Building Design Codes Research Articles

A limit state approach for considering greenhouse gas emissions in the structural design of buildings: Environmental Impact Limit State (EILS)

Recent reports underscore the growing significance of embodied greenhouse gas emissions in the building industry, necessitating sustainable structural designs to combat climate change. However, the current building and structural design codes require satisfying Ultimate and Serviceability Limit States (ULS and SLS) without setting limitations on embodied emissions in the design process of structural members. Thus, this study proposes an Environmental Impact Limit State (EILS), specifying allowable and design emissions for structural components, to be used alongside ULS and SLS. The EILS combines nominal emission intensities from parametric analysis with fuzzy-logic-based uncertainty factors, enabling standardized consideration of environmental impacts in sizing structural elements. The EILS calibration is demonstrated for flat slab and shear wall systems following Canadian codes. The calibration involved an extensive parametric study (450, 975, and 2160 configurations for flat slabs, columns, and shear walls) to evaluate the impact of design and loading parameters. A detailed numerical example is presented to showcase the incorporation of EILS in the design process, achieving emission reduction on magnitude of 25 % compared to non-EILS design process.

Out-of-plane behavior of unreinforced masonry walls with horizontal slip layers in RC frames

In some cases, the infilled walls may be subjected to in-plane（IP） earthquake and out-of-plane(OOP) earthquake action due to the uncertainty of earthquake action and infills’ position. As a new type of unreinforced masonry(URM) walls with horizontal slip layers, it can effectively reduce the in-plane damage of infilled walls of reinforced concrete frames under an earthquake. However，the infill wall out-of-plane damage has a greater security threat than in-plane damage. In this study, a numerical study about the difference of OOP behavior of URM walls with/without horizontal sliding layers are analyzed, mainly including failure mode, bearing capacity, displacement capacity and stiffness. The spacing of horizontal slip layers, length of annectent reinforcing bars and the friction efficient between slip layer and masonry unit are chosen to investigate the differences of OOP mechanical behaviors. The results show that the horizontal sliding layers reduce the integrity of URM walls in reinforced concrete frames, causing the constraint of surrounding frame on infilled wall and the arching effect inside infilled wall become weaker, and OOP bearing capacity to drop. It is found that i) the annectent reinforcing bars is conducive to reducing the out-of-plane failure of the wall; 2)the smaller the slip layer spacing of the wall is, the more serious the damage of the infill wall under the out-of-plane load is, and the smaller the out-of-plane bearing capacity and the out-of-plane stiffness of the wall are; iii) the influence of the friction coefficient between slip layers and masonry unit on OOP mechanical behaviors is small. Finally, Chinese building design code is also selected to estimate the OOP bearing capacity of URM walls with horizontal sliding layers. The value of λcr is recommended to be greater than 1.0, and the value of λP is greater than 3.3. The spacing of the slip layer should be greater than 1 / 5 of the wall height, and the length of the annectent reinforcing bars should not be less than 1 / 5 of the infilled wall length.

Predicting natural vibration period of concrete frame structures having masonry infill using machine learning techniques

The natural period of vibration is one of the most significant factors used in the seismic design of buildings. Although the building design codes and previous studies provide some empirical methods to compute the natural period of vibration (T), their marginal accuracy and inability to incorporate the effect of masonry infill on vibration period significantly limits their use. Thus, researchers are constantly trying to find new and accurate methods to calculate T of concrete structures. To this end, this study presents the novel approach to predict T of reinforced concrete framed buildings (RC buildings) using Multi Expression Programming (MEP), Extreme Gradient Boosting (XGB), and Gene Expression Programming (GEP) machine learning algorithms. For this purpose, an extensive dataset of 569 points was gathered from previously published studies and split into training and testing sets for training and testing the algorithms respectively by using several error evaluation metrices like coefficient of determination (R2), Root Mean Squared Error (RMSE), and Objective Function (OF) etc. The results of error evaluation showed that XGB is the most accurate algorithm having the least OF value of 0.012 compared to 0.037 of MEP and 0.048 of GEP. Additionally, several explanatory analyses like sensitivity and shapley analysis were conducted on the XGB model which showed that number of storeys and opening ratio are the most contributing variables to prediction period of vibration. Thus, the models developed in this study can be practically utilized for determining natural vibration period of reinforced concrete frames with masonry infill.

