A subsidence simulation system using displacement measurement techniques based on opto-electronic displacement measurement sensors has recently been developed, introduced for subsidence engineering education purpose. The results of subsidence analysis define subsidence parameters including angle draws, angle of break, subsidence factors, etc. Subsidence profiles are determined in mathematical forms. The outcomes is useful in helping understand field subsidence mechanism and simulations and enhance the teaching of subsidence concepts such as angle of draw, angle of break and subsidence factors to undergraduate student class. The developed subsidence modeling device also helps reinforce lateral stress pressure and soil shear strength estimation from the subsidence modeling.
Subsidence damages surface and subsurface structures such as foundations, utility lines, infrastructures, ground water regimes, etc. Subsidence is not a far and away issue only in other States, it also happens in Indiana. As shown in the Fig. 1, some southwestern counties of Indiana have some subsidence concerns . In order to avoid or reduce subsidence damages, it is imperative to know the subsidence characteristics of the particular site, and proper design work has to be performed to prevent or minimize subsidence hazards.
There are two types of subsidence : 1) pit, also called sinkhole or pot hole, and 2) trough or sag. Pit subsidence is characterized by an abrupt sinking of the surface, resulting in circular steep sided, crater-like features. Trough subsidence is a gentle, gradual depression of the surface. Subsidence is controlled by many factors, including width of unsupported cavity, height of cavity, thickness of overburden, strength and fracture system of rock, hydrology, and time [1, 2, 3].
In engineering geology class, undergraduate students are exposed to concepts the subsidence geohazards. To help them to visualize and understand the fundamental subsidence concepts and thus better prepared to minimize or prevent subsidence damage, it is necessary to understand subsidence phenomena. It is difficult to simulate or predict real subsidence development because of the complexity in physical characteristics such as rock failure and yield behavior, dimensional variations and time dependent behavior.