Performance of Reinforced Earth® bridge abutment walls in the 2010-2011 Canterbury earthquakes

2013 ◽  
Vol 46 (1) ◽  
pp. 11-24 ◽  
Author(s):  
John H. Wood ◽  
Donald E. Asbey-Palmer
Keyword(s):  
Design Procedure ◽  
Design Parameters ◽  
Critical Acceleration ◽  
Ground Shaking ◽  
Bridge Abutment ◽  
Reinforced Earth ◽  
Earthquake Design ◽  
Design Values ◽  
Canterbury Earthquake Sequence ◽  
Strong Ground

Reinforced Earth bridge abutment walls were subjected to strong ground shaking in one or more of the earthquakes in the Canterbury earthquake sequence of September 2010 to December 2011. Although the walls at three sites were subjected to ground motions of intensity greater than the design level none of the walls were damaged by the earthquakes. The paper describes the earthquake design procedure used for the Reinforced Earth abutment walls and back-analyses carried out after the earthquakes to investigate their performance. Calculations based on probable material strengths rather than the dependable design values, and assuming no strip corrosion, gave critical accelerations to initiate sliding movements of the walls that were about 20% greater than predictions based on the design parameters. No significant outward movements of the walls were observed following the earthquakes. This was consistent with the predicted critical acceleration levels for the walls in their condition at the time of the earthquakes.

Direct Displacement-Based Seismic Design of Propped Rocking Walls

2015 ◽  
Vol 31 (1) ◽  
pp. 179-196 ◽  
Author(s):  
Afsoon Nicknam ◽  
Andre Filiatrault
Keyword(s):  
Nonlinear Response ◽  
Design Procedure ◽  
Seismic Intensity ◽  
Ground Shaking ◽  
Direct Displacement Based Design ◽  
Seismic Force ◽  
Supplemental Damping ◽  
Displacement Based ◽  
Rocking Walls ◽  
Strong Ground

A direct displacement-based design (DDBD) methodology is described for propped rocking walls (PRWs). PRWs represent a novel seismic force-resisting system that combines passive supplemental damping devices with unbonded post-tensioned concrete rocking walls. The key aspect of the proposed design procedure is the closed-form derivation of the stabilized hysteretic response of PRWs under reverse cyclic loading. This allows the direct application of the DDBD procedure to satisfy desired displacement performance objectives under prescribed levels of seismic intensity. Nonlinear response analyses are conducted on a prototype PRW structure, designed according to the proposed DDBD procedure to evaluate its performance under strong ground shaking.

scholarly journals Evaluation of seismic design parameters for the museum of New Zealand site

1995 ◽  
Vol 28 (2) ◽  
pp. 118-133 ◽  
Author(s):  
J. H. Wood ◽  
G. R. Martin
Keyword(s):  
New Zealand ◽  
Seismic Design ◽  
Response Spectra ◽  
Lateral Spreading ◽  
Design Parameters ◽  
Acceleration Response ◽  
Ground Shaking ◽  
Acceleration Response Spectra ◽  
Time Histories ◽  
Strong Ground

Investigations carried out to evaluate the seismic design parameters, including acceleration response spectra and time-histories, for the design of the Museum of New Zealand, Te Papa Tongarewa, on the Wellington waterfront are described. The procedures used to assess the site stability under strong ground shaking and to determine the maximum likely lateral spreading and settlements are also summarised.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Nonlinear behavior of soil sediments identified by using borehole records observed at the Ashigra Valley, Japan

1995 ◽  
Vol 85 (6) ◽  
pp. 1821-1834
Author(s):  
Toshimi Satoh ◽  
Toshiaki Sato ◽  
Hiroshi Kawase
Keyword(s):  
Shear Strain ◽  
Main Part ◽  
Nonlinear Behavior ◽  
Strong Motion ◽  
S Wave ◽  
Ground Shaking ◽  
Wave Velocities ◽  
The One ◽  
Soil Sediments ◽  
Strong Ground

