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Behavior of Hostun sand for small stresses AbstractTraxial tests on loose and dense Hostun RF sand were carried out for confining pressures ranging between 20 and 100 kPa. Stress-strain curves are presented for drained, undrained and proportionnal strain path tests. They can be used as a tool to identify the constants of constitutive models, and test them on non-conventionnal paths. A one-test determination of the failure curve is also presented, which shows that the internal angle of friction is very much pressure-dependent in the low stress range. The variations of the angle of friction as a function of confining pressure and mean stress at failure are compared to usual correlations and results found in the literature for others sands. The variations of dilatancy angle and deformation modulus with confining pressure are also presented. These results show that constants of constitutive models should be identified, and models tested, for the range of stress in which models are to be used.

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Purpose -Pipe cooling is an important measure for controlling the temperature in mass concrete. Since the temperature field in mass concrete containing cooling pipes is unsteady and three-dimensional, and there are huge quantities of the cooling pipes in the concrete, the study of efficient and reliable algorithm is crucial. The purpose of this paper is to develop the composite element method (CEM) for the temperature field in mass concrete containing cooling pipes. Design/methodology/approach -Each cooling pipe segment is looked at as a special sub-element having definite thermal characteristics, which is located explicitly within the composite element. By the variational principle, the governing equation for the composite element containing cooling pipes is established. Findings -One of the remarkable advantages of the method proposed is that each cooling pipe can be simulated explicitly while the difficulty of mesh generation around cooling pipes can be avoided. Originality/value -The paper demonstrates how composite elements containing cooling pipes are degenerated to the conventional finite elements automatically when the first stage artificial cooling finished, and conversely, the conventional finite elements can also be transformed to the composite elements automatically when the second stage artificial cooling started. The comparison of the numerical example using FEM and CEM shows the rationality of the proposed method.

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Building information modeling (BIM) is the geometric way to present a life cycle construction project including geographic information. Recently, the Internet of Things (IoT) has been progressively used smart buildings in order to enhance living comfort, work productivity and entertainment. However, studies addressing the combination of these two technologies (BIM and IoT) focused on the automatic diffusion of data through sensors to BIM models [1]. Based on American College of Occupational and Environmental Medicine (ACOEM) a great portion of our time is spend inside buildings, in our offices, homes, schools, health care facilities, or in other private or public buildings. Hence the necessity to improve the basic human right to live in a healthy, safe and comfort environment is vital. This paper presents the use of BIM to support complex decisions concerning comfort conditions in buildings. This use is illustrated through a case study concerning a building of the AUST campus in Beirut.

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Augmented reality (AR) is based on supplementing the view of the physical world with a computer-generated content such as text, images videos, sound, 3D objects etc. The proliferation of smart mobile devices and their high computational capabilities combined with the possibility of GIS 3D visualization and interaction have enabled new kinds of mobile applications. AR is considered as an efficient technology for the underground utilities management. Damages to underground utility lines are considered as one of the major urban problems because incidents caused by unsafe digging practices can compromise community safety and disconnect people from vital services. A prospective study was conducted to identify examples and characteristics of each type of augmented reality. This paper summarizes researches about the types of AR and discuss how this technology could help in underground utilities repairing and maintenance. We present a new mobile location based augmented reality system using smart device sensors and the Real Time Kinematic (RTK) satellite navigation technology of ORPHEON network for the location accuracy. This system enables GIS data visualization to help field workers in outdoor maintenance of underground infrastructures.