|
|
||
 Selection of Site-specific Stabilization Techniques
5.1.1.2 Maintenance Requirements and Capability
Evaluating this factor involves weighing a lower initial cost or construction
expediency against the potential for deterioration of the project as a result of inadequate
inspection and maintenance.
If the project sponsor has the capability to monitor the condition of the project, and
maintain it as required, a less durable technique may be preferable to a more durable method
requiring a higher initial investment. This is particularly likely if inexpensive labor, equipment,
and local materials are available. However, the engineer should be cautious about relying too
heavily on future maintenance capability, for two reasons:
The capability of the sponsors to maintain the project may change due to
factors beyond their control; and
Human nature may make it easier for the sponsor to agree to an obligation to
be incurred in the future than to fulfill that obligation when it comes due.
This is a project-specific determination, but a decision to select a less durable
technique should not be made without a frank, even pessimistic, evaluation of the sponsor's
long-term commitment and capability, and the durability of the protection methods being
considered.
The consequences of failure of the project are linked both to maintenance
requirements and to the determination of required durability. However, it is more critical to
the detailed design of the project than to the selection of a particular method, since most
methods can be designed with a low risk of failure. This is discussed further in 6.6, "Safety
Factor."
5.1.1.3 Climatic Conditions
Climatic conditions affect durability through the action of:
Freezing and thawing cycles;
Ice floes;
Heaving;
Wetting and drying cycles; and
Sunlight (ultraviolet deterioration).
The primary vulnerabilities here are the effect of freezing and thawing on stone, the
effect of ice floes on armor and indirect protection structures, the effect of heaving on slope
armoring, the effect of wetting and drying (with the accompanying damage by bacterial
growth and insects, on wooden components), and the effect of sunlight on synthetic materials.
8
88
|
||
|
||