An Investigation of Seismic Behaviour of Prestressed Concrete Frame Structures using Pushover Analysis

Abstract: The prestressed concrete system is a prominent material in civil engineering, with applications ranging from buildings, bridges, foundations, piling, silos, stadiums, roadways, and other infrastructure. However, this work is primarily concerned with its applicability to building frame constructions subjected to seismic loading. The prestressed concrete system for frame constructions not only reduces the amount of structural components, but it is also a cost-effective technology that provides outstanding strength and stiffness, as well as quick and simple site erection. Hence, we will be able to use these prestressed concrete components to their full capacity, unlocking engineering and social benefits that were previously impossible. Prestressed concrete designs, as opposed to reinforced concrete designs, can give structures with substantially longer spans, no cracks, or fewer cracks with tiny crack widths. Nonetheless, research on the seismic behaviour of prestressed concrete frame structures is relatively restricted, with the majority of studies focusing on reinforced concrete structures. Finally, the provisional versions of modern building codes such as ACI 318, GB50010, and EC2 do not provide thorough processes for seismic design of prestressed concrete structures. In this work, the seismic design and behaviour of prestressed concrete building frames are explored using the most recent design code. Three model-building codes will be investigated and compared, including ACI 318- 14, Eurocode 2004-2, and Chinese GB500010-2010. The 10-story prestressed concrete frame system is subjected to gravity and seismic loading, and the strong-column weak beam mechanism is archived to conform with the newly implemented building design code. To examine the behaviour of prestressed concrete frame structures, nonlinear static pushover analysis is used to capture the reaction under earthquake loading. The stiffness and strength needed will be designed in compliance with the three major building codes indicated. In addition, the finite element model will be created using CSI Sap200 to capture its actions.

Experimental investigations on prefabricated interlocking prestressed tendon composite joint and its application to beam-column connection

This study proposes an interlocking prestressed tendon composite joint (I-PTCJ) that can be applied to a beam–column connection of the multi-story structure. First, the main structure and prefabrication process of the I-PTCJ were introduced. Next, three beam–column specimens using local and integral I-PTCJs (named specimens PT1 and PT2) and a traditional interlocking joint (I-J, specimen named TG1) were designed and manufactured. Furthermore, quasi-static experiments were performed on these three specimens to evaluate their seismic performance. In addition, the influence of the prestressed tendons (PTs) and the arrangement mode (local or integral) of the I-PTCJs were investigated in detail. Finally, a preliminary comparative analysis between the experimental and simulated results was carried out. The results showed that the introduction of the PTs reduced the degree of damage within the PT installation area, delayed the cracking of the interlocking interface, and improved the bond performance of the longitudinal rebar. However, it also aggravated the degree of damage outside the PT installation area and reduced the displacement ductility and energy dissipation capacity of the specimen. Compared with TG1 (using the traditional I-J), PT1 (using the local I-PTCJ) had a higher peak load, lower displacement ductility, higher shear deformation, gentler rigidity deterioration, and lower cumulative energy dissipation. Compared with PT1, PT2 (using the integral I-PTCJ) had a higher peak load, lower displacement ductility, lower shear deformation, lower cumulative energy dissipation, and better bond performance of the longitudinal rebar. Both the yield displacement angle and ultimate displacement angle met the deformability requirement of the existing building design codes. Thus, the proposed I-PTCJ can be applied to the beam-column connection of multi-story structures.

