Evaluation of peak side resistance for rock socketed shafts in weak sedimentary rock from an extensive database of published field load tests: A limit state approach

Pouyan Asem, Paolo Gardoni

Research output: Contribution to journalArticle

Abstract

This paper presents analyses of the measured peak side resistance of rock sockets constructed in weak claystone, shale, limestone, siltstone, and sandstone. The peak side resistance is obtained from in situ axial load tests on drilled shafts, anchors, and plugs. The parameters that affect the development of peak side resistance are determined using in situ load test data. It is found that peak side resistance increases with the unconfined compressive strength and deformation modulus of the weak rock, and decreases with the increase in length of the shear surface along the rock socket sidewalls. The increase in socket diameter also slightly decreases the peak side resistance. Additionally, it is found that the initial normal stresses do not significantly affect the measured peak side resistance in the in situ load tests. The in situ load test data are used to develop an empirical design equation for determination of the peak side resistance. The proposed model for peak side resistance and the reliability analysis are used to determine the corresponding resistance factors for use in the load and resistance factor design framework for assessment of the strength limit state.

Original languageEnglish (US)
Pages (from-to)1816-1831
Number of pages16
JournalCanadian Geotechnical Journal
Volume56
Issue number12
DOIs
StatePublished - Jan 1 2019

Keywords

  • Load test database
  • Peak side resistance
  • Resistance factor
  • Rock socket
  • Weak rock mass

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Geotechnical Engineering and Engineering Geology

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