『Abstract
Granite weathering profiles are widely distributed in South China.
Their engineering and geological characteristics are major geotechnical
subjects that are important in the design and construction of
civil engineering projects. This paper present a summary of the
weathering characteristics and zoning of granite weathering profiles
in South China and discusses their engineering and geological
properties. A five-grade scheme has been adopted in the zoning
of a granite weathering profile. Studies have shown that the completely
weathered granites (CWG) in South China have the following characteristics:
low moisture content, low to medium plasticity (WL=22.5-39.0%;
Ip=6.5-11.8%), medium void ratio (0.36-1.29),
weak shrinkage and medium compressibility (a1-2=0.24-0.8
MPa-1) and high shear strength (φ=20-30゜; c=20-40 KPa).
The CWGs are usually at a low or high plastic state and most of
them are over-consolidated soils. A majority of the physical and
mechanical properties have good statistical correlations with
the degree of weathering. The data presented in the paper are
important in geotechnical engineering projects such as slope stability
evaluation in China.
Keywords: Granite weathering profile; Weathering zoning; Engineering
geological characteristics; Slope stability』
『要旨
花崗岩の風化断面は南中国に広く分布している。それらの工学的および地質学的特徴は、土木工学事業の設計と建設に重要である主要な地質工学の対象となる問題である。本論文は、南中国の花崗岩風化断面の風化の特徴と分帯を要約し、それらの工学的および地質学的特性について議論している。5段階の分類が、花崗岩風化断面の分帯に採用されている。本研究から、南中国の完全に風化した花崗岩(CWG)は以下の特徴をもつことが示される:低含水比、低〜中可塑性(WL=22.5〜39.0%;Ip=6.5〜11.8%)、中間隙比(0.36〜1.29)、弱収縮性と中圧縮性(a1-2=0.24〜0.8 MPa-1)、および高剪断強度(φ=20〜30゜;
c=20〜40 KPa)。CWGは通常は低または高可塑性状態で、それらの大部分は過圧密土壌である。物理的および機械的な特性の大半は、風化度と統計的に良い相関をもつ。本論文に示したデータは、中国での斜面安定の評価のような土質工学的事業において重要である。』
1. Introduction
2. Development ofgranite weathering profiles in South China
2.1. Geochemical types
2.2. Typical profiles
2.3. Chemical and mineralogical compositions
3. Geotechnical zoning
4. Geotechnical properties
4.1. Main physical and mechanical properties
4.2. Geomechanical properties between unit weight and parameters
4.3. Mechanical effect of cement
4.4. Dynamics properties
4.5. Selection of shearing tests
5. Conclusions
Acknowledgements
References