Effect of axial-load ratio and shear-span ratio on seismic behavior of the prefabricated structures for cast-in-place RC boundary elements confined uniform hollow panels

To meet the requirements of seismic safety, energy efficiency, and convenient transport, while achieving efficient construction of low or multi-story building structures. A prefabricated structure was developed with uniform hollow panels as the main force elements and cast-in-place RC provides restraint. The safety of the connection between the elements was verified by a low cyclic loading experiment and numerical analysis. In addition, the influence of the axial-load ratio and the shear-span ratio on the seismic performance of the structure was investigated, and the damage characteristics of progressive failure were revealed. The study found that as the axial-load ratio increased from 0.15 to 0.30, the cracking of the uniform hollow panels progressed, but the cracking of the columns was delayed, and the tendency of the edge member to separate from the uniform hollow panel increased. The ultimate lateral load capacity increased by 9.96 %, but the deformation capacity decreased, and the ductility coefficient decreased from 3.19 to 2.45. As the shear-span ratio decreased from 1.35 to 0.95, the uniform hollow panel and the structural columns cracked earlier and later, respectively, and the ultimate lateral load-bearing capacity increased by 25.03 %. However, the cracks at the base of the column increased, the deformation capacity decreased, and the ductility coefficient decreased from 3.19 to 2.15. Meanwhile, it is observed that the structure exhibits a three-stage progressive failure characteristic, i.e., the joint working stage, transformation transition stage, and weak frame stage. This greatly improved the deformation and energy dissipation capacity of the structure, which maintained good stability even when the inter-story displacement angle reached 1/50. This paper also established the calculation method for the lateral load resistance of this prefabricated structure, which showed accurate and reliable results. In general, the results of this research can provide an important reference for building design code and the application of this structure.

Seismic Behavior of Reinforced Concrete Bridge and Control Measures for Seismic Pounding

India has had a variety of the world’s greatest earthquakes within the last century. In fact, quite one half area within the country is taken into account vulnerable to damaging earthquakes. The seismic building design code in India (IS 1893, Part-I) is additionally revised in 2002. The magnitudes of the look seismic forces are considerably enhanced generally, and also the seismic zonation of some regions has also been upgraded. There are many literature (e.g., IITM-SERC Manual, 2005) available that presents step-by- step procedures to gauge multi-storeyed buildings. The attention for existing bridges is relatively less. However, bridges are important components of transportation network in any country. The bridge design codes, in India, don’t have any seismic design provision at this time. A outsized number of bridges are designed and constructed without considering seismic forces. Therefore, it is important to gauge the capacity of existing bridges against seismic force demand. There are presently no comprehensive guidelines to help the practicing structural engineer to gauge existing bridges and suggest design and retrofit schemes. So as handle this this problem, this work aims to hold out a seismic evaluation case study for an existing RC bridge using nonlinear static (pushover) analysis. Nonlinear static (pushover) analysis as per FEMA 356 isn’t compatible for bridge structures. So, within the present study an improved pushover analysis is additionally won’t to verify the results.

Characteristics of earthquake ground motions governing the damage potential for Delhi and the surrounding region of India

The proximity of Delhi and the surrounding region to the active faults along with its geographical settings is a subject of discussion to comprehend the seismic resilience of the capital region of India. The region may be affected by the far-field earthquakes from the Himalayas as well as the near-field earthquakes associated with the local seismic activity. Considering the ordinary settings of this region, the present study is an insight to differentiate the damage potential of ground motion associated with near and far-field conditions to further see their consequences to understand the comprehensive seismic hazard of the region. The acceleration and velocity response analysis of recorded strong ground motions from far-field and near-field earthquakes exhibit a clear distinct behavior in the form of amplification and corresponding predominant period. The comparison of estimated normalized spectral accelerations with that of the seismic design code of the Bureau of Indian Standards (BIS), shows that the current Indian building design code is within the structural limits proposed for the seismic forces of long periods, however, exceeded amplitude of the normalized Spectral Acceleration for far-field earthquakes may be attributed towards the damage potential for the high rise buildings in the capital region of India. On the other hand, near-field earthquakes do not meet the criteria with the design code of BIS at lower periods from 0.02s to 0.09s along with the amplified Spectral acceleration. It also suggests that the structural heterogeneities within the subsurface of Delhi and the surrounding region have a strong bearing in contributing to the impact of seismic waves from near-field earthquakes producing short-period waves that may be disastrous for low-rise buildings. Based on the results, the study region affected by the distinct seismicity patterns is important to understand the shaking behavior of the different kinds of infrastructures/buildings in case of near-field and far-field earthquakes to appropriately utilize the information for constructing new buildings and strengthening the existing infrastructures in Delhi and the surrounding region of India.

