The tunnels due to their restrictions as a infrastructure work often overpass very disturbed tect... more The tunnels due to their restrictions as a infrastructure work often overpass very disturbed tectonic zones. In those zones due to overthrust geological processes the rockquality are extremely poor in one side, and changes abruptly on the other side. These changes impose differential deformation on soil and tunnel linings. Especially for near faults tunnelswhere the directivity pulse and fling step phenomena plays an important role in the characterization of the seismic motion. This article gives the theoretical explanation and design consideration concerning the above mention problems. A numerical simulation whichis indented to study the behavior of the tunnel during this type of seismic events is presented.This example is taken from the design of a tunnel that shall be constructed in Albania
Generally, the most important factor of destabilization of natural slopes is the high level of un... more Generally, the most important factor of destabilization of natural slopes is the high level of underground water table. It is significant the fact, that many slopes have failed during the winter, after heavy rainfall. Drainage is often a crucial measure due to the important role played by pore-water pressure in reducing shear strength. Because of its high stabilization efficiency in relation to cost, drainage of surface water by superficial ditches, and underground water by networks of trench drains, is one of the most widely used, and generally the most successful stabilization method. The following study is related to a problematic sliding zone in Shijak-Arapaj road.. The landslide in question obtains a specific importance because of its location is closed to the national roadway Tirane-Durres. The landslide has been active for years now. The average presence of a creeping movement of soil masses with a 0.25 m/year velocity. To be able to understand the geological conditions of th...
For seismic design of structures based on European Codes the designers take the peak ground accel... more For seismic design of structures based on European Codes the designers take the peak ground acceleration (PGA) values on ground type A (rock) from the seismic hazard map of Albania. Based on these values and the type of the ground is formed the response spectra which serves as input for seismic analysis of structures. Recent measurements and studies of different authors have emphasized that for the ground classification accepted in EC8 response spectrum values in some cases do not match with reality. So it is necessary, especially when we built on soft soils to do a detailed analysis for propagation and amplification of seismic waves. These analyses are even more important if for the calculation of the structure will be used seismic dynamic analysis in which time history of acceleration is used as input. The paper gives for a real example the wave propagation modelling, the choice of soil parameters, damping coefficients, boundary modelling, finite element size and the integration c...
Recently we are using the European Codes for the design of structures for earthquake resistance b... more Recently we are using the European Codes for the design of structures for earthquake resistance but in some cases even European Code doesn’t gives realistic results. For irregular structures the European Code gives very simplified recommendations that if will be used for the design gives results that could produce a very heavy and expensive construction. The present paper in the first part will provide information about the EN-Eurocode 8 for Design of Structures for Earthquake Resistance and its limitations. After that will be presented adaptive pushover procedure for nonlinear analysis of irregular structures. The APO theory will be used for the analyses of an existing structure. Firstly in the paper is given the information about the conditions of the existing structure. After that is performed the nonlinear analysis (adaptive pushover) and are given the structural measures suitable for retrofitting this type of structure. In the end, the paper makes recommendations on the methodo...
International Journal of Research in Engineering and Technology, 2015
Retrofitting an existing building is often considered to be more cost-effective than constructing... more Retrofitting an existing building is often considered to be more cost-effective than constructing a new building. It represents an opportunity to upgrade the overall performance, sustainability and efficiency of an existing building. Seismic retrofitting is mainly done to provide existing structures with more resistance to seismic activity due to earthquake. Earthquake creates great devastation in terms of life, money and failure of structures. Therefore, increasing the seismic resistance of structures is of utmost importance, especially in case of old structures, and tall or expensive structures. When a building has been designed according to a seismic code, but the code has been upgraded in the later years, it results in deficiencies to exist in design or construction of the structure. In Kerala, there exist several old buildings which were designed for seismic zone II, whereas, at present Kerala belongs to seismic zone III. In this paper, a building that was designed for seismic zone II is selected. The analysis of the structure is carried out and the structure is redesigned for seismic zone III. The additional seismic resistance required for the structure is determined and retrofitting methods are proposed to achieve the required seismic strength.
