ISSN: 1945-7545
CODEN: GTJODJ
Published Online: 1 March 2012
Page Count: 12

A Comparative Study on the Shear Behavior of an Interlayer Material Based on Laboratory and In Situ Shear Tests

Xu, Ding-Ping
State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan,

Feng, Xia-Ting
Professor, State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan,

Cui, Yu-Jun
Professor, Tongji University and UMR NAVIER/CERMES, Ecole des Ponts ParisTech, MARNE-LA-VALLEE CEDEX,

Jiang, Ya-Li
Engineer, East China Investigation and Design Institute, China Hydropower Engineering Consulting Group Co., Hangzhou,

Huang, Ke
Engineer, East China Investigation and Design Institute, China Hydropower Engineering Consulting Group Co., Hangzhou,

(Received 4 January 2011; accepted 12 October 2011)

Abstract

In order to evaluate the overall stability of the underground powerhouse at the future Baihetan hydropower station in China, the shear strength of a weak intercalation soil in the host rock has been investigated via in situ direct shear and laboratory shear tests. A comparative study was performed based on the two test results. It has been observed that both tests show elastic perfect-plastic behavior. A significant heterogeneity of the samples has been identified under both laboratory and field conditions. The samples’ disturbance seems to be a less important factor than the samples’ variability. The size effect has been evidenced by the friction angle obtained in the laboratory on small samples, which is greater than that obtained in the field on larger samples. The clay fraction has been found to be an important factor; its increase reduces the friction angle and increases the cohesion. Without considering some particular data due to the soil heterogeneity, a negligible effect of the initial degree of saturation has been identified. Comparisons between the results of the field tests and those from the laboratory tests show good consistency in terms of the effects of the clay fraction and the initial degree of saturation, indicating a relatively secondary effect of the sample size and variability.

Keywords:
Baihetan site, interlayer staggered zone, laboratory shear test, in situ shear test, shear behavior, comparative study

Paper ID: GTJ103742
DOI: 10.1520/GTJ103742
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