Applied Mechanics and Materials Vols. 548-549

Abstract: Dynamic compaction is a widely used foundation reinforcement technique. But the energy of the foundation spreading around in the earth by the form of wave will produces bigger effect of vibration on the surrounding environment. It brings a lot of adverse effects to nearby residents life, work, and even to the safety of the surrounding buildings. In actual engineering, we often determine the feasibility of the dynamic compaction construction scheme by the compaction test, which is time-consuming and laborious. Based on the monitoring of stadium area soil compaction in the new campus of Wuhan University of Technology, we use dynamic finite element software named LS-DYNA to simulate the dynamic compaction construction and establish a set to conform to the model parameters of the actual project. We can change the tamping compaction model according to the different adjusting scheme to guide the construction.

Abstract: A complex or unstructured problem is based on multi criteria not on a single criterion. A contractor selection problem is a multi-criteria problem. A correct decision-making is required for selecting the appropriate contractor for a construction project. Selection of a contractor is a key decision made by clients and the process of selection a contractor has become an important issue in construction projects. Many multi-criteria techniques have been proposed and applied to such problems solution. This paper aims to propose integrated model for MCDM. The integrated model contains two stages. First stage integrates two MCDM methods are AHP and ANN to prepare a shortlist of the best alternatives. Second stage apply statistical model COP to choose the optimum alternative from the best alternatives in a shortlist. Proposed model for tendering system provides automated a decision-making process that reduces the time and manpower requirements for processing tender

Abstract: The performances of the concrete structure with expansive additives are studied in this research. These expansive additives have helped in reducing the generation of cracks and have showed improved durability. This research evaluates the performance of actual structures through reviews of existing techniques with air permeability, surface water absorption, measurement of distortion of the actual structure and building surveys. The upshot of shrinkage, the significance of restraint and service life in reinforcement is observed in actual structure using concrete with expansive additives. The methods was found that it has a relatively dense surface quality and durability of the concrete structure is said to have endurance level of the planning period.

Abstract: In Kingdom of Saudi Arabia (KSA), the contribution from buildings towards energy consumption, both residential and commercial, has steadily increased reaching figures of 35% to 40% in the past few years. For this reason, energy efficiency in buildings is a prime objective for energy policy at regional, national and international levels. This research aims to provide design guidelines for buildings in Saudi Arabia taking into consideration the energy conservation principles. The proposed design parameters/guidelines are supported by computer simulation results of the software named “eQUEST” (Quick Energy Simulation Tool). This paper specifies minimum thermal resistance for walls and roofs, size and quality for glazing and performance standards for air conditioning (AC) systems.

Abstract: Taking a typical cylindrical solid pier as example, this paper utilizes the way of additional mass to consider the influences of hydrodynamic pressure on piers. It establishes dynamic response comparative analysis of single pier model under different earthquakes’ motivation taking ANSYS finite element software as computing platform. This draws conclusion that hydrodynamic pressure keeps characteristics of changing the seismic response of piers in which pier top displacement and pier bottom internal force are increased. Also it acquires the conclusion that weight and cycle of structure are related to the effect of hydrodynamic pressure. Through analyzing continuous beam bridge and continuous rigid-frame bridge, it is verified that there exists close relationship between effect of hydrodynamic pressure and inherent cycle of structure in which the higher inherent cycle becomes, the lower influence hydrodynamic pressure keeps on structure.

Abstract: To evaluate the compatibility between polycarboxylates high performance water-reducing admixture and cement, the initial Marsh-time or fluidity(T), loss rate of fluidity as time(FL), saturation point(P), setting time(ST) and bleeding rate(R) are considered simultaneously. Making the comparisons of these parameters between tested concrete and reference cement, the corresponding membership functions are established, and using the fuzzy mathematical evaluation method based on the program Matlab, breaking the limitation of reference cement, the more comprehensive and accurate evaluation can be made.

Abstract: The tree-like structure is a branch of space bionic structures,belonging to the Bionic Architectural Structures. Cast-steel joints with branches are the keys to build the tree-like structures.They are used widely,and the most common joints in our projects are cast-steel joints with two、three and four branches. The cast-steel joints with two branches are planar,while the joints with three and four branches are spatial.Until now,the basic theoretical researches about the cast-steel joints with branches are also relatively scarce.This paper did researches about mechanical properties, calculation methods and structural optimization of the cast-steel joints with three branches deeply and systematically. The result shows that the bending moment has a big influence on the value of the max stress. And the three main failure modes of the cast-steel joint with three branches are yield of the main tubular along the axial direction, local buckling at the connection of the main tubular and branches, and the tearing out of the branches.

Abstract: To explore the noise generated by bridges during operational period, the equivalent continuous sound pressure levels of 12 bridges in the city of Ningbo were measured and analyzed. The measured data show that (1) Although the measured sound levels of these bridges meet the requirement of Chinese codes, they are near the maximum limit and the vibration and noise reduction is necessary; (2) A-weighted sound level of bridge is close to that of the road nearby; (3) Z-weighted sound level of bridge is much greater than that of the road nearby, it indicates that the bridge noise contains much low frequency noise, so that A-weighted sound level can’t reflect the noise of bridge accurately, and Z-weighted sound level shall be used to evaluate the acoustic environment near bridges.

Abstract: When we think of paper-folding, we usually think first of the name that is usually associated with it: origami. But in the field of architecture, origami is more than just imagining an animal or flower which is what this word usually brings to mind. In architecture, we extend the meaning to take in the real essence of the word – that of great structural and constructional loads. The basic unit of origami – the fold – allows us to start manipulating space and even to create space itself. Paper-folding, with its spatial modelling potential, is to three-dimensionality what drawing is to two-dimensionality. It is after all an ancient Japanese art which encapsulates the advantages of intuitive thinking and fast modelling, once the basic elements of folding are known. Heino Engel (2001) in his book “Structural Systems”, describes intensive studies on types of structures which derive from this systematization. And the architect Ming Tang often uses structures in his projects which clearly originate in the concept of origami, and he correlates these structures with sustainable materials. The architect Michael Hansmeyer manages to incorporate all the beauty of the action of folding with the help of a computer, where the final result is a shape that approaches a real application at an architectural level. Over time, there have been numerous people who have found a relationship between the harmony and proportions of paper-folding and their own studies and projects. What is missing is a single point where clear concepts on the possibilities of folding and the results of those who have experimented with it can be brought together. This cataloguing, which is being carried out in this Master’s dissertation, is intended to be a contribution to the design method in architecture, through which the architect may achieve spatial dexterity over a piece of paper.

Abstract: The badminton gymnasium of Beijing University of Technology is the main built gymnasium for Olympic Games in 2008 in Beijing. Based on the design requirement, the velocity in the playing-field should be less than 0.2m/s in the region of 9m above the playing-fields ground. To guarantee the design requirement, this paper uses the methods of Computational Fluid Dynamics (CFD) technology and field test to optimize and modify the original design of the cavity’s structure. After optimization and modification, plenum makes obvious sense on air distribution of structure of the cavity, which guarantees the 9100 swirl diffusers uniform air supply under the grandstand seats, the velocity in the playing-field is less than 0.2m/s, which meets the design requirement. The results can be referred to optimization design of air-conditioning ventilation system in large badminton gymnasiums.