Horizontal Irregularities Research Articles

The Performance Assessment of the Structural Bracing Model for Multi-Story Building

Earthquakes are a severe issue for construction. The building collapsed due to the earthquake because it could not bear the earthquake load. Even more so, it was constructed using outdated and different building regulations that do not comply with modern building codes that account for seismic loads. As a result, disaster mitigation methods, such as retrofitting, must be implemented. Retrofitting procedures are commonly used in many developed countries. The bracing system is a typical retrofitting method used on building structures. In this study, a retrofitting program was carried out on The State Finance Building II Semarang, which was built in the 1980s, one of the old buildings in Semarang City, using a reinforced portal structure. This study's bracing system is a Concentrically Brace Frame (CBF) with Inverted V Brace and V Brace variations. The structural analysis software ETABS V.18.2.0 analyzes the building's structure. The structural review includes story drift, the P-Delta effect, and horizontal torsion irregularities. According to the results, steel bracing can minimize the period and displacement associated with story drift, making the structure more stable, with a maximum displacement reduction of 59.66% for inverted V-type steel bracing. Aside from that, steel bracing also can minimize the occurrence of torsion in the building. As a result, steel braces can be used to strengthen the structure.

Nonlinear Static Analysis of Tube in Tube structure with Horizontal Irregularity with constant plan area

Nonlinear Static Analysis of Tube in Tube structure with Horizontal Irregularity with constant plan area

Real-time temperature field and thermal deformation of slab track on cable-stayed bridge

This study aimed to master the real-time temperature fields of slab tracks on cable-stayed bridges and analyze the thermal deformations. The pivotal heat conduction parameters of the geotextile and rubber pad were obtained through testing, and the governing equations for heat conduction considering temperature variations were improved. A thermal-fluid-solid coupling model for slab track on cable-stayed bridge was proposed. The results indicated that the high temperatures of the track were concentrated within 0.05 m depth of the slab. Under the resistance of the isolation layer, the temperature on both sides of the geotextile isolation layer appeared obvious abrupt change. The time of maximum and minimum temperatures of the truss beam were the same as those of the air. The effects of real-time temperature change on the irregularity of the rail were obvious. In summer, the maximum vertical rail deformation was 201.88 mm and the transverse deformation was 17.87 mm. The temperature change in just one day caused vertical deformation of rail with a range of more than 60%. On a single day in summer, the maximum horizontal irregularity was 1.74 mm, which was less than the 2.0 mm specified in the code.

Study on Horizontal and Vertical Irregularities in Structures Under Seismic Load – A Review

An increase in population has led more often towards vertical development rather than horizontal development, because of this the demand for multi-storied buildings has increased and they constitute about 60-70% of the urban infrastructure. In the present time, the analysis of civil structures is generally carried out by various design software. Now a day’s irregular structures contribute a large portion of urban infrastructure. Irregular structures have certain physical discontinuities either in plan or in elevation or both which affect the performance of the structure subjected to lateral loads. This work reviews the analysis done by various researchers in multi storey reinforced concrete structures subjected to seismic load. Key Words: ETABS, Seismic Load, Multi Storey buildings, vertical and horizontal Irregularity.

