skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: A simple method for detecting cracks in soil–cement reinforcement for centrifuge modelling
This paper presents the development, implementation and experimental evaluation of a new crack detection mechanism for centrifuge modelling. The proposed mechanism is a brittle conductor bonded to cement providing a binary indication of if, and when, a sensor is cracked. The results of a pair of large centrifuge tests were used to evaluate the effectiveness of the proposed crack detection mechanism. Each test model included a soil profile consisting of a 23 m thick layer of lightly over-consolidated clay, underlain and overlain by thin layers of dense sand. The centrifuge models had two separate zones, a zone without reinforcement and a zone with an ‘embedded’ soil–cement grid, which had a unit cell area replacement ratio A r  = 24%. Models were subjected to 13 different shaking events with peak base accelerations ranging from 0·01 to 0·55g. The performance of the proposed crack detection mechanism was examined using (i) post-test crack mapping in the soil–cement grids, (ii) results of the crack detection system and (iii) time series of accelerations, displacements and footing rotation. The results from the centrifuge test showed that the proposed crack detection method accurately captured if, and when, cracking occurred in the soil–cement grid at the locations of the sensors.  more » « less
Award ID(s):
1520581
PAR ID:
10398469
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
International Journal of Physical Modelling in Geotechnics
Volume:
18
Issue:
6
ISSN:
1346-213X
Page Range / eLocation ID:
281 to 289
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Soil dynamics and earthquake engineering)
    A series of centrifuge tests of a sloping ground were conducted at Rensselaer Polytechnic Institute (RPI). These tests were used to monitor and assess the soil response, in terms of generated accelerations, excess pore water pressure (EPWP) and associated lateral spreading, as a function of variations in the dynamic input motion and soil relative density. This series of tests are part of the Liquefaction Experiments and Analysis Projects (LEAP-2017), an international effort to assess the repeatability and reproducibility of centrifuge experimental results, and verify and validate soil liquefaction numerical tools using the experimental data. 
    more » « less
  2. (, Proceedings of LEAP_UCD-2017 workshop)
    The experimental results of LEAP (Liquefaction Experiments and Analysis Projects) centrifuge test replicas of a saturated sloping deposit are used to assess the sensitivity of soil accelerations to variability in input motion and soil deposition. A difference metric is used to quantify the dissimilarities between recorded acceleration time histories. This metric is uniquely decomposed in terms of four difference component measures associated with phase, frequency shift, amplitude at 1 Hz, and amplitude of frequency components higher than 2 Hz (2 + Hz). The sensitivity of the deposit response accelerations to differences in input motion amplitude at 1 Hz and 2 + Hz and cone penetration resistance (used as a measure reflecting soil deposition and initial grain packing condition) was obtained using a Gaussian process-based kriging. These accelerations were found to be more sensitive to variations in cone penetration resistance values than to the amplitude of the input motion 1 Hz and 2 + Hz (frequency) components. The sensitivity functions associated with this resistance parameter were found to be substantially nonlinear. 
    more » « less
  3. ; ; ; ; ; ; (, Designsafe-CI)
    A centrifuge test (ODA01) was used as a proof-of-concept test to investigate the effect of vertical differential settlement on crack formation in a model levee. The Yolo loam embankment levee and its foundation were 250 mm and 62.5 mm high in prototype scale, respectively. Viscous pore fluid was used to simulate water behind the levee at a height of 225 mm and the test was conducted at 40g. The foundation of the levee included a moving part (a hydraulic table) and a non-moving part (a jointed wood table). The hydraulic actuators were extended to a maximum height of 25 mm before the start of the test. In the centrifuge, the hydraulic table was lowered to a maximum settlement of 25 mm to simulate the differential settlement of the levee. Hairline, transverse and longitudinal cracks were effectively induced in the levee through this vertical differential settlement. Furthermore, seepage flow was initiated through the cracks. The seepage flow stopped after some time without significant erosion, likely due to swelling of the soil around the crack and lowering of the upstream water level. 
    more » « less
  4. ; ; ; (, Sixth Biot Conference on Poromechanics)
    The experimental results of two centrifuge test replicas of a sloping (saturated-soil) deposit are used to assess the predictions of the (open source) software OpenSees. The discrepancy between recorded and computed acceleration time histories is expressed as a unique aggregate of three measures associated with shape, phase and frequency-shift. This decomposition sheds light on the level of consistency between computed and recorded soil accelerations and the likely source of inaccuracies in the used model prediction. 
    more » « less
  5. ; ; ; ; ; (, Earthquake Spectra)
    We present data and metadata from a centrifuge testing program that was designed to investigate the seismic responses of buried circular and rectangular culverts. The specimen configurations were based on Caltrans Standard Plans, and the scope of research was to compare the experimental findings with the design method described in the NCHRP Report 611 as well as to formulate preliminary recommendations for Caltrans practice. A relatively flexible pipe and a stiff box-shaped specimen embedded in dense sand were tested in the centrifuge at the Center for Geotechnical Modeling at University of California, Davis and were subjected to a set of broadband and harmonic input motions. Responses were recorded in the soil and in the embedded structures using a dense array of instruments. Measured quantities included specimen accelerations, bending strains, and hoop strains; soil accelerations, shear-wave velocities, settlements, and lateral displacements; and accelerations of the centrifuge's shaking table. This data paper describes the tests and summarizes the generated data, which are archived at DesignSafe.ci.org (DOI: 10.17603/DS2XW9R) and are accessible through an interactive Jupyter notebook. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email