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Showing 11 results for GE

Mohammad T. Dastorani, NiGEl G. Wright,
Volume 2, Issue 3 (September 2004)
Abstract

In this study, an artificial neural networks (ANN) was used to optimise the results obtained from a hydrodynamic model of river flow prediction. The study area is Reynolds Creek Experimental Watershed in southwest Idaho, USA. First a hydrodynamic model was constructed to predict flow at the outlet using time series data from upstream gauging sites as boundary conditions. The model, then was replaced with an ANN model using the same inputs. Finally a hybrid model was employed in which the error of the hydrodynamic model is predicted using an ANN model to optimise the outputs. Simulations were carried out for two different conditions (with and without data from a recently suspended gauging site) to evaluate the effect of this suspension in hydrodynamic, ANN and the hybrid model. Using ANN in this way, the error produced by the hydrodynamic model was predicted and thereby, the results of the model were improved.
M.h. Sebt, A. GErei, H. Naghash Toosi,
Volume 7, Issue 3 (Sept. 2009)
Abstract

Risks mean cases of uncertainty of project, the impact of which is realized as a threat (negative aspect) and/or opportunity (positive aspect). The traditional viewpoint on risk is a negative viewpoint that implies damages, loss and harmful consequences. Judgments such as this on risk merely emphasize on risks management and pay less attention to opportunities management. It is clear that some uncertainties might be profitable for the project as in many cases, it could be the source of loss. In a developed attitude, focus is made on a common process that could address the integrated management of both opportunities and risks to aim at maximizing the positive effectsopportunities-, and minimizing negative effects- risks-. Therefore, existence of causal-effect relations between risks, relationship, effects of risks and opportunities on each other and variety of strategies in facing risks gives no alternative for risk management team than taking integrated management of risks and opportunities. In another word, reaction to risks, with respect to risks and/or relevant opportunities, separately, will be never effective. In this paper, for the purpose of integrated management of risks and opportunities, the stages of quality analysis and reactions to risk are combined. The method which is used for reaction towards risk is a procedure based on dynamic system. Dynamic system is highly important among uncertainties due to considering the type and intensity of effects. By using dynamic system and attention to the relationship between uncertainties (risks/ opportunities), reaction to risk and decision making on employing suitable strategies to face risks will be more precise and accurate.
Gonçalo Sá, João Sá, JorGE de Brito, B. Amaro,
Volume 12, Issue 2 (Transaction A: Civil Engineering, June 2014)
Abstract

This paper presents an inspection and diagnosis system customized for rendered walls, both interior and external. It classifies all anomalies capable of affecting renderings and most of the likeliest corresponding causes and is supplemented by anomaly-cause and inter-anomaly correlation matrices. In addition, the diagnosis, repair and maintenance techniques suitable for these anomalies are classified. Examples of the files that contain the exhaustive characterization of the anomalies and diagnosis, repair and maintenance techniques are also presented. The system is the result of an intense literature review, which allowed collecting and organizing the information available on pathology of renders. Next it was validated by mathematical manipulation of the data collected from standard inspections of 55 buildings, in which 150 renderings (100 exterior and 50 interior) were examined. The system proposed may be included in a proactive maintenance strategy, since it is robust, reliable and has been statistically validated. The systematic structure of this system is innovative and can help the inspector by making his/her work more objective and standardizing procedures. Anomalies in wall renderings may be prevented/minimized if buildings are properly managed by developing and implementing proactive maintenance plans that cover the following areas: technology (adequate maintenance and repair solutions, including the selection of materials and execution techniques), economy (minimizing running costs) and functionality (appropriate use).
Fabrizio Palmisano, AnGElo Elia,
Volume 12, Issue 2 (Transaction A: Civil Engineering, June 2014)
Abstract