An inquiry into the effect of thermal energy meter density and configuration on load disaggregation accuracy

Initial and maintenance costs often prevent dense submeter installations that enable room-level thermal energy monitoring. Previous studies suggested that building automation system (BAS) trend data represents an untapped potential to disaggregate existing meter data for heating and cooling into device- and system-level end-uses. These techniques disaggregate meter data by analyzing trend data that provide contextual information regarding the operating status of energy-consuming equipment. However, the level of submetering required to enable end-use disaggregation has yet to be studied. To this end, this paper investigates the effect of submeter density and configuration on the performance of a regression-based disaggregation strategy using BAS trend data as predictors. The method was evaluated in two steps; first, using synthetic meter and BAS trend data generated by a building performance simulation (BPS) model of a government office building, and second, with submeter data from a real office building. The results highlight the factors affecting the minimum number of heating energy submeters needed to be installed in both buildings for accurate device- and system-level disaggregation. The methodology presented in the paper can also inform changes in building design codes and standards regarding the minimum density and appropriate configuration for submetering.

Seismic collapse performance of high-rise RC dual system buildings in subduction zones

The satisfactory ‘collapse prevention’ performance level of reinforced concrete (RC) buildings has been widely recognized during recent earthquakes in Chile. However, there is limited research on the actual level of seismic collapse protection. In this study, the seismic collapse behavior of high-rise RC dual wall-frame buildings representative of the Chilean inventory is quantitatively evaluated. A suite of four 16-story structural archetypes was carefully selected and code-based designed assuming two different locations (i.e., high and moderate seismicity zones) and two different soil types (i.e., very stiff and moderately stiff soils). The archetypes were analyzed considering the latest developments in performance-based earthquake engineering implementing incremental dynamic analyses for 3D nonlinear models with sets of Chilean subduction ground motions. Results, expressed in terms of the probability of collapse conditioned on the Maximum Considered Earthquake (MCE) hazard level (<10%) and the collapse probability in 50 years (<1%), showed that all archetypes fully met the targets specified by ASCE 7 for an acceptable ‘life safety’ risk level. These results indeed explain why a very small number of RC building collapses was observed in the recent megathrust earthquakes (Mw>8.0) in Chile. Nevertheless, it was also found that the seismic collapse performance is not uniform, due mainly to the soil type. This observation suggests that the design spectra indicated by the Chilean seismic design code for buildings might need to be revised.

A comparative study on the lateral displacement of a multi-story RC building under wind and earthquake load actions using base shear method and ETABS software

The aim of this study is to propose a comparison between wind and seismic loads on a multi-story reinforced concrete (RC) building. The investigation focuses on lateral displacements and story drifts of a 6-story RC structure, which are determined manually using the base shear method and with the aid of the ETABS software tool. The study considers a linearity of the structure and uses the Chinese building design code for lateral displacement analysis. The base shear method is a simplified method that only considers one degree of freedom for each story, neglecting the non-linearity of the structures. However, the Chinese building code permits its use when considering the consistent vertical distribution of the building's mass and stiffness, which leads to shear deformation prevailing during seismic and wind reactions. The lateral displacements under wind and seismic loads are estimated, and the story drift limitation criteria of the Chinese building design code are assessed. Both the base shear method and ETABS's story drift computation (story drift 1/550) meet the design code criteria. This indicates that the base shear technique approach of RC frame structures can reasonably predict the tale drift on each story, despite relying heavily on simplifications. To compare the outcomes from the ETABS program to the internal forces under seismic and wind load activities, the story displacements and drifts are computed. The results show little discrepancy between the base shear method and ETABS software. Hence, the base shear approach can be utilized when there is no irregularity, and the building height is less than 40 m. Overall, the findings of this study indicate that the base shear method can provide a good approximation for the lateral displacements and story drifts of multi-story RC constructions under wind and seismic loads, provided that the Chinese building code criteria are met. The study highlights the importance of using appropriate design codes and tools in ensuring the safety and reliability of structures. Further research can explore the applicability of similar simplified methods in more complex and irregular structures, and the development of more accurate and efficient design tools.

