Advanced Materials Research Vols. 243-249

Abstract: A collision between a 2600 DWT oil tanker and the substructure of one railway continuous beam bridge is simulated using ANSYS/LS-DYNA. In the simulation, the dynamic interaction between the soil and piles is considered through contact coupling algorithm and nodes sharing algorithm. The time history of ship collision force, penetration and velocity of the ship for the two different algorithms are presented, and relations of them are given. In addition, energy dissipation in every parts, deformation response and stress distribution of the substructure are analyzed in detail. The results indicate that rules of ship-bridge collision given by the two algorithms are in good agreement. Finally, reliability of the simulation in this paper is demonstrated through the comparison with specifications.

Abstract: For an extra heavy oil reservoir with top water in Liaohe Oilfield, it is inefficiently and hard to produce by conventional thermal recovery. In this regard, the numerical modeling software – CMG is used to analyze the recovery of this reservoir by Steam-Assisted Gravity Drainage (SAGD) and Steam and incondensable gas-assisted gravity push (SAGP). The production indicators, development effects and distribution of field parameters of these two techniques are contrasted and analyzed, and the injection and production parameters for application of SAGP in wells are optimized. The study shows that, for this extra heavy oil reservoir with top water, SAGP is more effective than SAGD, and the former can reduce the steam demand, improve the oil/steam ratio (OSR), prolong the development and enhance the recovery. It is recommended, during application of SAGP on site, to inject nitrogen at volume fraction of 30-40% and when the steam chamber expands to a section with 1/3 net pay thickness away to the top water.

Abstract: In this paper, the main beam, which is one of the critical components of Horizontal Directional Drilling (HDD) GD2800-L, is selected as a subject investigated. The geometric model of HDD is firstly established, its static and buckling analysis are also taken to get the stress and deflection distribution, buckling mode and critical load by the ANSYS. Acquired results show that the working condition of main beam is mainly decided by HDD penetrating angle and the most dangerous working condition is its working at maximum penetrating angle. In order to decrease weight of main beam, its optimization design has been further completed, and 13 percent of main beam weight is reduced, but stress and deflection distribution increase slightly within bounds. The methods can greatly improve design efficiency and reduce steel plate consumption and product manufacturing cost.

Abstract: Building Energy Efficiency is one of the most important goals for green architectural design. Natural ventilation is a building energy efficiency technique adapting to the environment. Compared with air conditioning, natural ventilation can reduce the energy consumption and bring new air to indoor space. However, air environment, as an important aspect of building optimal design, can be ignored easily in traditional research, the quantitative analysis aiming at the energy efficiency of natural ventilation is less. In this paper, we use Fluent Air-pak software and Wenyuan Building of TongJi University as an example, to analyze the air flow field of indoor natural ventilation and provide the method and theory of air-environment design.

Abstract: In China, the construction industry has been developing rapidly over the past decades, at the same time, generating a huge amount of construction and demolition waste (CDW). The stream of CDW must be dealt with special attention, at least because of the shortage of landfill space for disposal and the need of sustainable development. This paper presents solutions to manage and control major type of building CDW in a technically feasible and economically efficient manner, with an example of Xi’an City. Recommendations are made in order to promote sustainable CDW management in practice.

Abstract: The "Interim Measures for Construction Quality Margin" gave the provisions on the terms of defect liability period. These provisions have serious negative effects on the construction contract management. This negative effect is manifested in two aspects: firstly, it is difficult for people to distinguish defects liability period, defects notification period in FIDIC contract, and the warranty period in the law. Second is to cause a heavier burden on the contractors. This paper analyzes both the negative impacts and causes.

Abstract: Common agency is the main feature of public sector’s internal incentive mechanism. As the public sector, endogenous features of PACE will lead to defects of internal incentive system. Regarding the public agent-construction enterprise as an agent of two principals which are client and government, a common agent model is constructed and analyzed in-depthly. The findings of this paper clarify two aspects of theoretical basis for the regulatory policy: 1) the optimal conditions of an incentive contract; 2) the substitution relationship of the tasks of two principals causes distortion to the incentive mechanism and leads to incentive efficiency loss.

Abstract: To illustrate that the application of ERP in construction industry is feasible and necessary, this paper analyzes the business process of construction industry based on the four development phases of ERP in manufacturing -- basic MRP, closed-loop MRP, manufacturing resources planning(MRP-II), enterprise resource planning(ERP), and compares the business process between construction and manufacturing. Finally it concludes that there exist many similarities in construction and manufacturing and implement ERP in construction industry is feasible to some extent.

Abstract: To ensure good operations of BOT project and to prevent the project company's "malicious operation" (overload production, not timely maintenance and repair, management of confusion, etc.), in the transfer phase a set of scientific methods and procedures for the identification must be established. Fuzzy comprehensive evaluation is a kind of evaluation method based on fuzzy mathematics, which makes the quantitative description of the vague concept, then the overall evaluation can be quantified, thus reducing the subjectivity and one-sidedness. In this paper, by the analysis and research on application of multi-layer fuzzy comprehensive evaluation method in the transfer phase of the BOT project, a set of work procedure and system of evaluation will be established, which provides ideas and methods for the practical application in the transfer phase .

Abstract: The Whole Life Cycle Engineering Costing Management is an effective method to minimize the cost of an engineering project for the whole life, including the construction period, the operation period and the removal period. In this paper, we divided the Engineering Cost into three parts of labor costs, material costs and machinery costs. We have built a River-influx Model to calculate the social discount rate for the future, based on historical data and using MATLAB software to fit curves. We can then calculate the whole Life Cycle Engineering Cost for the future.