## 1 Introduction
Improvements to the standard testing scheme, associated with the conduction of multiple tests, have been made over time, mainly to reduce the required number of tests and thus the influence of sample heterogeneity, or to account for the material's stress-dependency. [PERSON] et al. [16] and [PERSON] [12] list some of the most important developments in this regard and discuss the associated benefits and deficiencies. [PERSON] et al. [17] proposed an iterative procedure to determine the five elastic constants by conducting uniaxial compression and Brazilian tests using specimens from a single-orientation core. More recently, strip load tests on single cylindrical test specimens with arbitrary isotropy plane inclinations have been used to determine the full set of transversely isotropic constants without the need to assume approximate relationships between individual parameters or to use special test apparatuses [18,19]. While the strip load test method thus overcomes the limitations of previous methods for determining the transversely isotropic constants on single-core samples, its practicality may still be limited by the computationally expensive strain inversion method involved [18] or the lack of availability of a trained artificial neural network (ANN) [19]. Despite ongoing developments with regard to calibration methods to derive transversely isotropic constants from tests on single samples, the most frequently used method remains the one involving measurement results from compression tests performed on multiple samples with different core angles [20, 21, 22]. Besides the adopted laboratory test schemes, the determination of accurate elastic constants is also influenced by the choice over suitable strain measurement techniques. In general, local strain measurements should preferably be used over global arrangements, such as cap-to-cap LVDT measurements. This is due to the influence of end-effects near the sample-platen contacts on the global measurements arising from surface friction [23]. To mitigate the influence of interface friction, [PERSON] et al. [24] proposed the use of a ball-bearing plate in between the sample's top surface and the loading platen within triaxial tests on anisotropic rocks. However, the need for such a measure could not be confirmed by the study of [PERSON] et al. [25], who carried out uniaxial compression tests on granitic rocks with a specific degree of anisotropy. The majority of studies in the literature dealing with the determination of the transversely isotropic elastic material constants involving uniaxial compression tests on cylindrical samples do not report the use of friction-reduction measures at the sample-planet contacts [13; 14; 20; 21; 26]. Nevertheless, the elastic parameters are calibrated by confronting the strain measurements containing the influence of end-effects with analytical strain equations derived from an ideal consideration. This introduces errors of uncertain magnitude into the determined elastic parameters compared to the true unaffected material constants of an assumed transversely isotropic elastic solid. In the current literature, it remains inadequately addressed to what extent the developing strain distributions around samples with different isotropy plane inclinations and the ascertainable material parameters are influenced by end-effects in combination with different inherent elastic constants. Uncertainty also exists as to whether friction-reducing measures are essential or dispensable in addition to local strain measurements in UCS tests on transversely isotropic rocks with varying elastic constants. The present study aims to explore uncertainties through a theoretical perspective. It focuses on the determination of developing elastic strains around the circumference of cylindrical transversely isotropic rock specimens for the case of uniaxial compression loading.