The tunnels due to their restrictions as a infrastructure work often overpass very disturbed tect... more The tunnels due to their restrictions as a infrastructure work often overpass very disturbed tectonic zones. In those zones due to overthrust geological processes the rockquality are extremely poor in one side, and changes abruptly on the other side. These changes impose differential deformation on soil and tunnel linings. Especially for near faults tunnelswhere the directivity pulse and fling step phenomena plays an important role in the characterization of the seismic motion. This article gives the theoretical explanation and design consideration concerning the above mention problems. A numerical simulation whichis indented to study the behavior of the tunnel during this type of seismic events is presented.This example is taken from the design of a tunnel that shall be constructed in Albania
Generally, the most important factor of destabilization of natural slopes is the high level of un... more Generally, the most important factor of destabilization of natural slopes is the high level of underground water table. It is significant the fact, that many slopes have failed during the winter, after heavy rainfall. Drainage is often a crucial measure due to the important role played by pore-water pressure in reducing shear strength. Because of its high stabilization efficiency in relation to cost, drainage of surface water by superficial ditches, and underground water by networks of trench drains, is one of the most widely used, and generally the most successful stabilization method. The following study is related to a problematic sliding zone in Shijak-Arapaj road.. The landslide in question obtains a specific importance because of its location is closed to the national roadway Tirane-Durres. The landslide has been active for years now. The average presence of a creeping movement of soil masses with a 0.25 m/year velocity. To be able to understand the geological conditions of th...
For seismic design of structures based on European Codes the designers take the peak ground accel... more For seismic design of structures based on European Codes the designers take the peak ground acceleration (PGA) values on ground type A (rock) from the seismic hazard map of Albania. Based on these values and the type of the ground is formed the response spectra which serves as input for seismic analysis of structures. Recent measurements and studies of different authors have emphasized that for the ground classification accepted in EC8 response spectrum values in some cases do not match with reality. So it is necessary, especially when we built on soft soils to do a detailed analysis for propagation and amplification of seismic waves. These analyses are even more important if for the calculation of the structure will be used seismic dynamic analysis in which time history of acceleration is used as input. The paper gives for a real example the wave propagation modelling, the choice of soil parameters, damping coefficients, boundary modelling, finite element size and the integration c...
Recently we are using the European Codes for the design of structures for earthquake resistance b... more Recently we are using the European Codes for the design of structures for earthquake resistance but in some cases even European Code doesn’t gives realistic results. For irregular structures the European Code gives very simplified recommendations that if will be used for the design gives results that could produce a very heavy and expensive construction. The present paper in the first part will provide information about the EN-Eurocode 8 for Design of Structures for Earthquake Resistance and its limitations. After that will be presented adaptive pushover procedure for nonlinear analysis of irregular structures. The APO theory will be used for the analyses of an existing structure. Firstly in the paper is given the information about the conditions of the existing structure. After that is performed the nonlinear analysis (adaptive pushover) and are given the structural measures suitable for retrofitting this type of structure. In the end, the paper makes recommendations on the methodo...
International Journal of Research in Engineering and Technology, 2015
Retrofitting an existing building is often considered to be more cost-effective than constructing... more Retrofitting an existing building is often considered to be more cost-effective than constructing a new building. It represents an opportunity to upgrade the overall performance, sustainability and efficiency of an existing building. Seismic retrofitting is mainly done to provide existing structures with more resistance to seismic activity due to earthquake. Earthquake creates great devastation in terms of life, money and failure of structures. Therefore, increasing the seismic resistance of structures is of utmost importance, especially in case of old structures, and tall or expensive structures. When a building has been designed according to a seismic code, but the code has been upgraded in the later years, it results in deficiencies to exist in design or construction of the structure. In Kerala, there exist several old buildings which were designed for seismic zone II, whereas, at present Kerala belongs to seismic zone III. In this paper, a building that was designed for seismic zone II is selected. The analysis of the structure is carried out and the structure is redesigned for seismic zone III. The additional seismic resistance required for the structure is determined and retrofitting methods are proposed to achieve the required seismic strength.
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