The increase in the computational capabilities in the last decade has allowed numerical models to be widely used in the analysis, leading to a higher complexity in structural engineering. This is why simple models are nowadays essential because they provide easy and accessible understanding of fundamental aspects of the structural response. Accordingly, this article aims at showing the utility and effectiveness of a simple method (i.e. the Load Path Method) in the interpretation of the behaviour of masonry buildings subjected to foundation settlements due to landslide. Models useful for understanding brick-mortar interface behaviour as well as the global one are reported. The global proposed approach is also validated by using Bi-directional Evolutionary Structural Optimization method. Moreover, drawing inspiration from a case study, the article shows that the proposed approach is useful for the diagnosis of crack patterns of masonry structures subjected to landslide movements.
D. F. Cao, W. J. GE, B. Y. Wang, Y. M. Tu,
Volume 13, Issue 1 (Transaction A: Civil Engineering March 2015)
Abstract

In order to investigate the flexural behaviors of RC beams after freeze-thaw cycles, compressive strength test of concrete cubes after 0, 50, 100, 125 freeze-thaw cycles were made, and static flexural experiment of 48 RC beams after 0, 50, 100, 125 freeze-thaw cycles were made. The relationships of relative compressive strength, mass loss rate, relative dynamic elastic modulus and numbers of freeze-thaw cycles were analyzed. The influences of different numbers of freeze-thaw cycles on the flexural behaviors of RC beams with different concrete grades were studied. The results show that concrete cubes’ mass, relative dynamic elastic modulus and compressive strength decrease with the increasing of freeze-thaw cycles, and high-strength grade concrete could slow down the damage caused by freeze-thaw cycles. Experimental values of test beams stiffness under short-term load were smaller than theory value. Some under-reinforced RC beams occurs over-reinforced failure mode after freeze-thaw cycles. Boundary reinforcement ratio of RC beams after certain numbers of freeze-thaw cycles was derived and its correctness was verified by experiment. Current code for design of concrete structures about crack load and ultimate load are still suitable for RC beams after freeze-thaw cycles.
Ch. Preece, H.y. Chong, H. Golizadeh, J. RoGErs,
Volume 13, Issue 3 (Transaction A: Civil Engineering, September 2015)
Abstract

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.
Mohsen GErami, Ali Kheyroddin, Abbas Sivandi-Pour,
Volume 14, Issue 1 (Transaction A: Civil Engineering 2016)
Abstract

Steel-concrete hybrid systems are used in buildings, in which a steel structure has been placed on a concrete structure to make a lighter structure and have a faster construction. Dynamic analysis of hybrid structures is usually a complex procedure due to various dynamic characteristics of each part, i.e. stiffness, mass and especially damping. Dynamic response of hybrid structures has some complications. One of the reasons is the different stiffness of the two parts of structure and another reason is non-uniform distribution of materials and their different features such as damping in main modes of vibration. The available software is not able to calculate damping matrices and analyze these structures because the damping matrix of these irregular structures is non-classical. Also an equivalent damping should be devoted to the whole structure and using the available software. In the hybrid structures, one or more transitional stories are used for better transition of lateral and gravity forces. In this study, an equation has been proposed to determining the equivalent uniform damping ratio for hybrid steel-concrete buildings with transitional storey(s). In the proposed method, hybrid buildings are considered to have three structural systems, reinforced concrete, transitional storey and steel. Equivalent uniform damping ratio is derived by means of a semi-empirical error minimization procedure.


JorGE Garcia-Sosa, Ismael Sanchez-Pinto, RoGEr Gonzalez-Herrera, Eduardo Escalante-Triay,
Volume 15, Issue 1 (Transaction A: Civil Engineering 2017)
Abstract

Based on the methodology of “Understanding by Design”, UbD, the course “Design of Hydraulic Structures” was developed and implemented. A series of learning experiences, with emphasis on hydraulics and hydrology, for civil engineering undergraduate students is presented that encourages the development of high technical and scientific competence, communication skills oral and in written, the ability for teamwork and the capability to learn. The experiences were designed, using the above methodology, based on learning that is desired. Once taught the course, the results obtained were compared based on the planned framework (expectations), the characterization of the student population, the course products as well as the activities, according to the students, considered relevant in the learning process.


