Showing papers on "Earthquake resistant structures published in 2020"

Nonlinear dynamics of earthquake-resistant structures using shape memory alloy composites:

Abstract: Earthquake-resistant structures have been widely investigated in order to produce safe buildings designed to resist seismic activities. The remarkable properties of shape memory alloys, especially ...

Editorial: Recent Advances and Applications of Seismic Isolation and Energy Dissipation Devices

Abstract: Department of Engineering, University of Messina, Messina, Italy, Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, United Kingdom, Department of Architecture and Architectural Engineering, Kyoto University, Kyoto, Japan, Department of Civil Engineering, University of Patras, Patras, Greece, 5 School of Architecture and Design, University of Camerino, Ascoli Piceno, Italy, 6 Faculty of Civil and Environmental Engineering, Technion-Israel Institute

Seismic resilience analysis of a retrofit-required bridge considering moment-based system reliability

Abstract: For a bridge, its columns or piers, which are the main seismically resistant members of the bridge, are generally retrofitted to improve seismic performance. However, retrofitting may cause unexpec...

Earthquake-resistant buildings with steel or composite columns: Comparative assessment using structural optimization

Abstract: This work investigates and compares the cost-effectiveness of seismically designed buildings having either pure steel or steel-concrete composite columns. In order to ensure an objective comparison of these two design approaches, the assessed building designs are obtained by a structural optimization procedure. Thus, any bias that would result from a particular designer's capabilities, experience, and subjectivity is avoided. Hence, a discrete Evolution Strategies optimization algorithm is employed to minimize the total cost of materials (steel and concrete) used in a structure subject to constraints associated with: (a) Eurocode 4 provisions for safety of composite column-members, (b) Eurocode 3 provisions for safety of structural steel members, and (c) seismic system behaviour and resistance. Extensive assessments and comparisons are performed for a variety of seismic intensities, for a number of building heights and plan configurations, etc. Results obtained by conducting 154 structural design optimization runs provide insight into potential advantages attained by partially substituting steel (as a main structural material) with concrete when designing the columns of earthquake-resistant buildings.

New structural seismic protection for high-rise building structures

Abstract: Presented Structural Seismic Isolation Method (SSIM) aims to provide high safety for Highly Reliable Structures (HRS) against strong earthquakes including near-fault and long-period ground motions. The examined structure is converted to Structural Seismic Isolation System (SSIS) by the SSIM method which exhibited inverse pendulum behaviour. For this purpose, structure foot base and foundation contact surfaces have been designed as any curved surfaces (spherical, elliptical, etc.) depending on the earthquake-soil-superstructure parameters and this contact surfaces have been separated by elastomeric (lead core rubber or laminated rubber bearings) seismic isolation devices. It would allow the structure foot base to turn around gyration centre through rubber bearing contact and maintains similar behaviour to the super-structure. SSIS system provides the possibility of keeping the natural-period of the structure in a larger interval, which is greater than the predominant-period of the majority of possible earthquakes (including near-fault pulse) using currently existing conventional elastomeric isolators with up to 4 second period. Thus, the structure can sustain its serviceability after strong and long-period earthquakes. In this study SSIS system’s performance is presented for high-rise building structures, for this aim, the finite element model of the building (Bg) structure with SSIS system (SSIS-Bg) has been prepared and the nonlinear dynamic analysis of the model has been conducted using strong and long-period ground motions. Results indicate that the base and top accelerations, base shear and base moment responses of the SSIS-Bg structure is 23.21 %, 75.47 % and 85.74 % in average lower than the Conventional Application Method of Seismic Base Isolation Devices for Building (CAMSBID-Bg) structures respectively and it is not prone to resonant vibrations under long-period earthquakes related with the excessive deformation in the isolation layers in case of using CAMSBID-Bg structures. It should be noted that in this study with the presented SSIM method and SSIS system, it is aimed to protect only the Highly Reliable Structures(HRS) from the effects of strong and long-period ground motions and these structures (HRS) are classified as follows: 1) Nuclear Containment Structures; 2) High-rise buildings that contain information, operating systems, sensitive instruments, communication systems, routing systems, bank operating systems, databases, management systems and other similar facilities that are linked to the security and economy of a country; 3) High-rise hospitals etc.

