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Analytical Methods
<br />SUAii\IARY AND CONCLUSIONS
<br />The influence of failure in the rock mass surrounding
<br />a cavity on the surface subsidence was investigated in this
<br />stud}'. Two possible modes of failure were considered: (i)
<br />compressive yielding, and (ii) failure under tensile stresses.
<br />Based on results o(these investigations and other studies,
<br />it was concluded that the occurrence of this type of failure
<br />in the proximity of the opening does not have a significant
<br />influence on the surface subsidence. However, this type of
<br />failure can propagate; and should the (allure progress to
<br />the surface, thin the massive subsidence associated with
<br />sinkholes and ground breakage can occur. Therefore, the
<br />development o(a computational technique which can in-
<br />vestigate the possibility of rock failure progressing to the
<br />surface is an important aspect in designing mining opera-
<br />tions to limit subsidence.
<br />For the majority of practical problems, failure does not
<br />propagate to the surface, and it is necessary to predict the
<br />subsidence that might occur from the creation of solution
<br />cavities. A computational technique which permits slip-
<br />page along bedding planes and other geological continui-
<br />ties has been developed. Based on a comparison with
<br />observed subsidence in two case histories, it was found
<br />that if slippage was permitted along bedding planes, there
<br />was reasonable agreement between measured and com-
<br />puted values.
<br />Based on the results of this and previous investigations,
<br />it can be concluded that the analytical methods presented
<br />in this report have the potential of predicting the sub-
<br />sidence above mined areas provided there is adequate in-
<br />formation on the geologic conditions.
<br />ACKNOWLEDG~IENT5
<br />The research described in this paper has been sup-
<br />ported by Solution Mining Research Institute, [tic. This
<br />support is gratefully acknowledged.
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