Abstract: This report focuses on improved physical techniques for small-scale reinforced concrete structures subjected to seismic loadings. Particular emphasis is placed on the development of a model concrete mix to accurately model the important strength and stiffness properties of full-scale prototype concrete. The gradation of aggregate used in the mix, along with the aggregate to cement ratio, are shown to be critical in achieving sufficiently low tensile strength while still maintaining acceptable critical strain levels at compressive failure of the model concrete. Four types of model reinforcement with different bond characteristics are also studied. Using these model materials, the adequacy of bond between model concrete and model reinforcement is then examined with experiments on a series of 1/6 scale model assemblages of a prototype beam subjected to reversing loads. It is concluded that small scale elements fabricated with annealed, threaded rod reinforcement best meet the similitude requirements for strength, stiffness, cyclic degradation of stiffness, energy absorption during fully reversing loads, and failure mode after severe cycling.
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Requesting from anyone who have this paper Ground movements due to pile driving in an excavation in soft soil by
I H Wong, T S Chua and published by Canadian Geotechnical Journal, 1999, Vol. 36, No. 1 : pp. 152-160
Hybrid Control of Seismic-Excited Nonlinear and Inelastic Structural Systems
Author: J. N. Yang, Z. Li and A. Danielians . | Size: 40 MB | Format:PDF | Quality:Scanner | Publisher: NCEER | Year: 1991 | pages: 110 | ISBN: Technical Report NCEER-91-0020
PART I
TABLE OF CONTENTS
SECTION TITLE PAGE
1. INTRODUCTION I-I
2. FORMULATION 1-4
2.1 General Nonlinear or Hysteretic Structures 1-4
2.2 Instantaneous Optimal Control 1-7
2.3 Time-Variant Linear Systems 1-9
2.4 Instantaneous Optimal Control with 1-11
Acceleration and Velocity Feedback
2.5 Simulation of Controlled Response for 1-12
Hysteretic Structural System
3. NUMERICAL EXAMPLE 1-16
4. CONCLUSION I-54
5. REFERENCES I-55
APPENDIX A FOURTH-ORDER RUNGE-KUTTA METHOD I-59
APPENDIX B INSTANTANEOUS OPTIMAL 1-61
CONTROL ALGORITHMS
PART II
TABLE OF CONTENTS
SECTION TITLE PAGE
1. INTRODUCTION II-I
2. OPTIMAL CONTROL OF INELASTIC 11-3
STRUCTURAL SYSTEMS
2.1 Nonlinear Hysteretic Model for Inelastic Systems 11-3
2.2 Equations of Motion 11-3
2.3 Instantaneous Optimal Control 11-8
2.4 Sufficient Condition for Optimal Control 11-10
2.5 Estimation of Hysteretic Component Vector V 11-10
3. NUMERICAL EXAMPLE 11-12
4. CONCLUSIONS 11-28
5. REFERENCES 11-29
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Modeling and Seismic Evaluation of nonstructural components Testing Frame for Experimental Evaluation of Suspended Ceiling Systems
Author: Andrei M. Reinhorn, Ki-Pung Ryu and Giuseppe Maddaloni | Size: 10.5 MB | Format:PDF | Quality:Original preprint | Publisher: MCEER , University at Buffalo, State University of New York | Year: 2010 | pages: 184 | ISBN: Technical Report MCEER-10-0004
This report describes the development of a new testing facility for the evaluation of suspended ceilings and
other nonstructural components that can be used with single or tandem shake tables. The 20 × 50 ft test
frame was designed to simulate realistic ceiling performance correlated with the response observed during
real earthquakes. The frame has dynamic characteristics with variable frequencies to match those typicallyfound in fl oors (or roofs) with suspended ceilings. It was also designed to accommodate various structural
materials and different framing layouts. Analytical models were developed using SAP2000 to estimate the
dynamic properties and complete the design of the test frame. The combined designs of the physical frame
and the shake table motion allow for testing a variety of suspended systems while simulating realistic fl oor
motions and eliminating side effects due to wall distortions. Finally, procedures for motion design that can
be implemented in other experimental facilities are introduced.
