the cable surface getting into touchwith the Cu sole is soldered with 60Sn40Pb ) the interior of the cable is not full of solder. Especially forthe Cr-coated strands of the cable, in order to reducethe AC losses, only the outside Cr coating on the surface of stranded cable getting into touch with the Cusole is removed, while those inside the stranded cableare not removed. For the PF coil conductor, the 0.05mm st…     

双钢板-再生混凝土组合剪力墙抗震性能有限元分析

为研究双钢板-再生混凝土组合剪力墙的抗震性能,在已有试验的基础上,使用有限元软件ABAQUS进行模型验证和分析,研究内容包括再生粗骨料取代率、距厚比、轴压比以及连接件形式.结果表明:(1)随再生粗骨料取代率的增加,试件抗弯承载力、抗剪承载力、初始抗侧刚度均出现不同程度的劣化;(2)当轴压比为0～0.5时,试件承载力随轴...     

栓钉连接双钢板-混凝土组合剪力墙抗剪性能数值分析

双钢板-混凝土组合剪力墙结构是一种新型高层建筑抗侧力构件,具有良好的应用价值和发展前景。根据其他学者的试验结果,结合相关文献中连接件的剪切滑移公式,拟合得出抗剪栓钉的剪力-滑移关系,并通过有限元软件ANSYS建立了双钢板-混凝土组合剪力墙的有限元模型。以分析组合剪力墙的剪切性能为目的,采用相关假定简化模型并与已有试验结果对比,验证有限元模型的合理性。采用验证过的有限元模型进一步对双钢板-混凝土组合剪力墙的抗剪性能进行非线性分析,研究抗剪栓钉间距、钢板厚度、混凝土板厚度、混凝土强度等级及组合剪力墙跨高比等主要参数的影响。数值结果表明,钢板、混凝土板厚度以及混凝土强度对双钢板-混凝土组合剪力墙的抗剪承载力的影响最显著,而栓钉间距会影响组合剪力墙的受剪破坏模式。     

Design and Manufacture of Full-Size Testing Joints for EAST

The conductors of both the toroidal field （TF） and poloidal field （PF） coils of EAST are NiTi cable-in-conduit conductors （CICCs）. The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm respectively. A relevant R＆D program has been carried out for three years at the Research and Manufacture Center （RMC） of the Institute of Plasma Physics, Chinese Academy of Sciences （ASIPP） to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals＇ super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape. Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.