Environmental Engineering Reference
In-Depth Information
1
Introduction
1.1
Basic Considerations
1.1.1
Human Activities and the Geologic Interface
The Geologic Environment
The geologic environment interfacing with human activities includes not only the basic
components of soil, rock, and water, but also the associated phenomena referred to as geo-
logic hazards, i.e., flooding, erosion, landslides and other slope failures, ground subsi-
dence and collapse, ground heave, and earthquakes.
Since the first edition of this topic was written in 1984, there rightly has been emphasis
on the features of the geologic environment that affect public health; i.e., asbestos, radon,
mold, and other pollutants in water and air. Except for incidental mention, health concerns
with regard to the geologic environment will not be addressed in this topic.
Interfacing Impacts
The impact of the geologic environment on human activities can be classified as direct or
indirect. Direct impact occurs during the use of geologic materials in construction, the
removal of materials in excavation, and while making provision for the secure support of
structures, excavations, and slopes. Such activities occur during the construction of build-
ings, dams, roadways, and tunnels that, for the most part, have an impact on their imme-
diate surroundings. Design objectives are economical construction and satisfactory
performance.
Indirect impact occurs during the extraction of materials from the surface, which can
cause adjacent ground subsidence, and extraction from the subsurface, which can cause
subsidence and collapse. Such activities occur during the development of mineral
resources by the subsurface extraction of water, oil, gas, coal, or other minerals that can
impact on areas substantially removed from the activity. The objective is to avoid or con-
trol these consequences of human activity.
Geologic occurrences impacting on human works in the form of floods, slope failures,
ground collapse, and earthquakes can occur naturally or as a result of human activities.
Prior to construction or development, a thorough assessment of the geological environ-
ment must be made to ensure that the interfacing is compatible.
Engineering Assessment
An adequate assessment of the geologic environment is a prerequisite to formulating
effective treatment for the consequences of these interfacing activities. This requires the