Abstract We evaluate the nonlinear behavior of soil sediments during strong ground shaking based on the identification of their S-wave velocities and damping factors for both the weak and strong motions observed on the surface and in a borehole at Kuno in the Ashigara Valley, Japan. First we calculate spectral ratios between the surface station KS2 and the borehole station KD2 at 97.6 m below the surface for the main part of weak and strong motions. The predominant period for the strong motion is apparently longer than those for the weak motions. This fact suggests the nonlinearity of soil during the strong ground shaking. To quantify the nonlinear behavior of soil sediments, we identify their S-wave velocities and damping factors by minimizing the residual between the observed spectral ratio and the theoretical amplification factor calculated from the one-dimensional wave propagation theory. The S-wave velocity and the damping factor h (≈(2Q)−1) of the surface alluvial layer identified from the main part of the strong motion are about 10% smaller and 50% greater, respectively, than those identified from weak motions. The relationships between the effective shear strain (=65% of the maximum shear strain) calculated from the one-dimensional wave propagation theory and the shear modulus reduction ratios or the damping factors estimated by the identification method agree well with the laboratory test results. We also confirm that the soil model identified from a weak motion overestimates the observed strong motion at KS2, while that identified from the strong motion reproduces the observed. Thus, we conclude that the main part of the strong motion, whose maximum acceleration at KS2 is 220 cm/sec2 and whose duration is 3 sec, has the potential of making the surface soil nonlinear at an effective shear strain on the order of 0.1%. The S-wave velocity in the surface alluvial layer identified from the part just after the main part of the strong motion is close to that identified from weak motions. This result suggests that the shear modulus recovers quickly as the shear strain level decreases.

scholarly journals Earthquakes on the surface: earthquake location and area based on more than 14 500 ShakeMaps

2018 ◽  
Vol 18 (6) ◽  
pp. 1665-1679
Author(s):  
Stephanie Lackner
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Earthquake Location ◽  
Primary Concern ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Geographic Context ◽  
The Social ◽  
Strong Ground

Abstract. Earthquake impact is an inherently interdisciplinary topic that receives attention from many disciplines. The natural hazard of strong ground motion is the reason why earthquakes are of interest to more than just seismologists. However, earthquake shaking data often receive too little attention by the general public and impact research in the social sciences. The vocabulary used to discuss earthquakes has mostly evolved within and for the discipline of seismology. Discussions on earthquakes outside of seismology thus often use suboptimal concepts that are not of primary concern. This study provides new theoretic concepts as well as novel quantitative data analysis based on shaking data. A dataset of relevant global earthquake ground shaking from 1960 to 2016 based on USGS ShakeMap data has been constructed and applied to the determination of past ground shaking worldwide. Two new definitions of earthquake location (the shaking center and the shaking centroid) based on ground motion parameters are introduced and compared to the epicenter. These definitions are intended to facilitate a translation of the concept of earthquake location from a seismology context to a geographic context. Furthermore, the first global quantitative analysis on the size of the area that is on average exposed to strong ground motion – measured by peak ground acceleration (PGA) – is provided.

scholarly journals Design of Biomechanical Legs with a Passive Toe Joint for Enhanced Human-like Walking

2017 ◽  
Vol 14 (2) ◽  
pp. 166 ◽  
Author(s):  
Riadh Zaier ◽  
A. Al-Yahmedi
Keyword(s):  
Design Procedure ◽  
Human Walking ◽  
Human Gait ◽  
Design Parameters ◽  
Sultan Qaboos University ◽  
Motion Trajectories ◽  
Normal Human ◽  
Working Principle ◽  
Mass Spring ◽  
Torsion Springs

