论对项目工程造价的有效控制

本文主要讨论了建筑工程项目造价存在的问题,并提出了各个阶段造价控制的方法,希望对以后项目工程造价控制有所帮助。     

工程成本控制管理与实战

本文对建筑工程企业施工阶段的成本进行了详细地探析,并提出了加强工程成本管理与控制的一些策略,以期能给相关工作人员一些建议。     

A linear programming model for cash flow management in the Brazilian construction industry

A linear programming model has been developed for optimal cash flow management addressing specific cash flow issues related to the construction industry. These include typical financial transactions, possible delays on payments, use of available credit lines, effect of changing interest rates, and budget constraints that often occur in the construction industry. A small size project from the Brazilian construction industry is provided as a case study, aiming at evaluating the potential benefits from using the model. Different changes to the basic structure of the model allow and establish the consistency of the results. Alternative formulations are suggested to deal with uncertainties, longer planning horizons, and multiple subcontractors and suppliers. In addition to the tangible financial earnings derived from the optimization process, the simple structure of the model, as a network flow and corresponding equations, provides much visual insight concerning the relationships between the external inputs and the variables of the problem. Optimal results have yet to be achieved in a real life situation, but a better view of whole cash flow management is provided when using the model.     

Reducing the use of resources in medium-sized Swedish construction enterprises: production managers’ views

What construction firms do—and do not do—to reduce the use of resources in construction projects is explored by adopting production managers’ views of their firms’ onsite activities. A literature review and empirical data are combined; 15 production managers have been asked how they perceived their company’s compliance with 31 recommendations to reduce the use of resources. The managers perceived their firms to primarily focus on identifying their customers’ real needs, stimulating employees to undertake further education, and striving for long-term customer–supplier relationships. In contrast, they perceived that less attention was directed to making use of all of the week’s hours, to supporting their main suppliers in their development, and planning feedback and training after project completion. The use of resources is examined by focusing on the perceived low priority given to gathering information and knowledge, as well as to reducing time and the need for long-term relationships with customers in contrast to short-term relationships with suppliers. The managers adopted a project-specific approach mainly to the use of material resources. A more holistic view of resources could enable the development of novel solutions in construction.     

The principal factors affecting construction project overhead expenses: an exploratory factor analysis approach

Estimation is the first step in the project development process. Information technology provides an efficient platform for estimators to obtain quotations and specifications for their bid estimates. However, in practice, project overhead estimation relies heavily on the professional judgement and intuition of the estimators. This reduces the overall accuracy and reliability of the bid and a better understanding of the factors affecting project overheads is fundamental before any improved estimating methods can be devised. Unfortunately, the published literature on this topic is very limited. Using exploratory factor analysis, we aim to bridge the current knowledge gap by highlighting the principal factors affecting project overheads. Questionnaires detailing 27 variables were sent to quantity surveying managers of large contractors in Hong Kong. Seventy-nine valid responses were analysed by exploratory factor analysis. From the results, eight factors were extracted with their latent properties identified with reference to the expert opinions collected from telephone interviews. The findings clarify some misconceptions about the factors affecting project overheads and provide useful evidence for practitioners and researchers to understand project overheads. Estimators who address the identified factors when assessing future project overhead costs can improve the accuracy of their cost estimates and project budgets.     

消火栓泵远程控制分析

分析多幢建筑物合用消火栓泵房的原因和存在的问题,结合工程案例分析计算多幢建筑远程控制消火栓泵的线路压降和消防控制室启停、信号反馈等问题,对现有标准图集中的控制电路图进行修改以解决线路安全和线路压降的矛盾,并对修改后的控制电路图使用注意事项进行说明。     

高层Loft建筑的暖通设计要点

对高层Loft建筑的防排烟系统、冷热源、末端系统设计过程中的要点进行了较详细的阐述,为高层Loft建筑的暖通设计提供了参考,同时对高层Loft建筑中需要预留条件进行了叙述。     

常见电气二次控制原理图设计思路

结合工程案例图．对常见的电气二次控制原理图的基本设计思路、易被忽视的细节问题,以及常见控制电器二次图的设计特点、常用备用相互切换互锁原理进行说明。     

基于温度应力效应下大体积混凝土裂缝防控策略探析

温度应力效应是大体积混凝土裂缝形成的一个重要原因,应当引起施工技术人员的重视.在温度裂缝的防控措施中,应重视施工方案设计、优选原材料、施工中质量控制和养护等.施工技术人员应根据工程具体情况,结合多种预防处理措施,制定合理可行的大体积混凝土施工方案和周密的技术措施,从而确保工程质量.     

抗震混合试验中预测-校正加载控制方法研究

为使抗震混合试验中电液伺服作动器加载与有限元分析同步进行,国外研究者将预测-校正加载控制方法引入该试验中,但在高频率模态或远离区间左端点处作动器命令信号的精确性不高。为提高该技术的精确性,本文对采样时间间隔内加速度变化规律的假设,以当前步的位移和速度为初始值,对加速度进行二次积分且以五阶精度的一、二阶导数作为速度、加速度,得到预测-校正表达式(PCVA-β),运用绝对误差限判断各种算法的精确性。使用Matlab/Simulink编程仿真模拟,结果表明:在较高阶频率且远离区间左端点处,这种方法不仅精确性较好且作动器能够连续平稳的运行。