Penetration and Relaxation in Dry Granular Materials: Insights from Photoelasticity

Sichuan Huang, Nariman Mahabadi Mahabad, Junliang Tao

Research output: Contribution to journalConference articlepeer-review


Penetration is involved in many geotechnical engineering practices such as site characterization and pile installation. In this study, we investigated the influence of pausing-induced stress relaxation on the penetration process using photoelasticity. A thin cone penetrometer was designed and penetrated a photoelastic granular specimen in two different ways: one is continuous penetration, during which the penetrometer penetrates the specimen continuously for a target travel distance; the other is termed as intermittent penetration, which consists of two short penetration stages separated by a long pausing stage. The penetration rate and overall penetrometer travel distance for the two cases are kept the same. Stress relaxation was observed during the pausing stage and the influence of stress relaxation on the subsequent penetration process was evaluated by comparing the penetration resistance, and force chains, stress field, and displacement field of the granular specimen. Results indicate that pausing-induced stress relaxation is due to particle rearrangement and causes reduction in penetration resistance within a limited travel distance.

Original languageEnglish (US)
Pages (from-to)130-139
Number of pages10
JournalGeotechnical Special Publication
Issue numberGSP 334
StatePublished - 2022
Event2022 GeoCongress: State of the Art and Practice in Geotechnical Engineering - Geophysical and Earthquake Engineering and Soil Dynamics - Charlotte, United States
Duration: Mar 20 2022Mar 23 2022

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Architecture
  • Building and Construction
  • Geotechnical Engineering and Engineering Geology


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