Despite existing theoretical and experimental studies on anchors, data remains scarce for field applications, particularly for low-capacity irregularly shaped anchors. This study addresses this gap by investigating the pullout capacity of such anchors in residual soil slopes. Field experiments used an irregular anchor (118 mm length, 92 mm width) installed horizontally and at 37° inclination, with embedment ratios ( \(H/h\) ) ranging from 2.20 to 6.50 (horizontal) and 2.20 to 5.30 (inclined). Pullout capacity results were compared with existing theoretical equations and empirical expressions from literature. Our main results reveal that: (i) pullout capacity and breakout factor increase with \(H/h\) , but breakout factor increase slows down for deeper inclined anchors; (ii) horizontal anchors outperform inclined ones for shallow depths ( \(H/h\) < 4), but inclined anchors are better indicated for deeper applications ( \(H/h\) > 4); (iii) field results for horizontal anchors exceeded theoretical predictions, especially for shallow depths; (iv) empirical equations showed good agreement with field results for breakout factors; and (v) a proposed empirical equation for inclined anchors yielded close results to field data. Our study offers new data and insights for improved prediction of the pullout behavior of irregular anchors in field-scale scenarios.
