ABSTRACT This paper presents a parametric investigation on the effects of viscous coupling on the seismic responses of subway stations in a saturated poroelastic half-space which is modeled as a two-phase medium by the Biot’s theory. Moreover, an equivalent single-phase model for the saturated poroelastic half-space is introduced, and comparisons between the single-phase solutions and the two-phase

ABSTRACT This paper provides a review of the procedure of customizing ShakeMap V4.0 provided by U.S. Geological Survey based on seismic characteristics of Iran. Selecting appropriate GMPEs, adopting a suitable spatial cross-correlation model and proper modeling of site condition are important factors in the context of the ShakeMap algorithm. The present paper technically reviews the aforementioned

ABSTRACT A seismic loss-based design framework is proposed. It relies on the introduction of a multi-objective loss-performance matrix that attempts to set an innovative design approach directly associating loss measures to performance levels as a function of the design seismic intensity and the social importance of the building. This approach provides higher awareness about the economic consequences

ABSTRACT This study proposed a general framework for adaptive delay compensation in real-time hybrid simulation(RTHS). This framework is composed of two main parts: an adaptive feedforward controller to handle variable time delay and amplitude discrepancies, and a feedback controller to enhance the robustness of compensation. In particular, the adaptive feedforward controller is determined using a

ABSTRACT Analysis of alatticed spherical shell is carried out by using the scaled and spectrum-matched records. The seed records for scaling and spectrum matching are selected, so their ground motion intensity measures are consistent with chosen targets. The analysis results indicate that the use of the spectrum-matched records leads to the coefficient of variation (COV) values of the load effects

ABSTRACT Centrifuge shaking table tests were conducted to reveal the intrinsic mechanisms of the effects caused by complicated seismic histories on the liquefaction resistance of a saturated sand deposit. The centrifuge model was shaken by a well-designed seismic sequence including 16 shakings in a certain order. Macroscopic and mesoscopic dynamic responses of the sand deposit were measured and analyzed

ABSTRACT The regional seismic damage assessment methods based on time-history analysis usually ignore the site-city interactions (SCI). The SCI may influence the simulated seismic responses and damage states of buildings. However, very few studies have been conducted to quantify the SCI effects on the damage states of buildings. In this study, the SCI effects on the seismic damage of buildings were

ABSTRACT After earthquakes, an accurate and efficient seismic-damage prediction is indispensable for emergency response. Existing methods face the dilemma between accuracy and efficiency. A real-time and accurate seismic-damage prediction method based on machine-learning algorithms and multiple intensity measures (IMs) is proposed here. 48 IMs are used for representing the ground-motion characteristics

ABSTRACT This paper investigates the seismic behavior of the rectangular-reinforced concrete columns subjected to pure flexure, pure torsion, and combined flexural-torsional loadings using 4 quarter-scaled experimental specimens. During flexural-torsional loading, the axial rotation to the relative displacement ratios were considered to be 2 and 4. The ultimate displacement capacity and the flexural

ABSTRACT Reinforced Concrete (RC) frame buildings with shear wall are widely used in severe seismic zones. However, the underlying soil-foundation system modifies the conventional fixed-base natural period through imparted flexibility. The currently available relationships for the modified natural period are mostly applicable to shallow foundations. Hence, those are not suitable for RC frame-wall buildings

ABSTRACT This study is focussed on the collapse performance assessment of steel truss moment frames (STMFs) with Vierendeel panels. The main parameters varied in this numerical study are the height of structures, bay width, aspect ratio of special segments, and number of ductile panels within the special segments. Incremental dynamic analyses are performed on twenty number of STMF archetypes having

ABSTRACT A study focused on evaluating the influence of higher modes of vibration on the seismic design of buildings with viscous dampers is presented. In the first part of the study, expressions to estimate velocity and acceleration correction factors, applicable to Mexico City, are proposed. In the second part, a numerical evaluation of two buildings with different characteristics is presented. Results

The seismic isolation technique is one of the most effective methods to control the seismic vibrations of structures by isolating them from the ground. In this research, an experimental and numerical study of a proposed elastomeric seismic isolator is presented. The proposed seismic isolator is composed of three components: rubber, top, and bottom connection plates, as well as steel rings, to enclose

A novel assessment method for rapid structural safety state assessment is developed based on state-of-the-art machine learning technology. In this paper, a deep neural network (DNN), which originated in computer science, is first introduced, including its concept, structure and related training algorithms. Then the evaluation procedure to determine the structural safety state based on the DNN is developed

This paper investigates the performance of the Magnetorheological damper as a smart dissipating device in the isolated buildings for prevention of seismic pounding. To that end, an isolated building was modeled by considering the pounding effect with different gap distances. Multi-objective optimization was performed to optimize the fuzzy logic control of damper for each gap distance. The results showed

