Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2750

Full Length Research Paper

Prediction of grout penetration length into the jointed rock mass using regression analyses

Omid Saeidi1*, Rahman Torabi1, Mohamad Ataei1 and Hakan Stille2
1Department of Mining Engineering Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran. 2Department of Civil and Architectural Engineering, Royal Institute of Technology, KTH, Stockholm, Sweden.
Email: [email protected]

  •  Accepted: 15 November 2012
  •  Published: 19 November 2012

Abstract

In this paper, new relations are proposed to predict the gout penetration length into jointed rock mass by means of multivariate linear and non-linear regressions. Numerical analysis was used to obtain the grout penetration length into the rock mass by considering all effective rock and grout properties. The results of numerical analysis were in a good agreement with analytical methods. As a case study Bakhtiary dam and power plant of Iran was used to assess the results of prediction models. Because of many effective properties on grout penetration length and restriction of simple regression models, multivariate regression analysis was used to correlate all parameters with penetration length of grout. Effective rock joint properties as joint hydraulic aperture, orientation, roughness, spacing and trace length along with grout properties including viscosity, yield stress, pressure and grouting time were used in regression analysis. Three possible relations one linear and two non-linear relations were proposed to predict penetration length. The validation of the equations was checked by the F-test (analysis of variance) analysis. The results of all three relations showed good cross-correlations with analytical method and field data. It is concluded that the proposed relations can predict grout penetration length into the rock mass, reasonably.

 

Key words: Multivariate regression, numerical modeling, grout penetration length,F-test analysis.

Abbreviation

J1, Joint set number 1; J2, joint set number 2; Sv, Sarvak formations in dam site; Imax, maximum penetration length; Pg, pressure of grout material; Pw, water pressure; , yield stress of grout; JRC, joint roughness coefficient; E&a, physical and effective hydraulic apertures; µg, grout viscosity; t0,characteristic grouting time; Vmax, maximum injected volume of grout; Q, flow rate;Dim, dimensionality of flow; PL, penetration length of grout; θ, joint set orientation;S, joint spacing; L, joint trace length.