Experimental Study and Fragility Analysis of Effective-length Factors in Column Buckling

The design of columns relies heavily on the basis of Leonhard Euler's Theory of Elastic Buckling. However, to increase the accuracy in determining the maximum critical load a column can withstand before buckling, a constant was introduced. This dimensionless coefficient is K, also known as the effective-length factor. This constant is often found in building design codes and varies in value depending on the type of column support that is applied. This paper presents experimental and analytical studies on the determination of the effective-length factor in the buckling stability of columns with partially-fixed support conditions. To this end, the accurate K value of the columns tested by the Instron Testing Machine (ITM) at California State University, Northridge’s (CSUN’s) Mechanics Laboratory is determined. The ITM is used in studying the buckling of columns where the supports are neither pinned nor fixed, and the material cross-section rather rests upon the machine while loading is applied axially. Several column specimens were tested and the experimental data were analyzed in order to estimation of the accurate effective-length factor. The calculations from the tested results as well as the conducted probabilistic analysis shed light on how a fragility curve may aid in predicting the effective-length value of future tests.

The Duration Effect of Pulse-Type Near-Field Earthquakes on Nonlinear Dynamic Analysis and Damage Evaluation of Hydraulic Tunnels

Current research trends in significant hydraulic engineering projects focus on investigating the seismological properties of intensity and frequency content of pulse-type near-field earthquakes on the structural response. Conversely, the duration impact is not expressly addressed in the seismic design code for underground buildings. Currently, various duration indicators of as-recorded strong ground motions mainly consider the effective duration of the initial acceleration component record. In contrast, the duration indicators for the effective velocity duration (EVD) of the original velocity time-history component record have rarely been addressed. Specifically, there is a gap between the effective velocity duration and the structural response. To illustrate the impact on the structural response, an EVD of pulse-type NFGM duration was used. This EVD can be calculated for seismic excitations with set threshold values that enable a quantitative examination of the duration effects. A fluid-hydraulic tunnel-rock interaction system was built and used to estimate the seismic response characteristics induced by different duration NFGMs. The investigation’s findings highlight that the inelastic dynamic response and damage degree are strongly affected by the EVD. Additionally, the fixed threshold value of 5–95% showed an excellent correlation coefficient with the structural response. The significant duration was also found to be the most suitable alternative indicator to replace the EVD index. In addition, the reduced time-history methodology of near-fault earthquake records is presented and validated, with this method being used to improve the efficiency of the dynamic time-history analysis of hydraulic arched tunnels.

Scalable risk assessment of large infrastructure systems with spatially correlated components

Risk assessment of spatially distributed infrastructure systems under natural hazards shall treat the performance of individual components as stochastically correlated due to the common engineering practice in the community including similarities in building design code, regulatory practices, construction materials, construction technologies, and the practices of local contractors. Modelling the spatially correlated damages of an infrastructure system with many components can be computationally expensive. This study addresses the scalability issue of risk analysis of large-scale systems by developing an interpolation technique. The basic idea is to sample a portion of components in the systems and evaluate their correlated damages accurately, while the damages of remaining components are interpolated from the sampled components. The new method can handle not only linear systems, but also systems with complex connectivity such as utility networks. Two examples are presented to demonstrate the proposed method, including cyclone loss assessment of the building portfolios in a virtual community, and connectivity analysis of an electric power system under a scenario cyclone event.