It is well known that seismic events at sea can lead to severe effects on marine facilities. A seismic event can generate amplifications due to local conditions of the place, that is, site effects. In this work, we show numerical results of seismic amplifications on the seabed where there is the presence of deposits formed by soft soils. We formulate the problem using an Indirect Boundary Element Method

A theoretical calculation method for RC bridge column hysteretic model in saline soil environment was proposed. The effects of axial compression ratio and corrosion rate were considered in the test. Based on the failure process of the specimen, a trilinear skeleton curve model was proposed and theoretically calculated. Through the regression analysis of the test results, the unloading stiffness of

This study investigates the soil–structure interaction (SSI) behavior of low- to medium-rise steel moment-resisting frames (SMRF) resting on loose Ganga sand through a series of resonant vibration tests. Three-dimensional models of a three-story and a six-story structure are used for this purpose. Horizontal harmonic excitations, tuned to the first two natural frequencies of the structures, are applied

In this study, experiments are conducted to investigate the effect of wall-to-frame connectors on in-plane/out-of-plane (IP/OOP) behavior of the steel frames infilled with autoclave-cured aerated concrete (AAC) wall to find a reasonable connection type. Six infilled frames with different connection designs were tested. In specimens with V-shaped and T-shaped connectors, the OOP stability of the wall

Potential effects of torsional components of ground motions (TGM) on the overall seismic response of symmetric skew highway bridges have been investigated. Analyses were conducted for various skew angles, plan dimensions, deck-abutment gap sizes, dynamic properties, and soil types (B and D). The models included nonlinear impact between deck-abutment explicitly. It was demonstrated that seismic response

Comprehending the behavior of gypsum partition walls, as well as their associated fragility curves, is an integral part of performing seismic risk assessment of buildings. Knowing this significant contribution, several experimental and verified analytical simulations are developed during the past two decades for partition walls. However, their fragility curves are limited to certain geometries due

The dynamic response of complex structures can be estimated by means of Generalized Single Degree of Freedom (G-SDOF) systems. The original concept of the G-SDOF system is revisited using an alternative viewpoint based on the equilibrium of the three resultant dynamic forces associated with the stiffness, mass and damping components, and applied to frame structures equipped with viscous dampers. In

This study evaluated the phase relationship among the input motion, ground response, and pile response, which is a key consideration in the analysis of the kinematic–inertial interaction for piles. Dynamic centrifuge tests were conducted on single and group piles embedded in slopes of dry sands. Test results showed that the single pile moved in the opposite phase with the ground movement, whereas the

The Srinagar region of Kashmir Valley in North West Himalayas, covers more than 2 million inhabitants and is exposed to high seismic risk. In order to gain insight on potential site effects and subsurface structure of the region, we carried out an extensive high-resolution microtremor ambient noise survey at 429 locations. The acquired dataset was processed using the Horizontal to Vertical Spectral

Beam-through tension-only concentrically braced frame (denoted as BTF) is being gradually accepted in building industries due to its rapid prefabrication and higher economic benefits. However, due to the limited energy dissipation capacity and high pinching hysteretic behavior of tension-only braces, the BTF buildings may be vulnerable to soft-story failure under rare seismic events. Here, an Energy-absorbing

Ground motions could be modelled as amplitude and frequency modulated process. The frequency modulation through a time transformation results in the modelled motions in the new timescale being a stationary process except for the amplitude modulation. The assessment of power spectral density (PSD) and the lagged coherence in the transformed timescale is presented in this study. It is shown theoretically

A cable-stayed bridge full model was tested to study the travelling wave effects on the transverse acceleration frequency spectra, seismic responses, and pile-soil interactions under transverse non-uniform excitations. The results indicate that the non-uniform excitations affect the transverse acceleration frequency spectra of the girder. The non-uniform excitations increase the displacement at 3/4-span

Among commonly used nondestructive testing techniques for evaluating the integrity of pile foundations, reflection methods based on stress wave propagation are widely accepted as cost-effective tools. For uncapped piles, the frequently used Impulse Response (IR) method has long been recognized as one of the most reliable methods. This paper extends prior developments on the IR method’s core mobility

This paper is devoted to the investigation into the lateral performance of cross-laminated timber (CLT) shear walls with different construction methods (i.e., platform construction and balloon construction). Quasi-static cyclic tests were conducted on four CLT shear wall specimens. The hysteretic performance, failure modes and contribution of deformability components of the specimens were obtained

This paper proposes an alternative time-dependent seismic fragility assessment framework considering the variable correlation of structural random parameters for aging highway bridges subject to non-uniform chloride-induced corrosion attacks. The proposed systematic framework is implemented to perform a probabilistic time-dependent seismic fragility assessment for a typical multi-span reinforced concrete

