Volume 3 Issue 1
Authors: Aniculaesi Mircea; Lungu Irina; Stanciu Anghel
Abstract: The use of eco-cement (GGBS) is well established in many cement applications. The use of eco-cement in expansive soil stabilization is a new process in the geotechnical field. This paper reports efforts to extend the use of GGBS to expansive soil stabilization by determining the beneficial effect it has on the reduction of expansion and improvement of mechanical properties. The paper describes the results of laboratory tests on expansive soil treated with 10% eco-cement (GGBS) and Portland cement. The tests determined the strength development of compacted cylinders at different curing periods. The results illustrated that 50% replacement of Portland cement with eco-cement improved the substantially their strength development.
Keywords: Eco-Cement; Portland Cement; Expansive Soil; Stabilization
Authors: G.E Ekodeck; V. Kamgang Kabeyene Beyala; M.A Nankam; R. Medjo Eko; A.S.L Wouatong
Abstract: The Magha region located in the Bambouto caldera is a rainy and mountainous spot in Cameroon. Between 1954 and 2003, more than eight disasters due to landslides have been recorded in the area, among which six were catastrophic. An investigation for understanding the mechanism of landslide occurrence in that region was recently performed. The study included geomorphological, mineralogical and geotechnical characteristics of the local soil material. Soil profiles examined showed that lenses of sand are found within the soil mass. These lenses are seats of substantial pore water pressure during rainfalls and they contribute to triggering landslides. Specimens collected from soil profiles revealed that the soil material is made of mainly smectite, some kaolinite, halloysite, and illite. It is found that high plasticity and substantial expandability of smectite infer a significant lubricant capacity to the local soils, which decreases the shearing resistance and the safety factor of slopes, and consequently trigger landslides.
Keywords: Magha; Weathering; Saprolite; Smectite; Kaolinite; Landslide
Authors: Hideki Okamoto; Yasushiro Gomi; Hirokazu Akagi
Abstract: Hydrogen gas is expected to be a clean, environmentally friendly future energy source. As a method to supply hydrogen gas to a fuel cell station, the use of buried pipelines is being studied in Japan and elsewhere. To realize this idea, ensuring safety is very important. Specifically, the understanding of hydrogen gas movement characteristics, including the extent and speed of movement within the ground in the event of a hydrogen leak, is extremely important, as is the reliability assessment of pipeline materials in order to establish the basis for the design and maintenance of safe facilities. To establish a foundation for ensuring the safety of buried hydrogen supply pipelines, full-scale experiments on underground hydrogen gas leakage and numerical simulation were performed. The release and movement characteristics of hydrogen gas within soil were investigated and measured with the objective of establishing hydrogen gas leak detection technology.
Keywords: Road Base; Buried Pipeline; Partially Saturated Soil; Hydrogen Gas Permeability
Authors: Shahin Nayyeri Amiri; Masood Hajali; Asad Esmaeily
Abstract: Overhanging slabs of bridges are the most sensitive part of the bridge deck, because they have to tolerate high moments and shear forces acting on the cantilever part. So, the behaviors of bridges with overhanging slabs under concentrated loads are complicated. Several load mechanisms can develop depending on the loading and the geometry of the structure. The overhanging slabs of spine beam bridges can be treated as infinite or semi-infinite cantilevers. In this paper, cantilever slabs of varying or constant thickness, with or without edge reinforcement are analyzed under the action of an arbitrary placed point load. The structural actions of spine beam bridges are composed of interacting between the longitudinal behavior and transverse behavior. Therefore, solutions were obtained by means of Fourier Integrals for the deflection, rotation, moment and shear values along the longitudinal and transverse sections of the cantilever. The numerical calculation was done in MATLAB program. Also, a Finite Element analysis was performed using ANSYS to exhibit the accuracy of the numerical solution.
Keywords: Exact Solution; Overhanging Slabs of Bridges; Arbitrary Concentrated Load
Authors: Valentino Rondello; Giuseppe Campione; Calogero Cucchiara
Abstract: In this study, the load carrying capacities of glass columns with rectangular, T and X cross-sections having different lengths were calculated. The proposed analytical procedure allows to calculate the load carrying capacity associated with strength of transverse cross-section including local and global flexural and/or torsional buckling phenomenon. Moreover, initial imperfections and time dependant effects, the latter associated with the viscoelastic behaviour of interlayer (PVB), were included in the model as suggested in the literature. Those effects were calculated by introducing the equivalent thickness of glass panels, which takes into account the shear modulus of PVB and the viscoleastic behaviour of a composite. Failure of the glass panels connected with structural silicone was not considered. Experimental research recently conducted by the authors was utilised for comparison with the analytical prediction. Cases of study were those of compressed glass panels constituted by single tempered glass jointed between PVB, and compressed members having T or X tranverse cross-sections and constituted by single layered panels jointed between structural silicone. The analytical model had good prediction accuracy, and the experimental results were in agreement with the failure modes observed experimentally.
Keywords: Laminated Glass; Glass Members; Theoretical Model
Authors: Ogundipe Olumide Moses
Abstract: This study investigates debonding effects on the performance of stress absorbing membrane interlayers (SAMIs) against reflective cracking. This was achieved by carrying out finite element modelling of a typical specimen used for a wheel tracking test. In the modelling, the loads were applied at two points (centre and edge) on the specimen. The predicted results (deflection and strain) were compared with those measured in the laboratory tests. The results showed that the predicted results for the debonding cases matched those measured better than the fully bonded cases. This indicates that the debonding of the interface is expected in a real pavement incorporating SAMIs. Also, the results showed that there was no benefit in using thick SAMI over thin SAMI. It was found that the predicted deflection, strain, and stress increase with increasing temperature.
Keywords: Finite Element; Overlay; Debond; Displacement; Strain; Stress
Authors: Azzedine Yahiaoui
Abstract: Demand for distributed simulations between control modeling and building performance applications is rapidly growing as the preferred means for supporting design studies of Automated Buildings (ABs) that are becoming increasingly complex because of urgent needs for developing sophisticated improvements in building indoor environments. In order to overcome problems in meeting the occupants’ needs while reducing energy use and greenhouse gas emissions, it requires using distributed simulations to study the impact of advanced control strategies on building performance applications through virtual representations rather than using experiments, which are usually time-consuming and cost-prohibitive. For this reason, this paper mainly describes the development and implementation of a framework for distributed simulations involving different software tools over a network. The main role of this framework is analogous to a cooperative middleware that distributes one or more building performance simulation tool(s) and control modeling environment by run-time coupling over a network as qualified by similarity to Building Automation and Control Systems (BACS) architecture. The paper finishes by giving an outlook on the present work for further developments.
Keywords: Systems Engineering; Distributed Dynamic Simulation; Building Performance Applications; Control Systems; Automated Building; Building Automation and Control Systems