Cross-Facility Validation of Dynamic Centrifuge Testing

Author(s):  
Ulas Cilingir ◽  
Stuart Haigh ◽  
Charles Heron ◽  
Gopal Madabhushi ◽  
Jean-Louis Chazelas ◽  
...  
Keyword(s):  
Author(s):  
Gopal S. P. Madabhushi ◽  
Samy Garcia-Torres

AbstractSoil liquefaction can cause excessive damage to structures as witnessed in many recent earthquakes. The damage to small/medium-sized buildings can lead to excessive death toll and economic losses due to the sheer number of such buildings. Economic and sustainable methods to mitigate liquefaction damage to such buildings are therefore required. In this paper, the use of rubble brick as a material to construct earthquake drains is proposed. The efficacy of these drains to mitigate liquefaction effects was investigated, for the first time to include the effects of the foundations of a structure by using dynamic centrifuge testing. It will be shown that performance of the foundation in terms of its settlement was improved by the rubble brick drains by directly comparing them to the foundation on unimproved, liquefiable ground. The dynamic response in terms of horizontal accelerations and rotations will be compared. The dynamic centrifuge tests also yielded valuable information with regard to the excess pore pressure variation below the foundations both spatially and temporally. Differences of excess pore pressures between the improved and unimproved ground will be compared. Finally, a simplified 3D finite element analysis will be introduced that will be shown to satisfactorily capture the settlement characteristics of the foundation located on liquefiable soil with earthquake drains.


2012 ◽  
Vol 49 (11) ◽  
pp. 1267-1284 ◽  
Author(s):  
Olajide Samuel Oshati ◽  
Arun J. Valsangkar ◽  
Allison B. Schriver

Earth pressure data from the field instrumentation of a cast-in-place reinforced rectangular box culvert are presented in this paper. The instrumented culvert is a 2.60 m by 3.60 m double-cell reinforced cast-in-place rectangular box buried under 25.10 m of fill constructed using the induced trench installation (ITI) method. The average earth pressure measured across the roof was 0.42 times the overburden pressure, and an average of 0.52 times the overburden pressure was measured at mid-height of the culvert on the sidewalls. Base contact pressure under the rectangular box culvert was also measured, providing field-based data demonstrating increased base pressure resulting from downward drag forces developed along the sidewalls of the box culvert. An average increase of 25% from the measured vertical earth pressures on the roof plus the culvert dead load (DL) pressure was calculated at the culvert base. A model culvert was also tested in a geotechnical centrifuge to obtain data on earth pressures at the top, sides, and base of the culvert. The data from the centrifuge testing were compared with the prototype structure, and the centrifuge test results agreed closely with the measured field prototype pressures, in spite of the fact that full similitude was not attempted in centrifuge testing.


2021 ◽  
pp. 875529302098197
Author(s):  
Jason M Buenker ◽  
Scott J Brandenberg ◽  
Jonathan P Stewart

We describe two experiments performed on a 9-m-radius geotechnical centrifuge to evaluate dynamic soil–structure interaction effects on the cyclic failure potential of fine-grained soil. Each experiment incorporated three different structures with a range of mass and stiffness properties. Structures were founded on strip footings embedded in a thin layer of sand overlying lightly overconsolidated low-plasticity fine-grained soil. Shaking was applied to the base of the model container, consisting of scaled versions of recorded earthquake ground motions, sweep motions, and step waves. Data recorded during testing were processed and published on the platform DesignSafe. We describe the model configuration, sensor information, shaking events, and data processing procedures and present selected processed data to illustrate key model responses and to provide a benchmark for data use.


Author(s):  
Shideh Dashti ◽  
Jonathan D. Bray ◽  
Juan M. Pestana ◽  
Michael Riemer ◽  
Dan Wilson
Keyword(s):  

2020 ◽  
Vol 11 (1) ◽  
pp. 17-44
Author(s):  
Soubhagya Karmakar ◽  
Rajiv Ranjan ◽  
Vedula Srinivasa Phanikanth

Combined pile raft foundation (CPRF) is one of the emerging concepts for providing a cost-effective and efficient solutions for heavily-loaded structures. However, predicting the behaviour of such foundations, especially the load sharing between raft and pile is a challenge due to its inherent complex interactions. Existing analysis methods are either bound within a range of simplifying assumptions or sometimes computationally demanding. Hence, an attempt has been made to evolve a simple and easily implementable methodology, considering non-linear degrading behaviour of soil in a rational manner. The approach has first been validated with measured response during an experimental centrifuge testing of a CPRF in soft Malaysian kaolin clay and an instrumented bridge (Impulsora) founded in soft clayey soil. Subsequently, a range of comparative parametric evaluation of load sharing and settlement characterstics has been carried out which has indicated the importance of pile layout, length and numbers to arrive at a safe and economic design.


Sign in / Sign up

Export Citation Format

Share Document