Preshake: A Database for Centrifuge Modeling of the Effect of Seismic Preshaking History on the Liquefaction Resistance of Sands

2016 ◽  
Vol 32 (3) ◽  
pp. 1925-1940 ◽  
Author(s):  
Waleed El-Sekelly ◽  
Tarek Abdoun ◽  
Ricardo Dobry
Keyword(s):  
Sandy Soils ◽  
Rensselaer Polytechnic Institute ◽  
Centrifuge Modeling ◽  
Polytechnic Institute ◽  
Liquefaction Resistance ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Analytical Applications ◽  
Testing Facility ◽  
Materials Used

Several researchers found that the behavior of natural preshaken soils can be very different from artificial recent fills. This paper presents an extensive database of two very long centrifuge experiments (CS-5-1-1 and CC-5-1-1) performed both on silty and clean sand at the geotechnical centrifuge testing facility at Rensselaer Polytechnic Institute (RPI). The two experiments test the effect of seismic preshaking history on the liquefaction resistance of sandy soils. The database described herein was generated using the NEEShub online DataStore tool under the name “PRESHAKE: Centrifuge modeling of the effect of seismic preshaking on the liquefaction resistance of sands” (DOI: http://dx.doi.org/10.4231/D38K74X78 ). The paper discusses the tools and materials used in the experiments along with an explanation of each item in the database. Sample analyses are also presented in the paper to give an insight on the capabilities of the database for numerical and analytical applications. The paper is concluded with some possible applications along with tips and limitations of the database.

A Database for the Experimental Study of Earthquake-Induced Liquefaction and Lateral Spreading in Sands

2016 ◽  
Vol 32 (2) ◽  
pp. 1261-1279
Author(s):  
Tarek Abdoun ◽  
Waleed El-Sekelly ◽  
Ricardo Dobry ◽  
Sabanayagam Thevanayagam ◽  
Marcelo Gonzalez
Keyword(s):  
Large Scale ◽  
Rensselaer Polytechnic Institute ◽  
Lateral Spreading ◽  
Soil Behavior ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Testing Facility ◽  
Large Scale Testing ◽  
Materials Used ◽  
The University

Centrifuge and large-scale testing in geotechnical engineering are very useful tools for modeling soil behavior under different loading conditions, particularly under earthquake loading. The paper presents an extensive database of nine centrifuge and large-scale liquefaction experiments performed both at the geotechnical centrifuge testing facility at Rensselaer Polytechnic Institute (RPI) and the large-scale testing facility at the University at Buffalo (UB). The database described herein was generated using the NEEShub online DataStore tool under the name “CENSEIS: Centrifuge and Large (Full)-Scale Modeling of Seismic Pore Pressures in Sands” (DOI: http://dx.doi.org/10.4231/D3GF0MX4F ). The paper discusses the tools and materials used in the experiments along with an explanation of each item in the database. Sample analyses are also presented in the paper to give an insight on the capabilities of the database for numerical and analytical applications. The paper is concluded with some possible applications along with tips and limitations of the database.

Performance of micropiled raft in sand subjected to vertical concentrated load: centrifuge modeling

2015 ◽  
Vol 52 (1) ◽  
pp. 33-45 ◽  
Author(s):  
A.M. Alnuaim ◽  
H. El Naggar ◽  
M.H. El Naggar
Keyword(s):  
Contact Pressure ◽  
Bending Moment ◽  
Centrifuge Modeling ◽  
Design Parameters ◽  
Concentrated Load ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Piled Raft Foundation ◽  
Overall Performance ◽  
Important Design

Initial applications of micropiles have involved retrofitting foundations of existing buildings. In these applications, the overall performance of the micropiles–raft (MPR) foundation system is similar to a piled raft foundation where the load is transmitted through both the raft and micropiles. However, there is no guidance available regarding the performance of MPR foundations. In this study, geotechnical centrifuge testing was conducted to investigate the behavior of MPR foundations in sand and evaluate their performance characteristics. The study investigated the effect of raft flexibility on a number of important design parameters, including raft total and differential settlements, raft contact pressure, raft bending moment, and load sharing between the raft and micropiles. In addition, the use of micropiles as settlement reducers was investigated. The results showed that the micropiles carried 42%–59% of the applied load for the MPR configuration considered, which resulted in redistribution of the raft contact pressure. It was found that the Poulos–Davis–Randolph (PDR) method can be used to evaluate the performance of MPR systems with relatively stiff rafts; however, it is not applicable for MPR with flexible raft. A correction factor was proposed to account for the raft flexibility in the PDR method.