PERFORMANCE ANALYSIS OF HORIZONTAL IRREGULAR BUILDINGS BASED ON RESPONS SPEKCTRUM AND TIME HISTORY METHODE

Indonesia is geographically located in the Pacific Ring of Fire, Especially on Java Island, which has the densest infrastructure and population and is located between the Indo-Australian plate and the Eurasian plate, causing this area to have many active volcanoes and has a high potential for earthquakes. Therefore, it is necessary to pay the planned earthquake load in planning the building structure design to minimize losses due to the earthquake. This study aims to determine the structure's performance against safeguards, deviations between levels, and structural stability limits against earthquake loads and to review horizontal structural irregularities based on SNI 1726: 2019 regulations in existing buildings at the Simpang Temu MRT Dukuh Atas Jakarta Building. The analysis process was carried out by 3D building modeling using the ETABS software program, analysis based on time history and spectrum response. Time History analysis uses recorded earthquakes of Kobe Japan, ChiChi Taiwan, and El Centro which match the earthquake response spectrum, the results of the analysis based on the program were carried out to compare the two methods used. Based on the results of the analysis, the building is classified into horizontal irregularities with excessive torque ratio > 1.4, average displacement value from the 2nd to 12th floor in the horizontal direction X exceeds the drift value limit. The results of the instability limit for structural stability against displacement based on the P-Delta effect still meet the structural stability limits so it can be stated that the structure is stable and safe.

Seismic control of vertically and horizontally irregular steel high-rise buildings by tuned mass dampers including SSI

The architectural requirements imposed on the structural design of buildings sometimes necessitate vertical and horizontal irregularities with their possibly dangerous effects when these structures are subjected to earthquakes. One of the greatest challenges in structural engineering is the design of a steel high-rise building (HRB) with vertical and horizontal irregularities. In this research, two irregular steel high-rise buildings (HRBs) were seismically analyzed as 3D models considering soil–structure interaction (SSI) and tuned mass damper (TMD) systems were used to mitigate their seismic response under different earthquakes. The two studied HRBs were a vertically irregular (step-pyramid-shaped) steel HRB, and a both vertically and horizontally irregular (L-shaped in-plan, stadium-shaped) steel HRB. The SSI provides the actual response of the tall buildings subjected to earthquake, and mitigation schemes using TMDs were suggested with arrangements of the TMDs on the top plan and along the elevation of the steel high-rise buildings to achieve seismic control of these structures. The present study has shown that the best efficiency in the mitigation of the effect of earthquakes on vertically and horizontally irregular steel high-rise buildings is obtained by implementing TMDs at the corners of the HRB plan on the top of the HRB and also at different floor levels along the upper half-height of the HRB.

State of art on seismic comparison of different types (V, diagonal and X) of bracings on different shapes of buildings (L, H, T and rectangular) with response spectrum method

Multi-storey buildings were particularly affected by the earthquake and tsunami. The real problem with the multi-storey building system is that the buildings are usually horizontal and resist lateral forces to control the floating sides of buildings. Structural analysis is a branch where it involves modelling a building, assigning sequential loading and analysing structural behaviour, and estimating the seismic responses of all building components. This project “Seismic comparison of different types (V, Diagonal, and X) of bracing on different shapes of buildings (L, H, T, and Rectangular) with response spectrum analysis” is an effort to perform analysis and design the commercial structure using the software ETABS. The steel bracing is quite economical and is easy to install, taking up little space and with design flexibility to reach the desired strength parameters and durability. For the thesis, it has been considered a building model with different types of binding systems based on the journals I have encountered, so the project focuses on other design features such as lateral displacement of story, Drift, and stiffness. During the earthquake, the behaviour of the building depends on the following factors, durability, and sufficient strength in the lateral direction, ductility, and normal configuration. The buildings with normal geometrical features and size with even distribution and durability and height have very little damage in comparison with conventional suspensions. But at present the need for the next generation and the Population density have made architects or engineers inevitable in planning unusual designs. Earthquake engineering had therefore developed significant effects while understanding the purpose of architectural planning. Irregularity is a variety of types such as vertical irregularity, and horizontal irregularity. Vertical irregularity refers to an immediate change in stiffness, strength, geometrical features, and the effect of mass on the abnormal transfer of energy or flexibility over the length of the structure.

