Rocking Stability of Masonry Arches in Seismic Regions

2008 ◽  
Vol 24 (4) ◽  
pp. 847-865 ◽  
Author(s):  
Matthew J. DeJong ◽  
Laura De Lorenzis ◽  
Stuart Adams ◽  
John A. Ochsendorf
Keyword(s):  
Experimental Testing ◽  
Base Excitation ◽  
Masonry Arches ◽  
Masonry Arch ◽  
Specific Criterion ◽  
Earthquake Motion ◽  
Time Histories ◽  
Rocking Motion ◽  
Failure Predictions ◽  
Primary Base

This study evaluates the susceptibility of masonry arches to earthquake loading through experimental testing and progresses toward a specific criterion by which arches can be quickly assessed. Five different earthquake time histories, as well as harmonic base excitations of increasing amplitude, were applied to model arches, and the magnitude of the base motion resulting in collapse was determined repeatedly. Results are compared with failure predictions of an analytical model which describes the rocking motion of masonry arches under base excitation. The primary impulse of the base excitation is found to be of critical importance in causing collapse of the masonry arch. Accordingly, a suite of failure curves are presented which can be used to determine the rocking stability of masonry arches under a primary base acceleration impulse which has been extracted from an expected earthquake motion.

Rocking Response of Unanchored Flat-Bottom Cylindrical Shell Tanks Subjected to Horizontal Base Excitation: Part I — Rigid Bottom Plate

2003 ◽  
Author(s):  
Tomoyo Taniguchi
Keyword(s):  
Cylindrical Shell ◽  
Liquid System ◽  
Bottom Plate ◽  
Base Excitation ◽  
Inertial Coordinate System ◽  
Flat Bottom ◽  
Coriolis Forces ◽  
Time Histories ◽  
Rocking Motion ◽  
Reaction Forces

The rocking dynamics of the tank is discussed by introducing the rock-translation interaction. The centrifugal, inertia and Coriolis forces accompanied with non-inertial coordinate system are incorporated into the conventional and translational tank-liquid system. Moreover, the reaction forces from the tank-liquid system are taken rocking system into account. As the beginning of series researches, using a rigid cylinder and a tank with rigid bottom plate, the necessity of the rock-translation interaction for evaluating rocking responses of the tank is highlighted. In addition, the sufficient friction to enter and sustain a rocking motion of the tank is discussed based on time histories of horizontal and vertical reaction forces on the pivoting edge.

Rocking Response of Unanchored Flat-Bottom Cylindrical Shell Tanks Subjected to Horizontal Base Excitation: Part II — Flexible Bottom Plate

2003 ◽  
Author(s):  
Tomoyo Taniguchi
Keyword(s):  
Cylindrical Shell ◽  
Effective Mass ◽  
Bottom Plate ◽  
Base Excitation ◽  
Base Shear ◽  
Flat Bottom ◽  
Time Histories ◽  
Rocking Motion ◽  
Reaction Forces ◽  
Overturning Moment

The mechanical analogy of the rock-translation interaction system of the tank is verified by comparing analytical results with experimental ones. To trace actual rocking behaviors of the tank, the existence of effective mass and moment inertia of liquid for a rocking motion, which is proportional to the uplift region of bottom plate, is assumed. The comparison of restoring moment defined by early investigators with overturning moment by proposed methods can identify the region of effective mass for a rocking motion in an iterative manner. Moreover, the base shear and uplift angle calculated agree with ones measured at previous shaking tests. These results corroborate the applicability of proposed methods. Finally, the sufficient friction to enter and sustain a rocking motion of the tank is discussed based on time histories of horizontal and vertical reaction forces on the pivoting edge.

Seismic Behaviour of Composite Panel Composed of Laminated Wood and Bearing Glass - Experimental Investigation

2013 ◽  
Vol 778 ◽  
pp. 698-705 ◽  
Author(s):  
Lidija Krstevska ◽  
Ljubomir Tashkov ◽  
Vlatka Rajčić ◽  
Roko Zarnic
Keyword(s):  
Earthquake Engineering ◽  
Experimental Testing ◽  
Shaking Table ◽  
Composite Panel ◽  
Seismic Excitations ◽  
Seismic Behaviour ◽  
Time Duration ◽  
Earthquake Motion ◽  
Scientific Project ◽  
Real Earthquake

Within the bilateral scientific project between the Institute of Earthquake Engineering and Engineering Seismology - UKIM-IZIIS, St. Cyril and Methodius University, Skopje, Republic of Macedonia and the Civil Engineering Faculty, University of Zagreb, Croatia, experimental testing of full scale composite timber-glass innovative panels was carried out on the seismic shaking table at IZIIS for the purpose of defining their behaviour and stability under real earthquake conditions. The seismic excitations selected for the shake-table testing of the model were four representative accelerograms recorded during the following earthquakes: El Centro, Petrovac, Kobe and Friuli. The idea was to investigate the seismic behavior of the model under several types of earthquakes, considering their different frequency content, peak acceleration and time duration. The performed tests showed clearly the behaviour of the composite panels and the failure mechanism under strong earthquake motion.