Incremental seismic retrofitting for essential facilities using performance objectives: A case study of the 780-PRE school buildings in Peru

This paper presents a methodology to develop incremental seismic retrofitting alternatives for essential buildings through a nonlinear analysis. The retrofitting levels are defined in terms of the performance objectives such as immediate occupancy, life safety, code compliance and collapse prevention. Each of these is associated with a seismic hazard linked to a return period equivalent to a frequent, occasional, rare, and extreme event. The methodological approach conceives the non-linear behavior of the system through the definition of plastic hinges for structural components such as beams and columns. As soon as the model is properly defined, a nonlinear pushover analysis is performed to obtain the seismic response of the buildings. In addition, an incremental dynamic analysis is carried on for the equivalent single degree-of-freedom models of the same buildings, to estimate the critical seismic intensity at which collapse occurs; this allows corroborating the suitability of the proposed retrofitting alternatives. Once the methodology was well explained, a school building typology designated as a 780-PRE was chosen as an interesting case study for validation purposes. A total of 40,000 of its type were designed (under the national building design code RNC-77) and constructed between 1977 and 1997 throughout all the Peruvian territory. Typically, this system is characterized by reinforced concrete moment-resisting frames with unreinforced infill masonry walls. Despite its widespread use, this system typology has shown to be highly vulnerable under previous seismic events, depicting repetitive short-column failure mechanisms and partial collapses. This confirms a fragile failure contrary to the intended original design behavior for the as-built condition. Based on the previous understanding of the problem, several alternatives of incremental seismic retrofitting were considered in this study, supported on a benefit-cost evaluation to come up with feasible seismic vulnerability reduction strategies. After the interventions were selected and implemented, a noticeable improvement of the seismic response was perceived, depicted by a reduction in the expected damage under low and moderate seismic demands. Finally, the analyses were extended to several seismic zones in Peru.

Evaluation and Assessment of Existing Design Codes and Standards for Building Construction

Building design codes (BDC) are used to control the construction industry in general and building design in particular. The BDC offers the construction sector with a standard language and set of requirements. There are several BDCs developed and utilized for construction purposes throughout the world. Certain design codes are employed in structural design to assure the structure’s health and safety, as well as its cost-effectiveness. It also assures that the structure is sufficiently sturdy to endure all potential climatic conditions, bear its intended load, and is integrated to ensure effective use of building materials and resources. This research aims to compare various building construction design codes to identify and explore the most appropriate standard in terms of safe design, economics, and availability of details. In Kurdistan and different parts of Iraq, many international companies have designed building structures with various codes during the past 20 years. This is a bad condition since the government has no control over the construction of the buildings, which includes both the code and the building materials. There is currently no overview of the design codes in use in Kurdistan, nor is it clear whether they are congruent with what students’ study in institutions.

Machine learning based design of reinforced concrete shear walls subjected to earthquakes

Civil engineering structural components are classified according to their projected structural performance in the present building code regulations and design standards. These building design codes are largely based upon previous experimental results of thousands of samples tested to failure and validated with analytical solutions. Machine Learning techniques (ML) is a subset of Artificial Intelligence (AI) that facilitates classification and prediction of structural performances for a broad spectrum of complex structures with greater accuracy. Machine learning models have the potential to make reliable predictions with the help of algorithms. Thereby, saving a tremendous amount of time and resources invested in experimental investigations of large structural components such as shear walls and columns. The ML algorithms can learn from the available data, deduce underlying inter-relationships, make inferences and detect patterns based on previous experience. In the present work, various ML algorithms were implemented to identify the influence of geometrical as well as mechanical characteristics. Database of 393 specimens of reinforced concrete shear walls with rectangular (R), flanged (F) and barbell (B) cross-sections are adopted for the analysis. Shear walls are fundamentally classified into four failure categories which include flexure or due to bending, shear, intermediate flexure-shear and sliding due to shear. The objective of this paper is to classify and predict the shear strength, flexural strength as per the Indian standard code provisions and failure modes of shear walls with the help of ML techniques. Algorithms such as KNearest Neighbors, Naive Bayes, Decision Tree, Random Forest, AdaBoost, LightGBM, XGBoost and Cat-Boost is implemented using Python. Highest accuracy of 85% is achieved on the test set by Random Forest, 83% by CatBoost and 81% by LightGBM boosting algorithms. It is observed that input variables such as aspect ratio (lw/tw), characteristic strength of concrete in compression (f ck ), characteristic yield strength of steel (f y ), percentage of steel (ρ), web vertical reinforcement, horizontal reinforcement, boundary element reinforcements play a vital role in governing the shear strength (V u ) and flexural strength (M u ) of shear walls.