--------------------
General TABLE OF CONTENTS
INTRODUCTION
TEST FRAME DESIGN
ANALYTICAL MODELING
DESIGN AND EVALUATION OF FRAME’S ROOF TESTING MOTION
COMPENSATION PROCEDURE FOR SHAKE TABLE SIMULATION
SUMMARY, CONCLUDING REMARKS AND RECOMMENDATIONS
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evaluation of seismic retrofit of reinfirced concrete structures , Part II - Experimental Performance and Analytical Study of a Retrofitted Structural Model
ABSTRACT
This report is Part II of a two part series on the evaluation ofseismic retrofit methods for concrete
frame structures. It deals with the behavior of the entire structural system when several retrofit
techniques are applied to individual components. An analytical and an experimental study was
done on a scaled model of a structure and several retrofit techniques were evaluated. Part I
describes the evaluation of individual components retrofitted and tested with cyclic loading,
thar provided the base for modeling of the entire structure presented in this report.
In this report the evaluation of three retrofit techniques, i.e., concrete jacketing method, masonry
jacketing method, and partial frame masonry inf1ll, is presented based on an analytical study of
retrofitting a typical lightly reinforced frame designed according to ACI 318-89 only for gravity
loads (I.4D + L7L).
The jacketing technique is further evaluated based on an experimental and analytical study using
a 1:3 scale structural model subjected to simulated earthquake motion supplied by the seismic
simulator (shaking table) at SUNY/Buffalo.
The (jacketing) technique was applied only to selective portions of the structure, and it achieved
the limited improvement of strength and damage control as required in moderate seismicity
areas and as anticipated. This selected retrofit required only minimal structural interference
and may prove to be economically attractive.
The analytical modeling, based on component infonnation (obtained from the study presented
in Part I of this report series), shows that the overall response of retrofitted structures can be
adequately estimated, if good infonnation is available for the components.
---------------------------
General TABLE OF CONTENTS
INTRODUCTION.
RETROFIT OF GLD RIC FRAME STRUCTURES.
EXPERIMENTAL STUDY OF RETROFITTED R/C MODEL.
PERFORMANCE OF RETROFITTED R/C MODEL DURING
EARTHQUAKES.
CONCLUDING REMARKS.
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Posted by: mary - 11-15-2012, 01:16 PM - Forum: Archive
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Hi
Soil stress field around driven piles
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Centrifugal model testing of foundation piles in axial loading
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Posted by: giguni - 11-15-2012, 11:11 AM - Forum: Archive
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New formulas derived from seismic interferometry to simulate phase velocity estimates from correlation methods using microtremor
Toshiaki Yokoi
Geophysics July 2010 v. 75 no. 4 p. SA71-SA83
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Posted by: andersen3 - 11-15-2012, 10:53 AM - Forum: Concrete
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Effect of adhesive stiffness and CFRP geometry
Author: Reeve Benjamin Zachary | Size: 2.54 MB | Format:PDF | Quality:Original preprint | Publisher: University of Pittsburgh | Year: 2005 | pages: 110
The current American Concrete Institute (ACI) recommendation intended to mitigate
debonding failure by limiting the allowable strain in the FRP (the limiting strain is referred to as
εfub) is shown to be non-conservative, overestimating the strain where debonding becomes likely
by two fold for the high modulus adhesive and less so for the low modulus adhesive. The
equation for estimating εfubrecommended by Teng et al. (2001), including the modifying kbterm,
appears to provide appropriatelyconservative estimates of debonding for the specimens having
low modulus adhesive although remains unconservative for the high modulus adhesive. This
indicates that the nature of the adhesive should be included in the calculation of limiting strain.
Proposed values for the coefficient kwhich accounts for the b b f/b ratio were found to generally
underestimate the effect of the width ratio for the test specimens. Therefore, not only is the ratio
bf/b (as represented by kb) a contributing factor to bond behavior, its contribution may be
underestimated. Cover delamination (end peel debonding) was effectively mitigated in all
specimens by extending the CFRP close to the support along the relatively long shear span.
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Author: Hayward, Alan / Weare, Frank / Oakhill, A. C. | Size: unknown MB | Format:PDF | Quality:Unspecified | Publisher: Wiley-Blackwell | Year: 2011 | pages: 184-192
This highly illustrated manual provides practical guidance on structural steelwork detailing. Examples of structures include single and multi-storey buildings, towers and bridges. The detailing shown will be suitable in principle for fabrication and erection in many countries, and the sizes shown will act as a guide to preliminary design. The third edition has been revised to take account of the new Eurocodes on structural steel work, together with their National Annexes. The new edition also takes account of developments in 3-D modelling techniques and it includes more CAD standard library details.
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