Mitigation of Rocking and Sliding Motion of a Free-Standing Structure Subjected to Base Excitation Using Coaxial Circular Cylinders Containing Highly Viscous Liquid in Annular Spaces

2019 ◽  
Author(s):  
Atsuhiko Shintani ◽  
Tomohiro Ito ◽  
Chihiro Nakagawa
Keyword(s):  
Rigid Body ◽  
Viscous Liquid ◽  
Analytical Model ◽  
Circular Cylinders ◽  
Base Excitation ◽  
Free Standing ◽  
Seismic Input ◽  
Sliding Motion ◽  
Standing Structure ◽  
Rocking Motion

Abstract In this study, the effectiveness of coaxial circular cylinders containing a highly viscous liquid in annular spaces for reduction of rocking motion of a free-standing structure is investigated both analytically and experimentally. First, an analytical model of coupled rocking and sliding motions of a free-standing structure, including the coaxial circular cylinders, subjected to seismic input was derived. The free-standing structure was modeled as a free-standing rigid body. The cylinders were attached to the bottom of the rigid body as a damping device. We then experimentally derived the friction coefficients, inertia moments, and a damping coefficient in the rotating direction. Furthermore, using these parameters, the effectiveness of this system in suppressing the rocking motion is investigated analytically. The proposed method was determined to be very effective in suppressing the rocking motion of a rigid body subjected to a seismic input by the experiment.

scholarly journals Experimental Investigation of the Behavior of Self-Form Segmental Concrete Masonry Arches

Fibers ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 58 ◽  
Author(s):  
Ali A. Abdulhameed ◽  
AbdulMuttalib I. Said
Keyword(s):  
Construction Materials ◽  
Plain Concrete ◽  
The Self ◽  
Fiber Reinforced Polymer ◽  
Masonry Arches ◽  
Masonry Arch ◽  
Reinforced Polymer ◽  
Concrete Masonry ◽  
Load Carrying ◽  
A New Technique

This research aims to introduce a new technique—off-site and self-form segmental concrete masonry arches fabrication, without the need of construction formwork or centering. The innovative construction method in the current study encompasses two construction materials forms the self-form masonry arches, wedge-shape plain concrete voussoirs, and carbon fiber-reinforced polymer (CFRP) composites. The employment of CFRP fabrics was for two main reasons: bonding the voussoirs and forming the masonry arches. In addition, CFRP proved to be efficient for strengthening the extrados of the arch rings under service loadings. An experimental test was conducted on four sophisticated masonry arch specimens. The research parameters were the Keystone thickness and the strengthening of the self-form arch ring at the intrados. The major test finding was that the use of thicker Keystone alters the behavior of the self-form arch and considerably increases the load carrying capacity by 79%. Partial strengthening of the intrados with CFRP fabrics of typical arch ring Keystone resulted considerable increase in the debonding load of fabrication CFRP sheets by 81%, increase in the localized crushing load by 13% and considerably increase voussoir sliding load by 107%.

On the Analysis of Minimum Thickness in Circular Masonry Arches

2011 ◽  
Vol 64 (5) ◽  
Author(s):  
Giuseppe Cocchetti ◽  
Giada Colasante ◽  
Egidio Rizzi
Keyword(s):  
Opening Angle ◽  
True Self ◽  
Minimum Thickness ◽  
Equilibrium Conditions ◽  
Masonry Arches ◽  
Masonry Arch ◽  
Tangency Condition ◽  
Basic Equilibrium ◽  
Internal Forces ◽  
Horizontal Thrust

In this paper, the so-called Couplet–Heyman problem of finding the minimum thickness necessary for equilibrium of a circular masonry arch, with general opening angle, subjected only to its own weight is reexamined. Classical analytical solutions provided by J. Heyman are first rederived and explored in details. Such derivations make obviously use of equilibrium relations. These are complemented by a tangency condition of the resultant thrust force at the haunches' intrados. Later, given the same basic equilibrium conditions, the tangency condition is more correctly restated explicitly in terms of the true line of thrust, i.e., the locus of the centers of pressure of the resultant internal forces at each theoretical joint of the arch. Explicit solutions are obtained for the unknown position of the intrados hinge at the haunches, the minimum thickness to radius ratio and the nondimensional horizontal thrust. As expected from quoted Coulomb's observations, only the first of these three characteristics is perceptibly influenced, in engineering terms, by the analysis. This occurs more evidently at increasing opening angle of the arch, especially for over-complete arches. On the other hand, the systematic treatment presented here reveals the implications of an important conceptual difference, which appears to be relevant in the statics of masonry arches. Finally, similar trends are confirmed as well for a Milankovitch-type solution that accounts for the true self-weight distribution along the arch.

