A Manual of Geology for Civil Engineers

The following sections are included:

• PREFACE

• ACKNOWLEDGEMENTS

• CONTENTS

The following sections are included:

• Plate Tectonics

• Uniformitarianism

• Superposition

• The Geochemical Cycle

• Geological Time and the Stratigraphic Column

• Geomorphic Systems

• Thresholds and Uniformity of Natural Systems
  • Example 1 — shearing strength of materials
  • Example 2 — stream flow

• Magnitude and Frequency of Forces in Geomorphic Processes

• Equilibrium of Geological Processes and their Disturbance by Engineering Activity
  • Example 1
  • Example 2
  • Example 3
  • Example 4
  • Example 5

Rocks of all kinds are made up of an assemblage of minerals, and most of the minerals, of which there are a vast number, have strange names. It is sufficient that only a small number of the commonest rock-forming minerals will be introduced to aid with rock identification. The engineering properties of the rocks often relate to the minerals which make up the rock, and their arrangement. The minerals may not be the original ones which formed the rock, and some of these secondary minerals are also introduced…

Rock structure is a term used to describe the overall relationship of rock masses, for example folding, jointing, cleavage, and unconformities. Folding of rock changes the orientation of rocks by lateral compression, the changes perhaps being most apparent in bedded rocks. The compressive forces causing folding, and indeed fracture structures as well, originate most usually at destructive plate margins. The tilting of rocks from their original horizontal position, and the fracturing of rocks, produces measurable directional properties in the rocks called strike and dip (Fig. 3.1). The strike is the direction at any point on a structural surface of a horizontal line drawn on the surface. The term is also used in the sense of the general trend of rocks. It is at right angles to the true dip. True dip is the vertical angle measured from the horizontal plane in the direction of greatest slope. The apparent dip is the dip in any direction from zero in the direction of strike to a maximum in the direction of true dip. The measurement of these properties by geologists is in terms of strike, measured as a whole compass bearing from north (for example, a bed striking NE-SW would have a strike of 045° or 225° — they are exactly the same), a dip angle, which is self explanatory, and a general dip direction, usually as one of the eight basic cardinal points of the compass. So, in Fig. 3.1, if north is in a horizontal plane passing directly into the page the bed illustrated would have the following approximate orientation…

The following sections are included:

• Weathering and its Significance in Geotechnical Engineering
  • Weathering processes
  • Weathering and weatherability
  • Weathering in humid tropical climate
  • Tests to assess weatherability

• Engineering Classification of Weathered Rock

• Erosion

Soil is a non-indurated aggregation of mineral and/or organic particles with air and/or water filled voids. Most soils result from the agencies of weathering, erosion, transportation and deposition. Organic soils such as peat, are not of this type, usually being an assemblage of vegetable remains which have not been destroyed by oxidation…

The following sections are included:

• Geological Maps and Strike Lines

• Three Point Problems

• Interpretation of Geological Maps

• Geotechnical Mapping
  • Stratigraphical mapping
  • Structural mapping
  • Geomorphological mapping
  • Hydrogeological mapping
  • Geomechanical mapping
  • Mapping the effects of man

The following sections are included:

• Logging of Rock Cores
  • General requirements of a borehole log
  • Information to be recorded
  • Information to be recorded on the borehole log
  • State of recovery of core

• Descriptive Geology

• The Description of Rock Masses for Engineering Purposes
  • Rock material description
  • Rock material indices
  • Rock mass indices

• Discontinuities
  • Weathering and altered state
  • Discontinuity spacing in three dimensions

• Techniques for Carrying Out Classification Tests

• Techniques for Obtaining Data
  • Observations
  • Discontinuity surveys
  • Recording and presentation of data

• Processing Discontinuity Data

The following sections are included:

• REFERENCES

• INDEX