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A study of the weathering of the bukit timah granite part a: Review, field observations and geophysical survey

  • J. Zhao
  • B. B. Broms
  • Y. Zhou
  • V. Choa
Article

Abstract

The Bukit Timah granite exhibits a full range of weathering grades. Examination of these exposures shows that the weathering has been rapid. Field observations and geophysical surveys show that the rock has been weathered up to 70 meters depth, and that the main mechanisms of weathering is chemical decomposition. The humid tropical condition in Singapore with high annual precipitation has produced secondary weathering of the residual soil. The weathering profiles suggest that the weathering of the Bukit Timah granite is stratified with weathered layers and a sharp boundary between the residual soil and the slightly to moderately weathered granite.

This paper (Part A) is a review of current weathering classification systems for weathered rock. Some results from field observations and geophysical surveys are also presented in the paper. A weathering classification and determination method is proposed for the Bukit Timah granite. Results from field and laboratory investigations of the weathering of the granite and material properties will be presented in Part B.

Keywords

Rock Mass Weathering Uniaxial Compressive Strength Granitic Rock Rock Material 

Étude de l'altération du granite de bukit timah (Singapour) 1re partie: Bibliographie, observations de terrain, études géophysiques

Résumé

Le granite de Bukit Timah présente toute une gamme d'états d'altération. L'examen montre que l'altération a été rapide. Les observations sur le terrain et les études géophysiques montrent que la roche a été altérée jusqu'à 70 mètres de profondeur, le principal mécanisme de l'atération ayan été la décomposition chimique. Les conditions tropicales humides de Singapour avec une pluviométrie très forte ont produit une altération secondaire du sol résiduel. Les profils d'altération suggèrent que l'altération du granite de Bukit Timah est stratifiée avec, des niveaux altérés et une limite brutale entre le sol résiduel et le granite légèrement ou modérément altéré.

Cet article (1re partie) présente d'abord, une bibliographie des différents systèmes de classification des roches altérées. Ensuite sont présentés des résultats des observations de terrain et des études géophysiques. Une classification en termes d'altération est proposée. Les résultats des études détaillées de terrain et de laboratoire sur les facies altérés du granite et leurs propriétés seront présentés dans une seconde partie.

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Copyright information

© International Association of Engineering Geology 1994

Authors and Affiliations

  • J. Zhao
    • 1
  • B. B. Broms
    • 1
  • Y. Zhou
    • 1
  • V. Choa
    • 1
  1. 1.School of Civil & Structural EngineeringNanyang Technological UniversitySingapore

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