Structural Effects of Brick Arrangement and Span Length on Mid-Pointed Arches

2010 ◽  
Vol 133-134 ◽  
pp. 411-416 ◽  
Author(s):  
Mehrdad Hejazi ◽  
Farshad Jafari
Keyword(s):  
Finite Element ◽  
Brick Masonry ◽  
The Finite Element Method ◽  
Structural Effects ◽  
Structural Behaviour ◽  
Masonry Arches ◽  
Masonry Arch ◽  
Persian Architecture ◽  
Element Technique ◽  
Structural Engineers

One of the most important, valuable and remarkable elments of Persian architecture is brick masonry arch. Structural behaviour of Persian brick masonry arches has not been studied in details. Any investigation into their characteristics can be beneficial for maintenance, retrofit, restoration and reconstruction of such arches. The effect of a brick arrangement in the fabric of arches, such as Roman and barrel arrangements, on structural behaviour of brick masonry arches has been a serious controversy among architects and structural engineers for many years. In this study, micro-modelling finite element technique has been used to analyse mid-pointed arches with two different brick arrangements, i.e. Roman and barrel arrangements, under static weight load using the finite element method. Analyses have been carried out and obtained results have been discussed to describe the effect of brick arrangement on structural behaviour of analysed arches with three different span lengths.

Analytical and Numerical Analysis on the Collapse Mode of Circular Masonry Arches

2010 ◽  
Vol 133-134 ◽  
pp. 467-472 ◽  
Author(s):  
Egidio Rizzi ◽  
Giuseppe Cocchetti ◽  
Giada Colasante ◽  
Fabio Rusconi
Keyword(s):  
Numerical Analysis ◽  
Angular Position ◽  
Discontinuous Deformation Analysis ◽  
Deformation Analysis ◽  
Opening Angle ◽  
Specific Reference ◽  
Minimum Thickness ◽  
Masonry Arches ◽  
Masonry Arch ◽  
Collapse Mode

In this paper, an analytical and numerical analysis on the collapse mode of circular masonry arches is presented. Specific reference is made to the so-called Couplet-Heyman problem of finding the minimum thickness necessary for equilibrium of a masonry arch subjected to its own weight (Heyman 1977). The note reports the results of an on-going research project at the University of Bergamo. First, analytical solutions are derived in the spirit of limit analysis, according to the classical three Heyman hypotheses and explicitly obtained in terms of the unknown angular position of the intrados hinge at the haunch, the minimum thickness to radius ratio and the non-dimensional horizontal thrust (Colasante 2007, Cocchetti et al. 2010). Results are then compared to Heyman solution. Though only the first of these three characteristics is perceptibly influenced in engineering terms, especially at increasing opening angle of the arch, the treatment settles an important conceptual difference on the use of the true line of thrust, along the line of Milankovitch work. Second, numerical simulations by the Discrete Element Method (DEM) in a Discontinuous Deformation Analysis (DDA) computational environment are provided, to further support the validity of the obtained solutions, with good overall matching of the obtained results (Rusconi 2008, Rizzi et al. 2010).

Toppling Fragility of Unrestrained Equipment

1998 ◽  
Vol 14 (4) ◽  
pp. 695-711 ◽  
Author(s):  
Z. Y. Zhu ◽  
T. T. Soong
Keyword(s):  
Fragility Curves ◽  
Response Spectra ◽  
Static Friction ◽  
Block Type ◽  
Base Excitation ◽  
Loss Of Function ◽  
Floor Response Spectra ◽  
Rocking Motion ◽  
Design Earthquake ◽  
Supporting Base

Block-type equipment without restraining devices and under earthquake loads can effectively be modeled as freestanding rigid blocks resting on supporting bases subjected to base excitations. Once the peak values of base excitation levels, the aspect ratio of the bock, and the static friction coefficient between the block and the supporting base are known, the motion type of the block that will be initiated under base excitation can be determined. One of the possible motion types is rocking. When rocking is initiated, the block may topple and suffer severe damage and permanent loss of function. The emphasis of this study is placed on quantifying the possibility of toppling of a rigid block during rocking motion given its geometry and design earthquake environment. Using floor response spectra to characterize excitation inputs, results are given in the form of toppling fragility curves, i.e., probability of toppling as a function of peak ground accelerations. Parametric sensitivity studies are also carried out to show the effects of several key parameters on the fragility results.

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