Heat Engineering Heterogeneity Of The Outer Walls Of Earthquake-Resistant Buildings

Abstract: When assessing the level of energy efficiency of civilian buildings, a special place is given to establishing the level of thermal protection of their external enclosing structures. Significant discrepancies in the results of theoretical and experimental studies of heat fluxes through the outer walls of buildings erected in seismic areas are associated with the design features of fences the presence of reinforced concrete elements in them: anti-seismic belts at the level of floors, cores at intersections of walls and along the edges of large window openings ... In addition, in recent years, external walls have become widespread, which are filling of bricks or aerated concrete blocks between the main structural elements of the frame monolithic reinforced concrete columns and

Experimental investigation on interlocking concrete block for masonry wall of non-engineered earthquake resistant buildings

Abstract: Most of the seismic damage of existing traditional buildings is due to the absence of practical beam and column structures as the main reinforcement of the building. While a masonry wall as a structural component is commonly negligible due to their relatively low strength in contributing to the frame structure. As a result, when the earthquake struck, the building collapsed, and the ruins of building elements hit the occupants seriously and caused many deaths. This paper presents the results of preliminary research on the experimental investigation of interlocking concrete block for the masonry wall applied to non-engineered earthquake-resistant buildings. The interlocking between concrete blocks is expected to contribute to the strength of the masonry wall in resisting the loads, either in-plane or out-of-plane directions. The novelty of this type of concrete block lies in the uniqueness of the interlocking shape, making it effective in withstanding the earthquake load. This research focuses on the testing of interlocking concrete block units in withstanding loads in the direction and perpendicular to the field and equipped with testing the compressive strength of the wall and diagonal shear strength. The results produce interlocking models of concrete block contribute to better strength than ordinary clay bricks for the masonry wall.

Sustainable Design of Earthquake-Resistant Buildings Through Case Studies

Abstract: Soil-pile-structure interaction (SPSI) plays an important role in assessing the vibrations internally generated within structures due to dynamic loads that could bring significant impacts on structural behavior. In this study, the effects of (SPSI) forces on the seismic response of three tall and massive building cases were investigated. The emergency hospital building is an existing reinforced concrete construction with concrete columns. Due to the importance of the building and its potential danger in failure cases of the load-bearing structure, earthquake analysis was first carried out by using a 3D finite-element model for the entire structure and FCONE program for the soil under the structure. This program utilizes the equivalent dynamic modeling concept in the analysis of soil dynamics and pile-foundation interaction. The implementation of simulation was conducted in two different conditions: namely, fixed-base behavior and soil-structure interaction are considered. In this case, soil-structure interaction is considered by assigning equivalent springs and dashpots located under foundation, and the analyses were carried out directly in the time domain for considering the effects of interaction. It is shown that the effects of soil-structure interaction are demonstrated as increasing the period of vibrations and the displacements. Based on the results obtained by using CONE method, the period of vibration in the case of concentrated piles with the correction factor for pile-group action, exhibiting the value of (1.2 s), which is increased up to 42% compared with the case of fixed base (0.7 s). Similar results were obtained for seismic analysis of two other cases. It has shown that the first period of vibration in the case of Silo project and MIT Science Building increased by about 74% (from 1.72 s to 3 s) and 11% (from 1.37 s to 1.53 s) with respect to the SPSI effect, respectively. Besides, a comparison was made between the structural responses of the obtained CONE method and 3D finite-element simulation in ABAQUS which indicated that these results were in good agreement with direct results. It was concluded that CONE model as a convenient, fast, and rather accurate method can be applied for foundation vibration and dynamic soil-structure interaction analysis in a practical engineering projects whenever possible.