"Comparative Study of RC Frame Building with NBC 105:2020 and IS Code 1893:2002"

Construction is a vital part of every developing country in this era. Every country has specific building design codes which provide the standards to engineers for the design of various structural components like beam, column and slab. RC building design of every country is based on their geographical location. In today world of globalization, an engineer must be efficient to understand and handle codes of various countries. Considering this the main focus of this research work is to bring out differences and similarities between different RC design codes and to use it to develop a common platform. In this research RC design code of NEPAL, INDIA are considered. The main focus is the relative gains and shortcomings of various buildings design codes under certain criteria like loading analysis, design analysis, ease of use and economical point of view. Several parameters for different cross-section and different building material on basis of strength are considered. Comparison work has worked out on the basis of loading comparison like live load, dead load, wind load and different parameters for various elements of the building such as beam, column and slab. Load factor and load combination are also compared. This comparison investigates the design capacities for various building design codes.In present study RCC building models having G+8 stories with regular plan is considered for analysis. The analysis of model is done using equivalent static method in ETABS software.

Comparative analysis of earth quake resistant building design by considering bracings and shear wall system in ETABS software

Earthquakes are one of nature's most prominent risks to life on this planet and have decimated incalculable urban areas and towns on for all intents and purposes each landmass. Earth quack resistant structure is one of the most important concept in structural engineering. According to building design codes, earth quake resistant is depending upon the seismic zones. As per IS code 1893:2015 code seismic zones are classified in to four types they are Zone V, Zone IV, Zone III and Zone II. Everyday new procedures are being produced for the advancement of living arrangements financially, rapidly and satisfying the prerequisites of the gathering specialists and creators do the crease work, arranging and design, and so on, of the developments. The bracing systems and shear wall systems are generally used for designing the earth resistant structures, due to its simple construction methods and easy to install at the site. Both bracing systems and shear wall methods reduces the deflection of building as per the considerations. In the present study a G + 12 building is modeled by using ETABS Software and analysis is carried out by using Response spectrum analysis. The results like storey drift, storey shear, storey bending, time period and frequency were compared for building models made with steel bracings and shear wall systems.

Problems and suggestions on site classification

The physical meaning of site classification is not clear in the current seismic design code for buildings, at the same time, the boundary of site classification is easy to cause the divergence of design ground motion parameters. For the above problems and deficiencies, some suggestions are given. To solve the problem that the physical meaning of site classification is not clear, on the basis of the current site classification method, according to the site classification index such as the covering layer thickness and the equivalent shear wave velocity, the sites are classified by two-level: the first level classification is consistent with the current one, which classifies sites based on the fundamental period of the site and the thickness of the overburden layer; the second level classification further considers the degree of hardness of the geotechnical medium based on the first level classification, and sub-classification according to equivalent shear wave velocity. Based on the current research on seismic disaster and seismic motion characteristics of thick soft site, combined with the development of long-period constructions, the site classification is expanded from the original four categories to five categories, at the same time, the boundary of each classification, especially the boundary of class II, III and IV sites, is limited from the original open type, which can effectively avoid the problem of divergence of design ground motion parameters caused by site classification. The related research results can provide reference for site classification and determination of design ground motion parameters.