Geomechanics and Engineering

  • 제20권1호
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  • Pages.1-7
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  • 2020
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  • 2005-307X(pISSN)
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  • 2092-6219(eISSN)
테크노프레스 (Techno-Press)
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DOI QR코드

DOI QR Code

Influence of time-dependency on elastic rock properties under constant load and its effect on tunnel stability

  • Aksoy, C.O. (Department of Mining Engineering, Dokuz Eylul University) ;
  • Aksoy, G.G. Uyar (Department of Mining Engineering, Hacettepe University) ;
  • Guney, A. (Department of Mining Engineering, Mugla Sitki Kocman University) ;
  • Ozacar, V. (Torbali Vocational School, Dokuz Eylul University) ;
  • Yaman, H.E. (Department of Mining Engineering, Dokuz Eylul University)
  • 투고 : 2019.01.22
  • 심사 : 2019.12.10
  • 발행 : 2020.01.10
⟨ 이전 논문 다음 논문 ⟩

초록

In structures excavated in rock mass, load progressively increases to a level and remains constant during the construction. Rocks display different elastic properties such as Ei and ʋ under different loading conditions and this requires to use the true values of elastic properties for the design of safe structures in rock. Also, rocks will undergo horizontal and vertical deformations depending on the amount of load applied. However, under constant loads, values of Ei and ʋ will vary in time and induce variations in the behavior of the rock mass. In some empirical equations in which deformation modulus of the rock mass is taken into consideration, elastic parameters of intact rock become functions in the equation. Hence, the use of time dependent elastic properties determined under constant loading will yield more reliable results than when only constant elastic properties are used. As well known, rock material will play an important role in the deformation mechanism since the discontinuities will be closed due to the load. In this study, Ei and ʋ values of intact rocks were investigated under different constant loads for certain rocks with high deformation capabilities. The results indicated significant time dependent variations in elastic properties under constant loading conditions. Ei value obtained from deformability test was found to be higher than the Ei value obtained from the constant loading test. This implies that when static values of elastic properties are used, the material is defined as more elastic than the rock material itself. In fact, Ei and ʋ values embedded in empirical equations are not static. Hence, this workattempts to emerge a new understanding in designing of safer structures in rock mass by numerical methods. The use of time-dependent values of Ei and ʋ under different constant loads will yield more accurate results in numerical modeling analysis.

키워드

과제정보

연구 과제 주관 기관 : TUBITAK

This research was supported by TUBITAK. Project number is 114M566. Authors would like to TUBITAK (THE SCIENTIFIC AND TECHNOLOGICAL RESEARCH COUNCIL OF TURKEY) to give financial support.

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