This paper presents the applicability of Reduced Length Buckling-Restrained Braces (RLBRBs) in combination with strut elements in deep excavations. Strut members are used as part of the lateral load resisting system. By proposing a new type of RLBRB section, the advantages of RLBRBs are demonstrated in dynamic soft soil-structure interactions. A numerical investigation is carried out to clarify the

The November 12, 2017, moment magnitude (Mw) 7.3 Sarpol-e Zahab earthquake, which occurred after a seismic quiescence, close to the Iran–Iraq border, is one of the largest events recorded in the Zagros fold and thrust belt. In this study, we analyzed strong-motion data of this event from 38 stations within an epicentral distance of 36 to 200 km. Spectral analysis of strong-motion data resulted in an

in this study, new prediction equations are proposed to determine the variables of gamma envelope-shape Function. Envelope-shape functions are employed for the simulation of ground motion using a stochastic method in order to form the white noise. A variety of Envelope-shape functions have been already proposed, among which gamma equations are more used in computational programs for the simulation

Cumulative absolute velocity (CAV) is a ground motion intensity measure that is considered more indicative of structure damage than other intensity measures (e.g., PGA). Nevertheless, most seismic hazard assessments are PGA-based rather than CAV-based. In this paper, the first CAV seismic hazard assessment for Taiwan was presented. According to this CAV seismic hazard assessment, central-western and

This paper investigates fire department response time to locations of ignition after an earthquake and proposes a framework to identify vulnerable areas in a community by considering both the likelihood of ignition and potential delays in response of the fire department. Delays are calculated as a function of bridge damage and blocked roadways due to building debris. Uncertainty in bridge performance

Precast beam–column connections, which are difficult to prefabricate and assemble, are critical members of concrete frames in high seismic regions. In this study, a novel type of precast hybrid connection with different connection configurations is developed for an easy and rapid construction. This steel–concrete connection involves a concrete column with an embedded steel skeleton, a concrete beam

As a matter of fact, structural drift is a random variable that is associated with several bases of the uncertainties related to the loading excitation and structural resistance. Hence, it seems essential to utilize the probabilistic philosophy to provide a design criterion of control the structural drift. The current study was conducted to propose a probabilistic approach to control the structural

Structures on coral reefs are often subjected to the earthquakes. However, few researches have been reported about the seismic response of coral sand site. Shaking table tests of structures supported by pile groups were performed to reveal the seismic response of pile-soil-superstructure system by comparing with quartz sand site. Moreover, the effects of pile number and shaking intensity on the dynamic

Owing to the remarkable differences in structural periods of vibration, cable-stayed bridges and their adjacent spans are highly susceptible to earthquake-induced pounding damages. Based on the proposed simplified analysis model, parametric analyses are conducted to investigate the effect of pounding on the seismic demands of a cable-stayed bridge and its adjacent spans. The results indicate that compared

Great earthquakes are likely to generate ground motions larger than those considered in design codes (over-design ground motions) and hence leading to a seismic demand that causes severe damages of structural components in general high-rise steel moment-resisting frames (SMRFs). Overall seismic behavior of high-rise SMRFs may be significantly affected by the local failure of members. This paper focuses

The present study proposes a statistical methodology to rate the habitability of different types of buildings after an earthquake. The first step was to rank variables that affect the vulnerability of a building and formulate a statistical study with a discrimination index that makes it possible to identify buildings as habitable or non-habitable. This ranking applied the criteria established in various

This paper presents a performance-based seismic design method of RC moment resisting frame with friction damped self-centering tension braces (FSTB-Frame). The structural configuration and theoretical model of FSTB is introduced, and the numerical model of FSTB is established and validated through cyclic loading tests of a FSTB specimen. Based on the equivalent linear method, the seismic design procedure

A framework to quantitatively evaluate seismic resilience of hospital systems is proposed. A typical hospital system is categorized and importance factors for different functional units, subsystems, and components are quantified. Resilience demand is expressed as desirable recovery time of hospital system after earthquakes. Seismic resilience is quantified based on probabilistic seismic fragility analysis

This paper presents a new hybrid passive control device, consisting of a viscoelastic and a friction damper connected in parallel, to mitigate the effects of wind and seismic events. The two components are synergized with the aid of a novel locking mechanism, which enables the action of one or both the components depending upon the device deformation. This provides an innovative two-phase energy dissipation

The method of incremental dynamic analysis (IDA) is one of the most accurate nonlinear seismic analyses. IDA is a time-consuming method and has a high computational cost. Also, an IDA curve should be obtained from the building analysis subjected to a series of earthquakes that should cover all regions of the structural responses. In this paper, the discrete wavelet transform is used to solve these