Seismic fragility of low-rise piloti buildings based on 2017 Pohang earthquake damage

Due to the 2017 Pohang earthquake, many low-rise piloti buildings suffered minor to severe damage. Low-rise piloti buildings in Korea are generally both vertically and horizontally irregular systems. The first floor is a weak and soft story, and the core wall is located at the corner or edge of the plan creating a horizontal irregularity. Furthermore, the damage investigation indicates that the insufficient amount of column hoops and poor detailing of reinforcement. It was presumed that the combination of soft story, torsional behavior and poor detailing brought brittle failure at the columns located at the furthest distance from the core. Such a brittle and irregular nature makes it difficult to predict damage with a HAZUS-type approach, which uses seismic fragility functions defined in terms of the spectral displacement and the capacity spectrum method based on pushover analyses. Comparison of pushover analysis results of piloti buildings indicated that location of peak and overall deformation capacity differed with the intensity of the torsional behavior and failure mode of the column. Therefore, this study aimed to develop an improved seismic fragility function for piloti buildings. To reflect the observed damage, the use of damage criteria based on member performance, including stress and strain, and spectral acceleration was proposed. Fragility functions for the piloti buildings were constructed by using three-dimensional incremental dynamic analyses. Damage estimates for piloti buildings in the target area that were obtained by using obtained fragility functions showed good correlations with damage survey data.

Seismic Analysis of Flat Slab Buildings on Hilly Ground

In India, hilly region especially northern part is more seismically active region. Flat Slab systems are widely popular in multi-storey buildings. Flat slab building has more advantages than a regular building like fast construction, free design space, reduced floor to floor height and economical. Flat slab buildings are also being built in high seismicity region. Buildings on hilly ground are vulnerable due to their vertical and horizontal irregularity and they undergo high shear and torsion during the earthquake. Further due to short column and soft storey on uphill side has higher lateral forces that are cause to failure of buildings. In this paper, an attempt has been made to assess the seismic behavior of flat slab resting on hilly slope with soft storey and set back configuration. The methodologies have been adopted are linear dynamic analysis i.e. response spectrum analysis. Building is analyzed and designed by Etabs software. Maximum displacement, maximum inter-storey drift and storey shear are determined as response quantities. It is observed from the study that for flat slab buildings on hill slopes the storey shear is very high in the bottom columns at higher ground level, therefore extra care should be taken to design these columns for earthquake load.

RESPON STRUKTUR AKIBAT PENEMPATAN DILATASI PADA BANGUNAN DENGAN KETIDAKBERATURAN HORIZONTAL

The placement of dilation in the building structure with horizontal irregularity causes a different response to the structure during an earthquake, because the structure is divided into several individual structures that stand alone so that they are different from the original structure. The proper placement of the dilation in a building will reduce the risk of collapse of the building during an earthquake as well potentially making structures simpler and more efficient. This study uses the design analysis method to compare the earthquake shear force, structural response, and internal forces in the structure due to the placement of the X-direction and Y-direction Dilatation. greater than the X direction dilatation, which is 42% in the X direction and 38% in the Y direction. The deviation that occurs in the Y direction dilation is greater than the X direction dilatation. X, but the internal force due to the Y direction of dilation on the beam is greater than the X direction dilation placement. So that the use of the Y direction dilation is slightly better than the use of the X direction dilatation in several things, such as the earthquake force and the inner force on the smaller column.

Performance of The Existing Building Under Earthquake Loads Based on Current Indonesian National Standard

This paper presents the results of an assessment of the existing 5-storey building built in 1980, which aims to determine the level of safety against the most recent standards. The method used is non-destructive testing, collecting planning data in the form of as built drawings and implementation data. The assessment of the existing structure consists of an evaluation of the condition of the material, structural system, and analysis of the structure using the latest load standards. The test results of the existing structural material show that the compressive strength of the concrete still meets the requirements based on SNI-2847-2019. The results of the evaluation of the structure against earthquake loads show that the performance of the structure has a mass participation of 100% and the dynamic base shear force (V) reaches 100% of Vstatic therefore it meets the requirements in SNI 1726-2019. The results of the evaluation of the performance of the structure show that the lateral drift and P-delta effects still meet the requirements of the most recent standards. Horizontal and vertical structural irregularities are found in the existing structural system. The structure's overall performance level (X and Y direction earthquakes) is Damage Control. These results are still permitted for structures with a priority factor (Ie) 1.50, with an earthquake return period of 2500 years.