This paper presents the design procedure of a biomechanical leg, with a passive toe joint, which is capable of mimicking the human walking. This leg has to provide the major features of human gait in the motion trajectories of the hip, knee, ankle, and toe joints. Focus was given to the approach of designing the passive toe joint of the biomechanical leg in its role and effectiveness in performing human like motion. This study was inspired by experimental and theoretical studies in the fields of biomechanics and robotics. Very light materials were mainly used in the design process. Aluminum and carbon fiber parts were selected to design the proposed structure of this biomechanical leg, which is to be manufactured in the Mechanical Lab of the Sultan Qaboos University (SQU). The capabilities of the designed leg to perform the normal human walking are presented. This study provides a noteworthy and unique design for the passive toe joint, represented by a mass-spring damper system, using torsion springs in the foot segment. The working principle and characteristics of the passive toe joint are discussed.  Four-designed cases, with different design parameters, for the passives toe joint system are presented to address the significant role that the passive toe joint plays in human-like motion. The dynamic motion that is used to conduct this comparison was the first stage of the stance motion. The advantages of the presence of the passive toe joint in gait, and its effect on reducing the energy consumption by the other actuated joints are presented and a comparison between the four-designed cases is discussed.

scholarly journals The Role of Seismological Networks in Civil Protection in Low and High Seismic Hazards

2021 ◽  
Author(s):  
Erzsébet Győri ◽  
Arman Bulatovich Kussainov ◽  
Gyöngyvér Szanyi ◽  
Zoltán Gráczer ◽  
Kendebay Zhanabilovich Raimbekov ◽  
...  
Keyword(s):  
Early Warning ◽  
Early Warning Systems ◽  
Economic Losses ◽  
Civil Protection ◽  
Warning Systems ◽  
Ground Shaking ◽  
Research Areas ◽  
Seismic Networks ◽  
Strong Ground

Earthquakes are one of the most devastating natural disasters on Earth, causing sometimes huge economic losses and many human casualties. Since earthquake prediction is not yet possible, the purpose of civil protection is to reduce damage and protect human lives, in which the seismological networks of different countries play a very important role. Special applications of seismic networks are the early warning systems that can be used to protect vulnerable infrastructures using automated shutdown procedures, to stop high velocity trains and to save lives if the general public is notified about imminent strong ground shaking. In this paper, we describe the aims and operation of seismological networks, covering in more detail the early warning systems. Then we delineate the seismotectonic settings and seismicity in Hungary and Kazakhstan, furthermore, describe the operating seismological networks and the related scientific research areas with emphasis on civil protection. Hungary and Kazakhstan differ not only in the size of their territory, but also in their seismicity, therefore, in addition to the similarities, there are also significant differences between the aims and problems of their seismological networks.

scholarly journals ARMOUR UNIT STRUCTURAL RESPONSE - A PARAMETRIC STUDY

1988 ◽  
Vol 1 (21) ◽  
pp. 176
Author(s):  
C. David Anglin ◽  
William F. Baird ◽  
Etienne P.D. Mansard ◽  
R. Douglas Scott ◽  
David J. Turcke
Keyword(s):  
Wave Height ◽  
Parametric Study ◽  
Structural Integrity ◽  
Design Procedure ◽  
Structural Response ◽  
Design Parameters ◽  
Coastal Structures ◽  
Log Normal ◽  
Wave Induced ◽  
Hydraulic Stability

There is a general lack of knowledge regarding the nature and magnitude of loads acting on armour units used for the protection of rubblemound coastal structures. Thus, a comprehensive design procedure incorporating both the hydraulic stability and the structural integrity of the armour units does not exist. This paper presents the results of a detailed parametric study of the structural response of armour units to wave-induced loading in a physical breakwater model. The effect of the following design parameters is investigated: breakwater slope, armour unit location, wave period and wave height. This research has made a number of significant contributions towards the development of a comprehensive design procedure for concrete armour units. It has identified a linear relationship between the wave-induced stress in the armour units and the incident wave height. In addition, it has shown that the conditional probability of waveinduced stress given wave height can be estimated by a log-normal distribution. Finally, a preliminary design chart has been developed which incorporates both the structural integrity and the hydraulic stability of the armour units.

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