Building Code Criteria Research Articles

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.

Constructing a greener future: A comprehensive review on the sustainable use of fly ash in the construction industry and beyond

An industrial by-product known as fly ash has several possible uses, especially in the building sector and others. Fly ash is used as a cement substitute in blended cement or concrete and is valued for its potential advantages, including greater structural strength, cost efficiency, and environmental sustainability. The distinctive particle size properties of fly ash, which support its adaptability and affordability, are important factors considered in this work. This work explores the inherent qualities of fly ash that can advantageously contribute to cement mortar and concrete compositions by a thorough investigation of various scientific literature, which includes empirical studies, case studies, and review articles. The analysis was conducted under the presumption that these advantages can be significantly increased with the right amount of fly ash. Findings demonstrated that structural concrete components need to be properly cured in both friendly and hostile circumstances. There is evidence that fly ash can boost strength to a certain extent, with a 30% fly ash mix being ideal for normal loading and a 20% fly ash mix for more difficult circumstances. Improved workability, lower heat of hydration, increased resistance to sulphate assaults, and stronger weather resistance are further noteworthy benefits. Fly ash is an essential component of sustainable construction since it complies with ASTM, LEED, and building code criteria. This study also looked at the numerous uses of fly ash outside of the building industry, emphasising its potential in industries including agriculture, soil stabilisation, and the manufacture of lightweight building materials. Future research into the creative application of fly ash in the Indian building industry appears to be quite promising. Last but not least, this investigation highlighted how employing fly ash has important environmental advantages, such as having the capacity to lower CO2 emissions, control the greenhouse effect, and lessen environmental contamination.

An isolation case study of a vertical caisson wall directly adjacent to an underground rail vibration source

A large concrete tower planned for construction was proposed at a site immediately adjacent to underground rail. The underground rail passenger trains pass frequently at a rate of once per 2-4 min 18–20 h per day. Excavation began and a caisson wall was constructed facing the underground vibration source. Preliminary measurements were made by placing an accelerometer on the East facing caisson wall. Attenuation was required in the 20-63 Hz frequency range. An isolation layer (GenieMat DM) was added to the caisson wall. The presentation will illustrate how this was done in combination with water proofing of the foundation and other onsite complexities. Large steel tie-backs are used to hold the caisson wall in place and these were treated to prevent any direct path for vibration. Upon completion of construction, measurements are taken and the level differences are presented. Attenuation exceeded the design and building code criteria at all one-third octave bands of concern.

Simple Method to Develop Seismic Microzonation Maps for Cities in Northern Haiti and Elsewhere

Many developing nations are situated in zones of high seismicity where earthquakes can lead to widespread property loss and loss of life. Similar-sized earthquakes are not nearly as devastating in developed nations because of access to state-of-practice engineering methods. Earthquake engineering to reduce property loss and loss of life includes geotechnical engineering to predict likely amounts of ground shaking. Herein, a simple geotechnical approach was implemented in four cities in northern Haiti, including Port-de-Paix, Cap-Haitien, Fort Liberte, and Ouanaminthe based. The approach was based on the use of a simple geophysical technique and the application of International Building Code criteria to calculate design levels of ground shaking. The Spectral-Analysis-of-Surface-Waves (SASW) method is a geophysical technique that was employed in the four test cities during a five-day test period utilizing three workers and a backpack full of equipment. As a result of this investigation, microzonation maps depicting design ground surface shaking parameters were rapidly and inexpensively developed, which can be used by structural engineers for guidance in designing earthquake-resistant structures. This method can be easily deployed in other developing nations to provide these populations with nearly the same level of knowledge and protection against earthquakes that is realized in developed nations.

A WebGIS Application for Rendering Seismic Hazard Data in Italy

In 2004, on behalf of the Department of Civil Protection (DPC—Dipartimento della Protezione Civile), the Istituto Nazionale di Geofisica e Vulcanologia (INGV) released a new Italian seismic hazard map. The entire scientific process was public and transparent: an international panel of experts conducted a peer review while the work was in progress, and all the input data, the final output, and the technical documentation was published. The details of the entire process are available on a dedicated Web site (http://zonesismiche.mi.ingv.it). The new hazard map provides the expected value of horizontal peak ground acceleration (PGA) with an exceedance probability of 10% in 50 years. This elaboration was recently adopted (ordinance 3519/2006 signed by the Prime Minister) as the “reference map” for assigning municipalities to one of four seismic zones according to building-code criteria. In the building code released in 2005 (ministerial decree 14/09/2005), the seismic zone assignment criteria is the expected PGA value; for each seismic zone the code also defines a standard design spectrum anchored to a fixed PGA value allowing designers to change the anchor value of the response spectra within a 20% discretionary margin when more detailed information on the expected shaking parameters of the site of interest are available. In addition to the scientific community, local administrators and professionals, typically civil engineers and architects, use seismic hazard values. Administrators use them to define the appropriate level of protection for the regions they oversee, while professionals refer to them to provide the best compromise between building costs and safety. Following the publication of the reference map, the DPC financed the S1 project to produce a set of additional elaborations that would better describe the Italian seismic hazard. This resulted in a set of maps expressed in terms of PGA and Sa (spectral accelerations), both evaluated for different …

Criteria for Estimating the Required Average Strength f'cr to Comply with the Specified Compressive Strength f'c

The ACI Building Code criteria for estimating the required average strength f'cr is evaluated using actual field data. Basically, the current criteria specify that the required average strength f'cr should be larger than the specified compressive strength f'c by a certain amount. The magnitude of overdesign or the difference between f'cr and f'c would depend on the quality control of the particular concrete suppier. The quality control, which is related to the variability of the strengths over a period of time, is usually measured in terms of standard deviation. The code specifies that the amount of overdesign should be based on the standard deviation obtained using a minimum number of specimens and a multiplying factor t. The factor t is chosen to result in no more than 1 in 100 low tests. The code equation is consistent with the recommendations of Committee 214, Strength Evaluation. Committee 214 also recommends a set of t values that can be used for any specified permissible low tests, such as 1.28 for 1 in 10 low tests. The numerical values of t are based on the assumption that the compressive strengths of a large population of specimens follow the normal frequency distribution curve. This basic assumption is evaluated in this paper using the field test data obtained from various geographic locations. The average compressive strength varied from 3,512 psi to 11,057 psi (24.3 MPa to 76.2 MPa). Quality control, measured in terms of standard deviation, varied from excellant to poor. The results show that the values of t obtained using normal distribution are generally conservative, but there is a variation in the occurrence of low tests. The field data is used to set the upper and lower limits of low tests for a given t. Modification of ACI Building Code equations is proposed for a more conservative estimate of the required average strength f'cr.

Commercially available structural engineering computer programs

The computer programs which are the subject of this paper are those which have been developed by private organizations and for usage of which a fee has to be paid. These programs as well as all engineering programs may be classified into three types: Artisan, Academic and Engineering. Artisan type programs are those which consist of computarization of old manual methods. Academic type programs are those which consist of computerization of advanced theoretical methods for a refined analysis, or for an exact optimization, or for an interactive design. Engineering type programs are those which consist of a combination of some features of the two previous types in order to design the lightest structures capable of supporting the governing combination of loading conditions and satisfying the pertinent Building Code criteria. The paper discusses each of these three program types and describes in some detail a few cases of application of engineering type programs.