Prediction Method of Heavy Load Wheel/Rail Wear Mechanical Properties Based on GA-BP Hybrid Algorithm

Due to its large axle load and high-density operation mode, heavy haul transportation has greatly improved the cargo transportation capacity, and is receiving unprecedented attention from all countries in the world. Since the development of heavy haul freight transport in China, wheel rail wear has been paid much attention, especially the use of heavy axle load locomotives on upgraded heavy haul lines, which makes reducing wheel rail wear and damage become a technical problem to be solved urgently. Considering that there are too many mechanical parameters involved in the prediction of heavy load wheel rail wear mechanical properties, the prediction accuracy is reduced. Therefore, this paper proposes a method based on GA-BP hybrid algorithm to predict the mechanical properties of heavy load wheel/rail wear. Hertz contact theory is used to simplify the wheel rail contact relationship, and the wheel rail contact model is established. According to the wheel/rail contact model, the expressions of heavy load wheel/rail in the case of vertical, horizontal, direction and gauge irregularity are analyzed, and based on this, a mechanical model of heavy load wheel/rail wear is established. In order to solve the problems of slow convergence speed and easy to fall into local optimum of BP neural network in the prediction of heavy load wheel/rail wear mechanical properties, the global convergence of genetic algorithm is used to optimize the BP network. According to the obtained mechanical parameters of heavy load wheel/rail wear, the mechanical parameters are input into the optimized model, and the relevant prediction results are output. So far, the research on the prediction method of heavy load wheel/rail wear mechanical properties based on GA-BP hybrid algorithm has been realized. The experiment is designed from three aspects of wear degree, hardness and tensile strength, and compared with the measured value, reference [4] method, reference [5] method and reference [6] method to verify the effectiveness of the proposed method. The experimental results show that the predicted results of wear degree, hardness and tensile strength by this method are closer to the measured results. It is proved that the proposed method has higher prediction accuracy and better practical application effect.

Analytical Modelling of T-Shaped Monolithic & Independent RCC Buildings

Abstract: During an earthquake the behaviour of the building depends on its overall shape, size & geometry. Now a day’s many buildings are asymmetric in plan and elevation because everyone wants to win the race of aesthetically beautiful and complex structures. Due to irregular distribution of mass, stiffness and strength, it may cause serious damage in structural system. There are various types of irregularities in the buildings depending upon their location and scope. Mainly two types of irregularities as per IS – 1893 (Part-1)-2002. are a) plan or horizontal irregularities b) vertical irregularities. Irregularity in structure makes analysis of the seismic behaviour very complicated. The objective of present study is to analyze and compare the behaviour of T shape monolithic and independent RCC structure under seismic loading. The comparison of both structures is studied by calculating, finding and tabulating comparative values of displacement, base moments and shear values. The study reflects that with change in structure i.e. the behaviour of structure towards earthquake changes, nodal displacement, moment, and base shear values shows drastic changes towards resistivity against seismic forces. The soft computing tool and commercial software STAAD-Pro is used for modelling and analysis also the study done over here thus helps to understand effect of earthquake on both structures for achieving stable and safe structure

Reliability-based assessment of progressive collapse in horizontally irregular multi-story concrete buildings

Structures’ resistance against progressive collapse varies depending on their design and taxonomy. However, despite numerous studies addressing the impact of geometric configuration, limited attention is given to the effect of irregularity. This study presents a reliability-based approach to evaluate the effect of horizontal irregularity on the progressive collapse potential of seismically designed concrete buildings. Incremental dynamic analysis is performed on three-dimensional nonlinear finite element models of six prototype buildings with different levels of horizontal irregularity subjected to four column removal scenarios. Probabilistic demand models are then derived to construct fragility curves based on the first-order reliability method. In addition, an analysis of covariance is performed to measure the sensitivity of demand models to column removal scenarios in terms of floor and location. The results show that the studied irregular buildings do not pose a greater risk of progressive collapse than the regular building. In addition, while the probability of collapse under sudden column removal is significantly low for the seismically designed concrete frames, all buildings are expected to experience significant damage under such abnormal loads.

