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In soft soil areas, equal-length piles are often adopted in the retaining system. A decrease in the bending moment value borne by the retaining structure along the pile depth (below the excavation bottom), leads to an inadequate use of the pile bending capacity near the pile bottom. This paper presents retaining systems with long and short pile combinations, in which the long piles ensure integral stability of the excavation while the short piles give full play to bearing the bending moment. For further analysis on pile and bottom heaves deformations and inner-force characteristics, three-dimensional models were built in order to simulate the stage construction of the excavation. The ratio between long and short pile numbers, and the effects on short pile length pile horizontal deformation, pile bending moment and bottom heave are investigated in detail. In the end, a feasible long-short pile combination is established. Obtained results from the simulation data and the field data prove that the long-short pile retaining system is feasible.

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The management philosophy, namely, Customer relationship management (CRM) has been widely accepted and successfully applied across a range of sectors. However, there has been very little research efforts in the field of CRM in the construction industry. This paper provides a review of the CRM philosophy and technology, and considers the implications benefits and challenges to construction organizations at a strategic business and operational level. Given the generally unstable economic and highly competitive marketplace, implementation of CRM throughout the lifecycle of assets may provide for more effective management of existing and prospective clients. The CRM approach would seem to be compatible with general trends in the construction industry towards more collaborative working and the paper provides that both the philosophy and technologies can be integrated with current initiatives such as building information modeling (BIM). Construction clients in the public and private sector are diverse in nature, complex in their buying processes and at varying levels of knowledge of the Industry. In addition to seeking value for money from their projects and assets, they have become more concerned about sustainability and environmental impact. It has been recognized that management of a broader range of business and project level stakeholders is necessary.

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In order to improve the utilization of high liquid limit soil, the fundamental properties of high liquid limit soil and its direct utilization method are studied in this paper. This work involves both laboratory and fieldwork experiments. The results show that clay and sandy clay both with high liquid limit can be directly used for the road embankment, and the degree of compaction can be controlled at 88 %. The pack-and-cover method in accordance with Chinese technical specifications is recommended to be operated in the engineering practice. The packed height should be less than 8 meters and the total height of embankment no more than 12 meters in the interests of settlement. From the view of stability, the optimal thickness value of top sealing soil layer and edge sealing soil layer is about 1.5 meter respectively, and the geogrid reinforcement spacing should be about 2.0 meters. In addition, based on Yun-Luo expressway in China filled with high liquid limit soil, the construction techniques and key points of quality control in subgrade with pack-and-cover method are compared and discussed in detail, and the feasibility of these schemes are verified by the experimental results.

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To fully explain hydropower unit operational problems, an optimal multi-objective dynamic scheduling model is presented which seeks to improve the efficiency of reservation regulation management. To reflect the actual hydropower engineering project environment, fuzzy random uncertainty and an integrated consideration of the natural resource constraints, such as load balance, system power balance, generation limits, turbine capacity, water head, discharge capacities, reservoir storage volumes, and water spillages, were included in the model. The aim of this research was to concurrently minimize discharges and maximize economic benefit. Subsequently, a new hybrid dynamic-programming based multi-start multi-objective simulated annealing algorithm was developed to solve the hydro unit operational problem. The proposed model and intelligent algorithm were then applied to the Xiaolongmen Hydraulic and Hydropower Station in China. The computational unit commitment schedule results demonstrated the practicality and efficiency of this optimization method.

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This paper has applied operation research to solid waste disposal by which two objective functions are optimized to minimize the expected operational costs (maximize revenues) and the expected net carbon dioxide equivalent (CDE) emissions. Types and uncertain amounts of solid wastes as well as costs of electricity were factored into the selection decision of solid waste disposal, i.e. landfill, incineration, composting and recycling. An optimization model was applied to the solid waste disposal of Bangkok, Thailand. In addition, a multi-objective optimization technique was proposed for a tradeoff decision-making between minimum operational costs and CDE emissions. Composting and landfill are effective alternatives for Bangkok’s solid waste disposal system. The operational costs and net CDE emissions are highly correlated with the quantity of solid waste. Policy-makers and plant operators could adopt the proposed optimization model under uncertainty in the selection of an optimal solid waste disposal.

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The reinforced concrete bifurcation in hydropower station is consistently under high internal water pressure, and its diameter is usually larger than common duct junctions. In order to diminish or to decrease the heavy plastic zone and stress concentration, structure rounding is commonly used on bifurcation. This will bring some changes to the flow characteristic of bifurcation, and it is an interesting attempt to figure out the influence of structure rounding optimization. The Realizable k-ε model was employed in Computational Fluid Dynamics numerical simulation. The water pressure distribution was compared quantitatively at several certain sections. Furthermore, uneven pressure is analyzed by relative standard deviation. Hydraulic characteristics are discussed as well, including flow pattern, excavation volume and head loss in different working conditions. The results indicate that the pressure of pipe wall is uneven, and the maximum and minimum pressure value has a differential of 0.3% - 1.2% compared to relative static water pressure. The pressure unevenness will increase after structure rounding, and it has a positive correlation with structure rounding radius. At the same time, it is more reasonable for structure rounding in obtuse angle region than that in acute angle region, on account of well-distributed flow conditions and better economic benefit.