A novel integrated precast concrete (PC) structural system, which maximizes instead of minimizing the interaction between the PC sandwich cladding panel and main structure, is proposed through the introduction of U-shaped dampers. To systematically validate the feasibility and reliability of this system, a full-scale PC wall-frame substructure equipped with an energy dissipation PC sandwich cladding

Seismic performance of postmainshock buildings considering seismic mainshock-aftershock sequences are studied. The case studies correspond to three SAC steel MRF buildings of three, nine and twenty stories. The 2-D models are able to capture important properties of deterioration of strength and stiffness. Endurance time method is used to predict the response of structures in different hazard levels

In regions of low-to-moderate seismicity where representative strong motion data is lacking, the modelling of seismic hazard relies on the use of seismological models. This paper presents a set of expressions that can be used as ground motion prediction equations that have been transformed from seismological models which resolve the generation of seismic waves into several components. The feature of

A weighted scaling method (WSM) is developed for the selection and modification of structure-specific earthquake records in time-history analysis. The matching errors and scaling factors are calculated by weighted least-squares method to match with target spectrum. The weight factors are determined by the modal-mass participation factors. The 3-, 9-, and 20-story steel moment-resisting frame structures

The 2017 M5.4 Pohang, South Korea, earthquake damaged numerous buildings. Immediately after the main shock event, 1,880 professional engineers inspected the damaged buildings and assigned three damage grades (“Usable,” “Restricted use,” and “Unusable”). We investigate factors influencing the building damage. The built year, number of stories, and estimated peak ground acceleration are strongly related

In this paper, the problem of dynamic stress concentration in the process of anti-plane motion caused by a single circular cavity in a strip medium and the non-circular cavity in a porous strip medium is studied. In the case of only a single circular cavity, a numerical calculating example is presented to solve scattering around a circular cavity with a given SH guided wave and describe dynamic stress

Assessment of liquefiable soils strength is a challenging task in engineering practice especially when a structure is founded on top of the liquefied soil. While it has been addressed and studied in the literature, the lack of practically feasible approaches to calculate the bearing capacity of soil in such a condition is tangible. In this study, simple analytical equations have been proposed to calculate

Structure-canyon-structure interaction is investigated using a whole model of two shear walls supported by rigid foundations on both sides of a semi-circle river-canyon embedded in a homogenous half-space. A closed-form analytical solution is presented for the model response to incident plane SH-wave based on the wave function expansion method. The analysis focuses on the effects of the structure-canyon-structure

A hybrid force/displacement (HFD) performance-based seismic design method is proposed for two types of plane reinforced concrete structures, i.e., infilled moment-resisting frames (I-MRFs) and wall-frame dual systems (WFDS). The HFD seismic design method is a force-based method which controls with high accuracy both structural and non-structural deformation limits. The behavior factor is related here

This study introduced a new design of the grouted corrugated duct connection (GCDC), which improves the structure integrity, bond strength and ease of constructability. A two-phase experimental program was performed to fully understand the connection behaviour. Phase I focused on the pull-out tests of 32 specimens in two batches with various conditions. It indicates that a connection length of 30 times

To assess the dynamic stiffness of shallow foundations, as an alternative to the existing rigorous approaches, it is convenient to idealize the soil as some semifinite truncated cones representing the infinite nature of the supporting soil. The one-dimensional wave equation for cones which is usually defined in frequency domain has been extended to be solved directly in the time domain. The recently

Newmark analyses of lateral spreading induced by liquefaction were conducted using a database of 22 documented case histories. Site stratigraphy and SPT values for the liquefiable soil were based upon the case-history documentation. The yield acceleration was estimated based on post-liquefaction residual shear strength estimated using three different correlations with SPT blow count. Representative

Under near-field ground motions, fluid viscous dampers (FVDs) are effective in controlling deck longitudinal displacement but lead to the increase of bending moment and shear force at tower base. Negative stiffness (NS) devices are introduced in combination of FVDs for the bridge. The NS devices lengthen the fundamental vibration period of the bridge to reduce the spectrum acceleration whereas FVDs

In timber structures, connections traditionally provide ductility and energy dissipation under seismic loading. Capacity design ensures that the global structural response is ductile by applying overstrength to the design demand of brittle elements. Overstrength is often derived experimentally which is costly and time-consuming. This paper proposes an analytical method to estimate the overstrength

In removal and replacement technique, yielded hoops from the damaged joint core are not removed for practical difficulties, and it remains inside the joint core after rehabilitation. An attempt has been made in the present article to study the effect of yielding of hoops on cyclic performance of seismically detailed beam-column joint. It was observed that in case of specimens with pre-yielded hoops