Response Spectrum Analysis with Regular and Irregular Structures with Diagrid Systems Using Etabs

Abstract: One of the most catastrophic natural disasters is an earthquake. that wreak havoc on buildings and the loss of life. The irregularities of a building or an asymmetrical system are often found in construction due to the need for architecture view in buildings. Today, the use of buildings and economic barriers requires that vertical and unusual structures be built in urban areas. Therefore proposing measures to reduce the damage to these buildings during an earthquake is important. Strict rules of design and analysis of unusual structures have been applied in view of their high risk of injury compared to conventional structures. There are different types of structural deficiencies depending on their location and width, but most importantly, they are divided into two groups - horizontal irregularities and vertical irregularities. In the study, both irregularities are considered. The current paper seeks to investigate the proportional distribution of lateral forces arising from earthquake action at each floor level due to changes in the strength of the frame in the irregular structure. In accordance with the provisions of the Bureau of Indian Standard (BIS) 1893: 2002 (part1), the unusual G + 14 vertical building is modeled as a model of the simplified lump mass to analyze the rigidity of the floors. To analyse parameters such as storey drift, storey displacement and story base shear under seismic force under dynamic analysis are studied

Sensitivity of Geometric Parameters in the Sustainability Development of Continuous Welded Rail

Continuous Welded Rails (CWR) are a key infrastructure element in the safety and efficiency of rail transportation. Their correct exploitation (operational) requires surveying and diagnostic monitoring based not only on the results of rail displacement measurements, but also on the geometric parameters of the track in the horizontal (H) and vertical (V) planes. Many researchers have proposed different approaches for surveying and diagnostic monitoring of CWR. However, they do not refer to the determination of railway track defectiveness (parametric defects, track defectiveness) respectively on straight and curvilinear segments. Research topics involving CWR constitute a continuous openness to research with particular application of synergy effects in the optimization of monitoring of CWR geometry shaped by exploitation processes. In this study, based on real measurement data of six geometric parameters (H: track gauge, gradient of track gauge, horizontal irregularities and V: cant, twist, vertical irregularities), the most sensitive parameters in sustainable development CWR are defined. The research answered that the most sensitive parameters in the sustainability development of CWR belong in the range of the plane H: gradient of track gauge and horizontal irregularities, and in the plane V: vertical irregularities. These escalate especially on curvilinear sections, requiring more significant maintenance capacity. Due to the growing importance of rail transportation as a sustainable, environmentally friendly, and mass transit mode, the research results provide a basis for life cycle management of CWR.

Дослідження можливості використання збурень, сформованих за записами нерівностей колії, для розрахунків динаміки швидкісного рейкового екіпажу

