Estimation of Pore Pressure in Disturbed Mudstone from Natural Water Content with Special Reference to Landslide and Squeezing-Swelling Tunnel.

Bibliographic Information

Other Title
  • Estimation of Pore Pressure in Disturbe

Search this article

Abstract

To elucidate the engineering significance of natural water content wn of mudstone disturbed into clay from the view point of Critical State Soil Mechanics, CD triaxial test (with top and bottom drainage only) and CD direct shear test were carried out and the unique relationship between log qmax (or log τmax) and w and that between w and log p' (or log σ'v) were obtained. Comparing the experimental results thus obtained, p' was found to be nearly equal to σ'v in fully softened shear zone. Thus, if wn at the depth of h is known, the effective confining stress p' at that depth can be known. Therefore the pore pressure acting at that depth can be calculated as u=γt·h-p'. Two example case histories, Mizunashi landslide and Nabetachiyama tunnel in Neogene mudstone of Shiiya formation in Niigata Prefecture are presented. In the former, by measuring wn of boring core of 90 m, several number of fully softened shear zones were found to exist where artesian pressure was acting and, in the latter, in the section where tunneling was very difficult due to squeezing pressure, wn of fault clay was found to correspond either to p' induced by the overburden weight or to p' decreased by the amount of methane gas pressure.

Journal

Citations (4)*help

See more

References(18)*help

See more

Details 詳細情報について

Report a problem

Back to top