Sensitivity Analysis for the Principal Strain Parameters of a Deformation Monitoring Network

Abstract

Strain tensor analysis plays an essential role in geophysics and engineering applications, because it provides a numerical measure on the relative deformation behavior of the object under investigation. A strain tensor can be estimated by observing the positional coordinates of the deforming network at different epochs. Consequently, the quality of a strain analysis is highly dependent on the accuracy of position measurement and network configuration. In this study, a strain sensitivity index, namely the minimum detectable principal strain parameter, has been developed based on the concept of the invariant function and statistical theory. A simulation test and a real case study have both been carried out to demonstrate the feasibility of the proposed approach. Based on the numerical results from the case study on the first-order global positioning system network in Taiwan, it has been revealed that the coastal areas in Taiwan have a lower capability in detecting surface strains because of poor network configuration. On the other hand, it has also been illustrated that, by incorporating the network optimization guidelines developed in this study, the strain sensitivity index can be substantially improved in these areas.