An urgent task for Ukraine during the post-war reconstruction of the country will be the upgrade of the entire railway transportation system, in particular the development of high-speed passenger traffic. The prediction of the dynamic performance of high-speed rail vehicles calls for the formation of new input arrays (track-induced disturbances) that would account for more stringent track geometry requirements. The aim of this work is to study the possibility of using track irregularities recorded in real sections of the Ukrainian railways to construct the components of track-induced disturbances acting on a rail vehicle moving at a high speed. This paper considers in detail standard specifications for the geometric parameters of a track suitable for high-speed traffic. The data are contained in the Standard DSTU EN 13848-5:2018, which is a European standard adopted in Ukraine as a national one by confirmation. Using the track subsidence and alignment irregularities recorded by a track measurement car in a number of sections of the Pryndiprovska railway during a scheduled track inspection, processes of actual vertical and horizontal irregularities were formed. The quality of those sections had not require any speed limitation. Irregularity parameters for those sections were calculated. A comparison between the calculated parameters and those specified by the DSTU EN 13848-5:2018 showed that among the sections considered there exist ones that meet the track geometry requirements and allow speeds at least up to 230 km/h. The use of the irregularities in the selected track sections as disturbance components in calculations was tested by the example of determining the ride performance of a standard passenger car with KVZ-TsNII-M trucks. The calculated results showed the possibility of using the generated disturbances in numerical calculations of the dynamic performance of rail vehicles at increased speeds and at the same time confirmed the need for new engineering solutions on the design of rail vehicles capable of operating at such speeds.

Analysis of dynamic instability of the wheel set of a railway vehicle using the method of generalized hill determinants

The article considers the tasks associate with the study of dynamic processes of interaction between rolling stock and railways. Studies of the interaction of a wheel with a rail, fitting the vehicle into curves when modeling critical and emergency situations do not allow oversimplification of basic differential equations. And they should be based on exact nonlinear equations that take into account the entire set of geometric and kinematic relationships without simplification. An objective assessment dynamic characteristic of the vehicle can only be obtained by simultaneously taking into account both its vertical and horizontal irregularities. In order to determine boundaries of parametric resonance, article proposes method of generalized Hill’s determinants, the application of which is possible without taking into account small parameters.

The Traditional House in North Sumatera Against the Earthquake: A Case Study of Karo and Toba

Indonesia is one of the countries that are susceptible to earthquakes. The traditional houses in Indonesia are generally able to resist the earthquake. They have a non-engineered structural system that was handed down from ancient traditions. Most of the damaged or collapsed houses were made of concrete. Meanwhile, the traditional house is made of wood or bamboo tend to survive. Karo and Toba regency is one of the areas in Indonesia which is known to be prone to earthquakes. Because it is located near Sibayak Mount and Sinabung Mount which is an active status. But the traditional houses there are still withstanding now. In this paper, we will analyze the traditional houses against the earthquake with the case study in Karo and Toba. These structures will be analyzed by the MDOF method and using SAP2000 software. The results are the structural concept of the traditional houses is relatively the same, only the type of the roof is significantly different. The traditional houses have symmetrical structures. There is no horizontal irregularity, but vertical irregularity exists. Furthermore, the earthquake performances show that the structures of the traditional houses in Karo and Toba are safe in terms of the period, the base shear force, the friction force, and the story drifts.

Comparative analysis of behaviour of horizontal and vertical irregular buildings with and without using shear walls by ETABS software

At present days building a structure with all the regular configurations is not feasible in most of the cases due to the irregular plot dimensions, aesthetic visual and functional requirements in the urban cities. The structure with more irregular configuration either horizontally or vertically are more vulnerable to earthquake & wind forces which leads to collapses of structure, property loss and casualties. Although a considerable amount of research effort was made on capturing the responses of irregular configuration structures under the earthquake forces, but well-accepted guidelines for multi storey irregular configuration structures are still yet to be framed. In this aspect a question might arise in the mind of structural engineers designing a high-rise structure i.e., which irregular configuration of structures and type of structures provide considerably good responses to the earthquake forces in reducing the damage caused by earthquakes and cost effective in implementing. A well-known answer is that shear walls provide good response to resist lateral forces when added to a structure.In the present study a structure with horizontal irregularity, vertical irregularity, Stiffness irregularity and Mass irregularity buildings with and without shear wall is considered and responses of the buildings are compared. Modeling of these 4 types of models with and without shear walls are done with ETABS software for G + 15 storey. The goal of the study is to compare model results like Stiffness, Displacement, Shear & Drift values and find out which model performs better. Vertical geometrical irregular building with shear wall has shown considerably better performance than other irregular buildings.