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Revista de Ingeniería Civil y Ambiental

Volumen 8, Asunto 3 (2018)

Artículo de revisión

Traffic Congestion and Impact on the Environment in Vietnam: Development of Public Transport System - Experience from Actual Operation of Bus in Hanoi

Dung Trong Nguyen and Yoshitaka Kajita

Rapid urbanization has led to a boom in travel demand. With high population density and urban structure, big cities in Vietnam, especially Hanoi and Ho Chi Minh City, are facing major challenges in urban transport such as traffic jams, accidents, environmental pollution, etc. One of the important factors that can help to solve these problems is to attract people to travel by public transport, firstly by bus and then moving forwards to fast-paced public transport such as a Bus Rapid Transit, Metro. Through analyzing the surveys about bus systems in Hanoi, this study presents some assessments and suggestions, contributing to the development of the public transport system in Hanoi.
Artículo de investigación

Endangering Residents in Shipitull Village by Landslide at the Surface Mining in South West Sibovc

Hysen Ahmeti and Vehbi Duraku

Facing the problem of the expropriation of the Shipitull village and the non-advancement of mining activity in the direction of the frontal work for the removal of the clay overburden for the use of coal, geo-mechanical drilling was performed to determine the most accurate physical-mechanical parameters to calculate the height of the partial and generals slopes with the safety factor Fs> 1.2, to create optimum conditions for the use of the detected coal reserves of 15 million tons of coal with the general 18° degree angle with safety factors Fs ≥ 1.27 according to the geotechnical standards. As the basis for calculating the slopes were taken physical-mechanical drilling parameters that were realized in 2015-2017, the tests were performed in the geotechnical laboratory at the INKOS Institute which is licensed to ISO 9001/2015 according to geotechnical standards. Based on the obtained results, statistical processing was performed for the classified parameters (physical) and the mechanical parameters obtained with the triangle test, the direct test and the tensile test. By comparing the physicochemical parameters based on the drilling of 2015 and 2017, there is change of values of angle ϕ0 and cohesion C in the lithological layers due to the presence of moisture. The calculations were carried out with Slide v6 and Geo5 Fine software. Two methods were used during calculation: Circular and Polynomial methods for partial angle of height (h)=30 m and angle (α)=48° with the safety factor Fs<1 and for a general angle of height (h)=55 m with angle (α)=13° with current useable reserves of 6.8 million tons of coal having Safety factor Fs ≥ 1.27.
Mini reseña

A New Approach of a Specific Sustainability Model

Corneliu Bob

The paper presents a new approach for obtained the sustainability of the construction works. In the technical literature there are a lot of models which evaluate the sustainability performance of the construction works with high applicability and very comprehensive. In many cases such models show some disadvantage: some models do not cover all three dimensions of the sustainability; all of them include a great number of criteria and many of them are difficult or impossible to quantify; they are focused manly on entire buildings and they can be applied with some difficulties on other types of construction works and activities. The first step to avoid such disadvantages was by proposal a so called specific model with some advantages: high degree of utilization includes only quantitative parameters, covers the three dimensions of sustainability. The second step is presented in this paper by a new approach which takes into account the price of each parameter and finally, the sustainability cost is established. The application of new model is presented on three different construction works. Using of the new approach some advantages are obtained: such calculation is easy understandably by specialists; by using the correction of the mechanical characteristics the most sustainable solution is obtained: costs of main parameters where taken from Romanian practice, but for different zones and countries, such costs will have to be used.
Artículo de investigación

Experimental Behavior of Bolted T-Stub Connections with IPE Standard Profile

Mahyar Maali, Mahmut Kilic, Merve Sagiroglu and Abdulkadir Cuneyt Aydin

In this research, new connection types were suggested, and their behaviors were determined using full-scale experiments. T-shaped combinations created using the IPE standard profile and T-shaped elements are different from those in the literature, which utilize welded plates. Thus, problems occurring at the welds of connections such as the occurrence of fracture points and inability to perform well in place are expected to be eliminated. To recommend the use of weld-less T connections, knowledge of the behavior of the connections was needed. In addition, in this research, the effects of changes in the dimensions of the connection members on the connection behavior were examined for the T-connection type. This provided information about the optimum sizes of the connection elements. The main parameters observed were the evolution of the resistance, stiffness, rotation capacity, ductility of a joint, and energy dissipation. The aim was to provide the necessary data to improve Eurocode 3 and efficiently use residue IPE standard profiles, rather than send them back to the consumption cycle.

Artículo de investigación

Collapse Analysis of a Reinforced Concrete Frame Due to Middle Column Loss by Explosion

Ghada Mousa Hekal

The subject of the overall structural collapse under hazardous loads in reinforced concrete frames has been addressed in various researches. However, most of those studies have examined the column removal scenario where one of columns is removed and the load of this column is applied vertically on the upper face to assess the behavior of the frame until failure. One of the shortcomings of the previous mechanism is that it neglects the main reason for the failure of the column and the impact of that reason on the different elements of the structure. The current work presents a numerical investigation of frame collapse as a result of sudden column failure due to an explosive wave. The frame of study has already been tested in a previous work of the author. It was a reinforced concrete frame that has been cast without an intermediate column and then dynamically loaded in the position of the missing column until collapse. In this study, the behavior of that frame is re-evaluated under the effect of instantaneous removal of the middle column due to explosion loads. Analysis was performed using Abaqus software where frame capacity and failure mode were monitored considering different locations of application of incident wave on the target column. Comparing the obtained results with the original model indicated that both capacity and mode of failure differ significantly by changing the location of application of incident wave.
Artículo de revisión

Hydro-mechanical Properties of Highly porous Limestone Rock used for Historic Monuments in North-East Tunisia

Yousr Koubaa, Mehrez Jamei and Houda Guiras

This paper deals with the study of the physical and hydro-mechanical characteristics of a porous limestone rock. It concerns a historic rock located at "El-Haouaria artificial caves" on the seacoast in the Northeast of Tunisia. The rock, object of study in this work, has undergone serious alterations, thus compromising the safety of the monuments. This paper focuses on the mechanical behavior of a sedimentary rock with a variable porosity; covering a wide range varying from 25% to 55%. This study is interested in identifying the mineralogical composition and the microscopic structure of the main rocks constituting the historic monument. Several tests were carried out and they showed that the rock’s mineralogical composition was calcite and quartz. The grain dimensions constituting the rock are variable. Its porosity is inter-granular and connected. This porosity changes over time due to weather conditions. Unconfined compressive tests and tensile tests were carried out on several samples with various porosities and in some cases in various saturation states. The performed tests showed the effect of both porosity and water content (suction) on strength characteristics. However, despite the rock’s dependency on the water content, the role of porosity remains more emphasized. Then, porosity seems to be the main factor affecting resistance properties due to the increase of the porosity and due to its variation as a source of humidity. A ‘’Li and Aubertin’s Model’’ was applied to predict the compression and tensile strength dependency on porosity. It highlighted a strong concordance between experimental and analytical model results. All strength characteristics evolutions with porosity and suction make up essential results obtained in this study. This will provide us with the required input data for modeling in order to predict cave structure degradation and eventually to monitor crack propagation.

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