Shake Table Modeling of Laterally Loaded Piles in Liquefiable Soils with a Frozen Crust

2012 ◽  
Vol 204-208 ◽  
pp. 654-658 ◽  
Author(s):  
Zhao Hui Yang ◽  
Xiao Yu Zhang ◽  
Run Lin Yang
Keyword(s):  
Lateral Spreading ◽  
Lessons Learned ◽  
Frozen Soil ◽  
Shake Table ◽  
Bridge Foundations ◽  
Pile Interaction ◽  
Main Input ◽  
Input Motion ◽  
Bridge Foundation ◽  
Laterally Loaded

One of the most important lessons learned from Alaska’s two major earthquakes in history is that the lateral spreading of frozen crust overlying on liquefiable soils generates significant lateral forces and have induced wide bridge foundation damages. When the ground crust is frozen, its physical properties including stiffness, shear strength and permeability will change substantially. A shake table test was conducted to study the soil-pile interaction in liquefiable soils with a frozen crust. Cemented sands were used to simulate the frozen crust and have successfully captured the mechanical parameters of frozen soil. With the 2011 Japan Earthquake as the main input motion, the mechanism of frozen soil-pile interaction in liquefiable soils is clarified. A brief discussion of the recorded data is analyzed. It turned out the existence of frozen soil is essential to consider in future seismic design of bridge foundations in cold regions.

Design procedure for landslide stabilization using sheet pile ribs

2019 ◽  
Vol 56 (4) ◽  
pp. 514-525 ◽  
Author(s):  
James R. Bartz ◽  
C. Derek Martin ◽  
Michael T. Hendry
Keyword(s):  
Limit Equilibrium ◽  
Unit Length ◽  
Design Procedure ◽  
Soil Reaction ◽  
Case Study Site ◽  
Rail Line ◽  
Pile Interaction ◽  
Stabilization Technique ◽  
Laterally Loaded

A design procedure was developed for a relatively unknown slope stabilization technique consisting of a series of parallel sheet piles installed parallel to the direction of slope movement. This technique was introduced in Alberta by R.M. Hardy in the 1970s and is locally referred to as “Hardy Ribs.” A case study is discussed where Canadian National (CN) Rail installed Hardy Ribs to stabilize a landslide affecting its rail line in western Manitoba. A proposed design procedure is discussed that consists of a de-coupled approach with a separate limit equilibrium slope stability analysis and laterally loaded pile analysis using p–y curves, where p is the soil reaction per unit length and y is the lateral deflection of the pile, to model the soil–pile interaction. Example calculations are provided for the proposed design procedure for the CN case study site to illustrate its use and to estimate the stabilizing effect from the Hardy Ribs at this site.

scholarly journals Automatic Management and Monitoring of Bridge Lifting: A Method of Changing Engineering in Real-Time

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5293
Author(s):  
Fang ◽  
Chou ◽  
Hoang ◽  
Lee
Keyword(s):  
Global Climate ◽  
Computer Software ◽  
Element Model ◽  
Earthquake Resistance ◽  
Bridge Foundations ◽  
Construction Period ◽  
Bridge Model ◽  
Temporary Support ◽  
Lower Structure ◽  
Bridge Foundation

In recent years, owing to the increase of extreme climate events due to global climate change, the foundational erosion of old bridges has become increasingly serious. When typhoons have approached, bridge foundations have been broken due to the insufficient bearing capacity of the bridge column. The bridge bottoming method involves rebuilding the lower structure while keeping the bridge surface open, and transferring the load of the bridge temporarily to the temporary support frame to remove the bridge base or damaged part with insufficient strength. This is followed by replacing the removed bridge base with a new bridge foundation that meets the requirements of flood and earthquake resistance. Meanwhile, monitoring plans should be coordinated during construction using the bottoming method to ensure the safety of the bridge. In the case of this study, the No. 3 line Wuxi Bridge had a maximum bridge age of 40 years, where the maximum exposed length of the foundation was up to 7.5 m, resulting in insufficient flood and earthquake resistance. Consequently, a reconstruction plan was carried out on this bridge. This study took the reconstruction of Wuxi Bridge as the object and established a finite element model using the SAP 2000 computer software based on the secondary reconstruction design of the Wuxi Bridge. The domestic bridge design specification was used as the basis for the static and dynamic analyses of the Wuxi Bridge model. As a result of the analysis, the management value of the monitoring instrument during construction was determined. The calculated management values were compared with the monitoring data during the construction period to determine the rationality of the management values and to explore changes in the behavior of the old bridges and temporary support bridges.

Asymmetric input motion for accumulation of lateral ground deformation in laminar container shake table testing

2020 ◽  
pp. 1-14
Author(s):  
Muhammad Zayed ◽  
Ahmed Ebeido ◽  
Athul Prabhakaran ◽  
Zhijian Qiu ◽  
Ahmed Elgamal
Keyword(s):  
Earthquake Engineering ◽  
Ground Deformation ◽  
Numerical Models ◽  
Lateral Spreading ◽  
Practical Significance ◽  
Shake Table ◽  
Shake Table Testing ◽  
Sloping Ground ◽  
Preferred Direction ◽  
Experimental Response

Due to seismic response, accumulation of permanent ground deformation (lateral spreading) is an important mechanism of much practical significance. Such deformations typically occur near a ground slope, behind retaining structures such as sheet-pile and quay walls, and in mildly sloping ground. In conducting a shake table test, the generation of permanent deformations further elucidates the underlying mechanisms and allows for related ground–foundation–structure response insights. In this paper, an approach for development of accumulated ground deformations is presented, in which asymmetric inertial loading results in a biased dynamic one-dimensional shear state of stress. As such, the proposed approach allows for further insights into the soil cyclic response and pore pressure build-up, with deformations accumulating in a preferred direction. To permit a virtually unlimited number of such loading cycles, focus is placed on motions that do not cause the shake-table actuator to accumulate displacement, in view of its possible limited stroke. Using this approach, representative experimental response is outlined and discussed. This experimental response can be used for calibration of numerical models to emulate the observed permanent strain accumulation profile and associated mechanisms. In addition to liquefaction-induced lateral spreading, this asymmetric shaking approach might be beneficial for a wide class of earthquake engineering shake table testing applications.

Development of a Seismic-Performance Assessment Method and Retrofitting Technology Against the Liquefaction of Existing Bridges

2019 ◽  
Vol 14 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Michio Ohsumi ◽  
◽  
Toshiaki Nanazawa ◽  
Shunsuke Tanimoto ◽  
Mitsuhiko Nakata
Keyword(s):  
Performance Assessment ◽  
Seismic Performance ◽  
Assessment Method ◽  
Shaking Table ◽  
Seismic Performance Assessment ◽  
Bridge Foundations ◽  
The Past ◽  
Existing Bridges ◽  
Bridge Foundation

In the past, earthquakes have caused critical damage to bridges built on liquefiable ground, resulting in their collapse or long-term closures. In particular, for existing bridges designed in an age when the liquefaction influence was not considered, appropriate measures should be taken as necessary. However, there are many existing stocks of bridges, which require expensive foundation reinforcement. Therefore, it is crucial to appropriately choose bridge foundations for which anti-seismic measures are a high priority and implement the measures efficiently and successively. The present study aims to develop a seismic-performance assessment method and retrofitting technology for coping with liquefiable ground. For this purpose, a large shaking-table experiment was conducted to determine the effects of the liquefiable ground on bridge-foundation behavior and verify the effect of the retrofitting technology. Based on disaster-case analyses and the results of the shaking-table experiment, a seismic-performance assessment method applicable to practical designing was proposed.

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