Performance of micropiled raft in clay subjected to vertical concentrated load: centrifuge modeling

2015 ◽  
Vol 52 (12) ◽  
pp. 2017-2029 ◽  
Author(s):  
A.M. Alnuaim ◽  
M.H. El Naggar ◽  
H. El Naggar
Keyword(s):  
Contact Pressure ◽  
Applied Load ◽  
Bending Moment ◽  
Centrifuge Modeling ◽  
Performance Characteristics ◽  
Concentrated Load ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Piled Raft Foundation ◽  
Raft Foundation

The overall behavior of a micropiled raft foundation (MPR) system is similar to a piled raft foundation where the load is transferred by both the raft and micropiles. However, there is no guidance available regarding the design of MPRs or indication of their performance. In this study, geotechnical centrifuge testing was conducted to investigate the behavior of MPR foundations in clay and evaluate their performance characteristics. The study evaluated the performance of MPRs compared to the isolated raft in terms of raft total and differential settlements; raft contact pressure; raft bending moment; and load sharing between the raft and the micropiles. The results showed that for the MPR configuration considered in the study, the raft carried 48% of the applied load. It was found that the Poulos–Davis–Randolph (PDR) method can be used to evaluate the performance of MPR for preliminarily design purposes with approximately 17% error.

Earth pressures exerted on an induced trench cast-in-place double-cell rectangular box culvert

2012 ◽  
Vol 49 (11) ◽  
pp. 1267-1284 ◽  
Author(s):  
Olajide Samuel Oshati ◽  
Arun J. Valsangkar ◽  
Allison B. Schriver
Keyword(s):  
Earth Pressure ◽  
Test Results ◽  
Overburden Pressure ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Drag Forces ◽  
Field Instrumentation ◽  
Earth Pressures ◽  
Box Culvert ◽  
Base Contact

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.

scholarly journals Centrifuge testing of soil–structure interaction effects on cyclic failure potential of fine-grained soil

2021 ◽  
pp. 875529302098197
Author(s):  
Jason M Buenker ◽  
Scott J Brandenberg ◽  
Jonathan P Stewart
Keyword(s):  
Soil Structure ◽  
Interaction Effects ◽  
Soil Structure Interaction ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Structure Interaction ◽  
Fine Grained ◽  
Stiffness Properties ◽  
Fine Grained Soil ◽  
Strip Footings

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.

Penetration Testing of Liquefaction Potential of Ashes due to Seismic Load

2016 ◽  
Vol 837 ◽  
pp. 140-145
Author(s):  
Ivan Slavik
Keyword(s):  
Sandy Soils ◽  
Unit Weight ◽  
Seismic Load ◽  
High Porosity ◽  
Liquefaction Resistance ◽  
Liquefaction Potential ◽  
Penetration Testing ◽  
Lake City ◽  
Penetration Tests ◽  
Cpt Test

Geomaterials with typical low unit weight and high porosity are significantly prone to liquefaction as a result of dynamic – seismic load. Investigation of geomaterials that are prone to liquefaction due to seismic load can use certain SPT and CPT penetration tests. The method of investigating liquefaction caused by seismic activity was developed based on numerous penetration tests of sandy or silty–sandy soils and was elaborated in detail at the Workshop on Evaluation of Liquefaction Resistance of Soil, NCEER, Salk Lake City, USA, 1996. In the present paper, the results of penetration CPT test conducted at the ash impoundment in Zemianske Kostoľany are analyzed using methodology NCEER.

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