Advanced Materials Research Vols. 168-170

Abstract: The application of Phase Change Material (PCM) to asphalt mixture can lighten the temperature-dependent disease of the asphalt pavement and improve the usability as well as extend the operating life of it. We choose agreeable PCM with comprehensive consideration to the technical requirement of its application in the construction industry and the characteristic of asphalt mixture. Through simulating temperature experiment, we make a conclusion that incorporate the carrier accompanied PCM into asphalt mixture can reduce the increasing rate and cooling rate of the mixture, which shows that PCM can put into use of adjusting the asphalt mixture operating temperature, softening the negative influence of ambient temperature variation on asphalt mixture.

Abstract: According to the practical project, settlement, reaction and bending moment of composite foundation with rammed soil-cement pile are recalculated, which based on the change of the original area replacement ratio, pile length and foundation thickness. The method of optimum design study on leveling variable Stiffness is investigated.

Abstract: Based on analyses on mineral composition, mechanical property and hydrology property, three kind of samples are made in both drying state and saturated state respectively. Large-scale triaxial shear test, compression test and vibration test are applied on these samples. Through comparative analysis of test data, wet-chemical property of the samples is studied. Studies show that three samples have wet-chemical property in saturated state, which appears as decreasing of strengthen and increasing of deformation. Mechanism of wet-chemical property is also studied in two ways. On the one hand, filling particles is lubricated by water and re-construction of structure takes place between particles. On the other hand, soften and wet-chemical properties of mineral component are the internal factor causing the deformation. At last, some suggestions are given on construction of roadbed filled with this highly weathered rock.

Abstract: Differential Evolution (DE) is a new algorithm. Displacement back analysis method based on the algorithm can effectively solve the problems of rock mechanics parameters which are not accurate. Constitutive integration algorithm divided into explicit and implicit integration is the key points of finite element analysis, which affect the convergence and accuracy of the results. Return mapping algorithm avoiding directly solving the equivalent plastic strain is a kind of implicit integration algorithm, which would achieve rapid and accurate for the solution of constitutive equations. This article describes the theoretical framework based on elastic-plastic, von Mises yield criterion conditions, using C + + language to carry out plastic simulation of Dalian metro station CRD excavation and parameter identification based on differential evolution algorithm. The calculated stress, displacement and deformation can determine the surface subsidence and the development of plastic zone, the stability analysis to provide a reference for the construction.

Abstract: A new anti-freezing method for construction joints in tunnels is put forward through effective drainage ensured by heating with warm air or ribbon heater. The heating system is intelligently controlled according to the monitoring and analysis of the surface temperature of the secondary lining. This method is characterized as the following: (1) preventing leakage without pressure increase is realized through effective drainage at the back of secondary lining with special drainable channels; (2) alternative heating resources including warm air and electrical energy are offered to heat the region around construction joints, which can prevent the drainable channels from freezing and jamming; (3) for efficient and economy purpose, heating can be carried discontinuously as well as partly at circumferential and longitudinal direction. Numerical simulations validate the availability of heating method for anti-freezing.

Abstract: In this paper, a new Indirect tensile tester (IDT) which can be cooperated with Industrial Computered Tomography (IDT) is developed. The new tester uses a set of sliders to transfer the vertical stress to hoop stress which applied to a hollow cylindrical sample. The micro-crack will be appeared and propagated in the weakest direction of hollow cylindrical sample with the increase of vertical stress and tensile strength can calculated with the maximum vertical stress. Due to the existence of central slider, the stress state of hollow cylindrical sample will be kept even after unloading and the mixture sample would not have recovery when it is moved for scanning with ICT. The test results show that the combination of the developed ICT with IDT will help obtain more useful information on understanding the nature of asphalt concrete with different tensile damage stages.

Abstract: This paper analyzes the interface problems of underground pipelines including pipe-soil contact interface and fluid-solid coupled interaction using finite element analysis software ADINA. In this analyzing work, the influence of site, fault and characteristics of pipelines are comprehensively considered. Then some key parameters greatly affect the failure of pipelines are present and some suggested countermeasures are put forward.

Abstract: The open-sea terminals are in bad natural conditions which cause mooring line failure and sudden vessel movement. Such an accident can lead to costly damage to cargo handling equipment or other nearby vessels and structures, oil pollution. Therefore, this paper proposes a multi-criteria fuzzy optimization model of open-sea oil terminal's layout. The model is to improve port operations and safety by considering line tensions and theirs non-uniformity coefficients, and vessel motions as criteria. Finally, its application of optimizing the layout of open-sea oil terminal is also given, and the results show that the proposed model is applicable in structural optimization.

Abstract: Basing on the particular characteristics of corrugated pipe heat exchanger, the calculation method of the submersible corrugated pipe sewage heat exchanger is put forward and set up the computational procedure. By using the urban sewage heat exchanger recovery system, the accuracy of design procedure is to be test. The test results show that the sewage heat exchanger designed by this way can satisfy the heat load for building. The optimization design and engineering application can be provided technical parameters of this research.

Abstract: To effectively evaluate the safety of houses and buildings, and its owners, users and managers in the usage and management of the process to provide guidance, establish the detailed impact of the third-level buildings safety evaluation index system. Based on the fuzzy theory, used AHP to determine the weight of each index and establish a housing building security fuzzy comprehensive evaluation model. Use this model to execute the security of a middle school as an example and the results shows that the evaluation method is feasible, scientific and reasonable.