L. Matmatte et al. : G.D.Q.-Expert: An Expert System for Geotechnical Data
241
Volume
V0L-~ __ -------'
Po
Pf
PI pressure
Figure 2. Pressuremeter curve and its typical values.
E and PI must be verified to be within typical range according to the soil
type.
• The ratios E/PI and PIlPf must be verified, as well as the value of Vo,
which is a good indicator of the calibration of the hole.
• The obtained curve shape must be checked, as it can show us any
deviations during the test execution.
6 METHODOLOGY AND SYSTEM DESIGN
To build any system in any specific area requires a good comprehension
of the problem domain and the system tasks. This understanding should be
formalized and explicitly expressed in order to facilitate knowledge exchange
between analyst, domain experts, and end users.
Building an "intelligent" system implies representing knowledge.
Knowledge representation consists, from an Artificial Intelligence point of view, of
finding appropriate data structures to store and manipulate information [6].
Object-oriented methodology satisfies these requirements and allows us to ensure a
good level of system stability, objects being the least volatile elements in system
specification [5].
6.1
Object definition and object relations
A geotechnical investigation is done by means of borings. For the Menard
pressuremeter test, a hole is drilled before performing the test; drilling the hole
must respect some rules in order to have a good calibrated hole with the most
intact faces. Two objects are defined to represent this knowledge: "the boring"
object and "the test" object. The "boring" is a class object, boring can be a
pressuremeter boring, a penetrometer boring ... , which are specializations of "the
boring" object. The generalization-specialization relation is represented by a half
circle symbol in Figure 3. Any boring involve layers and water (if any); "the layer"
object and "the water" object are parts of "the boring" object. In order to express
the system tasks in the best way, each test object involves two parts: "results" object
and "testing device" object ("probe" in this case).
241
Volume
V0L-~ __ -------'
Po
Pf
PI pressure
Figure 2. Pressuremeter curve and its typical values.
E and PI must be verified to be within typical range according to the soil
type.
• The ratios E/PI and PIlPf must be verified, as well as the value of Vo,
which is a good indicator of the calibration of the hole.
• The obtained curve shape must be checked, as it can show us any
deviations during the test execution.
6 METHODOLOGY AND SYSTEM DESIGN
To build any system in any specific area requires a good comprehension
of the problem domain and the system tasks. This understanding should be
formalized and explicitly expressed in order to facilitate knowledge exchange
between analyst, domain experts, and end users.
Building an "intelligent" system implies representing knowledge.
Knowledge representation consists, from an Artificial Intelligence point of view, of
finding appropriate data structures to store and manipulate information [6].
Object-oriented methodology satisfies these requirements and allows us to ensure a
good level of system stability, objects being the least volatile elements in system
specification [5].
6.1
Object definition and object relations
A geotechnical investigation is done by means of borings. For the Menard
pressuremeter test, a hole is drilled before performing the test; drilling the hole
must respect some rules in order to have a good calibrated hole with the most
intact faces. Two objects are defined to represent this knowledge: "the boring"
object and "the test" object. The "boring" is a class object, boring can be a
pressuremeter boring, a penetrometer boring ... , which are specializations of "the
boring" object. The generalization-specialization relation is represented by a half
circle symbol in Figure 3. Any boring involve layers and water (if any); "the layer"
object and "the water" object are parts of "the boring" object. In order to express
the system tasks in the best way, each test object involves two parts: "results" object
and "testing device" object ("probe" in this case).