Takayoshi Maruyama, Hideaki Karasawa, Shin-Ichiro Hashimoto, ShiGEyuki Date,
Volume 15, Issue 2 (Transaction A: Civil Engineering 2017)
Abstract

Pre-cast concrete products are sometimes manufactured in 2 cycles per day with one mold for the purpose of productivity improvement and so forth. In such a case, from the point of view of securing early-time strength which is required at the time of demolding, it is necessary to increase steam curing temperature and then the likelihood of temperature cracking becomes a concern. Moreover, self-compacting concrete (hereinafter refer as “SCC”) is increasingly used to which ground granulated blast-furnace slag is added, in consideration of environment surrounding a plant or operation environment. One choice then is to admix expansive agent in order to prevent cracking due to autogenous shrinkage. However, there is some possibility that high temperature curing required for 2 cycles per day production likely enhances cracking due to expansive agent admixing. In this study, the cause of cracking of large-sized pre-cast concrete products with high amount of expansive agent, in comparison of 1 cycle per day and 2 cycles per day productions was investigated.

As the result, it was confirmed that high temperature steam curing and early demolding of 2 cycles per day production promote thermal stress cracking in contrast to 1 cycle per day production, and at the same time, un expected cracking along main reinforcement is caused by excess expansion due to inappropriate curing of expansive agent.


G. P. Ganapathy, R. Gobinath, I. I. Akinwumi, S. Kovendiran, M. Thangaraj, N. Lokesh, S. Muhamed Anas, R. Arul Murugan, P. YoGEswaran, S. Hema,
Volume 15, Issue 3 (Transaction B: Geotechnical Engineering 2017)
Abstract

Soils with poor engineering properties have been a concern to construction engineers because of the need to strike a balance between safety and economy during earthworks construction. This research work investigates the effects of treating a soil having poor geotechnical properties with a bio-enzyme to determine its suitability for use as road pavement layer material. The elemental composition and microstructure of the soil was determined using energy dispersive X-ray spectroscopy and scanning electron microscopy, respectively. The specific gravity, Atterberg limits, compaction, strength and permeability characteristics of the soil was determined for various dosages of the bio-enzyme. The mountain soil is classified as clayey sand and A-2–4, according to unified soil classification and AASHTO classification systems, respectively. With increasing dosage of the bio-enzyme, the plasticity index, maximum dry unit weight and permeability of the soil decreased, while its 28-day California bearing ratio value, unconfined compressive strength and shear strength increased. Consequently, the application of bio-enzyme to the soil improved its plasticity and strength, and reduced its permeability. It, therefore, became more workable and its subgrade quality was improved for use as a road pavement layer material. The stabilized soil can be suitably used for constructing pavement layers of light-trafficked rural (earth) roads, pedestrian walkways and bicycle tracks.


Zhechao Wang, Ron C. K. Wong, Liping Qiao, WenGE Qiu,
Volume 15, Issue 3 (Transaction B: Geotechnical Engineering 2017)
Abstract

The effects of effective stress and void ratio on the secondary compressibility of the sandy and clayey soils were investigated in this study. The coefficient of secondary compression of Ottawa sand in single stage and stepwise loading tests increases with effective vertical stress while that of saturated kaolinite decreases with effective vertical stress. Multi-staged loading tests showed that at a given effective stress, the higher the void ratios of the soils, the higher the coefficients of secondary compression of the soils are. It was concluded that the secondary compressibility of a soil depends on not only the effective stress, but also the void ratio of the soil. A general relationship between the coefficient of secondary compression, and effective stress and void ratio was proposed for soil. The discrepancy of the dependency of secondary compressibility on effective stress for different soils was well explained using this relationship, moreover, the quasi-overconsolidated state of clayed soil induced by time effect and the effect of surcharge preloading on the secondary compressibility of soft ground were discussed in light of the general relationship.



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